SCIENCE (IN THE RENAISSANCE)

The story of science in the renaissance is essentially that of science in the 16th century. The limits, necessarily arbitrary, may be set as early as 1450, since the discovery of printing and the reproduction of numerous, identical copies of scientific books is an important Renaissance phenomenon. To extend much beyond 1600, however, would necessitate the inclusion of Galileo galilei, and while he represents a culmination of Renaissance thought, he is best considered as ushering in the modern era rather than bringing the Renaissance to a close.

This article discusses science in the Renaissance rather than the renaissance of science. During this period many of the concepts and the methods that paved the way for modern science began to emerge, but there was no "rebirth" in the sense of the return to the classics that characterized the literary renaissance. It was a period of questioning, of probing, of tentative steps forward, of confused viewpoints. Tycho Brahe placed observational astronomy on a firm foundation without abandoning astrological predictions, and kepler continued to cast horoscopes while enunciating his three laws; Paracelsus issued diatribes against current medical practice and urged the application of chemistry to medicine, but the chemistry he wished to apply contained some of the worst forms of alchemy; Leonardo produced some of the finest anatomical drawings known, yet he not only "saw" but drew the "invisible" pores in the heart, which made possible what Galen considered back and forth surging of the blood. There was assuredly a greater questioning of Aristotle, of Galen, of ptolemy, but most of the scientists who emerged in this period were not ready to abandon them completely; there was indeed a much greater reliance on observation and experiment so long as this did not conflict too drastically with existing notions.

The Renaissance abounds in great names, and in a summary such as this some of them will merely be catalogued. Most of them are the subjects of individual biographical articles elsewhere in the Encyclopedia. To these the reader is referred in order to fill out the picture.

One of the events that not only stirred the imagination of the people but encouraged scientific investigation was the discovery of the earth. The great voyages of discovery opened to man a new earth: there were new lands and new peoples, new plants and new animals—all for men to see and study. This pointed out the need for aids to navigation—instruments to plot one's course and adequate maps on which to locate one's position. It spurred interest in terrestrial magnetism, a knowledge of which would make the compass an effective instrument for long journeys.

Mathematics. The flurry of publication of mathematical books that characterized the period included not only Greek and Latin versions of Euclid, Archimedes, Appolinias, and Pappros but many original works of first importance. The De triangulis omnimodis libri quinti (1533) of Regiomontanus is the foundation of modern trigonometry. This was preceded by the work of G. Purbach and followed by the development by G. Rheticus (1514 to 1567) and B. Pitiscus (1561 to 1613) of accurate tables; these were to become almost useless after 1620, when the first set of logarithmic tables was published.

In algebra the cubic equation was solved by N. Tartaglia, and the solution was published and generalized by G. Cardano, in his Ars Magna (1545). L. Ferrari (1525 to 1565) then found the general solution of the quartic. Considering the cumbersome notation of the 16th century, these are outstanding achievements. Work on the theory of equations was continued by R. Bombelli in Italy and François Viète (1540 to 1603), the greatest French mathematician of the Renaissance. They not only systematized the existing knowledge but expanded it considerably.

The international character of this development is emphasized in the person of Simon Stevin of Bruges, who clarified the treatment of negative roots, but whose greatest achievement was his vindication of decimal fractions in 1585.

Astronomy. The publication (1543) of the De revolutionibus orbium coelestium of copernicus stands as the most significant astronomical event of the Renaissance. Though Copernicus's conception of the universe was neither original (Aristarchus had certainly expressed much the same ideas) nor correct, the restatement of the heliocentric theory coupled with the diurnal rotation of the earth was a bold step forward.

Tycho Brahe rejected the ideas of Copernicus both because the Copernican system disagreed with some of Brahe's observations and because he still could not understand the movement of the "sluggish" earth. Instead he substituted a system in which the sun revolved about the earth and the other planets revolved about the sun. Only when Kepler, using Brahe's data, abandoned the idea of circles and used ellipses instead was the heliocentric system placed in a form close to that accepted today. But Tycho Brahe was the greatest of pretelescopic observational astronomers. Two of his observations were of immediate importance. In 1572 he observed a new star in Cassiopeia and followed its gradual changes in magnitude until its disappearance 16 months later. By the absence of parallax he proved it was indeed among the fixed stars—and to an Aristotelean who held a doctrine of the immutable heavens, this was indeed a startling revelation. He also carefully observed the comet of 1577, showed that it was not in the sublunar region, where Aristotle had placed comets, and cast doubt on the "spheres" that carried the planets since the comet seemed to pass readily through these. Without Brahe's accurate observations, Kepler could not have arrived at his theory and the three laws that bear his name. And as Brahe paved the way for Kepler, so did Kepler pave the way for Newton and the scientific revolution that he fathered.

