QUESTION 80: OF THE APPETITIVE POWERS IN GENERAL
Next we consider the appetitive powers, concerning which there are four
heads of consideration: first, the appetitive powers in general; second,
sensuality; third, the will; fourth, the free-will. Under the first there
are two points of inquiry:
(1) Whether the appetite should be considered a special power of the
(2) Whether the appetite should be divided into intellectual and
sensitive as distinct powers?
Article 1: Whether the appetite is a special power of the soul?
Objection 1: It would seem that the appetite is not a special power of the
soul. For no power of the soul is to be assigned for those things which
are common to animate and to inanimate things. But appetite is common to
animate and inanimate things: since "all desire good," as the Philosopher
says (Ethic. i, 1). Therefore the appetite is not a special power of the
Objection 2: Further, powers are differentiated by their objects. But what we
desire is the same as what we know. Therefore the appetitive power is not
distinct from the apprehensive power.
Objection 3: Further, the common is not divided from the proper. But each
power of the soul desires some particular desirable thing---namely its
own suitable object. Therefore, with regard to this object which is the
desirable in general, we should not assign some particular power distinct
from the others, called the appetitive power.
On the contrary, The Philosopher distinguishes (De Anima ii, 3) the
appetitive from the other powers. Damascene also (De Fide Orth. ii, 22)
distinguishes the appetitive from the cognitive powers.
I answer that, It is necessary to assign an appetitive power to the
soul. To make this evident, we must observe that some inclination follows
every form: for example, fire, by its form, is inclined to rise, and to
generate its like. Now, the form is found to have a more perfect
existence in those things which participate knowledge than in those which
lack knowledge. For in those which lack knowledge, the form is found to
determine each thing only to its own being---that is, to its nature.
Therefore this natural form is followed by a natural inclination, which
is called the natural appetite. But in those things which have knowledge,
each one is determined to its own natural being by its natural form, in
such a manner that it is nevertheless receptive of the species of other
things: for example, sense receives the species of all things sensible,
and the intellect, of all things intelligible, so that the soul of man
is, in a way, all things by sense and intellect: and thereby, those
things that have knowledge, in a way, approach to a likeness to God, "in
Whom all things pre-exist," as Dionysius says (Div. Nom. v).
Therefore, as forms exist in those things that have knowledge in a
higher manner and above the manner of natural forms; so must there be in
them an inclination surpassing the natural inclination, which is called
the natural appetite. And this superior inclination belongs to the
appetitive power of the soul, through which the animal is able to desire
what it apprehends, and not only that to which it is inclined by its
natural form. And so it is necessary to assign an appetitive power to the
Reply to Objection 1: Appetite is found in things which have knowledge, above the
common manner in which it is found in all things, as we have said above.
Therefore it is necessary to assign to the soul a particular power.
Reply to Objection 2: What is apprehended and what is desired are the same in
reality, but differ in aspect: for a thing is apprehended as something
sensible or intelligible, whereas it is desired as suitable or good. Now,
it is diversity of aspect in the objects, and not material diversity,
which demands a diversity of powers.
Reply to Objection 3: Each power of the soul is a form or nature, and has a
natural inclination to something. Wherefore each power desires by the
natural appetite that object which is suitable to itself. Above which
natural appetite is the animal appetite, which follows the apprehension,
and by which something is desired not as suitable to this or that power,
such as sight for seeing, or sound for hearing; but simply as suitable to
Article 2: Whether the sensitive and intellectual appetites are distinct powers?
Objection 1: It would seem that the sensitive and intellectual appetites are
not distinct powers. For powers are not differentiated by accidental
differences, as we have seen above (Question , Article ). But it is accidental to
the appetible object whether it be apprehended by the sense or by the
intellect. Therefore the sensitive and intellectual appetites are not
Objection 2: Further, intellectual knowledge is of universals; and so it is
distinct from sensitive knowledge, which is of individual things. But
there is no place for this distinction in the appetitive part: for since
the appetite is a movement of the soul to individual things, seemingly
every act of the appetite regards an individual thing. Therefore the
intellectual appetite is not distinguished from the sensitive.
Objection 3: Further, as under the apprehensive power, the appetitive is
subordinate as a lower power, so also is the motive power. But the motive
power which in man follows the intellect is not distinct from the motive
power which in animals follows sense. Therefore, for a like reason,
neither is there distinction in the appetitive part.
On the contrary, The Philosopher (De Anima iii, 9) distinguishes a
double appetite, and says (De Anima iii, 11) that the higher appetite
moves the lower.
I answer that, We must needs say that the intellectual appetite is a
distinct power from the sensitive appetite. For the appetitive power is a
passive power, which is naturally moved by the thing apprehended:
wherefore the apprehended appetible is a mover which is not moved, while
the appetite is a mover moved, as the Philosopher says in De Anima iii,
10 and Metaph. xii (Did. xi, 7). Now things passive and movable are
differentiated according to the distinction of the corresponding active
and motive principles; because the motive must be proportionate to the
movable, and the active to the passive: indeed, the passive power itself
has its very nature from its relation to its active principle. Therefore,
since what is apprehended by the intellect and what is apprehended by
sense are generically different; consequently, the intellectual appetite
is distinct from the sensitive.
Reply to Objection 1: It is not accidental to the thing desired to be apprehended
by the sense or the intellect; on the contrary, this belongs to it by its
nature; for the appetible does not move the appetite except as it is
apprehended. Wherefore differences in the thing apprehended are of
themselves differences of the appetible. And so the appetitive powers are
distinct according to the distinction of the things apprehended, as their
Reply to Objection 2: The intellectual appetite, though it tends to individual
things which exist outside the soul, yet tends to them as standing under
the universal; as when it desires something because it is good.
Wherefore the Philosopher says (Rhetoric. ii, 4) that hatred can regard a
universal, as when "we hate every kind of thief." In the same way by the
intellectual appetite we may desire the immaterial good, which is not
apprehended by sense, such as knowledge, virtue, and suchlike.