Time

I. PSYCHOLOGICAL ASPECTSPaul Fraisse

BIBLIOGRAPHY

II. SOCIAL ORGANIZATIONJack Goody

BIBLIOGRAPHY

I. PSYCHOLOGICAL ASPECTS

Time is a dimension of our experience and our activity, but this dimension does not correspond to a simple physical reality. The concept of time is imposed on us by our experience of changes: the physicist and the biologist must introduce a parameter t to account for the evolution of natural phenomena.

Analysis of our experience and the requirements of science show that two fundamental aspects must be distinguished in the concept of time: (a) the sequence, and more precisely, the order of the changes; (b) the duration of the changes or of the period between them. The interlocking of order and duration defines the process of the change. We experience a great number of series of changes that are apparently autonomous—time of the seasons, time of day and night, time of human life, time of activities, and so forth.

History of the psychology of time. The psychology of time begins with Kant. Prior to him, the reality of time had not been questioned, even though philosophers disputed its nature. Kant declared that our notion of time is not imposed by a noumenal reality but by the activity of the mind: it is one of the forms of our sensibility.

In the nineteenth century, in a departure from Kant’s essentially rationalistic approach, men became concerned with the actual study of the sense of time and with perception of time, and no longer merely with the time of phenomena. A psycho–physics of time was developed by comparing estimates of duration with the measurements given by chronometers.

Henri Piéron, in 1923, was the first to define the psychology of time in a behaviorist framework, through the objective study of human behavior in relation to time. This point of view was developed by Pierre Janet (1928), who raised the question of our adaptation to time. Jean Piaget (1946) studied the development of the notion of time in the infant. Paul Fraisse (1957) provided a general analysis of temporal behavior.

Temporal behavior. The psychology of time is defined by studying temporal behavior, i.e., by our adaptations, at first to the sequence and duration of changes and later to the multiplicity of changing series in which we live.

These adaptations take place on two levels. The first is common to animals and man; through learning, activities become synchronous with series of changes. The second is peculiar to man, who is able to make symbols correspond to the various aspects of the changes. Society teaches these symbols to man, who uses them to represent the changes to himself, to orient himself within them, and also to control them.

Adaptation to sequence and order

Adaptation to sequence in conditioning. From the moment of their birth, organisms are subject to changes, and in particular, to their own internal changes. Stimuli precede the recurrence of needs and the means for satisfying them, which are reinforced by their reduction. Those stimuli that regularly precede need reduction become conditioned “signals.” The organism then adapts to the sequence. The signals orient his activity toward the future. The infant smiles at the bottle at first, then at his mother preparing the bottle, and so forth. Some months later, he will cooperate in getting dressed, his movement anticipating the subsequent action.

This Pavlovian type of conditioning is accompanied by an instrumental type of conditioning. The newborn child cries at annoyances in his first days, but he soon learns to make use of his crying to call for and evoke the action of others: he anticipates. At the age of about one year, the child adds to this behavior the act of designating what he wants by means of gestures and then by words. [See Learning, articles on Classical conditioningandinstrumental learning.]

Perception of sequence. To the physical sequence there corresponds a perceived sequence. The process of learning language reveals that the child is very soon able to repeat longer and longer ordered series of phonemes. This perception of an ordered sequence is spontaneous; it does not correspond to any superimposed contruction. Thus, it is always harder to repeat a series of digits in reversed order or in any order other than the one in which it was perceived. [See Language, article onlanguage development.]

The natural organization of the sequence is facilitated if the stimuli are of the same nature. For example, if we are presented visually with three digits in succession and if at the same time we are presented audibly with three other digits, we can only reproduce these stimuli by first repeating the visual series and then the auditory one, or vice versa (Broadbent 1958). [Seegestalt theory.]

The lower limit for the perception of sequence depends on the inertia of the sensory receptors: it is 10 ms. for hearing and touch and 100 ms. for sight, if the stimulations occur at the same site (Pieron 1945). Trained subjects can perceive two sensations of the same or different natures (sound and light, for example) as a sequence when they are separated by an interval of only 20 ms. (Hirsh & Sherrick 1961); an interval of 60 ms. is necessary for untrained subjects (Hirsh & Fraisse 1964). [Seehearing; senses; skin senses and kinesthesis; vision.]

The upper limit of the perception of sequence in the case of two stimuli has been determined by using rhythmic forms. This limit is about two seconds (Fraisse 1956). Beyond that, the sequence is no more perceived but is constructed.

Between these limits lies an optimum for the perception of sequence: an interval of about 600 ms. to 800 ms. This interval corresponds to that for spontaneous motor activity, to that for word association (Wundt [1873-1874] 1886, p. 322), to the spacing of the conditioned and unconditioned stimuli for optimal learning, to the time for which a series of two stimuli appears most natural, i.e., not too slow or too fast (Frischeisen-Kohler 1933), and to the time for which counting permits the most precise evaluation of the duration (Davis 1962).

Complex sequences. Perception of sequence is easy when the stimuli belong to a single series of changes. It is no longer so when two orders of succession have to be discriminated. For example, if two runners stop successively but the one that stops first in time is the one that goes the shortest distance spatially, a child of five will confuse the spatial order and the temporal order of the stops (Piaget 1946, p. 90).

Likewise, a child of five cannot organize two series of sequences experienced simultaneously, as for example the successive levels of liquid in a vase that is being emptied and the successive levels in another vase that is being filled at the same time (Piaget 1946, p. 7).

The coordination of complex sequences implies logical constructions and operations, to use Piaget’s vocabulary, that are possible for children only from age seven, approximately. [Seedevelopmental psychology, especially the article ona theory of development; Infancy.]

Estimating duration

Delayed conditioning . If a time interval separates the conditioned stimulus from the unconditioned stimulus, the conditioned reaction tends gradually to take place after an interval that is nearly equal to the interval between the two stimuli, as Pavlov showed as early as 1907. The conditioned reaction adapts to the duration, which acts as a second conditioned stimulus.

The activity of the animal can also take duration into account in operant conditioning. A rat that is reinforced at regular intervals only begins to respond toward the end of the interval (Skinner 1938). He can even be trained to space two responses at a given interval (Sidman 1956). It should be emphasized, however, that delayed conditioning of a defensive reaction is hard to obtain, no doubt because the animal cannot control his reaction spontaneously except in the case of double avoidance (Ruch 1931). The relative length of a confinement in the first branch of a T maze can also be a signal for taking the left or the right path (Cowles & Finan 1941).

Perception and estimation of duration . Man is able to estimate directly the duration of an event, with a precision that can be checked either by comparing two intervals or by reproducing the period.

If perception is an immediate discrimination reaction to a present stimulus, it may be asked whether it is possible to speak of perception of a duration. The answer is positive. Within the limits of the psychological present (Fraisse 1957), we may assume that the duration of an event is “present” for several seconds. Within these limits there is an interval of indifference of 700 ms., corresponding to the optimum sequence. Shorter intervals are overestimated, longer intervals underestimated.

Beyond a few seconds it is better to speak of estimation of time rather than of perception of it, since more complex processes, of which not too much is known, then enter into the picture. While there are certainly physiological recordings, e.g., from delayed conditionings, it is out of the question that the frequency of the heartbeat or the respiration should be direct factors, since no author has been able to find a correlation between these variables arid the estimated duration. Undoubtedly, a central process is involved. This biological estimation depends on the general level of biological activity. Thus, in experiments with sensory deprivation, duration is greatly underestimated (Vernon & McGill 1963). Michel Siffre (1963), who lived in a completely dark cave, isolated from the world and without any timepiece, estimated his stay of 58 days as having lasted 33 days.

Recent research on animals and human subjects (Fraisse 1963) shows that in general, stimulants (mescaline, thyroxine, caffeine, amphetamine) cause an overestimation of time, and inhibitors (quinine, barbiturates) an underestimation. On this point, however, our knowledge is still rudimentary.

Thus, many psychological variables alter the estimation of time. For durations of less than two seconds, the variability of reproduction is of the order of 10 per cent; for periods of several minutes, it rises to 20 to 30 per cent. Using the method of absolute judgments of duration, it is hardly possible to discriminate more than three stimuli, and the amount of information transmitted is less than two bits (Hawkes 1961).

Psychological factors in estimating time . We know that we can make major errors in estimating durations. Two sets of variables have been studied in particular.

The nature of the activity. Convergent results (Fraisse 1963) show that the more complex an activity is and the more it requires the attention of the subject, the shorter the time seems to be. Thus, copying a text or taking it down from dictation seems shorter than reading or listening (for equal objective durations of the activities). In the limiting case, during periods of inactivity duration seems very long.

A complex activity appears to be short because in the course of it we note fewer changes than during a simpler activity. Again, a more complex activity is generally more interesting, and this brings up the influence of motivation.

The influence of motivation. Whatever interests us seems to have a short duration, while what bores us seems interminable. Everybody has observed this law, which many experiments have confirmed. The best explanation of the phenomenon has been proposed by Katz (1906), who suggested that whenever attention is paid to the passage of time, the time seems to get longer. When we are bored, or waiting, or in a great hurry, time seems to go very slowly, because our attention is fixed on a number of changes, whereas an interesting activity absorbs us and puts us in a way “outside of time.” [See Attention.]

Quantification and measurement of duration . The quantification, and, more precisely, the measurement of duration, must be distinguished from the over-all estimation of it. The units of these measurements are regular and “calibrated” changes —the ticks of a clock or metronome, the rotation of the earth, atomic clocks, and so forth. But man also makes use of the duration of changes whose durations are less regular and less precise—the length of the distance covered, the number of pieces produced, and so forth.

Employing these units is not possible for the child until he has become able to perform intellectual operations, and not until adolescence is the duration of unit changes understood as independent of the concrete nature of the changes (Piaget 1946).

Orientation in time

Nychthemeral rhythm . We experience many changes simultaneously, some of them being periodic. The latter serve as points of reference, by means of which the others can be located. The nychthemeral rhythm is the most important for living organisms.

It is a remarkable fact that this originally exogenous rhythm becomes endogenous. The entire rhythm of the organism—the rhythms of alimentary activity, of sleep, of the body temperature, and of all physiological functioning—has a cycle of 24 hours that persists for several weeks even if the animal or the man’s ecological conditions change. We need only recall how tired we are made by an airplane trip that takes us across several time zones.

This rhythmic activity turns our organism into a regular clock and gives us points of reference by which we can orient ourselves to the time of day. Thus Siffre, who lived 58 days in a cavern, had 57 periods of sleep and waking during that period, whereas he estimated the duration at 33 days. His physiological clock had been more accurate than his estimates.

This transformation of exogenous rhythms into endogenous rhythms is an established fact, and Pavlovian conditioning provides an explanation of it. If a dog is fed every 30 minutes, it gradually reaches the point of starting to salivate only at the end of the 30-minute period (Feokritova 1912).

Temporal orientation of man . Man spontaneously makes use of the temporal points of reference provided by his organism. We are conditioned to the rhythm of meals, sleep, and so forth. Even a mental defective is able to demand his meal at a set hour (James 1890, vol. 1, p. 623). But in addition, the infant and then the adult learn to orient themselves to other periodic changes, the most important of which are’ the changes of nature (the solar day, the year).

Man also learns to employ more conventional points of reference, such as clocks, calendars, and so forth. The principle is always the same: to make the experienced moment correspond to the phase of a periodic change that serves as the system of reference.

The temporal horizon

The temporal horizon of action . Merely as the result of conditioning due to the repetition of cycles of activity, present signals make reference to a future action. The present stimulus has a previously acquired significance, and it triggers an activity that anticipates some aspect of the future. These cycles are present in animals as well as in man, but because of second-order and higher-order conditioning their period is longer the higher the place that the organism occupies in the phyloge-netic scale.

The temporal horizon of man . Man too is conditioned by the cycles of his activity, and his temporal horizon always depends on them. The horizon of the day laborer is one thing, that of the professor is another.

But, in addition, man is able to distinguish the present moment from what has been (the past) and what will be (the future). This ability is manifest from the youngest age at which the child is able to make adequate use of the adverbs of time (yesterday, tomorrow, and so forth) and the verb forms that refer to the past and the future.

Thus we see the child’s temporal horizon develop: from the age of 18 months on, he is situated between a recent past and a very immediate future. Little by little this horizon expands, as can be seen from the adequate use of adverbs of time and the localization of memories in the past and projects in the future.

From the age of seven or eight on, this horizon extends beyond personal experiences. The child becomes interested in the background of his parents and in his country’s history, and he becomes able to imagine future events that have not formed a part of previous cycles of his activity (his own marriage, for example).

This development is to a very great extent a function of intelligence, which makes possible, in particular, better organization of the past and better anticipation of the future (Kastenbaum 1961).

Temporal horizon and society . Past and future are made more precise by the learning of the society’s language. Along with language, society transmits its representations of the past and the future. Some of these representations, linked to the great philosophies, are of great generality. Among the Greeks, for example, a circular representation of time predominated. The Christians formed a continuous representation, starting from a creation ex nihilo down to the end of time. All men, in different degrees, use cyclical conceptions with respect to years, generations, civilization, or economic plans.

More specifically, each social framework (family, profession, church, nation, and so forth) has its own way of seeing time, and, with Gurvitch (1958), we may speak of the multiplicity of social times.

Certain societies, such as the Hopi Indians, hardly have a temporal horizon, if we are able to judge by their language, for their verbs have no tenses and they are said to be content with distinguishing “the earlier from the later” (Whorf 1950).

In a given society, the temporal horizon appears to be fairly closely bound up with the cycle of experienced expectations and satisfactions. Every man has the capacity to evoke very distant pasts or futures, but in practice the horizon that has solidity and reality for him is narrowly linked to his way of life. The time of the peasant is one thing, and the time of the city dweller another. For example, it has been found that workers’ children make up stories covering a shorter period of time than middle-class children (Leshan 1952).

Finally, it should be kept in mind that every man belonging to several social groups has multiple temporal perspectives. He has to pass from one to the other—from family time to office time, for example—and try to bring them into accord (Halb-wachs 1947).

Thus, every man, depending on his temperament, his intelligence, and the forms of socialization that formed him, comes to have his own temporal horizon, defined in its extent and polarity, assigning value to either the past or the future, or even just the present (Fraisse 1957, p. 174). Individual differences in temporal horizons, of which little is as yet known, are clearly present in mental pathology and have been emphasized in studies of juvenile delinquents (Barndt & Johnson 1955).

Mastery of time

Tolerance of delay . It is possible to set up delayed conditioning in animals when the unconditioned stimulus provides positive reinforcement. It seems impossible to obtain this result in rats when the reinforcement is negative (avoiding an electric shock); but it does seem possible to obtain conditioning to time in dogs to whom an electric stimulus on the paw is given every five minutes [see Dmitriev & Kochigina 1955; see alsolearning, article onavoidance learning].

Children are greatly put out by the frustrations arising from the postponement of satisfaction. They are noticeably better able to stand delays as they grow older (Orsini & Fraisse 1957) and thus become able to prefer a reward that is greater, but delayed, to one that is smaller but immediate (Mischel & Metzner 1962). This progress appears to be linked on the one hand to development, education, and intelligence, and on the other, to emotional stability (Fraisse & Orsini 1955). Adolescents with emotional troubles react more impulsively to the stresses of the environment (Levine & Spivack 1959).

Culture and the socioeconomic level (for the two are often linked) lead to the development of an appreciation of distant but valuable objectives and thereby of plans for organizing the future (Doob 1960). Maturity and culture make it possible to break free of the domination of the pleasure principle and to adjust better to the reality of time.

The notion of time . Even when man is able to tolerate delays, he is enraged by irreversible changes. He finds relative security in conforming to the demands of society, whose pressure increases in proportion to the complexity of the network of social relations ("La pression temporelle” 1953); this is why the city dweller uses a watch more often than a farmer does.

However, men seek to escape from the irrever-sibility of time by developing a notion of time that enables them to put the past and the future into the present. Cultivated men and societies like to set up memorials of their past in the forms of museums and archives and seek to survive their deaths by work that is as imperishable as possible.

Paul Fraisse

[See alsodevelopmental psychology, article ona theory of development; sleep. Other relevant material may be found inlanguage, article onlanguage development; Perception; Psychophysics; sensory and motor development.]

BIBLIOGRAPHY

Aschoff, Jurgen 1965 Circadian Rhythms in Man. Science 148:1427-1432.

Barndt, Robert J.; and Johnson, Donald M. 1955 Time Orientation in Delinquents. Journal of Abnormal and Social Psychology 51:343-345.

Broadbent, Donald E. 1958 Perception and Communication. Oxford: Pergamon.

Cowle76S, J. T.; and Fdjan, J. L. 1941 An Improved Method for Establishing Temporal Discrimination in White Rats. Journal of Psychology 11:335-342.

Davis, R. 1962 Time Uncertainty and the Estimation of Time-intervals. Nature 195:311-312.

Dmitriev, A. S.; and Kochigina, A. M. (1955) 1959 The Importance of Time as a Stimulus of Conditioned Reflex Activity. Psychological Bulletin 56:106-132. → First published in Russian.

Doob, Leonard W. 1960 Becoming More Civilized: A Psychological Exploration. New Haven: Yale Univ. Press.

Feokritova, Iuliia P. 1912 Vremia kak uslovnyi voz-buditel’ sliunnoi zhelezy (Time as a Conditioned Stimulus to the Salivary Gland). St. Petersburg: Tipo-graflia Shtaba Otdiel’nago Korpusa Zhandarmov.

Fraisse, Paul 1956 Les structures rhythmiques: Etude psychologique. Brussels: Erasmus; Univ. of Louvain.

Fraisse, Paul (1957) 1963 The Psychology of Time. New York: Harper. →First published in French.

Fraisse, Paul 1963 Perception et estimation du temps. Pages 59-95 in Paul Fraisse (editor), Traite de psychologie expeirimentale. Volume 6: La perception. Paris: Presses Universitaires de France.

Fraisse, Paul; and Orsini, Francine 1955 Etude ex-perimentale des conduites temporelles. I: L’attente. Annee psychologique 55:27-39.

Frankenhaeuser, Marianne 1959 Estimation of Time: An Experimental Study. Stockholm: Almqvist & Wik-sell.

Frischeisen-Kohler, I. 1933 Feststellung des weder langsamen noch schnellen (mittelmassigen) Tempos. Psychologische Forschung 18:291-298.

Gurvitch, Georges 1958 Structures sociales et multiplicite des temps. Societe Francaise de Philosophic, Bulletin 52:99-142. → Includes 26 pages of discussion and comments.

Halbwachs, Maurice 1947 La memoire collective et le temps. Cahiers internationaux de sociologie 2:3-31. → Published posthumously.

Hawkes, Glenn R. 1961 Information Transmitted Via Electrical Cutaneous Stimulus Duration. Journal of Psychology 51:293-298.

Hirsh, I.; and Fraisse, Paul 1964 Simultaneite et succession de stimuli heterogenes. Annie psychologique 64:1-19.

Hirsh, Ira J.; and Sherrick, Carl E., Jr. 1961 Perceived Order in Different Sense Modalities. Journal of Experimental Psychology 62:423-432.

James, William (1890) 1962 The Principles of Psychology. 2 vols. New York: Smith.

Janet, Pierre 1928 L’evolution de la memorie et la notion du temps. Paris: Chahine.

Kastenbaum, Robert 1961 The Dimensions of Future Time Perspective: An Experimental Analysis. Journal of General Psychology 65:203-218.

Katz, David 1906 Experimented Beitrage zur Psycho-logie des Vergleichs im Gebiete des Zeitsinns. Zett-schrift fur Psychologie und Physiologie der Sinnes-organe. 1. Abteilung. Zeitschrift fiir Psychologie 42: 302-340; 414-450.

Leshan, Lawrence L. 1952 Time Orientation and Social Class. Journal of Abnormal and Social Psychology 47:589-592.

Levine, Murray; and Spivack, George 1959 Incentive, Time Conception and Self Control In a Group of Emotionally Disturbed Boys. Journal of Clinical Psychology 15:110-113.

Mischel, Walter; and Metzner, Ralph 1962 Preference for Delayed Reward as a Function of Age, Intelligence, and Length of Delay Interval. Journal of Abnormal and Social Psychology 64:425-431.

Orsini, Francine; and Fraisse, Paul 1957 Etudes des conduites temporelles. II: Etude genetique de l’attente. Annie psychologique 57:359-365.

Piaget, Jean 1946 Le developpement de la notion de temps chez I’enfant. Paris: Presses Universitaires de France.

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II. SOCIAL ORGANIZATION

Since all human activities occur in time, the existence of a social system necessitates some organization of time. Such organization entails:

(1) systems of time measurement, based upon cosmic and human cycles;

(2) the allocation and scheduling of time by individuals; and

(3) a set of attitudes toward time past, time present, and time future.

While many thinkers have been interested in the basic categories of the understanding—time, space, and so on—it was Durkheim’s discussion of this subject (1912) that laid the basis for modern social scientific treatments. Durkheim argued, developing Kant’s view that the basic categories of the understanding exist in the mind, that these categories are not given a priori but are social constructs. It was Durkheim’s observations that encouraged other social scientists to study the way in which cultural variations in concepts such as time and space are related to other aspects of social life (see, for example, Granet on China [1934]; Mauss on the Eskimo [1906]; Evans-Pritchard on the Nuer [1940]) as well as to the way children acquire concepts about time (see, for example, Piaget 1946).