Physics. The work of Stevin on statics (1586) is a book solidly in the Archimedean tradition. Among other things Stevin expounded the law of equilibrium for an inclined plane and stated the hydrostatic paradox usually associated with Pascal. The use of gunpowder and cannon promoted the study of dynamics, since there was little use in possessing cannon unless the laws that governed the motion of a projectile were known. A noteworthy contribution was made by Tartaglia, who pointed out that a projectile fired horizontally did not move in a horizontal line and then suddenly fall vertically under the influence of gravity but rather that its path was curved since gravity was continually acting.

Little information is available concerning the status of mechanics in the 16th century, although writers during this period were responsible for transmitting the 14th-century development of mechanics and its terminology to such innovators as Galileo [see M. Clagett, The Science of Mechanics in the Middle Ages (Madison, Wisconsin 1959) for details]. Possibly the most original contribution in this period was that of the Spanish Dominican Domingo de soto, who had studied at Paris and was acquainted with the work of the Mertonians thomas bradwardine and william of heytesbury, and the Parisian nominalist albert of saxony. Soto is the first writer known to have applied the Mertonian rule for determining distance in a uniformly accelerated motion to the motion of freely falling bodies, thereby anticipating Galileo's famous law of falling bodies by more than 50 years (ibid. 658; cf. 555). His Quaestiones super octo libros physicorum Aristotelis (Salamanca 1545) went through ten editions and served as an important textbook in physics until the beginning of the 17th century.

One of the classics of science to appear in the Renaissance was the De magnete (1600) of William Gilbert of Colchester. Though he was a physician, Gilbert's fame rests on this book, to which he had devoted his leisure for 17 years, much of this time being devoted to careful experimentation. Gilbert studied the poles of elongated lodestones, broke them and detected the poles of the fragments, and found that he could increase the attractive power of a magnet by placing iron caps over its ends. Most significant of all he studied a spherical lodestone and concluded that the earth behaved as a huge magnet. This explained not only why a compass pointed north but also the declination and inclination of the needle. Unfortunately he identified the magnetic pole with the geographic pole and was unable therefore to give an adequate explanation of declination. In this work also, Gilbert posed the existence of a magnetic field and made the first clear distinction between magnetism and electricity.

Chemistry. Though the Renaissance witnessed an increase in chemical techniques and apparatus as well as the preparation of new compounds, the science of chemistry was still shackled by alchemical ideas. Despite the application of chemistry to medicine (iatrochemistry), which Paracelsus championed, and which certainly was a notable advance, Paracelsus not only adhered to the ideas of the four elements, four qualities, and four humors but also popularized the concept of the "three principles" (Sulfur, Mercury, and Salt) that were the embodiment of certain properties in various forms of matter. What was perhaps the most significant textbook of chemistry during this period still bore the title Alchemia (1597). The author, Libavius (Andreas Liban, c. 1540 to 1616), defended the traditional alchemical thesis of the possibility of the transmutation of base metals into gold. What advances there were during this period were in chemistry as a practical art; little was done to advance theoretical chemistry, and Lavoisier was still almost two centuries away.

Biology. Considerable interest in biological sciences developed in the 16th century, stimulated by a return to careful examination of both flora and fauna. In botany this was the period of the herbals, books giving careful descriptions and precise illustrations of plants with medicinal properties, real or supposed. In succeeding publications the authors included additional plants, even though they possessed no known medicinal value, and then initiated attempts at the classification of the specimens to remove some of the confusion resulting from unorganized presentation of species.

Most of the advances in animal biology developed in the medical schools, where the emphasis was on the exact description of human anatomy. In this premicroscope period, the main interest was in gross structure, but the careful dissections by men like Vesalius made possible the great discoveries of Harvey and Malpighi.

Botany. This discussion must begin with the "German fathers of botany." As naturalists began to realize the need for illustrations made directly from nature, they found at hand both artists and woodcut makers capable of transferring information to the printed page. Many of the drawings were both accurate and beautiful, and the herbals that this kind of collaboration produced are among the finest books of the period.

The first herbal was the work of Otto Brunfels of Mainz (d. 1534), with drawings by Hans Weiditz. Brunfels accompanied the illustrations of German plants with descriptions of plants of the Near East given by Dioscorides. Many of the resulting discrepancies were removed in the work of Jerome Bock (Tragus 1498 to 1544), where the plants were actually described from nature. The best herbal before 1550, however, was the De historia stirpium (1542) of Leonhard Fuchs (1501 to 1566), in which more than 500 plants were accurately described and illustrated. These and other Germans reawakened interest in botany, but with the growing curiosity about the plants and animals found in newly discovered lands, men of other countries produced popular works. Outstanding among these was the work of the Italian P. A. Mottiali (1500 to 1577), the various editions of which sold more than 30,000 copies. As herbals continued to appear, each was a bit better than its predecessors in scope, in completeness, in description, and in the quality of the illustrations. Three Flemings deserve mention in this connection: Dodonaeus (Rembert Dodoens, 1516 to 1585), Clusius (Charles de l'Écluse, 1526 to 1609), and Lobelius (Matthias de Lobel, 1538 to 1616). The last-named is particularly important since in his work (1570 to 1571) is found one of the first attempts at scientific classification of plants. Lobelius based his classification on characteristics of leaves and was thus able to indicate the distinction between dicotyledons and monocotyledons. The botanical interest of the period is indicated also by the foundation of numerous botanical gardens and the initiation of the practice of collecting dried plant specimens into herbaria.

