COMMUNICATION OF IDIOMS

An idiom, in theological usage, is equivalent to a natural property or attribute. Because of the mysterious union of natures in the one person of jesus christ, the question inevitably arises whether and under what conditions one may assign divine properties to Christ the man, and human properties to God. The special difficulty connected with this communication of idioms lies precisely in the fact of two natures in one person. The natures must not be confused by attributing to one nature what is proper to the other. Yet the one person must not be multiplied by denying to it the possession of anything included in the two natures, thereby implying the existence of another subject or person. It follows that the present question is not entirely a matter of correctness in terminology. Propriety or impropriety in the communication of idioms is also the clearest indication of the presence or absence of orthodox faith in the incarnation. It is the expression of the mystery of the hypostatic union itself.

Development. The New Testament makes use of the communication of idioms in attributing to God such natural human characteristics as birth in time according to the flesh, possession of a physical body, human life, sufferings, and death; and to the Son of Man such divine properties and operations as eternity, divine power and authority, elevation above all creatures, creation, and the sanctification of souls. The same usage was followed quite naturally by the earliest Fathers and in the primitive creeds and symbols of faith. More speculative development came only in time. Among the earliest to elaborate the theory of the communication of idioms were Origen, Ephraem, Athanasius, Cyril of Jerusalem, and most explicitly, Gregory of Nyssa in the East, along with Tertullian, Hilary, and especially Augustine in the West. Among those who accepted the true divinity and integral humanity of Christ, no critical difficulty arose concerning the communication of idioms until the Nestorian heresy.

Heresies. The Nestorians, by envisioning in Jesus two physical persons, inevitably destroyed His true unity and, quite as inevitably, the communication of idioms became purely a matter of words. When they said of the socalled moral person-of-union named Christ, Lord, or Son that man is God or God is man, they intended these expressions in a highly improper sense: God, who is not man, is closely joined with this man, or this man, who is not God, is morally joined with God. They especially denied that things belonging to Christ according to His humanity could be attributed to God. According to them, it ought not be said that the Word of God was born or suffered. Finally, a crucial point for both Nestorians and their opponents, Mary was not to be called Mother of God, θεοτόκος (see theotokos), but, at most, Mother of Christ, χριστοτόκος. At the opposite extreme, in attempting to restore the unity of Christ destroyed by the Nestorians, Monophysites and Eutychians confused and mixed the divine and human natures of Christ so that there was no longer a question of a communication of idioms, but of a simple attribution of both divine and human properties to the one resulting nature.

Magisterium. The reaction of the teaching Church to these two erroneous extremes is found mainly in the Councils of Ephesus (431) and Chalcedon (451). Ephesus, rejecting the moral union of two physical persons suggested by the Nestorians, declared that "the Word, according to hypostasis, united to Himself a body animated by a rational soul and so became man in an unexplainable and incomprehensible way…. And although thenatures are different, they have been brought together into true unity, making for us one Christ and Son; not because the difference of natures is removed in virtue of the union, but rather because the divinity and humanity by a mysterious and ineffable conjoining have achieved, in one person, our one Lord and Son Jesus Christ" (H. Denzinger, Enchiridion symbolorum, ed. A. Schönmetzer [Freiburg 1963] 250). Thus, the union in the Incarnation is in and according to person, and there are not found two real persons, divine and human, merely cloaked or covered by the Nestorian person-of-union. Consequently, by a true communication of idioms, the Council asserted that Mary is and is to be called Mother of God. The Council of Chalcedon declared against the Monophysites that the "one and same only-begotten Son, Christ the Lord, must be recognized in two natures without confusion, without change, without division or separation. The difference of the natures is in no way removed by the union, but the proper characteristics of each are the more preserved thereby; they are united in one person" (Enchiridion symbolorum 302). The union of the Word with human nature is not then a union in nature, but after the union, there remain in Christ whole, unmixed, and without change both human nature and divine nature, each preserving what is proper to itself. This vindication of the basis of the communication of idioms was later repeated in a number of places, including the Second Council of Constantinople (553) and the Council of Florence (1442).

