Of the Appetitive Powers in General

Of the Appetitive Powers in General — St. Thomas Aquinas asks: Whether the appetite is a special power of the soul?; Whether the sensitive and intellectual appetites are distinct powers?.

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:

Article 1: Whether the appetite is a special power of the soul?

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.

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 soul.

Article 2: Whether the sensitive and intellectual appetites are distinct powers?

The Philosopher (De Anima iii, 9) distinguishes a double appetite, and says (De Anima iii, 11) that the higher appetite moves the lower.

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.