The Enchiridion 35
35 Jesus Christ, Being the Only Son of God, is at the Same Time Man PL 40, 249
Wherefore Christ Jesus, the Son of God, is both God and man; God before all worlds; man in our world: God, because the Word of God (for “the Word was God”); and man, because in His one person the Word was joined with a body and a rational soul. Wherefore, so far as He is God, He and the Father are one; so far as He is man, the Father is greater than He. For when He was the only Son of God, not by grace, but by nature, that He might be also full of grace, He became the Son of man; and He Himself unites both natures in His own identity, and both natures constitute one Christ; because, “being in the form of God, He thought it not robbery to be,” what He was by nature, “equal with God.” But He made Himself of no reputation, and took upon Himself the form of a servant, not losing or lessening the form of God. And, accordingly, He was both made less and remained equal, being both in one, as has been said: but He was one of these as Word, and the other as man. As Word, He is equal with the Father; as man, less than the Father. One Son of God, and at the same time Son of man; one Son of man, and at the same time Son of God; not two Sons of God, God and man, but one Son of God: God without beginning; man with a beginning, our Lord Jesus Christ.
Christus Deus simul et homo. Contra errorem qui Leporii, et postea Nestorianorum fuit. Proinde Christus Jesus Dei Filius, est et Deus et homo. Deus ante omnia saecula, homo in nostro saeculo. Deus, quia Dei Verbum; Deus enim erat Verbum : homo autem, quia in unitatem personae accessit Verbo anima rationalis et caro. Quocirca in quantum Deus est, ipse et Pater unum sunt : in quantum autem homo est, Pater major est illo . Cum enim esset unicus Dei Filius, non gratia, sed natura, ut esset etiam plenus gratia, factus est et hominis filius: idemque ipse utrumque ex utroque unus Christus. Quia cum in forma Dei esset, non rapinam arbitratus est, quod natura erat, id est, esse aequalis Deo. Exinanivit autem se, accipiens formam servi , non amittens vel minuens formam Dei. Ac per hoc et minor est factus, et mansit aequalis, utrumque unus, sicut dictum est: sed aliud propter Verbum, aliud propter hominem: propter Verbum aequalis Patri, propter hominem minor. Unus Dei Filius, idemque hominis filius; unus hominis filius, idemque Dei Filius: non duo filii Dei Deus et homo, sed unus Dei Filius; Deus sine initio, homo a certo initio, Dominus noster Jesus Christus.