many precepts of the natural
law, it would follow that there are also many natural laws.

Obj. 2: Further, the natural law is consequent to human nature. But
human nature, as a whole, is one; though, as to its parts, it is
manifold. Therefore, either there is but one precept of the law of
nature, on account of the unity of nature as a whole; or there are
many, by reason of the number of parts of human nature. The result
would be that even things relating to the inclination of the
concupiscible faculty belong to the natural law.

Obj. 3: Further, law is something pertaining to reason, as stated
above (Q. 90, A. 1). Now reason is but one in man. Therefore there is
only one precept of the natural law.

_On the contrary,_ The precepts of the natural law in man stand in
relation to practical matters, as the first principles to matters of
demonstration. But there are several first indemonstrable principles.
Therefore there are also several precepts of the natural law.

_I answer that,_ As stated above (Q. 91, A. 3), the precepts of the
natural law are to the practical reason, what the first principles of
demonstrations are to the speculative reason; because both are
self-evident principles. Now a thing is said to be self-evident in
two ways: first, in itself; secondly, in relation to us. Any
proposition is said to be self-evident in itself, if its predicate is
contained in the notion of the subject: although, to one who knows
not the definition of the subject, it happens that such a proposition
is not self-evident. For instance, this proposition, "Man is a
rational being," is, in its very nature, self-evident, since who says
"man," says "a rational being": and yet to one who knows not what a
man is, this proposition is not self-evident. Hence it is that, as
Boethius says (De Hebdom.), certain axioms or propositions are
universally self-evident to all; and such are those propositions
whose terms are known to all, as, "Every whole is greater than its
part," and, "Things equal to one and the same are equal to one
another." But some propositions are self-evident only to the wise,
who understand the meaning of the terms of such propositions: thus to
one who understands that an angel is not a body, it is self-evident
that an angel is not circumscriptively in a place: but this is not
evident to the unlearned, for they cannot grasp it.

Now a certain order is to be found in those things that are
apprehended universally. For tha