Whether One Power of the Soul Arises from Another?
Objection 1: It would seem that one power of the soul does not arise
from another. For if several things arise together, one of them does
not arise from another. But all the powers of the soul are created at
the same time with the soul. Therefore one of them does not arise from
another.
Obj. 2: Further, the power of the soul arises from the soul as an
accident from the subject. But one power of the soul cannot be the
subject of another; because nothing is the accident of an accident.
Therefore one power does not arise from another.
Obj. 3: Further, one opposite does not arise from the other opposite;
but everything arises from that which is like it in species. Now the
powers of the soul are oppositely divided, as various species.
Therefore one of them does not proceed from another.
_On the contrary,_ Powers are known by their actions. But the action
of one power is caused by the action of another power, as the action
of the imagination by the action of the senses. Therefore one power
of the soul is caused by another.
_I answer that,_ In those things which proceed from one according to
a natural order, as the first is the cause of all, so that which is
nearer to the first is, in a way, the cause of those which are more
remote. Now it has been shown above (A. 4) that among the powers of
the soul there are several kinds of order. Therefore one power of the
soul proceeds from the essence of the soul by the medium of another.
But since the essence of the soul is compared to the powers both as a
principle active and final, and as a receptive principle, either
separately by itself, or together with the body; and since the agent
and the end are more perfect, while the receptive principle, as such,
is less perfect; it follows that those powers of the soul which
precede the others, in the order of perfection and nature, are the
principles of the others, after the manner of the end and active
principle. For we see that the senses are for the sake of the
intelligence, and not the other way about. The senses, moreover, are
a certain imperfect participation of the intelligence; wherefore,
according to their natural origin, they proceed from the intelligence
as the imperfect from the perfect. But considered as receptive
principles, the more perfect powers are principles with regard to the
others; thus the soul, according as it has the sensitive power, is
considered as the subject, and as something material with regard to
the intelligence. On this account, the more imperfect powers precede
the others in the order of generation, for the animal is generated
before the man.
Reply Obj. 1: As the power of the soul flows from the essence, not
by a transmutation, but by a certain natural resultance, and is
simultaneous with the soul, so is it the case with one power as
regards another.
Reply Obj. 2: An accident cannot of itself be the subject of an
accident; but one accident is received prior to another into
substance, as quantity prior to quality. In this sense one accident
is said to be the subject of another; as surface is of color,
inasmuch as substance receives an accident through the means of
another. The same thing may be said of the powers of the soul.
Reply Obj. 3: The powers of the soul are opposed to one another, as
perfect and imperfect; as also are the species of numbers and
figures. But this opposition does not prevent the origin of one from
another, because imperfect things naturally proceed from perfect
things.
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