nd partly to some extrinsic principle:
in one way, indeed, in the apprehensive powers; in another way, in
the appetitive powers. For in the apprehensive powers there may be a
natural habit by way of a beginning, both in respect of the specific
nature, and in respect of the individual nature. This happens with
regard to the specific nature, on the part of the soul itself: thus
the understanding of first principles is called a natural habit. For
it is owing to the very nature of the intellectual soul that man,
having once grasped what is a whole and what is a part, should at
once perceive that every whole is larger than its part: and in like
manner with regard to other such principles. Yet what is a whole, and
what is a part--this he cannot know except through the intelligible
species which he has received from phantasms: and for this reason,
the Philosopher at the end of the _Posterior Analytics_ shows that
knowledge of principles comes to us from the senses.

But in respect of the individual nature, a habit of knowledge is
natural as to its beginning, in so far as one man, from the
disposition of his organs of sense, is more apt than another to
understand well, since we need the sensitive powers for the operation
of the intellect.

In the appetitive powers, however, no habit is natural in its
beginning, on the part of the soul itself, as to the substance of the
habit; but only as to certain principles thereof, as, for instance,
the principles of common law are called the "nurseries of virtue."
The reason of this is because the inclination to its proper objects,
which seems to be the beginning of a habit, does not belong to the
habit, but rather to the very nature of the powers.

But on the part of the body, in respect of the individual nature,
there are some appetitive habits by way of natural beginnings. For
some are disposed from their own bodily temperament to chastity or
meekness or such like.

Reply Obj. 1: This objection takes nature as divided against reason
and will; whereas reason itself and will belong to the nature of man.

Reply Obj. 2: Something may be added even naturally to the nature of
a power, while it cannot belong to the power itself. For instance,
with regard to the angels, it cannot belong to the intellective power
itself capable of knowing all things: for thus it would have to be
the act of all things, which belongs to God alone. Because that by
which something is known, must needs be the ac