IDIOMI, COMUNICAZIONE of. — The term « i. », which according to its etymology means property and in common usage native language, philosophically indicates an attribute proper to a nature. The expression « c. degli i. » is then used by theologians in Christology to designate the mutual predication of human and divine attributes in Jesus Christ. The c. degli i. follows as a logical consequence from the fact that in Christ the divine and human natures are united; indeed, it is nothing other than the translation on the logical plane of that ontological communication or union existing in Christ between the human and divine natures and consequently between the attributes of each nature.
It is therefore readily understandable, and the history of dogma confirms it, that, while on the one hand the c. degli i., understood in a vague and indeterminate sense, is necessarily admitted by all who recognize in Christ the character of God-Man, a more precise and exact interpretation of it is bound up with the way of conceiving Christ’s unity and the relations in him between the divine and human natures.
Nestorianism (v.), which divided Christ into two accidentally united persons, admitted the c. degli i. only in the sense that the predicates of one person can be attributed to the other by a moral attribution, just as, in general, the dignity, authority, and honor of a father can be morally referred to his children.
The monophysitism (v. MONOFISITI), moving in a completely opposite direction, fused the two natures into one and carried the c. degli i. to the point of attributing the properties of one nature to the other.
Following a middle path between these two in-
terpretations, of which the first errs through defect and the second through excess, Catholic doctrine specifies the meaning of the c. degli i. as follows:
1) Human attributes can be predicated of the subject Christ, designated according to the divine nature, as in the propositions: the Word of God, the Son of God, was born in time, had a mother, suffered, died; and conversely, divine attributes can be predicated of Christ designated according to the human nature, e.g.: Christ the man, the son of the Virgin Mary, the Son of Man, is creator of the universe, is generated in eternity by the Father, is, with the Father, the principle of the Holy Spirit. Indeed, the hypostatic union entails that Christ is one « I », one person having two natures; hence propositions such as those cited above are true, in which the identity is established between the person possessing the properties of one nature and the person possessing the properties of the other nature.
2) On the other hand, however, hypostatic union (v.) entails that the two natures remain distinct and unconfused in Christ; consequently, they cannot mutually predicate, nor can the properties of one be predicated of the other. It would be a grave error to affirm that Christ’s human nature is omnipotent, eternal, omniscient; or that Christ’s divine nature is passible and mortal. One would fall into the same error by affirming that Christ, insofar as he is man, is eternal, or that Christ, insofar as he is God, died; for these qualifications « insofar as he is man » or « insofar as he is God » have the force of indicating in the nature of man or of God the reason for the predicate, and thus such propositions amount to affirming that one nature possesses the properties of the other, thereby falling into monophysitism.
In conclusion, according to the correct sense established by Catholic doctrine, the mutual attribution of human and divine properties in Jesus Christ does not occur directly between the human and divine natures, but rather between the person designated according to one nature and the properties of the other nature.
The fact of the c. degli i. is already clearly found in Sacred Scripture, for example, in the following passages: « And the Word was made flesh and dwelt among us » (Io. 1, 14); « The Son of God was made from the seed of David according to the flesh » (Rom. 1, 3); « From whom (the Hebrews) Christ was born according to the flesh, who is above all things, God blessed forever » (Rom. 9, 5); « Who (Jesus Christ), being in the form of God... emptied himself, taking the form of a servant... humbled himself, becoming obedient unto death, even to the death of the Cross » (Phil. 2, 6-7).
The doctrine of the c. degli i. was solemnly defined by the Church at the Councils of Ephesus and Lateran (Denz-U, 116, 124, 255). The Fathers, such as Origen, Cyril of Jerusalem, Cyril of Alexandria, St. John Damascene, developed it in the polemic against Christological heresies; and the scholastics expressed it in philosophical formulas, precisely establishing the laws that must govern our manner of speaking about Christ, among which we may recall the most important, concerning concrete and abstract names.
In the philosophical sense, concrete names are understood to be those that designate a subject possessing a nature or one of its properties, e.g.: mortal, corporeal man; « man » precisely means « a subject possessing human nature ». Abstract names, on the other hand, indicate a single part while prescinding from the concrete subject in which they are destined to be realized, e.g.: humanity, rationality, mortality, body, soul. Now, the scholastic rule states that human nature and its properties may be attributed to Christ the Word when they are expressed by concrete names, but not when they are expressed by abstract names. It is correct to say that the Word of God is corporeal, is mortal; it is false, however, to affirm that the Word is corporeality, is mortality, is a body. This rule finds its justification in the light of the dogma of the hypostatic union, according to which human nature, with its attributes and parts, is possessed by the Word, but is not the Word; hence, the Word is a person who possesses human nature, but is not human nature, still less its parts and properties.
When, however, divine attributes are at issue, it is legitimate to predicate them of the person Christ-Man, even when they are expressed in an abstract manner; e.g.: The son of the Virgin Mary is the Divinity; he is the Way, the Truth, and the Life. The reason for the exception lies in the fact that all divine perfections are subsistent, that they themselves are the substantial subject, and therefore the names expressing divine perfections may be taken as concrete names.
IDIORITMIA: MONACHISMO ORIENTALE.