Physiology. Two outstanding works of the Renaissance were the natural histories of Conrad Gesner (1516 to 1565) and Ulisse Aldrovandi. They were monumental works, and each was completed after the death of the originator. Gesner's Historia animalium (1551 to 1587) appeared in five folio volumes; Aldrovandi's (1599 to 1668) ran to 13 volumes, only four of which appeared during his lifetime. Much of the material in these books was legendary, but they contained accurate descriptions and drawings of many fish, birds, and animals, of both the Old and New World.

Anatomy and Medicine. Throughout history the dissection of human bodies was periodically forbidden, and always rare. Though never completely abandoned, dissections were seldom performed on the human corpse because of a superstitious fear of the dead or out of respect for the body precisely as human. Galen had dissected monkeys, and the medieval anatomical school at Salerno had dissected pigs—not because they were interested in either monkeys or pigs but in order to learn about the human body, which was similar. Many professors of anatomy considered themselves above the mundane task of dissection, preferring to gain their knowledge from books (Galen or Avicenna); and when experience contradicted the book, it must have been due to some deformity in the body under examination. The two great anatomists of this period were Leonardo da Vinci and the Fleming Andreas Vesalius, who worked at Padua. The bodies dissected were often those of executed criminals, and executions of several men condemned at the same time were often spaced to satisfy the needs of the medical school.

Vesalius. The De humani corporis fabrica of Vesalius appeared in 1543, the same year as the publication of the De revolutionibus of Copernicus. The Fabrica is a landmark in scientific history; here for the first time were accurate descriptions of the human body accompanied by admirable woodcuts to illustrate the text. Vesalius was a skilled dissector, and while he was not able to break away from the authority of Galen completely, his work struck the spark that kindled the anatomical interest, and led to the discoveries, of the next century.

Leonardo da Vinci. The man who perhaps best epitomizes the good qualities of the Renaissance is the Florentine Leonardo da Vinci. Artist, humanist, philosopher, scientist—Leonardo was all these and more; but his importance in the history of science is not what it should have been, for he published nothing. Therefore his influence was limited to the few who might have seen his notebooks. But this cannot diminish his personal glory, even as a scientist. His drawings of parts of the body, made during dissections he performed himself, are still among the best available. He also left behind sketches of animals, plants, rocks, and shells. He gave the first rational explanation of fossils. His fertile mind was constantly concocting new ideas, many that simply failed to mature, for he too soon turned his attention to something else. In him art and science met as perhaps they never have or never will again.

Others. Medicine had consisted of the study of botany and anatomy until Paracelsus added chemistry to these and asserted that the aim of alchemy was not to make gold but to prepare medicines. He introduced chemicals of nonvegetable origin into the treatment of disease. While not the founder of iatrochemistry, he was its chief exponent. There is much of what is superstitious combined with what is good in Paracelsus. If he was not a great discoverer, he was a tireless experimenter and an exciting person who could not be ignored. He shook the very foundations of Galenic medicine and helped establish a climate favorable to future discoveries. The discovery by servetus of the lesser or pulmonary circulation was another blow to the Galenic medicine since it did away finally with the invisible pores in the septum of the heart. Two more doctors deserve mention: Jean Fernel (1497 to 1558) and Ambroise Paré; the first, the founder of physiology; the second, of a new surgery. Fernel's Opera went through 34 editions before 1681. His physiology was the study of the body's normal functioning, and he divided his texts into circulation, respiration, digestion, muscular function, etc. He made no great discovery—many of these had to await the microscope, but he was a careful observer and a good physician who stimulated further research. Paré was a military surgeon who promoted the humane treatment of gunshot wounds, and his worth was such that he was surgeon to three kings.

Conclusion. This brief survey has tried only to indicate a few trends and to place some of the great Renaissance scientists in their historical context. The bibliography cites only general works; for material on particular scientists, see the bibliographies at the end of their respective biographies.

See Also: biology i (history of).

Bibliography: g. a. l. sarton, Six Wings: Men of Science in the Renaissance (Bloomington, Indiana 1957); The Appreciation of Ancient and Medieval Science during the Renaissance (Philadelphia 1955). w. p. d. wightman, Science and the Renaissance (Toronto 1962). a. r. hall, The Scientific Revolution, 1500–1800 (Boston 1954). a. c. crombie, Medieval and Early Modern Science, 2 v. (2d ed. Cambridge, Massachusetts 1961); ed., Scientific Change (New York 1963). w. c. dampier, A History of Science (4th ed. New York 1949). h. butterfield, The Origins of Modern Science, 1300–1800 (New York 1960).