Not all societies have the equivalent of the category “time.” Writing of the Nuer of the southern Sudan, Evans-Pritchard pointed out that for them the notion that we call “time” is not a separate idea but an integral part of social activities and of ecological and meteorological phenomena ([1940] 1963, pp. 104-108). Similarly, Bohannan has written of the Tiv of northern Nigeria: “Time is implicit in Tiv thought and speech, but it is not a category of it” (1953, p. 262).

But if time is not necessarily an explicit category, it is always an aspect of experience, implicit in thought and speech. The experience of time takes two major forms—sequence and duration. From the standpoint of sequence, events are seen as located in a particular order along a moving continuum. The experience of duration derives from the relative span of events and of the intervals between them. The experience of time as a continuum is often compared metaphorically to the movement of water, sometimes the linear flow of a river, sometimes the cyclical ebb and flow of the ocean; indeed, the English word “time” has the same root as “tide.”

Although all societies have some system of time reckoning, some idea of sequence and duration, the mode of reckoning clearly varies with the economy, ecology, and technical equipment; with the ritual system; and with the political organization. A peasant system has little need of elaborate scheduling, nor does it always possess the mechanical devices that permit accurate measurement. In nonindustrial societies the repetitive patterns of human life and the world of nature provide the basic measures of time reckoning, the counters for verbalizing the experience of duration. These measures can be thought of in terms of two main cycles, the human and the cosmic. In each cycle the main points of significant change are marked by rites of passage.

Sequence and duration, cyclical and linear patterns, and systems of reckoning occur in all human societies, but the emphases differ. The measurement of long periods of time (the chronology of the historian) could hardly begin before the urban revolution, which brought with it writing and the possibility of elaborate calculations concerning the movement of the heavens. Strict chronology began, according to Cumont (1912), with the establishment by the Chaldeans oc a fixed era, the Era of Nabonassar, in 747 B.C. The introduction of such a base point for the calculation of years was essential to the prediction (and to some extent the recording) of long-term periodic phenomena, such as eclipses. The use of a base point represents a partial disengagement from cyclical concepts: years now pass irretrievably, never to return; time accumulates and no longer just ebbs and flows. This idea of irreversible time, much stressed in Judaeo-Christian thought, is central to the development of science and history alike.

But such general changes in ideas as the shift from “the myth of the eternal recurrence” to the concept of linear, irreversible time are matters of degree rather than kind. Sacred (or liturgical) time, as distinct from profane time, continues to be largely dependent upon cyclical concepts; even the apocalypse, a thoroughly linear belief, is followed by rebirth into a timeless universe. We experience the events of our lives and the succession of the natural seasons in terms of both concepts; indeed, the attempt to erect long-term cycles continues to be a feature of the work of historians such as Spengler and Toynbee (although they tend to confuse the persistence of certain mechanisms with the repetition of specific events).

The same is true of the concepts of sequence and duration: they do not change radically. In simple societies the beginning of a ceremony is often determined by a natural event, or, as in the Tallensi ritual chain, it follows the performance of a similar ceremony by a neighboring group (Fortes 1936). Time indications tend to give way to time measurement with the invention of new mechanical devices; but even modern man, reviewing his own experience, often thinks in terms of the sequence of events rather than attempting to locate them in an absolute chronology. The subjective time of the “inner dialogue” (what Meyer-hoff calls “human time"), which forms one of the great concerns of Proust, Joyce, Mann, and Virginia Woolf, stands in contrast to the more rigid time reckoning required either by the social intercourse of urban society or by scientific endeavor; in the latter, I include the establishment of a chronology for historical reconstruction, as distinct from the personal recollection of past experience.

Since concepts of time and its social organization are basic to the development of modern science and technology, which, in turn, underlies the rise of modern industrial society, to what extent do the variations in these concepts account for differences in technological and industrial development? From the Chinese evidence, Needham has concluded (1965, p. 52) that differences in development cannot be attributed to concepts of time. These concepts vary only in degree and are not in themselves capable of preventing technological advance. Thus, in addition to the discrete cycles, the discontinuous “packaged” time of their general world outlook (Granet 1934), the Chinese also used the linear reckoning appropriate for historical narrative; both models were potentially available. It would appear that major changes in the concepts and organization of time follow rather than precede technological innovations.

Measurement of time—the cosmic cycle

The passage of time is calculated by reference to a series of repetitive units that are measured with varying degrees of precision. Certain of these units are based upon the movements of nature—the daily rotation of the earth, the regular phases of the moon, and the annual movement of the earth around the sun. The reckoning of days, months, and years occurs universally. But such units are not necessarily organized into an interlocking series, with one unit representing a specific fraction (or multiple) of another; instead, they may constitute a set of discontinuous time-indications.

Night and day . Time reckoning begins with the recurrent division into night and day that commonly regulates activity levels in most forms of animal life. The division of human life into light and dark, movement and rest, and waking and sleeping often provides a symbolic framework for many other social activities. Night is generally seen as linked with evil, with witchcraft, and with illicit behavior of all kinds. It is the time for supernatural agencies to reveal themselves in dreams and for spirits of varied shapes and sizes to roam the earth. Night is also the time for sleep and sex, for dreaming and for thievery. To daytime belong the productive activities.

In all societies, some division of the day is made according to the position of the sun in the sky; hence, concepts of dawn, forenoon, afternoon, and sunset, and the reckoning of time by the movement of light and shadow appear universally. Frequently, the periods of dawn and dusk, the times that call for a reorientation of activities from those of night to those of day, are further subdivided, and the terminology is refined. With the use of the sundial, the variation in the position of shadows can be formalized. Time reckoning thus moves in the direction of regular divisions of the night and the day into seconds, minutes, and hours, a systematization that runs counter to the experience of the inhabitants of lands where there are seasonal differences in the length of daylight.

Only with the development of mechanical devices can one divide night and day into equal units calculated against the rotation of the earth rather than on the basis of the length of sunlight. The precise divisions made by the clock are, of course, essential to any elaborate scheduling of the kind demanded by large-scale organizations like factories, offices, or communication systems. But the desire for more accurate time measurement long antedates the industrial revolution and relates to economic, ritual, military, and political needs. The sundial (or gnomon), the sandglass, and the clepsydra (or dripping water clock) were invented in Babylonia and Egypt, from whence they spread throughout the Old World. The oldest Egyptian water clock, graduated to show the lengths of hours at different seasons, dated from about 1500 B.C., and such instruments were further developed in Alexandria, in the Arabic world, and in Europe. The duties of the keeper of the clock are frequently mentioned in the rule books of monastic orders such as the Cistercians and included nightly adjustments according to observations of the stars.

From the Fertile Crescent, sundials and water clocks also spread to China. Lacking Euclidean deductive geometry, the Chinese never achieved the complexity of Arabic and western gnomonics. But the water clock evolved much further into a complex hydromechanical instrument, and by 725 the Chinese had succeeded in controlling the rotation of the water wheel by means of an “escapement” of linkwork, which operated a kind of gate. “Steady motion was thus secured by intersecting the progress of a powered machine into intervals of equal duration—an invention of genius” (Needham 1965, p. 18).

Whether or not this invention was the forerunner of the purely mechanical clock is uncertain. But by the mid-fourteenth century the technicians of western Europe had produced a weight-driven chronometer that depended upon a verge-and-foliot escapement to regulate its movement. From the time of Archimedes, men had constructed mechanical models of the planetary orbits, and most of the first clocks were “less chronometers than exhibitions of the pattern of the cosmos” their origin lay “in a complex realm of monumental planetaria, equatoria, and geared astrolabes” (White 1962, pp. 122-123). Indeed, the clock has been described as a machine to emulate the rotation of the earth.

Coincident with the invention of such a clock, the temporary, or variable, hour, which had been favored for liturgical purposes, finally gave way to the system of equal hours. The division of the day into 12 hours, based upon the duodecimal system of the zodiac, was established in ancient Greece. About the middle of the fourteenth century it became usual to divide the hour into 60 minutes and the minute into 60 seconds. The measurement of time was now removed from the context of events; its divisions were given an abstract framework, and its reckoning became increasingly dissociated from immediate human experiences, shifting from the sun or tides to the formal divisions engraved on the face of a mechanical device.

The next century saw the adaptation and use of the spring mechanism in clocks and later in watches. The new instrument was quickly taken up by the rich, particularly by the merchants, who had discovered, as Benjamin Franklin later said, that “time is money.” “To become ’as regular as clockwork’ was the bourgeois ideal, and to own a watch was for long a definite symbol of success” (Mumford 1934, p. 16). About the middle of the nineteenth century, the production of the cheap standardized watch, first in Geneva and then in America, made possible the wide use by individuals of devices for accurate, precise, and continuous time scheduling, as distinct from the communal (and less flexible) timekeeping of the muezzin’s call, the village drum, the church bell, and the town-hall clock.

In itself the clock is a technological achievement, but it also underlies four major aspects of modern life. First, it has made possible the precise measurement of time, which is perhaps the most fundamental operation in modern physics. Second, its manufacture has helped to train the craftsmen needed for further scientific endeavor, pure and applied. Third, it has provided a mechanical model for the operation of the universe. Fourth, it has permitted the detailed organization of time that an industrial system requires. In these ways, it has changed man’s attitudes and his categories of time, and, therefore, it has been called the key machine of the modern world, surpassing in importance the steam engine itself.

While accurate time measurement is a prerequisite of the complex social systems that mark industrial economies and of the scientific research on which they are based, earlier methods of timekeeping seem to have been stimulated by magical and religious concern as much as by pragmatic interests. Knowledge of the movements of the stars, although used for predicting seasonal changes and for determining direction, was often required for divinatory purposes. The Chaldean-derived horoscope consisted of observations of the configuration of the planets at a certain moment; the chosen time for the calculation was usually the moment of birth, which was believed to shape the individual’s whole destiny. Astrology represents the most elaborate form of divinatory technique; it exists only in conjunction with writing, but it is based also upon a widespread belief, apparent in the giving of day-names and similar practices, that men’s character and destiny are determined by the date of their birth.

The measurement of hours, by sundial and by sand, by candle and by clock, was an ecclesiastical demand, and so too were ideas of punctuality. Members of the “regular” clergy of the medieval monastery were enjoined to organize their lives “by rule,” that is, by a specific allocation of time for work, for sleep, and for worship. The ringing of the prayer bell seven times a day established time by recourse to instruments that divided the day into regular intervals. It was this rigid organization of time, combined with the intense devotion to work, that has led scholars to include the Benedictine order among the founders of modern capitalism.

Other world religions developed their own diurnal ordering of time. Followers of Islam, for example, are required to offer the five canonical prayers (salat) at fixed times during the course of the day. In practice, working people tend to restrict their devotions, leaving the full observances to clerics and to the retired, who are able to give their whole lives to the accumulation of religious grace. The working population concentrates upon the evening prayer, which carries the greatest weight; as in Judaism, it is the setting rather than the rising of the sun that initiates the daily cycle.

The week. The week lacks any definite basis in the external environment. It is an entirely social construct, varying in length from society to society: seven days in the Judaeo-Christian world and three, four, five, or six days in certain parts of west Africa, southeast Asia, and Central America. In early Rome it was eight days; in China it was ten. However, the weekly cycle always consists of a relatively small number of days (usually named) and is used to regulate short-term, recurrent activities, especially those of the market place. In Mesopotamia the seven-day period was linked to the five planets, together with the sun and the moon, in a planetary or astrological week. The seven-day week spread through Europe, north Africa, India, and the Malay Peninsula and is used more or less universally today; present names continue to indicate the pre-Christian origin.

The LoDagaa, a primarily agricultural society of northern Ghana, designate the six days of the week by the name of the village where a market takes place on the day in question. The very terms for “day” and “market” are the same (daa), and the weekly cycle is simply daar,“a plurality of markets,” so that the names of the days not only record the pattern of market gatherings but also serve as a measuring rod for other short-range activities.

The importance of market time is again illustrated in early medieval England, where each neighboring town held its market, or cheaping (hence “cheap"), on a different day of the week. The inhabitants of outlying districts would come in for the local trade and also for the opportunity of meeting together, so that disputes could be settled, marriages arranged, and leisure enjoyed. Thus, in many peasant societies the market week is a way of organizing social time as well as economic exchange.

The weekly cycle of markets differentiates one day from another and serves to break up the continuity of agricultural activities by providing some change of pace—substituting rest for work, exchange for production. In the Judaeo-Christian tradition, there is also a weekly shift from the profane to the sacred, for a special day is allocated for religious activity. In Islam this day is Friday, in Judaism Saturday, and in Christianity Sunday. These calendrical differences reflect distinctions of theology and organization. In Islam, Friday is the day for worship at the town’s main mosque, often with elaborate processions, but it is not a rest day in the full sense of the word; indeed, there is a maxim to the effect that it is blameworthy to abstain from work on Friday in imitation of the sabbath practices of Christians and Jews (Triminghaml959, p. 73).

The polytheistic religions of west Africa also have their day of rest, which sometimes coincides with the market day. Thomas suggested (1924, p. 199) that in west Africa, while the basis of the week is economic, the rest day is religious in origin; the days are usually named after markets, but sometimes after the gods worshiped on those days. Among the LoDagaa, one day each week is set aside as a “day of not using the hoe,” when iron implements are forbidden. It is on this day that important sacrifices are made to the Earth shrine, under whose aegis all major uses of the soil, housebuilding, farming, burial, and ironwork are undertaken.

Although modern industrial systems place a great premium upon the continuous use of industrial facilities, the day of rest is found even in those societies where its role as a day of worship has been abandoned. In the Soviet Union a continuous workweek was introduced in 1929, and each worker was given one day off in five. The result was considerable chaos, in the home as well as at work. Two years later a six-day week with a common day of rest was instituted on the grounds that the shifting five-day schedule encouraged irresponsibility with respect to jobs and employment (Moore 1963, p. 122). In 1940 the seven-day week was restored, with Sunday as the day of rest. The double functions of the week of providing discontinuity in work and time for leisure seem to be even more necessary in an industrialized society than in a purely agricultural one, where seasonal changes impress their rhythms on the productive process. Moreover, there are strong pressures for the weekly break to be held in common: since individuals spend the bulk of their day in specialized work groups, family and neighborhood groups would be of only peripheral importance if they did not have the week end as a focus for joint activities. In the absence of effective crosscutting ties, overwhelming stress would be placed upon the monolithic economic institutions, and this could result in both emotional and cultural impoverishment.

The month and the year . While itself consisting of a specified number of days, the week is rarely a subdivision of larger units of time measurement. The next unit in size, and one which is given universal recognition in some form or other, is the month, based upon the lunar cycle of 29.5 days. In nonliterate societies the month is calculated by direct reference to the waxing and waning of the moon, and special attention is paid to the three days of its death and rebirth, which are often seen as having a profound meaning for human life, being linked to ideas of immortality, death, and resurrection.

Unlike weeks, months are usually thought of as organized segments of a seasonal cycle, although some societies use names only for certain of the lunar divisions. Nevertheless, all societies recognize some kind of yearly cycle, since this is required by both agriculture and hunting. Agriculture in particular demands an annual scheduling that determines the allocation of work and of food as well as the setting aside of seed at harvest time to be preserved until the next planting season. No society can avoid some long-term budgeting of this kind; the tropical paradise where wild fruits offer a natural superabundance of food and drink is a figment of the imagination of urban Europeans. Nobody, in fact, just passes the time, although it often seems so to those dependent upon more demanding schedules. There are, of course, outstanding differences in the degree of accuracy required by different schedules.

While the weekly markets of medieval England catered to the local trade, there also existed the yearly fairs, or gearmarkets, to which traders came from far afield. The tolls for these fairs were often allocated to various eccelesiastical foundations, and the specific day on which the market took place was sometimes the saint’s day of the religious house, so that the fair doubled as a fete and the traders as pilgrims. An activity of this kind that brings people together from widely separated places at a specific time of the year clearly requires a more accurate calculus than is provided by a simple count of moons, loosely linked to a seasonal cycle. It demands a calendar (or natural occurrence) that is accurate, regular, and widely known, so that precise coordination on an annual basis is possible.

One difficulty in constructing such a system is that no sum of lunar months adds up to a yearly cycle. Intercalation is necessary in order to reconcile the year of 12 lunar months with the solar year on which the growth of crops depends. In the usual practice, no fixed number of days is assigned to the lunar month (in Islamic practice, for example, it begins when the new moon is seen), and likewise the year is considered to begin when the appropriate season comes round, the length of the months being adjusted accordingly. Thus, the harvest moon comes when the harvest is ready, and the planting moon is set by some biological clock, some natural phenomena, or what Linnaeus called the Horologe or “Watch of Flora.”

The abandonment of the lunar cycle results in a nonlunar month, or mense, under which term can be included any unit greater than ten days and less than a year (Thomas 1924, p. 188). For example, the Ashanti have the adae, a period of 42 days that is formed by the intersection of a six-day and seven-day weekly cycle, the first of local origin, the second probably of Muslim derivation. Both the great adae, which occurs after 18 days, and the little adae, which takes place after a further 24 days, were occasions for important sacrifices to the royal ancestors. As with the lunar reckoning of Islam, the adae (although unnamed) provides a continuous-chain type of calendar, divorced from the seasonal cycle but linked to a complex series of politico—religious festivals.

The necessity for a closer “fit” between lunar months and solar years came only with the introduction of written calendars, which eventually led to the abandonment of the lunar month, as in the Julian calendar, or to the relinquishing of the solar year, as in the Islamic system established by Muhammad (where the year of 12 lunar months is ten days shorter than the solar year). Historically, the first breakthrough toward the Western system appears to have been made in Egypt, which established a year of 12 nonlunar months, each with 30 days.

Writing permitted a further important formali-zation of the calendar. In nonliterate societies the accumulation of years takes place, if at all, against a background of regular ceremonies, which may occur every three, seven, or ten years (or occasionally more, as in the case of the 60-year cycle of the Dogon festivals). In early literate societies there was sometimes a set of names for the years, for example, the Year of the Mouse (China) and the Year of Moses (Islam). In ancient Greece, with its annual transfer of power, the years were known by the name of the particular archon. But monarchic systems often reckoned years from the beginning of a reign, and such regnal counts could also be made by the cutting of tallies, the counting of pebbles, or the tying of knots. In Sumeria (as elsewhere), the regnal system of reckoning years was associated with the idea that a new ruler brings with him a new dispensation, a theme of renewal that serves, like regular elections, to reconcile individuals to the gap between expectation and actuality. Similarly, the revolutionary regimes of eighteenth-century France and fascist Italy reckoned the beginning of a new era from the date of their coming to power. Time itself is seen as making a fresh start, the social order as being reborn.

The idea of an era depends upon the introduction of a fixed point at which numbering may start. Large-scale time is then no longer reckoned only by cycles or by recurrent series of occurrences; it acquires a more linear character. The fixed point used by the Chaldeans was arbitrary, but later such fixed points were calculated with reference to a unique event—the creation of the world or the birth of the prophet. Time is no longer experienced as largely repetitive (Gluckman 1963) but is seen as flowing in a single line (called variously “progress,” “evolution,” or “change") and, at the beginning of this shift in viewpoint, often in a chiliastic direction, toward an earthly millennium, the coming of a messiah; thus, certain years of the era, such as 1000, are invested with mystical properties.

The early formalization and elaboration of written calendars took place under a variety of pressures: the demands of agricultural planning. particularly in complex irrigation societies; the organization of trade, especially long-distance trade; and the coordination of the military and administrative activities of centralized polities. But as in nonliterate societies, magico-religious factors continued to be of prime importance in the arrangement and elaboration of the calendar, which mapped out the liturgical year as well as the economic year. Writing also made possible the recording of star positions and the development of mathematics, which were essential for the development of the horoscope as a means of forecasting future events and ascertaining divine will. Astrological and astronomical calculation always had much in common, and the mapping of the heavenly universe was important not only for divination but also for the development of chronometers and for navigation.

One factor that inhibited navigation was the existence of purely local systems of time reckoning, and the development of a world-wide network of communications has inevitably led to the adoption of a unified calculus. Sun time, which varies by one minute every eight miles, had to give way to conventional time belts, which were established in the United States around 1880 at the instigation of the transcontinental railroads. Some years later a world congress completed the standardization of time that had begun with the founding of the Greenwich observatory two hundred years before and that led to the coordination of ships’ chronometers with Greenwich mean time. Human action could now be synchronized on a world-wide scale.

Systems of time reckoning have developed from concrete time indications of a discontinuous kind to increasingly abstract, numerical, and regular divisions linked to a continuous calendar based primarily on diurnal and annual movements. Through the means of writing, astronomy, and mechanics, there occurs an increasing dissociation of time measurement from commonplace events —the movement of animals, the growth of crops, and the human activities to which they are directly linked. Thus, there emerges a formal framework of objective divisions that are as applicable in Delhi as they are in Dallas. But the development of more abstract time scales tends to supplement rather than replace more concrete ideas of time, which often continue to be the measure for much subjective experience.

