Is the natural law a habit [of the
It seems that the natural law is a
habit [of the soul]:
As the Philosopher says in Ethics 2, “There are
three sorts of things in the soul: powers, habits, and
passions.” But as is clear from going through each of
these one by one, the natural law is not one of the powers
of the soul or one of the passions. Therefore, the
natural law is a habit.
Basil says, “Conscience (conscientia) or synderesis
(synderesis) is our intellect’s law”—and by this he
cannot mean anything other than the natural law. But as
was established in the First Part (ST 1, q. 79, a.
12), synderesis is a certain habit. Therefore, the
natural law is a habit.
As will be shown below (a. 6), the natural law remains
within a man always. But a man’s reason, which is what
the law has to do with, is not always actually thinking
about the natural law. Therefore, the natural law is a
habit and not an act.
But contrary to this:
In De Bono Coniugali Augustine says, “A habit is
that by means of which something is done when there is
need.” But the natural law is not like this, since it
exists even in children and in the damned, who cannot act
through it. Therefore, the natural law is not a habit.
There are two senses in which something can be called
In the first sense, something is called a habit properly
and essentially, and in this sense the natural law
is not a habit. For it was explained above (q.
90, a. 1) that the natural law is something constituted
by reason, in the same way that a proposition is a work
of reason. But what someone does or makes
is not the same as that by means of which he
does it or makes it. For instance, it is by means
of the habit of grammar that someone makes a coherent
utterance. Therefore, since a habit is that
by means of which one acts, no sort of law can be
a habit properly and essentially.
the second sense, that which is had by means
of a habit can itself be called the habit—in the way
that the Faith is that which is held by means of faith.
And since the precepts of the natural law are such that
even though at times they are actually being considered
by reason, at other times they exist only habitually
in reason, one can say in this sense that the natural
law is a habit. In the same way, the indemonstrable
principles in speculative matters are not the habit
itself with respect to the principles; rather, they
are principles with respect to which there is a habit.
Reply to objection 1:
In this passage the Philosopher means to be looking for
the genus of virtue, and since it is clear that a
virtue is a principle of acts, he proposes only the sorts
of things that serve as the principles of human acts,
viz., powers, habits, and passions. However, besides
these three, there are other sorts of things that exist in
the soul. For instance, certain kinds of acts exist in
the soul, e.g., an act of willing exists in one who wills;
(b) again, things that are known exist in the one who
knows them; and (c) the natural properties of the soul
exist in the soul, e.g., immortality and others of this
Reply to objection 2:
Synderesis is called our intellect’s law because it is a
habit containing the precepts of the natural law, which
are first principles of human works.
Reply to objection 3:
The conclusion of this argument is that the natural law is
had in a habitual manner. This we concede.
Reply to argument for the contrary:
By the very fact that something exists habitually in a
man, he is sometimes be unable to make use of it because
of an impediment. For instance, a man who is sleeping
cannot make use of his habit of grasping [first]
principles (intellectus). In the same way, a young
child cannot make use of the habit of grasping [first]
principles or, again, make use of the natural law, which
exists in him habitually, because he is not the right age.