Communicatio idiomatum

Communicatio idiomatum (Latin: communication of properties) is a Christological concept about the interaction of deity and humanity in the person of Jesus Christ. It maintains that in view of the unity of Christ's person, his human and divine attributes and experiences might properly be referred to his other nature so that the theologian may speak of "the suffering of God".

The germ of the idea is first found in Ignatius of Antioch (c. AD 100) but the development of an adequate, agreed technical vocabulary only took place in the fifth century with the First Council of Ephesus in 431 and the Council of Chalcedon twenty years later and the approval of the doctrine of the hypostatic union of the two distinct natures of Christ. In the sixteenth century, the Reformed and Lutheran churches disagreed with each other on this question.

The philosopher J. G. Hamann argued that the communicatio idiomatum applies not just to Christ, but should be generalised to cover all human action: "This communicatio of divine and human idiomatum is a fundamental law and the master-key of all our knowledge and of the whole visible economy."