the formal principle of life, for since "in
living things to be is to live," as the Philosopher says (De Anima
ii, 37), just as everything is formally by its form, so likewise the
body lives by the soul: in this way a body could not live by the
Word, Which cannot be the form of a body.
_______________________

SIXTH ARTICLE [III, Q. 2, Art. 6]

Whether the Human Nature Was United to the Word of God Accidentally?

Objection 1: It would seem that the human nature was united to the
Word of God accidentally. For the Apostle says (Phil. 2:7) of the Son
of God, that He was "in habit found as a man." But habit is
accidentally associated with that to which it pertains, whether habit
be taken for one of the ten predicaments or as a species of quality.
Therefore human nature is accidentally united to the Son of God.

Obj. 2: Further, whatever comes to a thing that is complete in being
comes to it accidentally, for an accident is said to be what can come
or go without the subject being corrupted. But human nature came to
Christ in time, Who had perfect being from eternity. Therefore it
came to Him accidentally.

Obj. 3: Further, whatever does not pertain to the nature or the
essence of a thing is its accident, for whatever is, is either a
substance or an accident. But human nature does not pertain to the
Divine Essence or Nature of the Son of God, for the union did not
take place in the nature, as was said above (A. 1). Hence the human
nature must have accrued accidentally to the Son of God.

Obj. 4: Further, an instrument accrues accidentally. But the human
nature was the instrument of the Godhead in Christ, for Damascene
says (De Fide Orth. iii, 15), that "the flesh of Christ is the
instrument of the Godhead." Therefore it seems that the human nature
was united to the Son of God accidentally.

_On the contrary,_ Whatever is predicated accidentally, predicates,
not substance, but quantity, or quality, or some other mode of being.
If therefore the human nature accrues accidentally, when we say
Christ is man, we do not predicate substance, but quality or
quantity, or some other mode of being, which is contrary to the
Decretal of Pope Alexander III, who says (Conc. Later. iii): "Since
Christ is perfect God and perfect man, what foolhardiness have some
to dare to affirm that Christ as man is not a substance?"

_I answer that,_ In evidence of this question we must know that two
heresies have arisen with regard to the myster