III. Incarnation defined; personal subsistence communicated to the assumed nature
III. Incarnation is that by which the eternal Son of God, human nature having been assumed into the unity of person, at a definite time was made human from a woman, that He might act as mediator between God and humans. Its foundations are shown in Psalm 45:7; Isaiah 7:14; 1 Peter 1:20; John 1:14; Matthew 1:21 and 16:16; Galatians 4:4; 1 John 4:2; 1 Timothy 2:5; Hebrews 2:14. Of this grace the Apostle asserts in 1 Timothy 3:16 that it is the great mystery of godliness.
This incarnation, as we learn from the Scriptures, took place thus: the Holy Spirit coming upon the blessed virgin Mary and the power of the Most High overshadowing her, she conceived and bore the Son of God — that is, an individual and singular human nature, which without male seed, by the omnipotent power common to the Son with the Father and the Holy Spirit, the virgin had conceived, and which the Son assumed into the unity of person, or, what amounts to the same, personally united to Himself and communicated to that human nature the ultimate substantial term and degree by which an intelligent nature is completed in the category of being
For since a person is a rational nature as incommunicable substance, we call personality that very thing by which a person is constituted in the ultimate and complete personal being, and by which it is made incommunicable. Such personality the nature conceived from the virgin could have had of itself; but lest there be two persons rather than one, the Son of God therefore communicated His own to it and terminated the assumed nature by His first and intimate personal perfection, completed it substantially, and constituted it in the ultimate hypostatic and incommunicable being.
Latin
III. Incarnatio est, qua aeternus Dei Filius, natura humana in unitatem personae assumpta, definito tempore e muliere homo factus est, ut inter Deum & homines mediatorem ageret. Huius fundamenta exhibent Psal. 45:8; Esa. 7:14; 1 Pet. 1:20; Ioh. 1:14; Matth. 1:21 & 16:16; Gal. 4:4; 1 Ioh. 4:2; 1 Tim. 2:5; Hebr. 2:14. De hac gratia Apostolus 1 Tim. 3:16 asserit, quod sit magnum pietatis mysterium. Haec autem incarnatio ita facta est, quantum e scripturis discimus, ut superveniente in beatam virginem Mariam Spiritu sancto, & inumbrante eam virtute altissimi, ipsa conceperit atque pepererit Filium Dei, naturam videlicet humanam, individuam & singularem, quam sine virili semine, per omnipotentem virtutem ipsi Filio cum Patre & Spiritu sancto communem, virgo conceperat, Filius in unitatem personae assumpsit, sive, quod idem pollet, personaliter sibi univit & naturae illi humanae communicavit terminum & gradum ultimum substantialem, quo natura intelligens in genere substantiae completur. Cum enim persona sit rationalis natura incommunicabilis substantia, personalitatem nos dicimus id ipsum quo persona constituitur in esse personali ultimo & completo, & quo incommunicabilis efficitur. Talem personalitatem natura ex virgine concepta ex sese habere potuisset; at ne duae personae essent, sed una, idcirco Filius Dei suam propriam ei communicavit & assumptam naturam sua prima & intima perfectione personali terminavit, substantialiter complevit, atque in esse ultimo hypostatico & incommunicabili constituit.