Do all the moral precepts of the Old
Law belong to the law of nature?
It seems that not all the moral precepts
[of the Old Law] belong to the law of nature:
Objection 1: Ecclesiasticus
17:9 says, “He gave them teaching, and the law of life
for an inheritance.” But teaching (doctrina)
is distinct from the law of nature, since the law of
nature is not taught, but is instead had by natural
instinct (ex naturali instinctu). Therefore,
not all the moral precepts belong to the law of nature.
Divine law is more perfect than human law. But human law
adds some things pertaining to good morals to what belongs
to the law of nature; this is clear from the fact that the
law of nature is the same for everyone, whereas diverse
moral practices have been instituted among diverse
peoples. Therefore, a fortiori, it was fitting for
divine law to add some things pertaining to good morals
over and beyond the law of nature.
Just as reason induces men to good morals, so too does
faith; hence, Galatians 5:6 says, “Faith works through
love.” But faith is not included in the law of nature,
since what belongs to the Faith lies beyond natural
reason. Therefore, not every moral precept of divine law
belongs to the law of nature.
But contrary to this:
In Romans 2:14 the Apostle says, “The Gentiles, who have
not the Law, do by nature those things that are of the
Law.” This has to be understood as referring to things
that have to do with good morals. Therefore, all the
moral precepts of the Law belong to the law of nature.
The moral precepts—as opposed to the ceremonial and
judicial precepts—concern things that in their own right
(secundum se) have to do with good morals.
Now since human morals are set apart by their relation
to reason, which is the proper principle of human acts,
morals are called good when they are consonant with
reason and bad when they are at variance with reason.
And just as every judgment of speculative reason stems
from the natural cognition of first principles, so too,
as was explained above (q. 94, a. 2), every judgment
of practical reason stems from naturally known principles
on the basis of which one can proceed to make judgments
in various ways about various matters.
For instance, among human acts there are some so clear
that they can immediately, with very little consideration,
be approved of or disapproved of on the basis of these
general first principles.
By contrast, there are others such that judging them
requires an extensive consideration of various circumstances
that only the wise, and not just anyone, can carefully
investigate—in the way that the role of investigating
the particular conclusions of the sciences falls only
to the philosophers and not to just anyone.
Lastly, there are some acts such that in order for a
man to pass judgment on them, he needs to be assisted
by divine teaching. This is the cases with the
things that have to be taken on faith (credenda).
So, then, it is clear that since (a) the moral precepts
concern matters that belong to good morals, and (b)
these good morals are consonant with reason, and (c)
every one of human reason’s judgments stems in some
way or other from natural reason, it must be the case
that all the moral precepts belong to the law of nature—though
in different ways.
For there are some precepts of a sort that every man’s
natural reason judges immediately and per se
that such‑and‑such should be done or should
not be done, e.g., “Honor your father and your mother,”
“You shall not kill,” and “You shall not steal” (Exodus
20:12‑15). Precepts of this sort belong
to the law of nature absolutely speaking.
But other precepts are such that it is the wise who,
after a more subtle investigation by reason, judge that
they should be observed. And these precepts belong
to the law of nature, but in such a way that they require
the sort of teaching by which the young are instructed
by the wise—e.g., “Stand up in the presence of a hoary
head, and honor the elderly person” (Leviticus 19:32),
and others of this sort.
there are other precepts such that in order to make
a judgment about them, human reason needs divine instruction,
through which we learn about divine things, e.g., “You
shall not make for yourself a graven image, nor any
likeness ..... nor shall you take the name of your God
in vain” (Exodus 20:4,7).
Reply to objection 1 and objection 2
and objection 3: The
replies to the objections are clear from has been said.