Rites of passage in the cosmic cycle . For many social purposes, time is reckoned not by regular units of measurement but by the major festivals that break up the continuity of its passage ("Only 42 more shopping days to Christmas"). Such holidays and festivals may be linked to any of the major time divisions—to days, weeks, months, or years. In England, the week revolves around its “holy day” and has its regular days for pay, sport, and rest. These regular days dominate patterns of food consumption (the Sunday roast) and of family interaction, as well as the whole industrial system; however, I am here concerned with the annual festivals that have a marked influence on the long-range planning of human activities.

In agricultural communities, where productive activity is periodic, the major festivals of local religions tend to mark the beginning and end of the productive season. At the time of planting a rogation ceremony is often performed to obtain supernatural blessing for the growing crops; at harvest time a thanksgiving festival is held to acknowledge divine intervention in the productive process. In northern climes, where agriculture is much affected by the changing length of days and is influenced more by variations in sunshine than by the coming of the rains, ceremonies often cluster around the times of solstice and equinox, the major turning points of the solar year.

Annual festivals, although mainly religious in orientation, have other consequences, intended and unintended. In tribal societies annual gatherings, such as the Australian corroboree, are important for the initiation of adolescents, the re-enactment of myths, and the restatement of cultural values. In addition, they provide a meeting point for persons of neighboring social groups, who not only participate in communal rituals but also use the occasion for settling disputes, getting brides, repaying debts, and generally regulating their affairs. Such events are often marked by a limited expression of tensions between groups, although the likelihood of overt conflict is inhibited by ritual peace, supported by special sanctions against the outbreak of violence (Fortes 1936). In Islamic countries the month of the pilgrimage (Dhu ’l-hijja) is sandwiched between two months during which raiding is prohibited, thus encouraging a ritual peace for the business and religious activities of the pilgrims.

In state systems, festivals such as the Ashanti Odwira, the Hausa Gani, or the damba of northern Ghana are used to affirm political allegiance; on these occasions subordinate chiefs come to the capital to do public obeisance to their liege lords. Again, these occasions may also allow for the limited expression of conflict in rituals of rebellion directed against those in authority (Gluckman 1954).

As religious festivals, these ceremonies are obviously affected by changes in the beliefs of the participants. But often new cults that arise are forced to incorporate features from earlier rituals into their own because of the powerful hold of the traditional rites; indeed, the early Christians adopted Roman rituals to such an extent that Faustus, the Manichaean bishop, tried to convince the young Augustine that they were nothing better than idolaters.

Whereas the major ceremonies of local religions usually celebrate the birth and death of the year (sometimes represented by the life cycle of a god), the main rituals of the prophetic religions enact the life and death of their founder, whose life cycle is encapsulated in the yearly calendar. The freedom from particular seasonal rhythms makes such calendars more appropriate for the world religions, whose adherents span many environments, and more appropriate also for urban communities, whose way of life is not governed by climatic changes. Such a liturgical calendar represents a further step in the dissociation of objective time reckoning from immediate human activities.

Increasing secularism has meant that the political value of regular festivals has been openly acknowledged; the anniversaries of a nation’s birth are celebrated with the same pomp and circumstance found in public demonstrations of loyalty to leader, state, and party. But while most ceremonies have a particular religious or national significance, the increased interaction between nations is producing a basic standardization of ceremonial time, a universal ritual calendar. The seven-day week is now world-wide, and, with the exception of a few Arab states of the Middle East, so too is the Sunday break; the post-Independence changes in Ceylon, which introduced a shifting weekly holiday (poya) based upon the lunar calculation of the Buddhists, were inspired by political motives and seem unlikely to last. The most widespread public holiday is the first of January, the beginning of the Gregorian year, closely followed in popularity by Christmas and May Day. Despite the predominantly secularized character of the modern festival, a few groups reject the celebration of Christmas on religious grounds, but gift giving is often shifted to a nearby occasion—to Hanukkah among Jewish minorities and to New Year’s Day in the European communist states. In some countries the first of May, the day on which the labor movement traditionally shows its strength, is celebrated as a holiday, but under certain right-wing regimes, as in Spain, all public manifestations of the holiday are banned, although this very denial has added to its value as a day of protest. In most of the new nations the day is celebrated as one of solidarity and exhortation to increased national effort. In this case, the element of protest has been transferred from inside the social system to external targets, especially to the “neocolonial” activities of the major European powers.

The number of bank holidays provides a rough scale of the degree of national “puritanism": Roman Catholic countries have the most, Protestant ones fewer, and the communist states fewest of all; Brazil has 18, Britain 6, and Bulgaria 5. New nations display an eclectic choice that reflects their political situation, ideological tenets, and religious composition: Ceylon, for example, recognizes Christian, Muslim, and Buddhist festivals, together with May Day, Independence Day, and a few other holidays, making a total of 15.

Measurement of time—the human cycle

Objectively, the passage of time in both the cosmic and human cycles is measured by the units already described—days, weeks, months, and years. But just as the year is divided into seasons that broadly characterize its main phases, so too the life span of human beings is divided into such categories as infancy, adolescence, and adulthood. The movement of an individual from one age grade to another is often celebrated by a rite of passage. In some societies these stages of growth form the basis of social groups of coevals, and in others a continuing series of such groups (age sets) is linked in an over-all age organization, which may serve important political and military functions. In modern nation-states, age-determined groups are the basis of educational organization, of informal associations of adolescents, and often of military recruitment, but they are of little importance in later phases of the life cycle.

The position of an individual in the life cycle not only influences the role he plays and the groups to which he belongs but also has a number of less obvious effects on his behavior. The composition of the unit around which his domestic life revolves inevitably changes radically over time. One consequence of this fact for sociologists is that the “average family” can never be directly derived from a synchronic census but must be seen in dynamic perspective, that is, in terms of the developmental cycle (Fortes 1958). This approach not only illuminates residential patterns and divorce statistics but also is important in analyzing changing attitudes and beliefs. Durkheim, for example, demonstrated the inverse correlation between suicide rates and family integration, while Argyle (1958) showed the link between age and religious commitment, the latter being highest at 18, dropping to a nadir at 30, and gradually increasing in strength the nearer the prospect of death. Clearly, an individual’s perception of the social universe changes as his relationships with the living shift: the child defers to his elders, while the adult is deferred to. Rites of passage in the human cycle. The major changes in an individual’s life are marked by rites of passage which announce and enact the acquisition of a new role, of new rights and duties. Thus, birth is usually followed by baptism, marriage rites celebrate the establishment of an enduring sexual union, and death is accompanied by elaborate funeral ceremonies that serve to dissociate an individual from his network of mundane relations and dispatch him to the world of the dead. In preindustrial societies funerals are usually the most important of the life-cycle ceremonies, since they have to accomplish the transfer of a man’s rights and duties, especially over property, women, and office, to other members of the community; this process is necessarily gradual and hence often marked by a double funeral, the first stage of which is a burial service and the second a kind of memorial (Hertz 1907; Goody 1962). Ceremonies accompanying such distributions are particularly important in agricultural societies, where the volume of fixed and enduring property transmitted by kinship succession is high and where the ceremonies themselves often have integrative and cathartic functions for the local group. In urban industrial communities, where neighborhood and kinship ties are weak, where property inheritance is of more limited significance (since most people cannot bequeath the means of production), such ceremonies tend to become more perfunctory, especially as literacy permits the witnessing function of these rites to be accomplished by the issuing of licenses. But marriage, which involves the expression of intent by the participants, is still a significant public display in many industrial communities; birth continues to be the focus of important ceremonies among people of property; and the funeral complex (including published obituaries) often takes a highly elaborate form in the case of those who have done the state some service. The burial of great men performs an integrative function on a national level, restating the values the society holds dear and recalling the specific contributions made by other former citizens.

The allocation of time

Members of all societies have to make some allocation of the time to be spent on any one activity as against any other. In simple economies the basic allocation is closely linked to nature, being dominated by diurnal and seasonal rhythms. More accurate and more complex scheduling goes hand in hand with an increasing complexity of organization. It is made possible first by the development of writing, then by the invention of mechanical time keeping, and finally by the democratization of literacy through paper and the printing press. Time allocation, like other bureaucratic operations, can be removed from the uncertain sphere of memory and attached to objects in the outside world—"Make a note of that,” “Put that in writing.”

But it is above all the watch that dominates the organization of time in modern societies. While radio signals, the factory siren, and the town-hall clock establish public time, the increasingly complex schedules of contemporary life are made possible by the mass-produced watch, a personal time keeper that individuals consult with the obsessive regularity of the White Rabbit in Alice in Wonderland. The coordination of joint activities, whether over large distances or within complex organizations, requires that each individual make precise measurements: army orders for the movement of troops may end with the synchronization of watches, and civilians display the same concern about being “on time.” The watch is often a man’s first major gift to his adolescent son, a stimulus to adopt the adult virtue of punctuality, an emblem of approaching responsibilities.

Since many of the operations of industrial life occur at regular intervals, people are able to rou-tinize their behavior and so reduce the strain of organizing schedules and making decisions. In the commuter’s life (the epitome of routinized time allocation), the pattern is largely imposed from the outside, by factory, train, and office. However, elaborate scheduling also spills over into leisure hours; many individuals have regular times for washing the car, for going on walks, and for entertaining guests, and in this way themselves impose an order on these potentially less structured situations.

As Mumford has pointed out, such regimentation was both essential to and the product of the rise of capitalism: “The new bourgeoisie, in counting house and shop, reduced life to a careful, uninterrupted routine: so long for business: so long for dinner: so long for pleasure—all carefully measured out, as methodical as the sexual intercourse of Tristram Shandy’s father, which coincided, symbolically, with the monthly winding of the clock. Timed payments: timed contracts: timed work: timed meals: from this period on nothing was quite free from the stamp of the calendar or the clock. Waste of time became for protestant religious preachers, like Richard Baxter, one of the most heinous sins” ([1934] 1964, p. 42).

Mechanical devices (like writing) can make for easier manipulation of time categories; when schedules are linked with natural events such as the budding of trees, they are less easy to adapt to innovations such as new crops. At the same time, these devices enabled man to accelerate the pace of life to fit more activities into the day. A major development in late medieval technology was the control of power, and increasing power quickened the tempo of social life. Production and transport were speeded up, and in this century the concern with speed has even affected sport; the stop watch became the tool of the athletic coach as well as of the time-motion study experts.

Because the diversity of an individual’s roles is so often tied to particular places, such as shop, clinic, or office, it demands very specific allotments of time. A man or woman at work has to meet a more exacting schedule than does a housewife, whose routine turns upon the husband’s employment and the children’s school. Economic and domestic roles are segregated in time and space; and to take on any additional ("voluntary") roles, such as that of local councilor, party chairman, or committee member, means a further careful allocation of this scarce commodity, since each one necessitates a whole set of timed appearances. In societies that lack a complex division of labor, the role structure is more homogeneous in that during their lives most people fill most roles and in that the activities themselves rarely involve so great a separation in space and time.

The more elaborate the division of labor and the less ascriptive the recruitment to roles, the greater are the number of possible role opportunities open to the individual. Selection among these alternatives is a matter of allocating time over the whole span of a person’s life, and adults speak feelingly of “the wasted years” or of “having their time over again,” sentiments likely to be less important in undifferentiated communities, where a new life would tend to be much like the old. In Hindu society, which, although differentiated, is still based on the ascription of roles, movement through the role structure is left to future incarnations and depends upon an individual’s performance in his existing status. Such an eschatology provides the possibility of future mobility as a compensation for the unchangeable present.

“Career scheduling” involves choices on the part of both the senior and junior generations that often entail consideration of comparative rewards over the long term. Lengthy career training means the postponement of gratification in money, sex, and independence. The ability to carry out such a program derives from professional interest, the attraction of greater rewards, and the pressures of parents and peers; it is also supported by moral factors, such as the commitment to the Protestant ethic. The higher the desired status and the more complex the economy, the longer the time perspective needed to attain one’s ends. On a national scale, there is a parallel problem concerning the restriction of immediate spending in the interests of investment. The running of any economy, whether socialist, capitalist, or mixed, requires a deliberate consideration of present action in the light of future needs.

Attitudes toward time

The past. In nonliterate cultures ideas and attitudes concerning the past tend to reflect present concerns. To some extent this happens in all societies, especially in those situations where we rely upon memory. But where the transmission of culture is entirely dependent upon oral communication, upon an interlocking series of conversations, the past is inevitably swallowed up in the present (Goody & Watt 1963). In the strictest sense, history begins with writing. Before (and partly after) the widespread use of writing, the past is a backward projection of the present, going straight back to the mythical age that saw the emergence of humanity and its present way of life. While stories of migration and genealogies contain much in the way of historical fact, they often constitute collective representations of contemporary relationships and act as the “charters” of existing institutions. For example, the variations in the average depth of genealogies are to be related not to intrinsic differences in short-term and long-term memories of the people concerned but to differences in the social groups that these genealogies help to tie together. However, in many centralized societies, accounts of dynastic events are often passed down by various mnemonic devices that partly shield their contents from the transmuting effects of oral tradition.

It is only when writing gives a material embodiment to speech that the distant past can represent more than a backward extension of the present. Although each age still rewrites its own history, the past begins to acquire an independent existence of its own. Today an individual’s cultural equipment is no longer limited to what is handed down orally from one generation to the next but includes, potentially at least, the entire contents of the libraries, the written records of the past ages and dead societies, and the thoughts of distant scholars. The cultural heritage is vastly extended and with it the whole conceptualization of space and time. Change and duration become a more concrete part of one’s existence. With the extension of writing into the personal and the ephemeral, by means of letters, newspapers, and diaries, even one’s own past can achieve a modicum of objectivity, providing memory with an individual check list. Recording the speech of people over time and over space widens human experience and increases the likelihood of further change by making skepticism and disagreement articulate and therefore cumulative; literate traditions of dissent open up vistas of alternative forms of human organization.

With the articulated calendar, the passage of time takes on a measured regularity. Old men can no longer look back unchallenged upon a past of 200 summers; with the registration of births and deaths, the specification of exact age becomes an intrinsic part of life and death. The reckoning of annual birthdays, whether for customary celebration or for astrological calculation, is a literate device. The Akan of west Africa named their children according to the weekday of birth (for example, Kwame is Saturday’s child), which was seen as determining a child’s character and sometimes functioned as a self-fulfilling prophecy; however, the system specified only the name of the day, not the day of the month or the year.

The recognition of age differences and age order is a feature of all societies, but people in Western societies are preoccupied with specific age. An adult’s first question to a child, after hearing his name, is about his age, and age will be the first entry in a man’s obituary and the main feature on his tombstone. Numerical age rather than physical condition determines adult status; the patterned ages of 7, 14, and 21, so important in medieval law, have been largely replaced by new numbers that define an individual’s ability to marry, to fight, and even to work, for bureaucratic organizations increasingly enforce compulsory retirement by age rather than by capacity. But characteristically this restriction applies to the employee more than to the director, to civil servants more than to politicians.

The present. Literacy influences attitudes not only to the past but to the present and future as well. The permanency of written records makes a radical difference in the accumulation and storage of knowledge and opinions and thus creates the possibility of more rapid change. But literacy brings with it an often troublesome inability to forget the past, so that the present has to engage in a deliberate struggle with older modes of thought and action. Individuals, groups, and governments strive to repeal laws which in nonliterate societies would have quite simply been forgotten or else would have undergone imperceptible changes to bring them into line with the new conditions. Unlike statutes, the Bible, the Koran, and other books of God cannot be amended, but their contents are reinterpreted over time and what was once intended literally is later seen as allegory and symbol, as metaphor and myth.

But above all, attitudes toward time present focus upon the alternative uses of time that are offered by an elaborate division of labor, the minute scheduling that this division of labor entails, and the continual presence of a watch upon the wrist, which makes man ever conscious of the fleeting moment. In most literary traditions, writers express their regret at the passing of pleasure and the shortness of human life, but it is the perpetual concern with the passage of time that is characteristic of industrial man. Made aware that time is his scarcest resource, he learns to “spend” and “save” it like money. The ideology that stands at the center of industrial society stresses the full and productive use of time, a commodity that requires the most careful husbanding. This concern is as characteristic of socialist systems as of capitalist systems; during the industrialization of the Soviet Union an association was formed to encourage the carrying of watches and to expound the benefits of punctuality. Managers often find that the behavior of newly industrialized workers in developing countries deviates sharply from these enunciated values. The peasant is not used to “watching the clock” or to the demanding (and desiccating) routine of much of factory life. “Slaves?” I was once asked by an African visitor when he first saw rows of women working on an assembly line, their exits and entrances timed by “the clock,” their every move organized by time and motion studies. For the peasant, time has been nature’s time, and the organization of his activities largely his own affair.

The future. The factors that bear upon attitudes toward the present are also relevant to attitudes toward the future; indeed, the difference simply turns on the question of scheduling over the longer term, as compared to the shorter term. In peasant communities the scheduling of production operates on an annual basis, but it is largely repetitive and future activity is mainly a continuation of the present. With the development of centralized political systems planning became more elaborate and included the storage of grain against famine, the construction of capital works, the build-up of supplies for military campaigns, and the organization of long-distance trade. But while the future may be visualized in terms of the success or failure of such undertakings, which are recognized as responsive to human foresight and control, deliberate social change is at first organizational rather than structural; even changes in the political order are a matter of rebellion rather than revolution, of replacing the officeholder rather than changing the over-all distribution of power.

The possibility of long-range planning is vastly increased by the existence of writing. Literacy not only makes it technically possible to follow a complex plan but also to project and publicize a variety of alternative worlds (and the programs for their attainment) that vary along a continuum ranging from the pragmatic to the Utopian. And by the process of “ideological feedback,” these programs often influence, and sometimes dominate, the direction of change.

Plans, the projected organization of future time, are as much a requisite of the personal sphere as of the national and industrial domains. The maintenance of a yearly balance between production and consumption is not in itself enough: in most professional and managerial groups there is the necessity of planning for a surplus throughout a man’s total career, a surplus that is required for heavy expenses such as house purchases and educational fees; and since the dominant attitudes favor providing for individual security rather than familial dependence, there is the problem of making provision for old age. A man’s total perspective of time future extends beyond the end of this life to an afterlife. Beliefs in the continuity of some element of the human personality after death characterize all cultures, with the possible exception of communist societies and minority groups in secularized Western states.

In most societies the distant past and future tend to be of peripheral interest. However, the idea of an earlier golden age, a Garden of Eden, is not an uncommon way of dealing with the universal “problem of evil,” of explaining the actual imperfections and potential perfectibility of man. And when a culture of the less complex kind is hard pressed, typically by contact with European society, there is a tendency to seek comfort in ritual designed to bend time backward to an earlier paradise or to leapfrog time and hurry on the advent of the Messiah, the coming of the millennium [Worsley 1957; Thrupp 1962; see alsomillenarism].

By and large, the “other world” of agricultural societies is visualized as a continuation of this world, although there is usually some distribution of rewards and punishments for behavior on earth, so that those who have escaped from mundane punishments get their due in the afterlife. Societies with elaborate status hierarchies may redress the balance of this world by a reversal of status in the next; it is the rich rather than the poor who are told that it is difficult to enter the Christian heaven.

The afterlife may be seen either as the final destination of humanity or as a stage in the continuous flow of life which leads back again into this world by some process of reincarnation or transmigration. Here again, the element of status reversal may be present; the relative lack of social mobility in Hindu society is partially offset by the fact that the worthy fulfillment of a man’s present role may qualify him for a higher status in his next incarnation.

The increasing pace of social change and individual mobility in industrial societies, combined with an increasing skepticism and secularization, makes such eschatologies of decreasing importance to society. Millennial dreams are replaced by political Utopias, the idea of a fixed destiny by a concern with educational mobility, and the belief in immortality by a concept of social progress and continuity. Nevertheless, few men, as they advance in age, do not feel the urge to extend the limits of their tenure, by church attendance, public activities, the written word, or identification with their progeny. It is difficult, if not impossible, for men to envisage a final end to time, on either a cosmic or an individual level, and the continuous chain of familial living helps to mitigate the prospect of complete finality.

Jack Goody

[See alsoperiodization.]

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TIME

Time has frequently struck philosophers as mysterious. Some have even felt that it was incapable of rational discursive treatment and that it was able to be grasped only by intuition. This defeatist attitude probably arises because time always seems to be mysteriously slipping away from us; no sooner do we grasp a bit of it in our consciousness than it has slipped away into the past. This entry will argue, however, that this notion of time as something that continually passes is based on a confusion.

