is cannot be said of charity, for even the slightest
charity extends to all that we have to love by charity. Hence the
addition which causes an increase of charity cannot be understood, as
though the added charity were presupposed to be distinct specifically
from that to which it is added.

It follows therefore that if charity be added to charity, we must
presuppose a numerical distinction between them, which follows a
distinction of subjects: thus whiteness receives an increase when one
white thing is added to another, although such an increase does not
make a thing whiter. This, however, does not apply to the case in
point, since the subject of charity is none other than the rational
mind, so that such like an increase of charity could only take place
by one rational mind being added to another; which is impossible.
Moreover, even if it were possible, the result would be a greater
lover, but not a more loving one. It follows, therefore, that charity
can by no means increase by addition of charity to charity, as some
have held to be the case.

Accordingly charity increases only by its subject partaking of
charity more and more subject thereto. For this is the proper mode of
increase in a form that is intensified, since the being of such a
form consists wholly in its adhering to its subject. Consequently,
since the magnitude of a thing follows on its being, to say that a
form is greater is the same as to say that it is more in its subject,
and not that another form is added to it: for this would be the case
if the form, of itself, had any quantity, and not in comparison with
its subject. Therefore charity increases by being intensified in its
subject, and this is for charity to increase in its essence; and not
by charity being added to charity.

Reply Obj. 1: Bodily quantity has something as quantity, and
something else, in so far as it is an accidental form. As quantity,
it is distinguishable in respect of position or number, and in this
way we have the increase of magnitude by addition, as may be seen in
animals. But in so far as it is an accidental form, it is
distinguishable only in respect of its subject, and in this way it
has its proper increase, like other accidental forms, by way of
intensity in its subject, for instance in things subject to
rarefaction, as is proved in _Phys._ iv, 9. In like manner science,
as a habit, has its quantity from its objects, and accordingly it
increases by addition, when a man