It is a clear conclusion from the teachings of the Church that the real communication of idioms in Catholic dogma is not between the natures of Christ, that is, the properties of one nature never become the properties of the other. The true communication of idioms is in the one person of Jesus. He who is truly God, the only-begotten Son, Second Person of the Trinity, became truly man and the Son of Mary. God the Word is man and this man Jesus Christ is God, but divinity is not humanity nor is humanity divinity. Therefore, once the Incarnation has taken place, whatever is affirmed of this one person when He is named or indicated according to one nature can be affirmed of the same person when He is named or indicated according to the other nature. The person is always one and the same even though at one time called God because of His divine nature and at another time called man because of His human nature. What is affirmed of one nature cannot rightly be affirmed of the other nature since the natures always remain different and distinct.

Rules. Since the hypostatic union is itself the deepest mystery, it is unlikely that any set of rules governing the manner of speech about Christ can be completely adequate. However, certain generally accepted norms should be observed so that faith in the Incarnation does not suffer from faulty expression. (1) The communication of idioms is generally legitimate for concrete affirmations, illegitimate for abstract affirmations. One says that the Son of Man is omnipotent and eternal, but not that humanity is omnipotent and eternal; that God was born and died, but not that divinity was born and died. (2) There is an important difference between affirmative and negative propositions. The negatives are more sweeping. Therefore, whatever belongs to Christ according to one nature may be simply affirmed of Him; but what does not belong to Him according to one nature should not be simply denied. One says that Christ died, but not that He did not die, even though in His divine nature He did not die. (3) When the person is named with an additional expression emphasizing one nature, the communication of idioms ceases. One may properly say that Christ is eternal, but not that Christ as man is eternal. (4) While safeguarding the distinction of natures, one may attribute opposed and contrary properties to the one person. Christ is uncreated, eternal, and omniscient; Christ was created, mortal, and grew in knowledge. (5) The communication of idioms supposes that the hypostatic union has already taken place and should not be extended to the time before the Incarnation. In addition to these norms, good theological judgment would suggest that curiosities and novelties not be indulged, that accepted and traditional usages be followed, and that ambiguous expressions be clarified or avoided.

Moment. The communication of idioms is of deeper significance than correctness in the formalities of speech. It concerns the heart of the dogma of the Incarnation. The true foundation for communication is the hypostatic union. By virtue of this, divine and human natures are found in Jesus Christ in one person. All the properties of both natures consequently belong to this one person, and the communication of idioms is fundamentally nothing other than the hypostatic union itself. To be deficient or erroneous in it is necessarily to be deficient or erroneous in faith in the Incarnation. Scripture, the Fathers, and the teaching Church have employed the communication of idioms to stress the reality and the important consequences of the hypostatic union. Historically it has provided the clearest test of orthodoxy about the Incarnation. It is significant that Mary's title as mother of god is nothing other than a proper communication of idioms. Even the greatest vigilance in observing the norms for correctness of expression about the person and natures of Jesus Christ is therefore more than justified. One's desire must be not only to avoid erroneous expressions, but to express the mystery of two natures in one person as fully as one is able to grasp it.

See Also: nestorianism; monophysitism; eutychianism.

Bibliography: a. michel, Dictionnaire de théologie catholique, ed. a. vacant et al., (Paris 1903–50) 7.1:595–602; Tables générales 2:2574–75. k. forster, Lexikon für Theologie und Kirche, ed. j. hofer and k. rahner (Freiberg 1957–65) 5:607–609. i. solano, Sacrae theologiae summa, ed. Fathers of the Society of Jesus, Professors of the Theological Faculties of Spain (Madrid 1962) 3:1, 370–407. b. m. xiberta y roqueta, Enchiridion de Verbo Incarnato (Madrid 1957) Index doctr. 16.

[j. f. rigney]