St. Augustine's Puzzles

The apparent mysteriousness of time can make puzzles about time seem more baffling than they are, even though similar ones arise in the case of nontemporal concepts. St. Augustine, in his Confessions, asks, "What is time?" When no one asks him, he knows; when someone asks him, however, he does not know. He knows how to use the word "time" and cognate temporal words, such as "before," "after," "past," and "future," but he can give no clear account of this use. Trouble arises particularly from the form in which he puts his question: "What is time?" This looks like a request for a definition, and yet no definition is forthcoming. However, most interesting concepts cannot be elucidated by explicit definitions. Thus, to explain the meaning of the word "length," we cannot give an explicit definition, but we can do things that explain how to tell that one thing is longer than another and how to measure length. In the same way, it is possible to give an account of the use of the word "time" even though it is not possible to do so by giving an explicit definition. In short, this puzzle of St. Augustine's is not of a sort that arises peculiarly in the case of time. Beyond pointing this out, therefore, it is not appropriate here to go further into the matter.

Augustine was also puzzled by how we could measure time. He seems to have been impressed by the lack of analogy between spatial and temporal measurement. For example, one can put a ruler alongside a tabletop, and the ruler and the tabletop are all there at once. However, if one were to measure a temporal process, it would be done by comparing it with some other process, such as the movement of the hand of a watch. At any moment of the comparison, part of the process to be measured has passed away, and part of it is yet to be. It is not possible to get the thing to be measured in front of a person all at once, as one could with the tabletop. Moreover, if two temporal processes are compared—say, a twenty-mile walk last week with a twenty-mile walk today—they are compared with two different movements of a watch hand, whereas two different tabletops are compared with the same ruler. Augustine is led to see a puzzle here because he demands, in effect, that non-analogous things should be talked about as though they were analogous.

In any case, the two things are not, in fact, as non-analogous as they appear to be at first sight. If we pass to a tenseless idiom in which material things are thought of as four-dimensional space-time solids, the difference becomes less apparent. For in the case of the tables we compare two different spatial cross sections of the four-dimensional object that is the ruler with spatial cross sections of the two tables. Augustine seems to have been influenced by the thought that the present is real, although the past and future are not (the past has ceased to exist, and the future has not yet come to be); consequently, the measurement of time is puzzling in a way in which the measurement of space need not be (where the whole spatial object can be present now). This thought—that the present is real in a way in which past and future are not real—is part of the confusion of the flow or passage of time. This is not to say that presentism has not recently been intelligently defended, however implausibly, as by John Bigelow (1996). Apodeictic proof has rarely been possible in metaphysics, and we fall back eventually on trading plausibilities. One of the central objections to presentism is the difficulty it has in analyzing cross-temporal statements such as "Smith will have come before you have finished breakfast." Perhaps the most important objection relates to the explanatory value of four-dimensional space-time in relativity theory to be discussed below.

The Myth of Passage

We commonly think of time as a stream that flows or as a sea over which we advance. The two metaphors come to much the same thing, forming part of a whole way of thinking about time that D. C. Williams has called "the myth of passage"(Williams 1951). If time flows past us or if we advance through time, this would be a motion with respect to a hypertime. For motion in space is motion with respect to time, and motion of time or in time could hardly be a motion in time with respect to time. Ascription of a metric to time is not necessary for the argument, but supposing that time can be measured in seconds, the difficulty comes out clearly. If motion in space is feet per second, at what speed is the flow of time? Seconds per what? Moreover, if passage is of the essence of time, it is presumably the essence of hypertime, too, which would lead one to postulate a hyper-hypertime and so on ad infinitum.

The idea of time as passing is connected with the idea of events changing from future to past. We think of events as approaching us from the future, whereupon they are momentarily caught in the spotlight of the present and then recede into the past. Yet in normal contexts it does not make sense to talk of events changing or staying the same. Roughly speaking, events are happenings to continuants—that is, to things that change or stay the same. Thus, we can speak of a table, a star, or a political constitution as changing or staying the same. But can we intelligibly talk of a change itself as changing or not changing?

It is true that in the differential calculus we talk of rates of change changing, but a rate of change is not the same thing as a change. Again, we can talk of continuants as coming into existence or ceasing to exist, but we cannot similarly talk of a "coming-into-existence" itself as coming into existence or ceasing to exist. It is nevertheless true that there is a special class of predicates, such as "being past," "being present," "being future," together with some epistemological predicates such as "being probable" or "being foreseen," with respect to which we can talk of events as changing. Significantly enough, these predicates do not apply to continuants. We do not, for example, naturally talk of a table or a star as "becoming past" but of its "ceasing to exist." There is something odd about the putative properties of pastness, presentness, futurity, and the like, whereby events are supposed to change. One might conjecture that the illusion of the passage of time arises from confusing the flow of information through our short-term memories with a flow of time itself.

token-reflexive expressions

Leaving aside the epistemological predicates, we may suspect that the oddness arises because the words "past," "present," and "future," together with "now" and with tenses, are token-reflexive, or indexical, expressions. That is, these words refer to their own utterance. If italics are allowed to indicate tenselessness in a verb, then if one says, "Caesar crosses the Rubicon," the speaker does not indicate whether the crossing is something before, simultaneous with, or after the assertion. Tenseless verbs occur in mathematics where temporal position relative to a person's utterance is not even in question. Thus, we can say, "2 + 2 is equal to 4" not because we wish to be noncommittal about the temporal position of 2 + 2 as being 4 but because it has no temporal position at all.

The token-reflexiveness (or more generally the indexicality) of the word "past" can be seen, for example, if a person who said that a certain event E is past could equally well have said, "E is earlier than this utterance." Similarly, instead of saying, "E is present," he could say, "E is simultaneous with this utterance," and instead of "E is future," he could say, "E is later than this utterance." The phrase "E was future" is more complicated. It means that if someone had said, "E is future" or "E is later than this utterance," at some appropriate time earlier than the present utterance (the utterance which we now refer to as "this utterance"), he would have spoken truly. Thus, if we say that in 1939 the battle of Britain was in the future, we are putting ourselves into the shoes of ourselves as we were in 1939, when, given a certain amount of prescience, we might have said truly, "The battle of Britain is later than this utterance." Apart from this imaginative projection, we are saying no more than that the battle of Britain is later than 1939. Another way of dealing with this problem, one that is preferred by Michael Tooley (1997) would be to interpret the token reflexive expressions as referring not to utterances but to times of utterance.

It follows that there is a confusion in talking of events as changing in respect of pastness, presentness, and futurity. These are not genuine properties, which can be seen if the token-reflexiveness is made explicit. "E was future, is present, and will become past" goes over into "E is later than some utterance earlier than this utterance, is simultaneous with this utterance, and is earlier than some utterance later than this utterance." Here the reference is to three different utterances. However, if we allow simultaneity, being later, and being earlier as relations to times as well as events we could render the tensed sentence above by saying, "E is later than some time earlier than this utterance, is simultaneous with this utterance, and is earlier than some time later than this utterance." Also, the troubling sentence "Once there were no utterances" could go over to "There are times earlier than this utterance when there were no utterances." A failure to recognize the direct or indirect indexicality of words such as "past," "present," and "future" can lead us to think wrongly of the change from future to past as a genuine change, such as the change in position of a boat that floats down a river.

Nevertheless, there is probably a deeper source of the illusion of time flow. This is that our stock of memories is constantly increasing, and memories are of earlier, not of later, events. It is difficult to state this matter properly because we forget things as well as acquire new memories. With a very old man there may well be a net diminishing of his stock of memories, and yet he does not feel as if time were running the other way. This suggestion is therefore tentative and incompletely worked out. Possibly we confuse a flow of information through our short-term memories with a flow of time itself (Smart 1987). The subordinate question of why our memories are of the past, not of the future, is an extremely interesting question in its own right and will be answered in a later section.

tenses

Not only words such as "past" and "future" but also tenses can be replaced by the use of tenseless verbs together with the phrase "this utterance." Thus, instead of saying, "Caesar crossed the Rubicon," we could have said, "Caesar crosses the Rubicon earlier than this utterance." For the present and future tenses we use "simultaneous with this utterance" and "later than this utterance." Of course, this is not a strict translation. If one person says, "Caesar crosses the Rubicon earlier than this utterance," that person refers to his utterance, whereas if another person says, "Caesar crossed the Rubicon," she is implicitly referring to her utterance. Nevertheless, a tensed language is translatable into a tenseless language in the sense that the purposes subserved by the one, in which utterances covertly refer to themselves, can be subserved by the other in which utterances explicitly refer to themselves.

A second qualification must be made. In the case of spoken language the token or "utterance" can be taken to be the actual sounds. In a written language the "token," the configuration of ink marks, is something that persists through time. By "this utterance" we must therefore, in the case of written language, understand the coming-into-existence of the token or perhaps the act of writing it. It has sometimes been objected that this account will not stand because "this utterance" means "the utterance which is now," which reintroduces the notion of tense. There does not seem to be any reason, however, why we should accept this charge of circularity. We have as good a right to say that "now" means "simultaneous with this utterance" as our opponent has to say that "this utterance" means "the utterance which is now." The notion of an utterance directly referring to itself does not seem to be a difficult one.

Tenses and their cognates may be seen to be indexical expressions. The truth conditions of sentences containing them cannot be given by translation into a nonindexical language. Nevertheless they can be given in a nonindexical metalanguage. The idea derives from Donald Davidson and is advantageous because there is a recursively specifiable infinity of sentences in a language but not of utterances or inscriptions. Equally with the token reflexive account it removes the mystery that one might feel about tenses and cognate expressions.

Tensers, such as Quentin Smith (1993), argue that the words "past," "present" and "future" refer to intrinsic properties of events, though Smith defines "past" and "future" in terms of "present." This makes him in a sense a presentist, though only a mild one as he does not deny the reality of the past and future. Davidson's suggestion for the semantics of tenses is to say that (say) "I will come" is true as (potentially) spoken by person P at time t if and only if P comes later than t. As Heather Dyke, in her doughty defense of the token-reflexive approach (Dyke 2002, 2003), has remarked, without the "potentially" (of which critics of modal logic may be suspicious) the Davidsonian schema comes out trivially true in cases where (say) "I will come" is not uttered by P at t. Perhaps one might reply that trivial truth is still truth and so harmless, or one might treat the Davidsonian schema as an idealization. Dyke has urged that one should abandon aspirations of the old token reflexive theory for a translation of tensed sentences into tenseless ones but argue that a tensed sentence states the same fact about the world as can be stated by a tenseless one. Thus she wants a semantics based on tokens of sentences, not sentences, and so abandons recursiveness. A similar appeal to the notion of "fact" is made by D. H. Mellor in his influential Real Time II (1998), where he says that ontology can be separated from considerations of semantics. Of course this metaphysical notion of "fact" has been thought problematic, as by Davidson himself. Nevertheless, the difference between the token reflexive account and the metalinguistic one is not of great ontological significance. Dyke contests arguments by Quentin Smith (1993), who has been an immensely prolific defender of the tensed notion of time.

duration

The philosophical notion of duration seems to be heavily infected with the myth of passage. Thus John Locke in his Essay concerning Human Understanding (1690) says that "duration is fleeting extension" (bk II, ch. 14, paragraph 1). In the early nineteenth century, Henri Bergson (1910, 1911, 1913) made the notion of duration (durée ) central in his philosophy. According to him, physical time is something spatialized and intellectualized, whereas the real thing, with which we are acquainted in intuition (inner experience), is duration. Unlike physical time, which is always measured by comparing discrete spatial positions—for example, of clock hands—duration is the experienced change itself, the directly intuited nonspatial stream of consciousness in which past, present, and future flow into one another. Bergson's meaning is unclear, partly because he thinks that duration is something to be intuitively—not intellectually—grasped. Duration is closely connected in his thought with memory, for in memory, Bergson says, the past survives in the present. Here he would seem to be open to the objection, urged against him by Bertrand Russell in his History of Western Philosophy (1945), that he confuses the memory of the past event with the past event itself, or the thought with that which is thought about.

Even though the Bergsonian notion of duration may be rejected because of its subjectivism and because of its close connection with the notion of time flow or passage, there is nevertheless a clear use of the word "duration" in science and ordinary life. Thus, in talking about the duration of a war, we talk simply about the temporal distance between its beginning and its end.

mctaggart on time's unreality

The considerations thus far adduced may well be illustrated by considering how they bear on John McTaggart Ellis McTaggart's well-known argument for the unreality of time, which was put forward in an article in Mind (1908) and in his posthumous Nature of Existence (1927). For McTaggart, events are capable of being ordered in two ways. First, they can be ordered in respect to past, present, and future. He calls this ordering of events "the A series." Second, events can be ordered in respect to the relations "earlier than" and "later than." He calls this "the B series." McTaggart then argues that the B series does not by itself give all that is essential to time and that the A series is contradictory. Neither leg of his argument can stand criticism. His reason for saying that the B series misses the essence of time is that time involves change and yet it always is, was, and will be the case that the Battle of Hastings, say, is earlier than the Battle of Waterloo. It has already been shown, however, that it is not just false but also absurd to talk of events' changing. The Battle of Hastings is not sempiternally earlier than the Battle of Waterloo; it simply is (tenselessly) earlier than it. The notion of change is perfectly capable of being expressed in the language of the B series by saying that events in the B series differ from one another in various ways. Similarly, the proposition that a thing changes can be expressed in the language of the B series by the statement that one spatial cross section of it is different from an earlier one, and the proposition that it does not change can be expressed by saying that earlier and later cross sections are similar to one another. To express the notion of change, we are therefore not forced to say that events change. Nor, therefore, are we forced into referring to the A series, into saying that events change (in the only way in which we can plausibly say this) in respect to pastness, presentness, and futurity.

Nevertheless, if we do retreat to the language of the A series, we can perfectly well do so without contradiction. Just as McTaggart erred by using tensed verbs when talking of the B series, he in effect made the correlative error of forgetting tenses (or equivalent devices) when talking of the A series. For the contradiction that he claimed to find in the A series is that because any event is in turn future, present, and past, we must ascribe these three incompatible characteristics to it; but an event cannot be future, present, or past simpliciter but only with reference to a particular time—for example, one at which it was future, is present, and will be past. If we restore the tenses, the trouble with the A series disappears. Unsuccessful though McTaggart's argument is, it provides an excellent case study with which to elucidate the relations between tensed and tenseless language.

Space-Time

The theory of relativity illustrates the advantages of replacing the separate notions of space and time by a unified notion of space-time. In particular, Minkowski showed that the Lorentz transformations of special relativity correspond to a rotation of axes in space-time. He showed how natural the kinematics of special relativity can seem, as opposed to Newtonian kinematics, in which, in effect, we should rotate the time axis without correspondingly rotating the space axes. Since the theory of relativity it has become a commonplace to regard the world as a four-dimensional space-time manifold. Nevertheless, even in the days of Newtonian dynamics, there was nothing to prevent taking this view of the world, even though it would not have been as neat as it is in relativity theory. If we pass to the four-dimensional way of looking at things, it is important not to be confused about certain conceptual matters. Confusion will arise if the tenseless way of talking, appropriate to the four-dimensional picture, is mixed with our ordinary way of talking of things as enduring substances, "the permanent in change."

In ordinary language the word "space" itself is used as the name of a continuant. We can say, for example, that a part of space has become, or has continued to be, occupied. Space-time, however, is a "space" in a tenseless sense of this word, and because time is already in the representation, it is wrong to talk of space-time as itself changing. Thus, in some expositions of relativity it is said that a certain "world line" is a track along which a material body moves or a light signal is propagated. The body or light signal, however, cannot correctly be said to move through space-time. What should be said is that the body or the light signal lies (tenselessly) along the world line. To talk of anything's moving through space-time is to bring time into the story twice over and in an illegitimate manner. When we are talking about motion in terms of the space-time picture, we must do so in terms of the relative orientations of world lines. Thus, to say that two particles move with a uniform nonzero relative velocity is expressed by saying that they lie (tenselessly) along straight world lines that are at an angle to one another. Similarly, the recent conception of the positron as an electron moving backward in time is misleading because nothing can move, forward or backward, in time. What is meant is that the world lines of a positron and electron, which are produced together or which annihilate one another, can be regarded as a single bent world line, and this may indeed be a fruitful way of looking at the matter.

In popular expositions of relativity we also read of such things as "consciousness crawling up the world line of one's body." This is once more the confusion of the myth of passage and, hence, of the illegitimate notion of movement through space-time. It is instructive to consider how H. G. Wells's time machine could be represented in the space-time picture. A moment's thought should suffice to indicate that it cannot be represented at all. For if a line is drawn extending into the past, this will simply be the representation of a particle that has existed for a long time. It is not surprising that we cannot represent a time machine because the notion of such a machine is an incoherent one. How fast would such a machine flash over a given ten-second stretch? In ten seconds or minus ten seconds? Or what? No sensible answer can be given, for the question is itself absurd. The notion also involves the contradiction, pointed out by D. C. Williams in his article "The Myth of Passage" (1951) that if a person gets into a time machine at noon today, then at 3 a.m., say, that person shall be both at 3 p.m. today and at, say, a million years ago. There is nevertheless a more consistent notion of time travel though misleadingly so called. A person as a space-time entity might lie along a bent-back world line. It might curve back and then would go back to your great grandmother's time and then a bit forward while you saw your great grandmother. Paradox lurks because if the great grandmother had been shot you would not have existed. David Lewis has proposed a banana skin solution. Since you could not have shot your great grandmother some accident, such as your slipping on a banana skin or your pistol jamming, must have prevented you from harming her. One would wish, however, for a solution of the paradox by reference to the laws of nature.

Though D. H. Mellor ably defends the four-dimensional ontology in his Real Time II, he nevertheless says something that may puzzle four-dimensionalists—for example, that a person from birth to death, or a stone over a long period of time, is said to have a certain property at time t, but not that a mere time slice or temporal stage of the person or stone has the property. The puzzle is perhaps resolved if we note that Mellor thinks of the thing S as reidentifiable or a sortal as discussed by Peter Strawson. This is understandable because a child could hardly—and an adult could not easily—reidentify the mereological fusion of a bird, a bishop, and Mount Everest. Even so, the four-dimensionalist need not discern a difference between "S is A at t " and "S at t is A." The time slice may be referred to by reference to the salient four-dimensional object of which it is a slice. Mellor rightly stresses the importance for agency and practical matters of notions of reidentifiable sortals and for the determination of the strengths of beliefs and desires by a method originally due to F. P. Ramsey.

Absolute and Relational Theories

Isaac Newton held to an absolute theory of space and time, whereas his contemporary Gottfried Wilhelm Leibniz argued that space and time are merely sets of relations between things that are in space and time. Newton misleadingly and unnecessarily expressed his absolute theory of time in terms of the myth of passage, as when he confusingly said, "Absolute, true and mathematical time, of itself and from its own nature, flows equably without relation to anything external" (Principia, in the Scholium to the Definitions of Mathematical Principles of Natural Philosophy ). The special theory of relativity has made it impossible to consider time as something absolute; rather, it stands neutrally between absolute and relational theories of space-time. The question as between absolute and relational theories of space-time becomes especially interesting when we pass to the general theory of relativity. According to this theory, the structure of space-time is dependent on the distribution of the matter in the universe. In most forms of the theory there is nevertheless a residual space-time structure that cannot be thus accounted for. A curvature is usually attributed to space-time even in the complete absence of matter, and the inertia of a body, according to this theory, depends in part on this cosmological contribution to the local metrical field and hence not solely on the total mass of the universe, as a purely relational theory would require.

Research on this question is still going on, and until it has been decided, Mach's principle (as Einstein called it), according to which the spatiotemporal structure of the universe depends entirely on the distribution of its matter, will remain controversial. But even if Mach's principle were upheld, it might still be possible to interpret matter, in a metaphysical way, as regions of special curvature of space-time. Graham Nerlich (1994) has given a striking and simple argument against those who, like Leibniz, defend relational theories by asking how one could tell whether everything had not doubled in size. He pointed out that this depends on the assumption that space is Euclidean. Relational theorists usually make the relevant relation that of cause and effect. If this is defined by the use of counterfactual propositions one may object that the murkiness or contextual nature of these contrasts with the absolute theory's reliance on the limpid clarity of geometry. Here I use "absolute" to contrast with 'relational' not as contrasted with "relativistic." An objection to a causal theory of time is that there could be uncaused events and that there are uncountably more space-time points than there are events. Michael Tooley separately assumes an ontology and topology of instants of time, but uses a causal theory to define temporal direction.

Time and the Continuum

An absolute theory of space-time, as envisaged above, need not imply that there is anything absolute about distance (space-time interval). Because of the continuity of space-time, any space-time interval contains as many space-time points as any other (that is, a high infinity of them); space and time do not possess an intrinsic metric, and there must always be an element of convention in definitions of congruence in geometry and chronology, as Adolf Grünbaum has pointed out (Grünbaum1973). This means that the same cosmological facts can be expressed by means of a variety of space-time geometries, provided that they have the same topological structure. (Topology is that part of geometry which treats only of those properties of a figure which remain the same however that figure is transformed into a new one, with the sole restriction that a point transforms into one and only one point and neighboring points transform into neighboring ones. Thus, the surface of a sphere and that of a cube have the same topology, but that of a sphere and that of an infinite plane do not.)

zeno and cantor

The continuity of space and time can be properly understood only in terms of the modern mathematical theory of infinity and dimensionality. Given the concepts available to him, Zeno rightly rejected the view that an extended line or time interval could be composed of unextended points or instants. (See Aristotle, Physics 231a20–231b18 and De Generatione et Corruptione, 316a15–317a17.)

