Was it necessary for there to be
such a thing as divine law?
It seems to have been unnecessary for
there to be such a thing as divine law:
Objection 1: As has been
explained (a. 2), natural law is within us a kind of
participation in eternal law. But as has been said (a.
1), eternal law is a divine law. Therefore, it is
unnecessary for there to be a divine law in addition to
natural law and the human laws that stem from it.
Ecclesiasticus 15:14 says, “God left man in the hand of
his own counsel.” But as was established above (q., 14,
a. 1), counsel is an act of reason. Therefore, man was
left to the governance provided by his own reason. But as
has been explained (a. 3), a dictate of human reason is
human law. Therefore, it is unnecessary for man to be
governed by some other divine law.
Human nature is more self-sufficient than non‑rational
creatures. But a non‑rational creature does not have any
divine law in addition to the natural inclination that has
been instilled in it. Therefore, a fortiori, a
rational creature should not have any divine law in
addition to natural law.
But contrary to this:
David asked God for a law to be imposed on him, saying,
“Set before me for a law the way of Your justifications, O
Lord” (Psalm 118:33).
In addition to natural law and human law, it was necessary
for us to have divine law in order to direct human life—and
this for four reasons:
First, through law man is directed to his own acts in
relation to the ultimate end. And if man were
ordered just to an end that is not disproportionate
to man’s natural power, then it would be unnecessary
for man to have any directive from reason in addition
to natural law and the humanly posited law that stems
from it. However, since, as was established above
(q. 5, a. 5), man is ordered to the end of eternal beatitude,
which is disproportionate to natural human power, it
was necessary that, in addition to natural law and human
law, he should also be directed to his end by a law
that is divinely given.
Second, due to the uncertainty of human judgment, especially
about contingent and particular matters, different people
can make diverse judgments about human acts, and these
diverse judgments lead to diverse and contrary laws.
Therefore, in order that man might be able to know without
any hesitation what he should do and what he should
avoid doing, it was necessary that he be directed in
his proper acts by a law that is divinely given and
is clearly such that it cannot be mistaken.
Third, man is able to make law with respect to those
things which he is in a position to make judgments about.
But human judgments cannot encompass interior movements,
which are hidden, but only exterior acts, which are
observable. Yet for the perfection of virtue it
is required that a man be upright with respect to both
sorts of acts. So human law was unable to restrain
and to order interior acts adequately, and divine law
had to be added for this purpose.
Fourth, as Augustine says in De Libero Arbitrio
1, human law is incapable of prohibited or punishing
all evil deeds. For if it tried to do away with
all evils, many goods would likewise be destroyed as
a result, and the benefits of the common good, which
is necessary for human living, would be impeded.
Therefore, in order that no evil would remain unforbidden
and unpunished, it was necessary that there should be,
in addition, a divine law by which all sins would be
These four reasons
are touched on in Psalm 18:8, where it says, “The law
of the Lord is unspotted ....,” i.e., does not permit
any foulness of sin; “..... converting souls ....,”
since it directs not just exterior acts, but interior
acts as well; “..... the testimony of the Lord is faithful
.....,” because of the certitude of what is true and
of upright; “..... giving wisdom to the little ones,”
insofar as it orders man to his supernatural and divine
Reply to objection 1:
Natural law participates in eternal law in a way
proportioned to the power of human nature. But man has to
be directed in a deeper way to his ultimate supernatural
end. And so there is, in addition, a divinely given law,
through which eternal law is participated in more deeply.
Reply to objection 2:
Counsel is a certain sort of inquiry, and so it must
proceed from given principles. But it is not enough that
it should proceed from naturally instilled principles,
i.e., from the precepts of the natural law—and this for
the [four] reasons explained above. Rather, it is
necessary that certain other principles should be added,
viz., the precepts of divine law.
Reply to objection 3:
Non‑rational creatures are not ordered to a higher end
than the end that is proportioned to their natural power.
And so the arguments are not parallel.