One Precept?

Objection 1: It would seem that the Old Law contains but one precept.
Because a law is nothing else than a precept, as stated above (Q. 90,
AA. 2, 3). Now there is but one Old Law. Therefore it contains but
one precept.

Obj. 2: Further, the Apostle says (Rom. 13:9): "If there be any other
commandment, it is comprised in this word: Thou shalt love thy
neighbor as thyself." But this is only one commandment. Therefore the
Old Law contained but one commandment.

Obj. 3: Further, it is written (Matt. 7:12): "All things . . .
whatsoever you would that men should do to you, do you also to them.
For this is the Law and the prophets." But the whole of the Old Law
is comprised in the Law and the prophets. Therefore the whole of the
Old Law contains but one commandment.

_On the contrary,_ The Apostle says (Eph. 2:15): "Making void the Law
of commandments contained in decrees": where he is referring to the
Old Law, as the gloss comments, on the passage. Therefore the Old Law
comprises many commandments.

_I answer that,_ Since a precept of law is binding, it is about
something which must be done: and, that a thing must be done, arises
from the necessity of some end. Hence it is evident that a precept
implies, in its very idea, relation to an end, in so far as a thing
is commanded as being necessary or expedient to an end. Now many
things may happen to be necessary or expedient to an end; and,
accordingly, precepts may be given about various things as being
ordained to one end. Consequently we must say that all the precepts
of the Old Law are one in respect of their relation to one end: and
yet they are many in respect of the diversity of those things that
are ordained to that end.

Reply Obj. 1: The Old Law is said to be one as being ordained to one
end: yet it comprises various precepts, according to the diversity of
the things which it directs to the end. Thus also the art of building
is one according to the unity of its end, because it aims at the
building of a house: and yet it contains various rules, according to
the variety of acts ordained thereto.

Reply Obj. 2: As the Apostle says (1 Tim. 1:5), "the end of the
commandment is charity"; since every law aims at establishing
friendship, either between man and man, or between man and God.
Wherefore the whole Law is comprised in this one commandment, "Thou
shalt love thy neighbor as thyself," as expressing the end of all
commandments: because love of o