In modern terms it may be said that not even a denumerable infinity of points can make up a nonzero interval. Cantor has shown, however, that there are higher types of infinity than that which belongs to denumerable sets, such as the set of all natural numbers. Cantor showed that the set of real numbers on a line, or segment of a line, is of a higher type of infinity than is the set of natural numbers. Perhaps the right cardinality of "dimensionless points" can add up to a nonzero length. This answer is on the right track. Nevertheless, the cardinality of a set of points does not by itself determine dimensionality.

For example, Cantor showed that there is a one-to-one mapping between the points of a plane and the points of a line. However, a mathematical theory of dimension has been developed that accords with our intuitions in assigning 0, 1, 2, 3, and so on, dimensions respectively to points, lines, planes, volumes, and so on, and which also assigns dimensions to other sorts of sets of points. For example, the set of all rational points on a line has dimension 0. So does the set of all irrational points. In these cases an infinity of "unextended points" does indeed form a set of dimension 0. Because these two sets of points together make up the set of points on a line, it follows that two sets of dimension 0 can be united to form a set of dimension 1. Strictly speaking, it is even inaccurate to talk of "unextended points." It is sets of points that have dimension. A line is a set of points, and the points are not parts of the line but members of it. The modern theory of dimension shows that there is no inconsistency in supposing that an appropriate nondenumerable infinity of points makes up a set of greater dimensionality than any finite or denumerable set of points could.

The theory of the continuum implies that if we take away the lower end of a closed interval, what is left is an open interval, an interval without a first point. In fact, Zeno's premises in his paradox of the dichotomy do not lead to paradox at all but are a consistent consequence of the theory of the continuum. Motion is impossible, according to the paradox of the dichotomy, because before one can go from A to B, one must first get to the halfway mark C, but before one can get to C, one must get to the halfway mark D between A and C, and so on indefinitely. It is concluded that the motion can never even get started. A similar argument, applied to time intervals, might seem to show that a thing cannot even endure through time. The fallacy in both cases comes from thinking of the continuum as a set of points or instants arranged in succession. For if a continuous interval had to consist of a first, second, third, and so on point or instant, then the dichotomy would provide a fatal objection. However, points or instants do not occur in succession, because to any point or instant there is no next point or instant. Such considerations enable us to deal with Zeno's paradox of Achilles and the tortoise, in which similar difficulties are supposed to arise at the latter end of an open interval.

kant's antinomies

A related paradox is Kant's first antinomy, in his Critique of Pure Reason (1929 [1781]). As was shown by Edward Caird (1889) in his commentary on Kant's Critique, the antinomies (or paradoxes which Kant had constructed about space, time, and causality) were as important as Hume's skeptical philosophy in arousing Kant from his "dogmatic slumbers." Kant's first antinomy relates to both space and time; the concentration here is on Critique as it relates to time. There are two antithetical arguments. The first states that the world had a beginning in time, whereas the second, with equal plausibility, seems to show that the world had no beginning in time. The first argument begins with the premise that if the world had no beginning in time, then up to a given moment an infinite series of successive events must have passed. But, says Kant, the infinity of a series consists in the fact that it can never be completed. Hence, it is impossible for an infinite series of events to have passed away.

It can be seen that Kant's argument here rests partly on the myth of passage. Kant thinks of the world as having come to its present state through a series of past events, so that an infinite succession would therefore have had to be completed. Otherwise, he would have been just as puzzled about the possibility of an infinite future as about an infinite past, and this does not seem to have been the case. Just as the sequence 0, 1, 2 … can never be completed in the sense that it has no last member, the sequence——, –2, –1, 0 cannot be completed in the sense that it has no first member. This is not to say, of course, that an infinite set need have either a first or last member. Thus, the set of temporal instants up to, but not including, a given instant, has neither a first nor last member. However, Kant is clearly thinking not of the set of instants but of a sequence of events, each taking up a finite time. The set of instants does not form a sequence because there are no instants that are next to one another. Kant's definition of infinity, besides being objectionably psychologistic, is clearly inapplicable to infinite sets of entities which do not form a sequence, such as the points on a line or a segment of a line. Concerning an infinite set of events which form a sequence, however, Kant is not justified in supposing that its having a last member is any more objectionable than its having a first member. There is a perfect symmetry between the two cases once we rid ourselves of the notion of passage—that is, of the one-way flow of time.

In Kant's antithetical argument, he argues that the world cannot have had a beginning in time, so that, contrary to the thesis of the antinomy, there must have been an infinity of past events. His reason is that if the world had begun at a certain time, all previous time would have been a blank and there would be no reason that the world should have begun at the time it did rather than at some other time. Previously, Leibniz had used the same argument to support a relational theory of time. If time is constituted solely by the relations between events, then it becomes meaningless to ask questions about the temporal position of the universe as a whole or about when it began. In an absolute theory of time (or of space-time) Kant's problem remains, but further discussion of it cannot be pursued here because it would involve a metaphysical discussion of causality and the principle of sufficient reason.

Temporal Asymmetry

We have just seen that Kant was puzzled about the infinity of the past in a way in which he was not puzzled about the infinity of the future. Further, it has been suggested that the myth of passage had something to do with this inconsistency. If we reject the notion of passage, we find ourselves with a new, though soluble, problem. This is the apparent temporal asymmetry of the universe, which contrasts sharply with its large-scale spatial symmetry. For example, if we look out at the galaxies, they appear to be distributed evenly in all directions, and yet a time direction seems to be specified by the fact that they are all receding from one another, not approaching one another. On a more mundane level, the temporal asymmetry of the universe is forcibly striking in many ways. For example, there is nothing in our experience analogous to memory but with respect to the future. Nor is there anything like a tape recording or a footprint of the future—that is, there are no traces of the future. A memory is indeed a special case of a trace. This asymmetry about traces explains how we can be so confident about the past history of the human race and about the past evolution of living creatures, whereas it would be a bold person who would try to guess the political history of even the next hundred years or the organic evolution of the next few millions. The question "Why are there traces only of the past, not of the future?" is thus a fundamental one.

We must first rule out a purely verbalistic answer to this question. Someone might say that traces are always of the past, never of the future, because it is part of the meaning of the word "trace" that traces are of earlier, not of later, events. This would be to suppose that the earlier question is as stupid as the question "Why are bachelors always male, never female?" This account of the matter is not good enough. Admittedly, in the English language as it is, the expression "female bachelor" is a self-contradictory one. Nevertheless, it is easy to imagine a variant of English in which "bachelor" simply meant "not yet married person" and according to which spinsters could therefore be called "bachelors." For example, if one were to call a spinster a "female analogue" of a bachelor, then it is possible to silence the verbalistic objection to the question about why traces are always of the past, never of the future, by recasting it in the form "Why are there no future analogues of traces?"

temporal asymmetry and physical laws

The temporal directionality of the universe or, at the very least, of the present cosmic era of the universe would therefore appear to be a deep-lying cosmological fact, which is not to be glossed over by verbalistic explanations. How is it to be explained? We must first dismiss the suggestion that the asymmetry lies in the laws of physics. The laws of classical dynamics and electromagnetism, as well as of quantum mechanics, are all expressed by time-symmetrical differential equations. In other words, if ƒ(t ) is a solution to these equations, so is ƒ(–t ). (Actually to take care of recondite matters, twenty-first century physicists believe not in T symmetry but in CPT symmetry, reversal of time, reversal of charge, and reversal of parity. P symmetry can be thought of as reversal in a space mirror just as C symmetry is a matter of thinking of an antiparticle as a backwards-in-time particle. So CPT symmetry can be thought of as a deeper form of space-time symmetry.)

It follows that if a cinematographic film were taken of any process describable by means of these laws and then run backward, it would still portray a physically possible process. It is true that phenomenological thermodynamics would provide a contrary case, because its second law does contain time explicitly. Thus, if someone put a kettle full of ice on a hot brick, that person finds that the system turns into one in which a kettle full of water sits on a cool brick. A film of this process cannot be reversed to show a process which is possible in phenomenological thermodynamics; we cannot have a system of a kettle filled with water on a cool brick turning into one in which the water has frozen and the brick has become hot. In spite of all this it must still be asserted that the laws of nature are time symmetrical. This is because phenomenological thermodynamics provides only an approximation of the truth (it is refuted by the phenomenon of Brownian motion, for example) and, more importantly, because the detailed explanation of the facts of which phenomenological thermodynamics treats at the surface level is to be found in statistical thermodynamics. Statistical thermodynamics bases itself on the laws of mechanics, which are time symmetrical.

According to statistical thermodynamics, the situation in which the water in the kettle freezes while the brick gets hotter is indeed a physically possible one, though it is an almost infinitely unlikely one. Why it is unlikely has to do not with the laws of nature themselves but with their boundary conditions. There is indeed a puzzle here, because if all the velocities of a closed system are reversed, what results is a configuration that, according to statistical mechanics, is as likely as the original one. Therefore, the process seen on the reversed cinematographic film should be as likely as the original one. The answer to this objection (the reversibility objection) lies in the fact that corresponding to a given macroscopic description (cold kettle on hot brick, say), there is a whole ensemble of possible microstates. It follows that though any microstate is as probable as any other, this is not so with macrostates, and given the information that a body is in a macrostate A, it is highly probable that it will turn into a macrostate B rather than vice versa if B corresponds to an ensemble of microstates which is vastly more numerous than the ensemble of microstates corresponding to A.

An analogy with a pack of cards will help to make this clear. Consider a well-shuffled pack of cards. Any order of the cards is as probable as any other provided that the order is precisely described. Given any one such order P, it is, of course, just as probable that in shuffling, P will turn into the order (call it Q ) in which the pack is arranged in suits as that Q would turn into P. But if P is described simply as haphazard, there is a vast number of states other than P which are also haphazard. Thus, although a shuffling which turns Q into P is no more probable than one which turns P into Q, there are far more shufflings which turn Q into a state abstractly described as haphazard than there are shufflings which turn a particular haphazard state—say, P —into Q.

Suppose we started with our cards arranged in suits, the state Q. If we shuffled them, they would soon get into what we should call a well-shuffled state. Nevertheless, if we went on shuffling long enough, we should eventually get back to the unshuffled state Q. This illustrates the following interesting point. Let us for the moment toy with the almost certainly false cosmological hypothesis that the universe is a finite nonexpanding collection of particles without spontaneous creation or annihilation. Then, just as with our pack of cards, such a universe will eventually return to any given state. The universe will get more and more shuffled until we get the so-called heat death, in which everything is a featureless uniformity and will then become less and less disordered. In the era in which, as we should put it, the universe was getting less disordered, time would seem to run in the opposite direction to that in which it seems to run to us. (Thus, denizens of this era would still say that the universe was getting more disordered.) Indeed, there would be an infinite sequence of cosmic eras, much as is supposed in some Buddhist cosmologies, except that time would seem to run in opposite ways in alternate eras. In a sufficiently large view there would be temporal symmetry in this universe, though not on the scale of any single cosmic era. This is what makes the hypothesis of a finite nonexpanding universe philosophically instructive, even though it is probably contrary to fact.

trace formation and entropy

It is now possible to deal with the formation of traces. Although a wide, relatively isolated part of the universe is increasing in its state of being shuffled, or, to use the more precise notion developed by physicists, in its entropy, subsystems of the wider system may temporally decrease in shuffling, or entropy. Thus, an isolated system, such as that consisting of a cube of ice in a beaker of water, may well have lower entropy than its surroundings. This reduction of entropy is bought at the expense of a more than compensating increase of entropy in the surroundings. There will, for example, be an increase of disorderliness in the system containing the coal and air that react chemically and drive the generators that provide the electric power that drives the refrigerator that makes the ice cube. (The system consisting of coal and oxygen is a more highly ordered one than is that which consists of the ashes and used up air.) Eventually the ice cube melts and becomes indistinguishable from the water in which it floated.

branch systems

The formation of a trace is the formation of a subsystem of temporarily lower entropy than that of its surroundings, and the trace is blotted out when the entropy curve of the subsystem rejoins that of the larger system. A footprint in sand is a temporarily highly ordered state of the sand; this orderliness is bought at the expense of an increased disorderliness (metabolic depletion) of the pedestrian who made it, and this extra orderliness eventually disappears as a result of wind and weather. Hans Reichenbach (1956) calls such systems of temporarily lower entropy "branch structures." It is an observable fact, and one to be expected from considerations of statistical thermodynamics, that these branch structures nearly all (in practice, quite all) go in the same direction. This direction defines a temporal direction for the universe or at least for our cosmic era of it.

On investigation it will be seen that all sorts of traces, whether footprints on sand, photographs, fossil bones, or the like, can be understood as traces in this sense. Indeed, so are written records. The close connection between information and entropy is brought out in modern information theory, the mathematics of which is much the same as that of statistical thermodynamics. A coherent piece of prose is an ordered part of the universe, unlike a completely random sequence of symbols.

It is possible that the formation of branch systems may be linked to deeper cosmological facts. Thomas Gold (1958, 1962) has argued persuasively that the formation of such a system is possible only because the universe provides a sink for radiation, and this is possible, again, only because of the mutual recession of the galaxies. It may therefore ultimately be the expansion of the universe that accounts for the direction of time. Beyond noting this interesting suggestion of a link between the small-scale and large-scale structure of the cosmos, we can for our present purposes take the formation of branch systems for granted without linking it to uncertain cosmological speculations.

popper's account

The theory of branch systems outlined above has been developed rigorously by Reichenbach and Grünbaum, whose work partly goes back to that of Ludwig Boltzmann (1895). (A rather similar account of temporal direction has been independently given by O. Costa de Beauregard [1963].) We must now consider a different account of the direction of time, one that was conceived by Karl Raimund Popper.

Slightly changing Popper's example, consider a spherical light wave emitted from a source, as when a small electric bulb is turned on. Consider how this process would look in reverse. We should have a large spherical wave contracting to a point. This would be causally inexplicable. In order to get a spherical light wave coming in from the depths of an infinite space, we should have to suppose a coordinated set of disturbances at every point of a vast sphere, and this would require a deus ex machina. Moreover, this would still not provide the reverse of an outgoing wave expanding indefinitely. Thus, although the contracting wave is as much in accordance with the laws of optics as is the expanding one, it still is not compatible with any physically realizable set of initial conditions. Once more, as with the Reichenbach-Grünbaum solution, it can be seen that temporal asymmetry arises from initial, or boundary, conditions, not from the laws of nature themselves.

Popper's criterion of temporal direction does not shed light on the concept of trace, as does the criterion of branch systems. And traces, particularly memory traces, give us our vivid sense of temporal asymmetry in the world. It is also interesting that if we consider a finite but unbounded nonexpanding universe, a contracting spherical wave would be physically realizable. Just as an expanding series of concentric circles on the earth's surface which have their original center at the North Pole would become a series of circles contracting to the South Pole, so in a symmetrical, finite, but unbounded universe a spherical wave expanding from a center would eventually become a contracting wave, shrinking to the antipodal point of the point of emission. If we included the facts of radiation in our finite nonexpanding universe, we should have to suppose a finite but unbounded space, and Popper's criterion of temporal direction would become inapplicable. Including such facts would therefore also not conflict with our supposition of alternate cosmic eras in such a universe. In such a universe the Reichenbach-Grünbaum account of temporal direction for particular cosmic eras would still be applicable. There are still anthropocentricities to be brought to light, a task which has been impressively achieved by Huw Price in his book Times Arrow and Archimedes' Point (1996). He has clearly discussed the time symmetry (or one might say CPT symmetry) of microphysics. On the macro level, causation is at least in our cosmic era asymmetrical because the concept of it is closely related to that of agency and so to the temporal asymmetry of memory traces.

What is presented here is not an analysis of the ordinary language concept of earlier and later. This is learned to some extent ostensively, and we may perfectly well know how to use words such as "earlier" and "later" without knowing anything about entropy or branch systems. As Wittgenstein might have said, "We know the language game." Here the concern is with a deeper problem: what are the general features of the universe which enable us to play the language game? Indeed, if the universe did not contain traces, it would be impossible for there to be any thought at all. It should be noted that Mellor in his aforementioned book rejects the relevance of considerations of entropy and the like and relies on the notion of probability: the cause is an event that raises the objective chance of the event that is the effect. As mentioned above, Tooley also has a causal account. Even so, considerations of entropy could be needed to explain the asymmetry of causation on the macro level. On the micro level, causation is time symmetric and Price has neatly suggested defending locality, and perhaps hidden variables, in quantum mechanics and in the face of John Bell's well-known inequality, by means of backward causation. Curiously, according to Price, Bell had once considered such a solution but had rejected it for dubious philosophical reasons connected with the notion of free will.

Compromise Theories

Storrs McCall and Michael Tooley have proposed theories that contain elements of both tensed and tenseless theories. Tooley, in his Time, Tense, and Causation (1997), worked out a sophisticated theory that is partly similar to one that C. D. Broad proposed in his Scientific Thought (1923). According to this view, only past and future are real and the universe is continually getting bigger as more and more of the future becomes present and past. Tenseless theorists will still see this as open to the objections to notions of time flow and of absolute becoming that were canvassed above. So also will they see McCall's theory according to which reality keeps getting smaller. McCall is inspired by the Everett-Wheeler interpretation of quantum mechanics. Space-time reality is like a giant poplar tree with branches corresponding to possible futures, with trunk, branches of branches, and so on, all pointing up in timelike directions. At every interaction between particles, branches (real possibilities) get lopped off. According to the tenseless theorist, reality must be like a stack of poplar trees, ordered according to the inclusiveness of the sets of branches. The mind boggles. Tooley's (though not McCall's) theory requires an absolute present and Tooley is bold enough to consider modifying special relativity. However, a reconciliation with special relativity could have been acquired at less cost as follows. The equality in all directions of the cosmic background radiation may give an approximation to a preferred frame of reference at each point of space. This will, because of the expansion of the universe, yield a curved hypersurface of cosmic simultaneity. Tooley defends his view of the increase of reality against the objection that it requires a hypertime. However, time travel is not like space travel because we may travel to a place, say the Taj Mahal, where we have not been before. The four-dimensional equivalent of a place is a timelike world-line, which in the example may intersect the world line of the Taj Mahal. The space of commonsense talk and of Newton's Principia is a continuant, not like the atemporal space of Euclid. Tooley's cutting off of the future may put in question the explanatory (as opposed to instrumental) value of full Minkowski space, though perhaps less so than presentism.

The tenseless four-dimensional account sits well with mereology, the theory of part and whole. Indeed some philosophical problems come out as easily as shelling peas when one goes four-dimensional. Consider Robert Louis Stevenson's story of Dr. Jekyll and Mr. Hyde, in which the personalities of the virtuous Jekyll and the criminal Hyde alternate in the one body. Mereology distinguishes three objects, the spatiotemporally scattered objects Jekyll and Hyde and the continuous fusion of these two. The problem is not one about identity, which is a clear notion in logic, but about "person" and the problems about these are more legal and psychiatric than philosophical.

Causal Theories of Time

There are theories of the structure of time, or of space-time, that are based on the notion of causality. Objections to such theories have been made as follows (Smart 1987). How do we deal with points of space-time that are not occupied with events that are neither causes nor effects? Perhaps we could rely on causal connectibility and not on connectedness. Connectibility is a modal notion and so will not be liked by philosophers such as those influenced by W. V. Quine, who are suspicious of modality. In special relativity the notion of connectibility can be defined directly in terms of the geometry of Minkowski space by that of belonging in the same double light cone and then properties of space-time defined by axioms. Still, in face of the beautiful clarity of geometry we may prefer to characterize space-time directly, without trying to define the geometry by reference to causality. Tooley avoids these objections because he has an absolute theory of space-time and uses causality simply to define temporal direction. Possibly some of these objections make difficulty for Mellor who has a relational theory. However his notion of probability is that of objective chance and may depend on a theoretical posit and avoid modality. Tooley also needs a realistic theory of causality which some philosophers will find problematic.

Time and Free Will: The Sea Fight Tomorrow

It is sometimes thought that the picture of the world as a space-time manifold is incompatible with free will. It is thought that if a single action of one's future actions exists (tenselessly) in the space-time manifold, then it is fated that the person will do this action; one cannot be free not to do it. To evade this conclusion, philosophers have sometimes been inclined to reject the theory of the manifold and also to deny that propositions about the future have to be either true or false. This view can be contested at several levels. First, the fact that this singular future action exists in the space-time manifold does not mean that the person is fated to do it, in the sense that the person comes to do it independently of what it was he or she does in the meantime. It will still be that person's choice. Second, the doctrine of the space-time manifold does not even imply determinism. Determinism asserts that the laws of nature connect earlier and later spatial cross sections of the manifold in a determinate way, whereas indeterminism denies this. Indeterminism is compatible with the theory of the manifold as such but is no friend to free will. Acting by pure chance is not being free. Third, it could be argued that free will is perfectly compatible with determinism anyway. On three counts, therefore, we may assert that the theory of space-time has, in fact, nothing at all to do with the question of free will.

