Do all the acts of the virtues
belong to the law of nature?
It seems that not all the acts of
the virtues belong to the law of nature:
Objection 1: As was
explained above (q. 90, a. 2), it is part of the notion
of law that it is ordered toward the common good.
But as is especially clear in the case of acts of temperance,
some acts of the virtues are ordered toward the individual’s
private good. Therefore, not all the acts of the
virtues fall under the natural law.
All sins are opposed to some virtuous act or other.
Therefore, if all the acts of the virtues belonged to the
law of nature, then, as a result, all sins would seem to
be contrary to nature. But this is said specifically
[only] of certain sins.
All share in those things which are in accord with
nature. But it is not the case that all share in acts of
the virtues, since something that is virtuous for one
person is vicious for another. Therefore, not all the
acts of the virtues belong to the law of nature.
But contrary to this:
In [De Fide Orthodoxa] 3 Damascene says, “The
virtues are natural.” Therefore, virtuous acts likewise
fall under the law of nature.
We can speak of virtuous acts in two ways: (a)
first, insofar as they are virtuous and (b) second,
insofar as they are acts of certain kinds considered
in their own proper species.
Thus, if we are speaking of the acts of the virtues
insofar as they are virtuous, then in this sense all
the acts of the virtues belong to the law of nature.
For it was explained above (a. 2) that everything toward
which man is inclined in accord with his nature belongs
to the law of nature. But every entity is naturally
inclined toward action which is appropriate for it in
light of its form, in the way that fire is naturally
inclined to give warmth. Hence, since the rational
soul is the proper form of man, every man has a natural
inclination toward acting in accord with reason—which
is just to act in accord with virtue. Hence, in
this sense all the acts of the virtues belong to the
natural law, since the faculty of reason proper to each
man dictates by nature that he act virtuously.
contrast, if we are speaking of virtuous acts in their
own right, i.e., insofar as they are considered in their
own proper species, then in this sense not all virtuous
acts belong to the natural law. For many things
done in accord with virtue are such that nature does
not incline one toward them in the primary sense; rather,
it is through reasoned inquiry that men have discovered
these things to be, as it were, advantageous to living
Reply to objection 1:
Temperance has to do with sensory desires for food and
drink and sexual pleasure, all of which are ordered toward
the common good of nature, just as other matters
pertaining to the law are likewise ordered toward the
common moral good.
Reply to objection 2:
By ‘nature of man’ one can mean either (a) those things
that are proper to man, and in this sense all sins, since
they are contrary to reason, are likewise contrary to
nature, as is clear from Damascene [in De Fide
Orthodoxa] 2; or (b) those things that are common to
man and the other animals, and in this sense certain
specific sins are said to be contrary to nature; for
instance, sexual intercourse between males is contrary to
the sexual union between male and female, which is natural
to all animals, and is in a special sense called a vice
contrary to nature.
Reply to objection 3:
This argument has to do with acts considered in their own
right. For in this sense, because of the diverse
conditions men find themselves in, it happens that some
acts are virtuous for some people in the sense of being
proportioned to and suitable for them, which are
nonetheless vicious for others in the sense of not being
proportioned to them.