ody. Therefore grace is a quality.

_I answer that,_ As stated above (A. 1), there is understood to be an
effect of God's gratuitous will in whoever is said to have God's
grace. Now it was stated (Q. 109, A. 1) that man is aided by God's
gratuitous will in two ways: first, inasmuch as man's soul is moved
by God to know or will or do something, and in this way the
gratuitous effect in man is not a quality, but a movement of the
soul; for "motion is the act of the mover in the moved." Secondly,
man is helped by God's gratuitous will, inasmuch as a habitual gift
is infused by God into the soul; and for this reason, that it is not
fitting that God should provide less for those He loves, that they
may acquire supernatural good, than for creatures, whom He loves that
they may acquire natural good. Now He so provides for natural
creatures, that not merely does He move them to their natural acts,
but He bestows upon them certain forms and powers, which are the
principles of acts, in order that they may of themselves be inclined
to these movements, and thus the movements whereby they are moved by
God become natural and easy to creatures, according to Wis. 8:1: "she
. . . ordereth all things sweetly." Much more therefore does He
infuse into such as He moves towards the acquisition of supernatural
good, certain forms or supernatural qualities, whereby they may be
moved by Him sweetly and promptly to acquire eternal good; and thus
the gift of grace is a quality.

Reply Obj. 1: Grace, as a quality, is said to act upon the soul, not
after the manner of an efficient cause, but after the manner of a
formal cause, as whiteness makes a thing white, and justice, just.

Reply Obj. 2: Every substance is either the nature of the thing
whereof it is the substance or is a part of the nature, even as
matter and form are called substance. And because grace is above
human nature, it cannot be a substance or a substantial form, but is
an accidental form of the soul. Now what is substantially in God,
becomes accidental in the soul participating the Divine goodness, as
is clear in the case of knowledge. And thus because the soul
participates in the Divine goodness imperfectly, the participation of
the Divine goodness, which is grace, has its being in the soul in a
less perfect way than the soul subsists in itself. Nevertheless,
inasmuch as it is the expression or participation of the Divine
goodness, it is nobler than the nature of the soul, thou