29 There is another enemy of the faith of Chalcedon, widely diffused outside the fold of the Catholic religion. This is an opinion for which a rashly and falsely understood sentence of St. Paul's Epistle to the Philippians (ii, 7), supplies a basis and a shape. This is called the kenotic doctrine, and according to it, they imagine that the divinity was taken away from the Word in Christ. It is a wicked invention, equally to be condemned with the Docetism opposed to it. It reduces the whole mystery of the Incarnation and Redemption to empty the bloodless imaginations. 'With the entire and perfect nature of man' - thus grandly St. Leo the Great - 'He Who was true God was born, complete in his own nature, complete in ours' ( Ep . xxviii, 3. PL . liv, 763. Cf. Serm . xxiii, 2. PL . lvi, 201).
Source: Sempiternus Rex Christus (Vatican.va)