ll. Thus it
is right and true for all to act according to reason: and from this
principle it follows as a proper conclusion, that goods entrusted to
another should be restored to their owner. Now this is true for the
majority of cases: but it may happen in a particular case that it
would be injurious, and therefore unreasonable, to restore goods held
in trust; for instance, if they are claimed for the purpose of
fighting against one's country. And this principle will be found to
fail the more, according as we descend further into detail, e.g. if
one were to say that goods held in trust should be restored with such
and such a guarantee, or in such and such a way; because the greater
the number of conditions added, the greater the number of ways in
which the principle may fail, so that it be not right to restore or
not to restore.

Consequently we must say that the natural law, as to general
principles, is the same for all, both as to rectitude and as to
knowledge. But as to certain matters of detail, which are
conclusions, as it were, of those general principles, it is the same
for all in the majority of cases, both as to rectitude and as to
knowledge; and yet in some few cases it may fail, both as to
rectitude, by reason of certain obstacles (just as natures subject to
generation and corruption fail in some few cases on account of some
obstacle), and as to knowledge, since in some the reason is perverted
by passion, or evil habit, or an evil disposition of nature; thus
formerly, theft, although it is expressly contrary to the natural
law, was not considered wrong among the Germans, as Julius Caesar
relates (De Bello Gall. vi).

Reply Obj. 1: The meaning of the sentence quoted is not that whatever
is contained in the Law and the Gospel belongs to the natural law,
since they contain many things that are above nature; but that
whatever belongs to the natural law is fully contained in them.
Wherefore Gratian, after saying that "the natural law is what is
contained in the Law and the Gospel," adds at once, by way of
example, "by which everyone is commanded to do to others as he would
be done by."

Reply Obj. 2: The saying of the Philosopher is to be understood of
things that are naturally just, not as general principles, but as
conclusions drawn from them, having rectitude in the majority of
cases, but failing in a few.

Reply Obj. 3: As, in man, reason rules and commands the other powers,
so all the natural inclinati