Aristotle canvassed some of these matters in his well-known passage about the sea battle (De Interpretatione, ch. 9). Aristotle held that it is necessary that either there will be a sea battle tomorrow or there will not be, but that it is not necessary that there will be a sea battle tomorrow, nor is it necessary that there will not be a sea battle tomorrow. He held, however, that all present and past events are necessary, as are some future ones, such as an eclipse of the moon. It is clear, therefore, that Aristotle's notion of necessity here is not the modern notion of logical necessity. Nor by "necessary" can he even mean "predictable" or "retrodictable." Because past events, though not all retrodictable, may have at least left traces, perhaps Aristotle may have meant by "necessary" something like "knowable in principle." But how about past events whose traces have been blotted out? It is hard to give a coherent interpretation of Aristotle here, and certainly to try to give one would be to go into metaphysical subtleties not especially connected with time. Some commentators have interpreted Aristotle as saying that the proposition "There will be a sea battle tomorrow" is neither true nor false. It would seem, however, that this was not Aristotle's view.

Finally, it must be pointed out that the difference between past and future is misleadingly expressed by the common remark that we can change the future but not the past. It is true that we can affect the future and we cannot affect the past. We cannot, however, change the future, for the future is what it will be. If a person decides to take the left-hand fork in a road instead of the right-hand one, that person has not changed the future, for in this case the future is that person's going left. To talk of changing the future is indeed to relapse into talking of events changing and of the notion of passage.

See also Causal Approaches to the Direction of Time; Physics and the Direction of Time; Time, Being and Becoming.

Bibliography

general works

An important book is Hans Reichenbach, The Philosophy of Space and Time (New York: Dover, 1958), which is a translation of a book published in German in 1928. Reichenbach partially modified his ideas in this book in his later work The Direction of Time (Berkeley: University of California Press, 1957). A wide-ranging book on the philosophy of time is The Natural Philosophy of Time by the cosmologist G. J. Whitrow (London: Nelson, 1961). Other important books are Adolf Grünbaum, Philosophical Problems of Space and Time (New York: Knopf, 1963), and O. Costa de Beauregard, La notion du temps (Paris: Hermann, 1963) and Le second principe de la science du temps (Paris: Éditions du Seuil, 1963). See also Adolf Grünbaum's long essay "The Nature of Time" in Frontiers of Science and Philosophy, edited by R. G. Colodny (Pittsburgh: University of Pittsburgh Press, 1962).

A valuable essay is Wilfrid Sellars's "Time and the World Order," in Minnesota Studies in the Philosophy of Science, vol. 3 (Minneapolis: University of Minnesota Press, 1962). An earlier essay of considerable value is the article "Time" by C. D. Broad in Encyclopedia of Religion and Ethics, vol. 12 (Edinburgh and New York: 1921). Several essays of interest are also in The Problem of Time, University of California Publications in Philosophy, vol. 18 (Berkeley: University of California, 1935).

A book of readings on space and time is Problems of Space and Time, edited and with an introduction by J. J. C. Smart (New York: Macmillan, 1964). The history of philosophical thought about time is presented in M. F. Cleugh, Time and Its Importance for Modern Thought (London: Methuen, 1937).

st. augustine's puzzles

Augustine's reflections on time are to be found in his Confessions, bk. 11, chaps. 14–28; a good translation is A. C. Outler, St. Augustine: Confessions and Enchiridion, vol. 7 of the Library of Christian Classics (Philadelphia: Westminster, 1955). Augustine much influenced Wittgenstein. For evidence of this see Ludwig Wittgenstein, The Blue and Brown Books, p. 26 (Oxford: Harper, 1958). W. H. Watson, a physicist who had attended lectures on philosophy by Wittgenstein, quotes a passage from Augustine on time (in order to show what a typical philosophical problem is like) in the first chapter of his On Understanding Physics (Cambridge: The University Press, 1938). Part of the article by J. N. Findlay, "Time: A Treatment of Some Puzzles," in Logic and Language, first series, edited by A. G. N. Flew (Oxford: Blackwell, 1951), discusses Augustine's puzzles. See also Ronald Suter, "Augustine on Time, With Some Criticisms from Wittgenstein," in Revue internationale de philosophie 16 (1962): 319–332.

the myth of passage

On the topic of the myth of passage see especially D. C. Williams's brilliant criticism in "The Myth of Passage" in Journal of Philosophy 48 (1951): 457–472. In chap. 35 of C. D. Broad, Examination of McTaggart's Philosophy, vol. 2, pt. 1 (Cambridge: The University Press, 1938), are relevant arguments against the notion of passage, even though in the end Broad does not free himself from it. An earlier view of Broad's is given in his Scientific Thought (London: K. Paul, Trench, Trubne, 1923). On Broad's changing views about time see C. W. K. Mundle, "Broad's Views About Time," in The Philosophy of C. D. Broad, edited by P. A. Schilpp (La Salle, IL: Tudor, 1959). A criticism of the notion of passage is in J. J. C. Smart, "The River of Time," in Essays in Conceptual Analysis, edited by A. G. N. Flew (London: Macmillan, 1956), and "Spatialising Time" in Mind 64 (1955): 239–241. A contrary point of view is defended by A. N. Prior, "Changes in Events and Changes in Things" (The Lindley Lecture, University of Kansas, 1962); "Time After Time," in Mind 67 (1958): 244–246; and "Thank Goodness That's Over," in Philosophy 34 (1959): 12–17. The last mentioned article defends tensed theories as explaining the difference between our attitudes to past and future pains respectively. A reply by Jonathan Cohen to the last article is to be found in the same volume, and a recent explanation of a biological point of his is in "'Thank Goodness That's Over': The Evolutionary Story," by J. Maclaurin and H. Dyke in Ratio 15 (2002): 276–292. Ned Markosian has defended passage in his "How Fast Does Time Pass?" in Philosophy and Phenomenological Research 53 (1993): 829–844.

J. McT. E. McTaggart's argument for the unreality of time is to be found in his Philosophical Studies, chap. 5 (London: E. Arnold, 1934; originally published as an article in Mind, 1908), and in his Nature of Existence, vol. 2, chap. 33 (Cambridge: The University Press, 1927). For criticisms of this see C. D. Broad's Examination of McTaggart's Philosophy ; Paul Marhenke's article in the book The Problem of Time ; D. W. Gotshalk's "McTaggart on Time" in Mind 39 (1930): 26–42; and part of D. F. Pears's article "Time, Truth and Inference," in Essays in Conceptual Analysis, edited by A. G. N. Flew. On the other side see Michael Dummett, "A Defense of McTaggart's Proof of the Unreality of Time," in Philosophical Review 69 (1960): 497–504; and L. O. Mink, "Time, McTaggart and Pickwickian Language," in Philosophical Quarterly 10 (1960): 252–263. A sympathetic and scholarly work on McTaggart is P. T. Geach, Truth, Love, and Immortality (London and Berkeley: Hutchinson, 1979).

On tenses and similar token-reflexive expressions see Hans Reichenbach, Elements of Symbolic Logic, secs. 50–51 (New York: Macmillan, 1947); Nelson Goodman, The Structure of Appearance, chap. 11 (Cambridge, MA: Harvard University Press, 1951); and Bertrand Russell, An Inquiry into Meaning and Truth, chap. 7 (New York, 1940). Also see Yehoshua Bar-Hillel, "Indexical Expressions," in Mind 63 (1954): 359–379; Jonathan Cohen, "Tense Usage and Propositions," in Analysis 11 (1950–1951): 80–87; and R. M. Gale, "Tensed Statements," in Philosophical Quarterly 12 (1962): 53–59, together with ensuing discussion notes on this. The article by Sellars, "Time," has much on tenses. Zeno Vendler, "Verbs and Times," in Philosophical Review 66 (1957): 143–160, shows that tenses have more functions than one might first suppose. A tense logic is worked out by A. N. Prior in his Time and Modality (Oxford: Clarendon, 1957); and R. M. Martin, in his review of this book in Mind 68 (1959): 271–275, questions whether this is legitimately part of logic. See also Jonathan Cohen's critical notice of the same book in Philosophical Quarterly 8 (1958): 266–271. A tenseless language is advocated by W. V. Quine, Word and Object, sec. 36 (Cambridge, MA: Technology Press of the Massachusetts Institute of Technology, 1960). Tensed language is advocated by J. N. Findlay in his article, "An Examination of Tenses," in Contemporary British Philosophy, edited by H. D. Lewis (New York: Macmillan, 1956). The token reflexive approach has been well defended by Heather Dyke in several articles, especially "Tokens, Dates and Tenseless Truth Conditions," in Synthese (2002): 329–351, and "Tensed Meaning: A Tenseless Account," in the Journal of Philosophical Research 28 (2003): 65–81. The tenseless metalinguistic account of the semantics of indexicals is both defended and attacked in articles in The New Theory of Time, by L. N. Oaklander and Quentin Smith (New Haven, CT: Yale University Press, 1994). See also J. J. C. Smart, "Time and Becoming," reprinted in his Essays Metaphysical and Moral (Oxford: Blackwell, 1987), which contains the conjecture mentioned in the text of a possible source of the illusion of the flow of time. Jeremy Butterfield, in his "Seeing the Present," in Mind 93 (1984): 161–176, relates the different ways that common sense sees space and time respectively to the difference between the high velocity of light compared with the timescale of our physiological and electrochemical processes. Also Smart's criticism of causal theories of time and his defense of the reality of the future are reprinted in the same volume. Quentin Smith defends his own tensed theory in his Language and Time (New York: Oxford University Press, 1993).

Other articles are R. G. Collingwood, "Some Perplexities About Time," in PAS 26 (1925–1926): 135–150; and the symposium "Time and Change" by J. Macmurray, R. G. Braithwaite, and C. D. Broad in PAS, Supp., Vol. 8 (1928): 143–188. On the status of the past see A. J. Ayer, "Statements About the Past," in his Philosophical Essays (London: Macmillan, 1954).

See also Richard Taylor, "Spatial and Temporal Analogies and the Concept of Identity," in Journal of Philosophy 52 (1955): 599–612; and "Moving About in Time" in Philosophical Quarterly 9 (1959): 289–301; as well as Bernard Mayo, "Objects, Events, and Complementarity," in Philosophical Review 70 (1961): 340–361.

F. H. Bradley's argument for the unreality of space and time is given in his Appearance and Reality, 2nd ed., chap. 2 (Oxford: Clarendon, 1930). Henri Bergson's accounts of time and duration are given in his Time and Free Will (New York: Macmillan, 1910), Matter and Memory (New York: Macmillan, 1911), and Introduction to Metaphysics (London: Putnam, 1913). Bertrand Russell in his History of Western Philosophy (London: Allen and Unwin, 1945) gives a succinct criticism of Bergson. Like Bergson's, A. N. Whitehead's metaphysics took for granted a form of the myth of passage. His views are to be found especially in An Enquiry concerning the Principles of Natural Knowledge (Cambridge: The University Press, 1920), chaps. 3–6, and parts of Process and Reality (Cambridge: The University Press, 1929). See also V. C. Chappell, "Whitehead's Theory of Becoming," in Journal of Philosophy 58 (1961): 516–528.

space-time

Hermann Minkowski's classic paper "Space and Time" can be found in The Principle of Relativity, a collection of papers by Einstein and others, translated by W. Perret and G. B. Jeffery, with notes by Arnold Sommerfeld (London: Methuen, 1923). Popular accounts can be found in A. S. Eddington, Space, Time and Gravitation (Cambridge: The University Press, 1920), and Moritz Schlick, Philosophy of Nature, chap. 7 (New York: Philosophical Library, 1949). Milič Čapek, in his The Philosophical Impact of Contemporary Physics (Princeton, NJ: Van Nostrand, 1961), criticizes the theory of the space-time manifold and defends the concept of becoming.

absolute and relational theories

A relational theory of space and time is defended by Leibniz. See especially his third and fifth papers in The Leibniz-Clarke Correspondence, edited by H. G. Alexander (Manchester: Manchester University Press, 1956) A brilliant argument against Leibniz is in Graham Nerlich, What Spacetime Explains (Cambridge, U.K.: Cambridge University Press, 1994). On space-time in the general theory of relativity see Adolf Grünbaum's paper "The Philosophical Retention of Absolute Space in Einstein's General Theory of Relativity" in Problems of Space and Time, edited by J. J. C. Smart (New York: Macmillan, 1964), and references given therein. Also see Graham Nerlich, The Shape of Space, 2nd ed. (Cambridge, U.K.: Cambridge University Press, 1994). The issue between three and four dimensionalism is thoroughly discussed in Theodore Sider, Four-Dimensionalism: An Ontology of Persistence and Time (Oxford: Clarendon, 2001).

time and the continuum

A good discussion of the paradoxes of Zeno will be found in Adolf Grünbaum, Modern Science and Zzeno's Paradoxes (London: Allen and Unwin, 1968). Since 1951 many articles on Zeno's paradox of Achilles and the tortoise have appeared in Analysis. See also V. C. Chappell, "Time and Zeno's Arrow," in Journal of Philosophy 59 (1962): 197–213; and Harold N. Lee, "Are Zeno's Paradoxes Based on a Mistake?" in Mind 74 (1965): 563–570. Also of interest is Paul Benacerraf, "Tasks, Super-Tasks and the Modern Eleatics," in Journal of Philosophy 59 (1962): 765–784. A useful account of Zeno's paradoxes is to be found in Kathleen Freeman, Pre-Socratic Philosophers: A Companion to Diels, Fragmente der Vorsokratiker, 3rd ed. (Oxford: Basil Blackwell, 1946).

Kant's antinomies about space and time occur in The Critique of Pure Reason. There is a translation of this book by Norman Kemp Smith (London: Macmillan, 1929). Zeno's and Kant's antinomies are discussed by Bertrand Russell in lectures 6 and 7 of Our Knowledge of the External World (London: W. W. Norton, 1922). See also C. D. Broad, "Kant's Mathematical Antinomies," in PAS 55 (1954–1955): 1–22. The commentary by Edward Caird, mentioned in the present article, is The Critical Philosophy of Immanuel Kant (Glasgow: J. Maclehose, 1889).

the direction of time

Besides Reichenbach's book The Direction of Time and the book by Grünbaum, Philosophical Problems, see especially Adolf Grünbaum's paper "Carnap's Views on the Foundations of Geometry" in The Philosophy of Rudolf Carnap, edited by P. A. Schilpp (La Salle, IL: Open Court, 1962), which, despite its title, contains a thorough discussion of the present problem, and Grünbaum's essay "The Nature of Time." See also Erwin Schrödinger's fine paper "Irreversibility" in Proceedings of the Royal Irish Academy 51 (1950): 189–195; and Norbert Wiener, "Newtonian and Bergsonian Time," which is chap. 1 of Cybernetics, 2nd ed. (New York: M.I.T. Press, 1961). Also see Ludwig Boltzmann, "On Certain Questions of the Theory of Gases," in Nature 51 (1895): 413–415. Reichenbach's book depends to a great extent on Boltzmann's ideas. There is a readable treatment of some of these issues in the final appendix of Schlick's Philosophy of Nature. A different solution to the problem is to be found in notes by K. R. Popper in Nature 177 (1956): 538; also vol. 178 (1956): 382; vol. 179 (1957): 1,297; and vol. 181 (1958): 402–403, in connection with which see the note by E. L. Hill and Adolf Grünbaum, in Nature 179 (1957): 1,296–1,297. See also O. Costa de Beauregard, "L'Irreversibilité quantique, phénomène macroscopique," in Louis de Broglie, edited by A. George (Paris, 1953). Grünbaum has examined Popper's view in his essay "Popper on Irreversibility" in The Critical Approach to Science and Philosophy: Essays in Honor of Karl Popper, edited by Mario A. Bunge (New York: Free Press of Glencoe, 1964). There are two beautiful articles titled "The Arrow of Time" by the cosmologist Thomas Gold in La Structure et l'évolution de l'univers, proceedings of the eleventh Solvay Conference, pp. 81–91 (Brussels: R. Stoops, 1958), and in The American Journal of Physics 30 (1962): 403–410. "The Direction of Time" by Max Black in his Models and Metaphors (Ithaca, NY: Cornell University Press, 1962), is written from the point of view that scientific considerations are irrelevant to the problem of the direction of time. D. H. Mellor rejects the relevance of considerations of entropy and statistical mechanics in his Real Time II (Cambridge, U.K.: Routledge, 1998). An absolutely outstanding discussion of temporal symmetry and asymmetry in which he identifies unrecognized anthropocentric confusions is Huw Price, Time's Arrow and Archimedes' Point (New York: Oxford University Press, 1996).

A readable discussion of the experiment by James H. Christenson, James W. Cronin, Val L. Fitch, and René Turlay, which suggests a possible violation of time symmetry in the laws of nature themselves, can be found in Eugene P. Wigner's article "Violations of Symmetry in Physics" in Scientific American 213 (December 1965): 28–42.

time and free will: the sea fight tomorrow

On fatalism see R. D. Bradley, "Must the Future Be What It Is Going To Be?" in Mind 68 (1959): 193–208; Richard Taylor, "Fatalism," in Philosophical Review 71 (1962): 56–66, with the discussion on this by Bruce Aune in the same volume, pp. 512–519; and A. J. Ayer, "Fatalism," in his The Concept of a Person and Other Essays (London: Macmillan, 1963). On the sea battle see Aristotle, De Interpretatione, chap. 9. Extensive notes and a translation can be found in J. L. Ackrill's Aristotle's Categories and De Interpretation, vol. 1 of the complete works of Aristotle edited by Jonathan Barnes (Princeton; NJ: Princeton University Press, 1984). This passage has also been translated and discussed by G. E. M. Anscombe in "Aristotle and the Sea-Battle" in Problems of Space and Time. See also Colin Strang, "Aristotle and the Sea Battle," in Mind 69 (1960): 447–465. Many journal articles on the subject, following on D. C. Williams's interesting "The Sea-Fight Tomorrow," appear in Structure, Method, and Meaning, edited by Paul Henle, Horace M. Kallen, and Susanne K. Langer (New York: Liberal Arts Press, 1951). See especially the discussion note "Professor Donald Williams on Aristotle" by Leonard Linsky and the rejoinder by Williams in Philosophical Review 63 (1954): 250–255, and Richard Taylor, "The Problem of Future Contingents," and Rogers Albritton's reply in Philosophical Review 66 (1957): 1–46. The seventeenth-century English philosopher Thomas Hobbes also wrote on the sea-fight; see his Works, edited by William Molesworth, vol. 4, p. 277 (London: J. Bohn, 1839), and discussion by A. G. N. Flew, "Hobbes and the Seafight," Graduate Review of Philosophy 2 (1959): 1–5.

Other references are to Storrs McCall, "Objective Time Flow," in Philosophy of Science 43 (1976): 337–362; and his "A Dynamic Model of Temporal Becoming," Analysis 44 (1984): 172–176; and to McCall's book, A Model of the Universe: Space-Time, Probability and Decision (Oxford: Clarendon, 1994). Mellor's Real Time II was published in London in 1998. Michael Tooley's Time, Tense and Causation was published in Oxford in 1997. See also Michael Tooley, "The Metaphysics of Time" in The Argument of Time, edited by Jeremy Butterfield, pp. 21–42 (London: Oxford University Press, 1999), and "Basic Tensed Sentences and their Analysis" in Time, Tense, and Reference, edited by Aleksander Jokic and Quentin Smith, pp. 409–447 (Cambridge, MA: MIT Press, 2003). John Bigelow defends presentism in his "Presentism and Properties," in Philosophical Perspectives 10, Metaphysics (1996): 35–52.

J. J. C. Smart (1967, 2005)

TIME

The term nominally means duration, an interval of motion, or the measure of either. Some philologists, tracing the word to an Old Teutonic root denoting "to extend," give time the etymological sense of extent of motion. Greek and Roman expressions are derived from Sanskrit roots meaning light and burning.

This treatment of time is divided into two parts. The first sketches the history of the concept of time, dealing with representative ancient, medieval, modern, and contemporary opinions. The second, or analytical, part then discusses natural time and its definition, measure, perception, existence, unity, and irreversibility—all from the viewpoint of Aristotelian-Thomistic philosophy.

History of the Concept of Time

Some vague knowledge of time is as old as man, but the rule of cultural development, primum vivere deinde philosophari (live first, then philosophize), kept the earliest cultures and civilizations for tens of thousands of years from probing the theoretical character of time. Unreflective awareness then, like the idea of time provided by common sense, remained preanalytic and practical in bent; time served to date lives and to inflect verbs.

Ancient period. The Babylonians refined methods of time-reckoning and the pre-Socratics groped toward the foundations of natural change, but it was not until plato that Western thought achieved a detailed and coherent theory of time. Plato's predecessors, like heraclitus and parmenides, did not detach time from change; or, like zeno of elea, treated it only dialectically; or, like the Pythagoreans and democritus, sketched only fragmentary or superficial definitions. Aristotle, Plotinus, and St. Augustine were the only thinkers in the ancient world after Plato to propound theories at least equal, perhaps superior, to his. The views adopted by Epicurus, Chrysippus, and Zeno the Stoic seem to be imprecise residues of Aristotle's analysis. The Stoic doctrine of recurrent conflagrations, like every myth of eternal return, is strictly not a theory of time but a cyclic conception of cosmic destiny.

