Whether the Precepts of the Decalogue Should Have Included a Precept
of Prudence?
Objection 1: It would seem that the precepts of the decalogue should
have included a precept of prudence. For the chief precepts should
include a precept of the chief virtue. Now the chief precepts are
those of the decalogue. Since then prudence is the chief of the moral
virtues, it seems that the precepts of the decalogue should have
included a precept of prudence.
Obj. 2: Further, the teaching of the Gospel contains the Law
especially with regard to the precepts of the decalogue. Now the
teaching of the Gospel contains a precept of prudence (Matt. 10:16):
"Be ye . . . prudent [Douay: 'wise'] as serpents." Therefore the
precepts of the decalogue should have included a precept of prudence.
Obj. 3: Further, the other lessons of the Old Testament are directed
to the precepts of the decalogue: wherefore it is written (Malach.
4:4): "Remember the law of Moses My servant, which I commanded him in
Horeb." Now the other lessons of the Old Testament include precepts
of prudence; for instance (Prov. 3:5): "Lean not upon thy own
prudence"; and further on (Prov. 4:25): "Let thine eyelids go before
thy steps." Therefore the Law also should have contained a precept of
prudence, especially among the precepts of the decalogue.
The contrary however appears to anyone who goes through the precepts
of the decalogue.
_I answer that,_ As stated above (I-II, Q. 100, A. 3; A. 5, ad 1)
when we were treating of precepts, the commandments of the decalogue
being given to the whole people, are a matter of common knowledge to
all, as coming under the purview of natural reason. Now foremost
among the things dictated by natural reason are the ends of human
life, which are to the practical order what naturally known
principles are to the speculative order, as shown above (Q. 47, A.
6). Now prudence is not about the end, but about the means, as stated
above (Q. 47, A. 6). Hence it was not fitting that the precepts of
the decalogue should include a precept relating directly to prudence.
And yet all the precepts of the decalogue are related to prudence, in
so far as it directs all virtuous acts.
Reply Obj. 1: Although prudence is simply foremost among all the
moral virtues, yet justice, more than any other virtue, regards its
object under the aspect of something due, which is a necessary
condition for a precept, as stated above (Q. 44, A. 1; I-II, Q. 99,
AA. 1, 5). Hence it behooved the chief precepts of the Law, which are
those of the decalogue, to refer to justice rather than to prudence.
Reply Obj. 2: The teaching of the Gospel is the doctrine of
perfection. Therefore it needed to instruct man perfectly in all
matters relating to right conduct, whether ends or means: wherefore
it behooved the Gospel teaching to contain precepts also of prudence.
Reply Obj. 3: Just as the rest of the teaching of the Old Testament
is directed to the precepts of the decalogue as its end, so it
behooved man to be instructed by the subsequent lessons of the Old
Testament about the act of prudence which is directed to the means.
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