Communicatio Idiomatum a doctrine of the Lutheran Church as to the person of Christ. In the ancient Church the question arose if a real personal unity of the divine and the human elements in the person of Christ could be effected without destroying the distinction of natures. The ancient Church maintained the reality of the personal unity of the two elements by condemning the Nestorian, Monophysite, and Monotheletic doctrines. The Lutheran theology undertook to show the possibility of this union. Luther laid the foundation of the doctrine by the assertion that Christ, according to his humanity, fills all things, and is ubiquitous. He did not use, however, the expression communicatio idiomatum, which was first employed in the Formula Concordiae (q.v.). Three classes of Scriptural passages were adduced by the old Lutheran writers in behalf of this doctrine: 1, those in which qualities belonging to one nature only are attributed to the whole person; 2, those which predicate of one nature an activity which belongs to the work of redemption, consequently to the whole person; 3, those which transfer divine attributes to Christ's human nature. The Formula Concordiae, however, expressly rejects a restriction of the divine nature, in consequence of its union with the human. Zwingle, with whom, on the whole, the theologians of the Reformed Church agreed, rejected the doctrine of a real communicatio idiomatum (peculiar qualities of the two natures), and explained the passages adduced by the Lutherans as figures of speech (ἀλλοίωσις). The Supranaturalistic school of the later German theology does not expressly reject the doctrine, but explains it away. The Rationalistic, AEsthetic, and Speculative schools of Germany either reject it entirely, or partly put upon it an ethical or speculative construction. The revived Lutheran orthodoxy of the 19th century partly restricts itself to a mere revival of the old doctrine, and partly attempts to complete it by asserting a self-restriction of the divine nature in Christ, in consequence of his union with the human. According to this doctrine, which was in particular developed by Sartorius (Dorpater Beitrage zu den theologischen Wissenschaften, Hamburg, 1832) and Thomasius (Beitrage zur kirchlichen Christologie, Erlangen, 1845). the Lagos, from the moment of his incarnation, renounced his divine self-consciousness in order to develop himself in a merely human form. See, besides the works already mentioned, Dorner, History of the Person of Christ, Edinb. translation, vol. ii; Hase, Evangelische Dogmatik, p. 221 sq.; Gieseler, Church History, edited by Smith, vol. iv, § 37; Hagenbach, History of Doctrines (Smith's), § 266, 267; Pearson On the Creed, art. ii; and the article CHRISTOLOGY, p. 281.