According to Plato (Tim. 37C–39E, 46C–47B), time is "the moving image of eternity" or "the everlasting image revolving according to number." In particular, time is the movement of the sphere of the fixed stars, whose unvarying circular course imitates the unchangeable life of the Living Creature. Its revolutions mark out or number the intervals called days. In their wandering but regularly repeated motions, the seven planets serve as instruments of time, determining and preserving the numbers or fixed intervals of time.

Particular defects in this view, like the implicit equivalence of part and whole, did not escape Aristotle (Phys. 217b 29–224a 16). But its radical fallacy lies in its metaphysicism; it obtrudes a metaphysical explanation on what wants natural induction, i.e., it tells what time is in virtue of what it is not. For Aristotle time is "the number of motion according to before and after." (This celebrated and controverted definition is examined below in the analytical section.)

A Platonic rebuttal had to await plotinus (Enn. 3.7.7–13). Making time number, he argues, answers only how much but not what time is. Because nature is within time but time outside nature, time properly resides in the discrete operations of the Soul insofar as the Soul successively makes and sustains nature. The stars in their courses manifest and measure the quantity of time that remains essentially one with the generative life of the Soul. Though this grand metaphysical stroke liquidates some problems, Plotinus's metaphysicism, like Plato's, has its defects: the gulf between the Soul and nature is unbridged; and proper time is spiritual and discrete, while its natural counterpart is unaccountably continuous and material.

An acknowledged debt to Plotinus did not prejudice St. augustine against a natural psychological solution (Conf. 11.14.17–11.28.38). If time is the measure of change, it demands a present beyond the fleeting instant and above bodily motion. Time, he shows inductively, is a distension of the soul, with future and past segments stretching bilaterally from the distended present of attention. Many have misread this quasi-physical time line as an offshoot of Plotinus or a forebear of Kant or Bergson. But in contrast to Plotinus and Kant, Augustine scrupulously transcribes the empirical data, and his interior spatializing of time differs essentially from Bergson's treatment. Augustine's closest kin is Aristotle. Though the two part company on the physical primacy of the now, they join hands on the totality of time, where both assign the soul's activity to hold all at once fluent parts unable to exist all at once.

Medieval period. With "the master of those who know" bestriding their world like a colossus, medieval thinkers devoted themselves to elucidating the Aristotelian text. The exegeses of Avicenna, Averroës, St. Albert the Great, St. thomas aquinas, and William of Ockham differ on the meaning of number, the perceived unicity, and the objective reality of time.

avicenna (An-Najat. 186–192) ascribes the number of parts to motion itself and considers time the measure of passage from one part to another, while the observer, imaginatively making cuts in the flux, gives being to instants. As the measure of all possible change, time is indirectly applicable to everything affected by mutability.

averroËs (In 4 phys. 98–132), anxious to reconcile the letter of Aristotle with time's universality, takes number to mean a mathematical entity. Next, the unicity of time seems to clash with concrete awareness: if time is subjectified in the primary motion, how can anyone not knowing this know time? Perceiving change, each notes himself changing, he answers, and through selfconsciousness indirectly gains hold of primary motion. As regards the existence of time, Averroës introduces the seminal idea that time, potential in motion, becomes actual number through the soul's numbering of motion.

St. albert the great (In 4 phys. 3.3–17) departs from Averroës on two counts but agrees with him on unicity. Averroës's formal number mathematicizes time, he maintains, whereas time is number sui generis, both formal and material. Next, awareness of inward change contains a virtual awareness of the primary motion, because this latter is "habitually" operative in all other motions. However, flatly opposing Averroës, Albert declares time to be materially as well as formally independent of the soul. In the view, to be elaborated below, of his fellow Dominican, St. Thomas Aquinas (In 4 phys. 15–23), the nows rather than continuous parts are numbered before and after; the primary motion exists secondarily in other motions; and time is primarily a being of nature, needing the soul to fix its totality.

william of ockham (Phil. nat. 4.1–16) generally reproduces Averroës in a logically elegant dress. Though signifying principally what motion signifies, time consignifies both the soul and its judgment of the before and after. Time is predicated per se of its subject, the primary motion, as risible is predicated of man. Measurement of the primary motion renders all things formally temporal; time is virtually everywhere. Although time enjoys the same objective reality as a branch on a tree, the soul must intervene if primary motion and the branch are to serve as measures, i.e., the soul completes the being of time only when actually using the primary motion to measure passage.

The Renaissance scholastic F. suÁrez (Disp. meta. 50) shifts to the metaphysical plane in defining time as the successive duration of a material being. Time is formally continuous, i.e., in accord with Averroës, time as number is constructed by the soul's actual numbering of the parts of motion. Since every entity possesses an intrinsic duration, time is not one but intrinsically many and diverse. Oddly, early in the 20th century, D. Nys refurbished the opinion of john of st. thomas (Curs. phil. 2.369–376), who substantially champions Suárez on this point, and presented it as that of Aquinas, so that many textbooks in natural philosophy still force physical time into the frame of metaphysical duration.

Modern period. Duration comes to the fore again, now in mathematical garb, in the monumental natural philosophy of Sir Isaac Newton. "Absolute, true, and mathematical time, of itself and from its own nature, flows equably without regard to anything external, and by another name is called duration." "Absolute" differentiates duration from the relative public time of particular observers; "true" means that it is the cosmic standard; "mathematical" means that it is quantity subsisting apart from particular subjects; "of itself" denotes that it is nature's intrinsic metric; and "equably" refers to perfectly uniform and unalterable passage.

G. W. leibniz, Newton's stoutest antagonist, holds that absolute time violates the metaphysical principles of sufficient reason and the identity of indiscernibles. For in a time divorced from events, the interchangeability of before and after instants renders temporal sequence irrational, and the plurality of instants vanishes. Time is, like number, independent of particulars and hence distinct from duration, which characterizes particular intervals. Elliptically put, time is the order of inconsistent and successive possibles; Socrates's walking today, for example, cannot simultaneously occur with his walking tomorrow. His polemic against Newton does not rescue Leibniz from an absurdity that his own mathematicized timeorder inflicts on him—a temporal aspect at once a part of events and apart from events.

I. kant transplants absolute time into human sensibility. Newtonian time, of itself prior to anything external, becomes an a priori sensuous form empirically real but transcendentally ideal. Unlike space, time is a onedimensional successive continuum and an inner form directly arranging internal perceptions. If before, after, and simultaneous are added to content, Kant argues, the mind must antecedently supply them. Again, if one can think of time apart from objects and not vice versa, time is an a priori intuition. However, the assumed absolute time is self-refuting, for no abstract quantity can flow. Again, the alleged antecedence suggests only that time is objectively necessary to events. Finally, a time cut off from events is a preposterous void, for the fact is that awareness of motion precedes awareness of time.

Contemporary period. H. bergson starts with a critique that deposes rather than presupposes the reigning mechanism. A closed system of mechanical causation, he thinks, suppresses change and totally spatializes time. Man recovers real time, in contrast to clock time, in the primacy of change. Each state of unceasingly changing psychic life melts into its neighbor in an unbreakable flow. The intuition of change as pure duration is at one stroke the intuition of the time itself: real time is convertible with pure duration. However, dialectical brilliance cannot nullify the facts that successiveness always stamps process and that the flow involves a spatial environment. Pure change, moreover, is change turned into homogeneous duration.

A. N. whitehead celebrates process more sweepingly but less lucidly than Bergson. He discovers in total experience organically interrelated actual occasions, space concretely fused with time, and epochal durations as fundamental temporal quanta. Nature displays a becoming of continuity but no continuity of becoming: a becoming of continuity, for extended regions, not instants, coincide with the creative advance ultimate in things; but no continuity of becoming, for time, like the actual occasions it measures, comes in atomic droplets or pulsations. Whitehead's crude union of time with motion engenders a brood of paradoxes: multiple yet simultaneous time-regions; an irreversible time in reversible processes; one time made many in different events; and durations distinct without distinguishing instants.

In contrast to the Western tradition, M. heidegger derives his conception from practical or human time. Because Dasein or human being is a being-toward-death, the future is primary in primordial time. Man becomes fully man by projecting himself into the future to illumine the banal present and transfigure the inertial past; he becomes truly free by integrating the ecstasies of present-future and present-past firmly oriented toward death. However, it is pure sophistry to declare human time naturally prior to a world-time that clearly preexists and postdates individual human life. It is boldly fallacious also to link values essentially with time; a Jack the Ripper may confront death in the authentic Heideggerian manner while forging an inhuman or morally inauthentic destiny.

Aristotelian-Thomistic Analysis

Time means many things to many minds. First, time is deemed a practical condition or instrument for realizing human goods. A religious outlook meditates on the sacramental value of each moment for eternity, the historian dates the glories and tragedies of social man, and in a businessman's civilization believing "time is money," social time is like raw material to be harnessed by capital. Second, primitive "lived time" or I-time is the felt sense of duration in the person shaped by his past and advancing toward his future. Third, biological time regulates the build-up and breakdown of tissues, the length of cicatrization, the life-span of mayfly and tortoise. Fourth, mathematical-physical time, sometimes called public time, constitutes a metric intersubjectively applicable to every change. Each of these branches out from natural time. The religious, historical, and social significations take for granted a prior temporal structure measuring the human condition. The succession of inner states in psychic time is rooted in matter and motion. Biological time presupposes a deeper-lying periodicity within life-processes. The metric of mathematical-physical time abstractly imitates a primordial regularity built into nature.

Natural time. The definition of natural time develops from three inductive determinations: time as something of motion, time as continuous, and time as number.

Time and Motion. Disparity of attributes rules out the fusion of time and motion avowed by process and causal theories. Motions are either specifically or particularly diverse, but time is physically universal, i.e., not wholly circumscribed by one species or particular subject. Again, unlike motion, time is uniform. To predicate fast or slow of time amounts to the fruitless measuring of time elapsed by the identical time elapsed. Rather, time inevitably accompanies motion. Tales in world literature concerning the monk rapt in contemplation and Rip Van Winkle illustrate that awareness of time is indissolubly wedded to awareness of motion. Concomitance in awareness mirrors concomitance in nature.

Time as Continuous. Time is a continuum because it resides in motion that traverses continuous magnitude. A continuum is formally one and materially partitive; the parts joined to one another make up an order of local before and after. Not motion as such, but motion concretized in the spatial continuum, is properly called motion according to before and after. Data from nature and art attest that man estimates time by noting motion according to before and after. Time's passage is punctuated by the sun's rising and setting, the moon's phases, the here and there of star and planet, the ebb and flow of tides, and for urban man by bells, whistles, and hands on a dial.

Where nominally defined (Aristotle, Cat. 4b 24), time is classified, along with magnitude, as a proper measure, but a strictly physical inquiry discovers that time, like motion, shares secondarily and derivatively in the continuity proper to magnitude. Thus one may speak of a time line or time dimension in the broad acceptation. The fourth dimension of relativity mechanics means nothing more than that a particular measurement of time is necessary to describe exactly events in a particular coordinate system. It is irresponsible to rhapsodize with H. Minkowski that space and time, being themselves "shadows," henceforth fuse into a hyphenated third entity.

One indirectly demonstrates the observed continuity of time by showing the absurdities its denial entails; e.g., if indivisibles make up the time line, no body can be measured as faster or slower than another. The famous paradoxes of Zeno of Elea impugning observed continuity rest upon the erroneous assumption that what is infinitely divisible into smaller parts is already actually divided into an infinity of partless units. Turned about, the paradoxes ironically establish the realistic view: if time is a string of discontinuous nows, then all motion and time are illusions. B. russell and A. Grünbaum have recently tried to answer Zeno, but in basing their solutions on G. Cantor's transfinite number, both implicitly concede Zeno's fatal assumption that a continuum is actually composed of discontinuous elements.

Time as Number. The insight that time is number completes the definition. Number is a multitude measured by unity; its plurality arises from the division of the continuum. Time springs from the division of the motioncontinuum by the nows bounding its passage. The pluralized motion is raised to the estate of number when one visualizes before and after under the common aspect of the now and counts them as two nows. The full-fledged definition emerges when the mind says, in effect, now… now. The nows, the correlates of the before and after in motion, are the numbered terminals of a continuum that may be diagrammed.

Three corollary remarks may help dispel certain misinterpretations. First, the words "before" and "after" do not render the definition circular. Despite the fact that current usage may accord them a fundamental temporal reference, before and after primarily denote the order of parts to magnitude. The here-before and the thereafterward of space underlie the positional character of the time line terminated by the before-now and the after-now. Second, the illusion persists that before and after are convertible with past and future. Man does perceive time, but both past and future, being nonactual, are strictly unperceivable. Too, past and future denote part-times in the scheme of time, whereas before and after signify not parts but the partless nows numbered in motion. Third, number does not mean absolute or mathematical number divorced from passage. Time is numbered number, part and parcel of the process as the number of and in motion. It is indeed the numbered terminals indissociable from the flux, the very nows numbered before and after.

Scope of the definition. One attains the definition of time at the level of the general science of nature, i.e., the philosophy of nature, which aims to systemize concepts concerned with the most general features of nature. At this level, the mind achieves a quasi-abstraction from more concrete modes of natural philosophy. Thus a definition of time as an all-pervasive feature of common experience does not depend upon contemporary physical research, but it is analyzed out of the universal fact of motion that modern physics presupposes rather than supersedes. It is foolish, then, to comb the fundamental definition for hints about time in relativistic or quantum mechanics, but it is no less illusory, conversely, to imagine that the basic definition is toppled by revolutions that overturn the status quo in the more concrete provinces of natural science.

Measure of motion. Since time is number and measure is the property of number, time's principal property is to be the measure of motion; it is the standard that manifests the proper quantity of motion. Time and motion measure each other along different causal lines. Time in itself is the primary existential measure, while quoad nos man may determine unit-intervals of time by motions like the sun's apparent orbit or the movements of a quartz crystal clock.

Time measures motion alone in the per se sense. Everything else in nature is in time inasmuch as it is connected with motion. Hence, not the very substance of mobile being but only its duration or concrete length of existence is temporally determined. To make mobile being subject to time entails, of course, the suppression of substance. As natural substance, however, a mobile being enjoys an existential duration from generation to corruption properly measured by time. Generation-corruption itself, marking the outer bounds of duration, is measured by the limiting now.

The relation of the human soul to time is less clearcut. Because the human soul qua spiritual is per se supratemporal, its intransmutable substance is measured by the aevum. The operations that the soul coauthors with the body are subjectively under time; physical time necessarily governs sensory cognitions and desires that involve motion. Spiritual or discrete time properly measures purely intellectual operations. Yet these immaterial operations are extrinsically related to natural time; objectively, in the dependence of the intellect on the phantasm; associatively, in the termination of the enunciation in the ipsum esse rei, the existential mode that includes a determined time.

In addition, one may truly call time a per se cause of corruption in the sense that it is number imbedded in a motion that betokens the essential indeterminateness of matter. Now, matter possesses its own, an absolute, necessity determining all things to breakdown and destruction. But time's causality remains no more than extrinsic and formal, for though one may list old age as a cause of death and imagine time bearing a scythe, time is merely incidental to the agent precipitating the destruction.

Perception of time. The perception of time matches its peculiar mode of existence. Since time coexists with motion in magnitude, man coperceives it with motion across extensive magnitude. In sensing time, he senses not just motion but the successiveness within motion, which bespeaks units before and after. The sense of time, then, comes down to the sense of concrete number in local motion. Furthermore, man formally perceives time in virtue of the sensus communis or central sense, which refers the time line cognized to ongoing process. Time is first impressed on the central sense, then reimpressed on the imagination. The imaginative impress, because worked by the central sense, is said to be the proper effect of the central sense. The imagination is, in this case, materially causative; it retains its image in the service of the outward-directed central sense. Imagination plays, nonetheless, a significant role. Only imagination, among the internal senses, represents singularized quantities, such as lines and circles. Subsequently, the imagination detaches the numbered local motion from its qualitative surroundings, so that it appears as this time, as a quasi-mathematical entity of one dimension. Yet its later refinement in the imagination does not isolate the species of time from reference to sensible matter, for what is represented as a line answers to a flowing continuum in nature. Moreover, where contact with the outer flux is occasionally broken off, time-awareness arises from internal sensory activity. The cogitative power embraces every sensory power, internal as well as external, within its cognitive reflection; awareness of inner time is simply a special case of this self-awareness.

Existence of time. The totality of time, the primitive schema present to perception and conception, depends on the soul to combine in one whole never coexistent parts as if they were coexistent. Time in its quantitative totality is a relation of reason; one, however, different from a sheerly logical relation constructed to order concepts. It faces outward and bears on the natural universe. Despite its dependence on the soul, time is first and foremost a being of nature and only secondarily, from the viewpoint of definitional totality, a being of reason. It is permissible, though ambiguous, to state that time does not exist without the soul, but it is more exact to hold that time exists without the soul. Time is rooted and has imperfect being in the now. The incomplete being of time copies the imperfect existence of motion; the fleetingness of the now imitates that of the indivisible moment. Time is, then, as physically real as motion: it shares motion's imperfect mode of being that needs the supplementary work of the mind to eke out its totality. This realistic answer diverges sharply from the Averroistic account, still strongly favored by scholastics, that time exists formally in the mind but fundamentally in motion. This self-contradictory formulation is tantamount to saying that time is formally a relation of reason but fundamentally a relation of reason; motion in its totality cannot serve as time's physical foundation, because it is no less a relation of reason than time.

Unity of time. It is self-refuting to regard time as specifically one but diversified according to its varied embodiments in motion. If two concurrent motions demand different times, equal times (hours or days) must simultaneously coexist. However, two divisions of time the same in every way are not two, but one time. Thus the notion of pluralized times entails the numerical unity of time supposedly done away with. Time, then, is not an abstractly universal continuum; it must properly reside in a numerically one subject.

This one time must be situated in the most basic of motions, a local motion. This primary subject also must be maximally regular among motions, primary among local motions. Fundamental natural analysis reveals one more trait: the primary motion belongs to the universal physical cause (see motion, first cause of). The inherent causal inadequacies of univocal agents necessitate a universal physical cause. Such agents are of themselves powerless to produce substantial changes; a horse's parents that were its per se adequate cause would be at once causative of the equine species itself and of their own existence. It is the overriding influence of the universal physical cause also that maintains species outlasting their individual instances. Plainly, the ubiquity and uniformity of time are mediated by the primary motion of the universal physical cause. Insofar as its number resident in the primary motion is secondarily exhibited in every other motion, time stretches to the farthest reaches of the cosmos; it is coterminous with an efficacy equivocally exercised by the universal cause. Yet it remains uniform because the primary motion possesses a quasi-perpetual invariance. Here warranted knowledge stops; man cannot put his finger on which motion is the primary subject of time. It must be stressed that the foregoing propositions have been scientifically analyzed out of a general experience of nature unaffected by the vicissitudes of specialized observations; they are no more open to discard than are the general hylomorphic make-up of natural entities and man's soul-body composition because of the extinction of the ancient theory of the four elements.

A crude commingling of the general and specialized sectors of natural science underlies certain attempts to equate Einstein's special theory of relativity with a fundamental relativization of time itself. Relativity theory applies only to the measurement of natural time. Time as measured is always pluralized according to coordinate systems; time as measured is always relative to the measurer; time as measured never discloses simultaneous events. So-called time-dilatation is an elliptical way of expressing the retardation of a clock in motion relative to an observer; not time itself but clocks and their observed readings vary from system to system. Second, as a sophisticated hypothesis of time-measurement, relativity theory must assume an antecedent analysis. Its second postulate, the constancy of the velocity of light, depends on prior awareness of time, for velocity is roughly the ratio between distance and time. Again, relativistic simultaneity presupposes the natural unity and simultaneity of time. Were there no uniformly one time implied in the comparison, it would be meaningless to compare varied interpretations of the earlier-later relations of two light signals flashed to observers in various coordinate systems. Moreover, the statement that one cannot measure the simultaneity of two events involves some knowledge, at least vague, of what coinstantaneous occurrence means.

Irreversibility of time. It is a misunderstanding to base irreversibility on entropy and cause-effect sequences. A thermodynamic reversal would not involve the reversal of before and after, for man measures the normal or reversal course of entropy according to before and after. So also with one-way causal sequences: even if an extranatural agency reversed the cause-effect order, the reverse would be measured by an irreversible relation of before and after.

That time cannot recur follows from its unity. No power in heaven or on earth can undo the fact that Socrates sits down after he has run. Reversing time in this sense amounts to claiming that what is unique and determinate is really nonunique and indeterminate; in a word, a reversible time-order means the destruction of time. Irreversibility is, at bottom, necessary because it bespeaks the before and after that are properties of time. Time is necessarily unidirectional because each phase of the primary motion is numerically distinct from its neighbors before and after. One whole revolution may be constantly repeated, but the identity of the successive revolutions is specific rather than numerical. A time sheerly number would include an interchangeable past and future, and a time identical with motion would be reversible as process. But time is numbered number, imbedded primarily in one particular motion, so that the date of each event, its position on the time line, is always irrevocably different. Indeed, the very now terminating an event uniquely determines the event; that is to say, time is irreversible because the now, its principle and measure, is always formally other.

See Also: eternity.

Bibliography: General. m. f. cleugh, Time and Its Importance in Modern Thought (London 1937). j. a. gunn, The Problem of Time (London 1929). j. sivadjian, Le Temps (Paris 1938). m. j. adler, ed., The Great Ideas: A Syntopicon of Great Books of the Western World (Chicago, Ill. 1952) 2:896–914. a. aliotta, Enciclopedia filosofica (Venice-Rome 1957) 4:1124–31. r. eisler, Wörterbuch der philosophischen Begriffe (Berlin 1927–30) 3:646–664. Particular. h. l. bergson, Time and Free Will, tr. f. pogson (New York 1910; repr. 1950). j. f. callahan, Four Views of Time in Ancient Philosophy (Cambridge, Mass. 1958). a. grÜnbaum, Philosophical Problems of Space and Time (New York 1963). m. heidegger, Being and Time, tr. j. macquarrie and e. robinson (London 1962). a. mansion, "La Théorie aristotélicienne du temps chez les péripatéticiens médiévaux," Revue néoscolastique 36 (1934) 275–307. b. r. russel, Human Knowledge (New York 1948). a. n. whitehead, Process and Reality (New York 1929).

[j. m. quinn]

Time

Published weekly without interruption since March 3, 1923, Time: The Weekly News-Magazine(the final word is no longer hyphenated) pioneered a new genre of publication that was invented in the United States after the First World War and spawned many imitators at home and abroad. Time was the first mass-circulation magazine to offer a weekly digest of current events and commentary organized into departments, written in an oft-parodied breezy, idiosyncratic style. As the inaugural publication in Henry Luce's publishing empire that within little more than a decade included Fortune, Life, and Architectural Forum, the periodical quickly established itself as a "lengthened shadow" of its founder, who maintained close control over its content and used it to shape public opinion toward accepting his views about the role of the United States in "the American Century." As such, it frequently was thought to be a Republican-oriented publication: it published highly favorable coverage of the presidential aspirations of Herbert Hoover, Wendell Willkie, and Dwight Eisenhower—though, surprisingly, Luce voted for Alfred E. Smith, Hoover's Democratic opponent in 1928. Not surprisingly, Time's opinions were frequently at odds with that of Franklin D. Roosevelt, though Luce gave his wholehearted support to the administration in the interest of national unity during World War II. Time was one of the earliest and most vocal critics of the right-wing tactics of Senator Joseph McCarthy in the 1950s. Even though the Time-Life empire had evolved into Time-Warner by the 1990s, with Time, Inc. New Media establishing a brand-conscious presence on the World Wide Web, Time "the weekly newsmagazine" still maintains an important role as one of the three leading American newsweeklies along with Newsweek and U.S. News and World Report.

The genesis of Time magazine had its roots in the deep but often contentious friendship between two old schoolmates from Hotchkiss and Yale: Henry R. Luce and Briton Hadden. Luce was born and raised in China, the son of a Presbyterian missionary and the grandson of a Scranton, Pennsylvania grocer. Hadden was a native of Brooklyn, New York, the son of a stockbroker and the grandson of a bank president. The two had worked together on publication boards at their alma maters and served in a military-reserve unit during World War I, an experience that convinced them that the typical American was poorly informed of current events. They graduated with Yale's class of 1920, Luce winning the DeForest award for oratory with a speech that foreshadowed his later "American Century" editorial stance at Time and Life with its idealism in advocating American benevolent hegemony as "the great friend of the lame, the halt and the blind among nations, the comrade of all nations that struggle to rise to higher planes of social and political organization.…"

It was while working together as reporters on the Baltimore News in 1922 that Luce and Hadden hatched plans for their weekly magazine, which they originally wanted to call Facts. Earlier, while working briefly as a reporter for the New York World,Luce had proposed to Hadden an idea "for a magazine that comes out every Friday with all the news condensed so you and all the other rich millionaires commuting home for the weekend can catch up on the news that they have missed. How's that?" The two men quit the Newsafter three months, drew up a prospectus, convinced some wealthy friends to invest in their enterprise, and spent most of 1922 setting up editorial offices in New York and hiring a staff. Among the part-timers listed on Time's first masthead were two men who later became somewhat prominent poets: Stephen Vincent Benét, a book reviewer, and Archibald MacLeish, who wrote the Education section for ten dollars a week. For National Affairs editor, Luce hired Alan Rinehart, the son of novelist Mary Roberts Rinehart. In days when gender roles were somewhat stratified, men were hired as editors and reporters while women researchers were hired as "secretarial assistants."

Luce projected a first-year income of $155,000, most of it from twenty-five thousand subscriptions at $5 each, and the remaining $30,000 from advertising. The fledgling publishers were disappointed when a mailing of half a million promotional pieces yielded only six thousand subscribers. Another five thousand were earmarked for newsstand distribution. The folksy tone affected in a stockholders' report just before Christmas 1922 hardly suggests that the fledgling venture would within a generation grow into one of the world's most powerful media conglomerates: "Time knows well that the people that will help it most are those who are best satisfied with it. For that reason it does not desire to antagonize any of its stockholders by asking to do anything that is distasteful. From time to time summary requests will be made… : 'Give me a letter to this potential advertiser.' 'Get me 13 subscriptions."'

A sketch of retiring House Speaker Joseph G. Cannon graced the cover of Time's Volume I, No. 1 when it was published on March 3, 1923. The thirty-two-page magazine (including covers) carried a relatively steep newsstand price of fifteen cents. Half of the news-stand's allotment of five thousand copies came back unsold, for a total of about nine thousand copies circulated, far less than optimistic projections of twenty-five thousand. For the first year or so, both circulation and advertising revenue remained sluggish. When Volume I was completed, the publishers sent bound copies to charter subscribers. Among those who sent back endorsements was Franklin D. Roosevelt, the unsuccessful vice-presidential candidate in 1920, who wrote in part "I do not think the articles are too brief—they are just about right in length and they are unbiased as far as it is possible for red-blooded Americans to make them so."

There was little original reporting in Time's early issues, which were cobbled together from newspapers, wire-service reports, speeches, and other sources, rewritten in the inimitable Time style that was largely the brainchild of Briton Hadden. The first issue defined what would remain Time's approach over the years, with only minor variations: items organized into departments such as national news, foreign news, the arts (and their subdivisions), books, religion, education, finance, and so forth. The first issue also featured three light-humor departments: Imaginary Interviews, Point with Pride, and View with Alarm. Stories were created by teams of writers and researchers, supplemented in later years by reporters and correspondents from bureaus around the world. A brief New York Times notice heralding the launch of the publication was headlined "Time a New Weekly—First Issue of Magazine Devoted to Summarizing Progress." True to its mission as articulated by Luce to Hadden, the magazine was designed to be read by busy millionaires and others in less than an hour; columns were at first restricted to seven inches. An unusual feature of the new magazine was its regular coverage of the number of lynchings in the Southern states. Robert T. Elson, in his semiofficial two-volume history The World of Time Inc., quoted Luce: "We were what would be called pro civil rights for Negroes from the beginning. One of the things in which we may have been useful is the fact that we tried to report every single lynching. We tried to print the exact story, without moralizing." Time was also the first publication to apply the honorific "Mr." to both black and white subjects.

Time, especially in its earlier decades, is perhaps best known for the idiosyncratic style favored by Hadden, which has been variously termed "breezy," "arch," or "cute." It was notable for the liberal use of word coinages, especially portmanteaus or puns, as in describing a young would-be newspaper publisher as a "Hearstling"; for its resuscitation of words and allusions from classical Greek such as "kudos" or "katabasis"; for its syntax-bending, especially through the use of inverted word order, as in "Forth from the White House followed by innumerable attendants, Mr. and Mrs. Warren G. Harding set out. …" (their return, not surprisingly, was termed a "katabasis"); for its historical and literary allusions; and for its pomposity-deflating identification of subjects with their middle names, as in "Walter Percy Chrysler," or with nicknames in parentheses, as in "Bernarr ('Body Love') Macfadden." Time's stylists also pioneered in the stringing together of frequently alliterative adjectives, as when describing George Bernard Shaw as "mocking, mordant, misanthropic"; and in the uncanonical use of nouns as attributives, as in "Teacher Scopes." Clearly, Time was being written for an educated and well-read audience: Elson suggested that Hadden's admiration for Homeric Greek prompted him to pepper his copy with a plethora of hyphenated modifiers: "At all times Hadden had by him a carefully annotated translation of the Iliad. In the back cover he had listed hundreds of words, especially verbs and the compound adjectives, which had seemed to him fresh and forceful. The classic ring of this vocabulary, which he frequently reviewed, served him as a tuning fork for the language that he wanted in Time." Luce is credited for the popularization of several words, such as "tycoon," a term previously used to describe a Japanese shogun which he applied to American business moguls, and "pundit," after the name of a Yale literary club he had joined.

As a cost-saving measure, Time's editorial offices moved to Cleveland, Ohio, in 1925 but returned to New York City within three years. By the end of the 1920s, the publication had published several sixty-page-plus issues and was reporting net profits of $125,000 on total revenues of $1.3 million, with a circulation guarantee approaching three hundred thousand. Newsstand sales doubled in a year, to twenty-three thousand copies. In 1928, with the selection of Charles Lindbergh, Time initiated its notable custom of selecting a "Man of the Year"—hero or villain—which over the years has been expanded to included women, anonymous groups (such as the under-thirty generation), and even the personal computer. The Man of the Year philosophy echoed Luce's secular-evangelical belief that history was mightily shaped by individual will, a phenomenon he saw himself embodying as the most influential publisher of his era at the time of his death in 1967.

In February of 1929, Hadden, then thirty-one, died of a streptococcal infection exacerbated by overwork, and Luce assumed even greater day-by-day oversight of the publication, confirming his reputation as a shrewd businessman as well as a savvy journalist. In the months before the stock-market crash ushered in the Great Depression, Time's tilt toward business had become quite evident. Within a month after Hadden's death, Luce said in a speech, with characteristic flourish: "Business is, essentially, our civilization; for it is the essential characteristic of our times.… Business is our life. It is the life of the artist, the clergyman, the philosopher, the doctor, because it determines the conditions and problems of life with which either artist or philosopher, let alone ordinary mortals, have to deal." It thus struck some observers as strange that Luce should have packed the editorial staff of his new publication, Fortune (which debuted February 1930), with such imaginative writers as Archibald MacLeish, Dwight Macdonald, and Russell Davenport. "There are men who can write poetry, and there are men who can read balance sheets," said Luce. "The men who can read balance sheets cannot write.… Of necessity, we made the discovery that it is easier to turn poets into business journalists than to turn bookkeepers into writers."

During the early 1930s, Luce enlisted the new medium of radio to expand Time's reach while simultaneously shaping the way radio would present news and documentary material. Luce hired Fred Smith of a Cincinnati radio station to develop a radio program based on Time's weekly content. Originally titled Newscasting, the project quickly evolved into the News Acting, in which short news items were dramatized with sound effects, and then into the full-blown radio program The March of Time, which employed leading radio performers and announcers to reenact the week's events in a Friday night, half-hour, CBS-network program, introduced by a fanfare and the words "On a thousand fronts the history of the world moves swiftly forward. …" Agnes Moorehead and Orson Welles were among the graduates of the early broadcasts of The March of Time. Within a few years, a moving-picture-newsreel version was created, and the legend "Time Marches On" soon became a familiar sight on movie screens from coast to coast. Although, as Elson wrote, "the method of The March of Time is no longer acceptable as journalism … TV, the modern film documentary, the new school of cinéma véritéowe much to its pioneering methods."

Despite the success of this and other ventures, Time and its sister publications suffered through the Depression years, especially when factoring in the huge start-up costs of Lifein 1936. In the period before the United States entered World War II—Time coined that designation in a September 1939 issue when it confidently reported "World War II began last week at 5:20 a.m. (Polish time) Friday, September 1"—Luce had come to believe that Americans had a fateful role to play in world affairs and urged military aid to the beleaguered European allies. After Pearl Harbor, Luce committed Time to the cause of "absolute victory." He also threw his support to the Nationalist Chinese forces of Chiang Kai-shek, much to the consternation of Time's correspondent in China, Theodore H. White (later of Making of the President fame), who broke with Luce when ordered to write flattering pieces about the man White called "China's somber tyrant." John Heidenry complained in his New York Times review of a 1995 book about Luce and White that the publisher "believed that ideological distortion of the news was often preferable to objectivity, particularly where China and the Republican Party were concerned." In the years that followed, Time maintained a firm anti-Communist tack, but it also was among the first publications to challenge the demagoguery of Wisconsin Senator Joseph McCarthy. Still, Time during the 1950s and 1960s was perceived as having a Republican bias—at least an "Eastern establishment" Republican bias, for Time endorsed, for the first time, the Democratic presidential candidate in 1964, favoring Lyndon B. Johnson over Barry Goldwater. Luce had retired as editor-in-chief earlier that year, handing over the reins to Hedley Donovan. Andrew Heiskell had already taken over as chairman of the parent company. At Luce's retirement, the firm that had started forty-some years earlier with an investment of $86,000 had grown to a conglomerate with revenues of more than $400 million.

In January of 1990, Time, Inc. and Warner Communication combined to form an even larger conglomerate, the largest in the United States, bringing together Luce's company "with its rich journalistic history and its aristocratic, traditional leadership" and Warner, "with its lucrative stable of movie, entertainment and cable television properties," in the words of the New York Times. During the 1980s, the management of Time, Inc. decided that it was time to deemphasize the role of its magazines as future sources of revenue and corporate viability, leading some observers, like Richard M. Clurman, to worry about the future of its journalistic integrity, as described in his 1992 book To the End of Time: The Seduction and Conquest of a Media Empire. Clurman's fear of "people in Time Warner who believe and act as if the purpose of business is only business" stands ironically against Henry Luce's declaration in 1929 that "Business is, essentially, our civilization."

In 1998, Time celebrated its seventy-fifth anniversary with a gala at New York's Radio City Music Hall to which were invited all living men and women who had appeared on the magazine's cover, a star-studded affair with guests ranging from President Bill Clinton to Russian ex-premier Mikhail Gorbachev to Billy Graham to Sharon Stone to Toni Morrison. By century's end, managing editor Walter Isaacson has been credited with restoring some of the old luster of Time's authority and credibility in a "post-magazine" era by leading the publication into the new-media era via its Pathfinder Internet service, by increasing science and technology coverage, and by planning The Time 100 series on CBS Television. Revenues at the publication increased 21 percent in 1997 to about $94 million, and circulation rose slightly to 4.2 million, earning Time the designation "Hottest Magazine of '97" by Adweek.

—Edward Moran

Further Reading:

Clurman, Richard. To the End of Time: The Seduction and Conquest of a Media Empire. New York, Simon & Schuster, 1992.

Elson, Robert T. Time, Inc.: The Intimate History of a Publishing >Enterprise 1923-1941. New York, Atheneum, 1968.

——. Time, Inc.: The Intimate History of a Publishing Enterprise 1941-1960. New York, Atheneum, 1973.

Griffith, Thomas. Harry and Teddy: The Turbulent Friendship of Press Lord Henry R. Luce and His Favorite Reporter, Theodore H. White. New York, Random House, 1995.

Hamblin, Dora Jane. That Was the Life. New York, W. W. Norton &Co, 1977.

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time / tīm/ • n. 1. the indefinite continued progress of existence and events in the past, present, and future regarded as a whole: travel through space and time one of the greatest wits of all time. ∎  the progress of this as affecting people and things: things were getting better as time passed. ∎  time or an amount of time as reckoned by a conventional standard: it's eight o'clock Eastern Standard Time. ∎  (Time or Father Time) the personification of time, typically as an old man with a scythe and hourglass.2. a point of time as measured in hours and minutes past midnight or noon: the time is 9:30. ∎  a moment or definite portion of time allotted, used, or suitable for a purpose: the scheduled departure time should we set a time for the meeting? ∎  (often time for/to do something) the favorable or appropriate time to do something; the right moment: it was time to go it's time for bed. ∎  (a time) an indefinite period: traveling always distorts one's feelings for a time. ∎  (also times) a more or less definite portion of time in history or characterized by particular events or circumstances: Victorian times at the time of Galileo the park is beautiful at this time of year. ∎  (also times) the conditions of life during a particular period: times have changed. ∎  (the Times) used in names of newspapers: The New York Times. ∎  (one's time) one's lifetime: I've known a lot of women in my time. ∎  (one's time) the successful, fortunate, or influential part of a person's life or career: in my time that was unheard of. ∎  (one's time) the appropriate or expected time for something, in particular childbirth or death: he seemed old before his time. ∎  an apprenticeship: all of our foremen served their time on the loading dock. ∎  dated a period of menstruation or pregnancy. ∎  the normal rate of pay for time spent working: if called out on weekends, they are paid time and a half. ∎  the length of time taken to run a race or complete an event or journey: his time for the mile was 3:49.31. ∎  (in sports) a moment at which play is stopped temporarily within a game, or the act of calling for this: the umpire called time. ∎  Soccer the end of the game: he scored five minutes from time.3. time as allotted, available, or used: we need more time it would be a waste of time. ∎ inf. a prison sentence: he was doing time for fraud.4. an instance of something happening or being done; an occasion: this is the first time I have gotten into debt the nurse came in four times a day. ∎  an event, occasion, or period experienced in a particular way: we had a good time | she was having a rough time of it.5. (times) (following a number) expressing multiplication: five goes into fifteen three times it burns calories four times faster than walking.6. the rhythmic pattern of a piece of music, as expressed by a time signature: tunes in waltz time. ∎  the tempo at which a piece of music is played or marked to be played.• v. 1. [tr.] plan, schedule, or arrange when (something) should happen or be done: the first track race is timed for 11:15 the bomb had been timed to go off an hour later. ∎  perform (an action) at a particular moment: Williams timed his pass perfectly from about thirty yards.2. [tr.] measure the time taken by (a process or activity, or a person doing it): we were timed and given certificates according to our speed | I timed how long it took to empty that tanker. 3. [tr.] (time something out) Comput. (of a computer or a program) cancel an operation automatically because a predefined interval of time has passed without a certain event happening.PHRASES: about time used to convey that something now happening or about to happen should have happened earlier: it's about time I came clean and admitted it.against time with utmost speed, so as to finish by a specified time: he was working against time.ahead of time earlier than expected or required.ahead of one's time having ideas too enlightened or advanced to be accepted by one's contemporaries.all the time at all times. ∎  very frequently or regularly: we were in and out of each other's houses all the time.at one time in or during a known but unspecified past period: she was a nurse at one time.at the same time1. simultaneously; at once.2. nevertheless (used to introduce a fact that should be taken into account): I can't really explain it, but at the same time I'm not convinced.at a time separately in the specified groups or numbers: he took the stairs two at a time.at times sometimes; on occasions.before time before the due or expected time.behind time late.behind the times not aware of or using the latest ideas or techniques; out of date.for the time being for the present; until some other arrangement is made.give someone the time of day be pleasantly polite or friendly to someone: I wouldn't give him the time of day if I could help it.half the time as often as not.have no time for be unable or unwilling to spend time on: he had no time for anything except essays and projects. ∎  dislike or disapprove of: he's got no time for airheads.have the time1. be able to spend the time needed to do something: she didn't have the time to look very closely.2. know from having a watch what time it is.in (less than) no time very quickly or very soon: the video has sold 30,000 copies in no time.in one's own time (also in one's own good time) at a time and a rate decided by oneself.in time1. not late; punctual: I came back in time for Molly's party.2. eventually: there is the danger that he might, in time, not be able to withstand temptation.3. in accordance with the appropriate musical rhythm or tempo.keep good (or bad) time1. (of a clock or watch) record time accurately (or inaccurately).2. (of a person) be habitually punctual (or not punctual).keep time play or rhythmically accompany music in time.lose no time do a specified thing immediately or as soon as possible: the administration lost no time in trying to regain the initiative.no time a very short interval or period: the renovations were done in no time.on one's own time outside working hours; without being paid.on time punctual; punctually: the train was on time we paid our bills on time.out of time1. at the wrong time or period: I felt that I was born out of time. ∎  not following or maintaining the correct rhythm (of music): every time we get to this part in the song, you are out of time.2. with no time remaining to continue or complete something, esp. a task for which a specific amount of time had been allowed: I knew the answers to all the essay questions, but I ran out of time.pass the time of day exchange greetings or casual remarks.time after time (also time and again or time and time again) on very many occasions; repeatedly.time immemorial used to refer to a point of time in the past that was so long ago that people have no knowledge or memory of it: markets had been held there from time immemorial.the time of one's life a period or occasion of exceptional enjoyment.time out of mindanother way of saying time immemorial.time was there was a time when: time was, each street had its own specialized trade. (only) time will tell the truth or correctness of something will (only) be established at some time in the future.