Aquin.: SMT FP Q[78] Out. Para. 1/2

OF THE SPECIFIC POWERS OF THE SOUL (FOUR ARTICLES)

 We next treat of the powers of the soul specifically. The theologian, 
however, has only to inquire specifically concerning the intellectual and 
appetitive powers, in which the virtues reside. And since the knowledge 
of these powers depends to a certain extent on the other powers, our 
consideration of the powers of the soul taken specifically will be 
divided into three parts: first, we shall consider those powers which are 
a preamble to the intellect; secondly, the intellectual powers; thirdly, 
the appetitive powers.

Aquin.: SMT FP Q[78] Out. Para. 2/2

 Under the first head there are four points of inquiry:

 (1) The powers of the soul considered generally;

 (2) The various species of the vegetative part;

 (3) The exterior senses;

 (4) The interior senses.


Aquin.: SMT FP Q[78] A[1] Thes. Para. 1/1

Whether there are to be distinguished five genera of powers in the soul?

Aquin.: SMT FP Q[78] A[1] Obj. 1 Para. 1/1

 OBJ 1: It would seem that there are not to be distinguished five genera 
of powers in the soul---namely, vegetative, sensitive, appetitive, 
locomotive, and intellectual. For the powers of the soul are called its 
parts. But only three parts of the soul are commonly assigned---namely, 
the vegetative soul, the sensitive soul, and the rational soul. Therefore 
there are only three genera of powers in the soul, and not five.

Aquin.: SMT FP Q[78] A[1] Obj. 2 Para. 1/1

 OBJ 2: Further, the powers of the soul are the principles of its vital 
operations. Now, in four ways is a thing said to live. For the 
Philosopher says (De Anima ii, 2): "In several ways a thing is said to 
live, and even if only one of these is present, the thing is said to 
live; as intellect and sense, local movement and rest, and lastly, 
movement of decrease and increase due to nourishment." Therefore there 
are only four genera of powers of the soul, as the appetitive is excluded.

Aquin.: SMT FP Q[78] A[1] Obj. 3 Para. 1/1

 OBJ 3: Further, a special kind of soul ought not to be assigned as 
regards what is common to all the powers. Now desire is common to each 
power of the soul. For sight desires an appropriate visible object; 
whence we read (Ecclus. 40:22): "The eye desireth favor and beauty, but 
more than these green sown fields." In the same way every other power 
desires its appropriate object. Therefore the appetitive power should not 
be made a special genus of the powers of the soul.

Aquin.: SMT FP Q[78] A[1] Obj. 4 Para. 1/1

 OBJ 4: Further, the moving principle in animals is sense, intellect or 
appetite, as the Philosopher says (De Anima iii, 10). Therefore the 
motive power should not be added to the above as a special genus of soul.

Aquin.: SMT FP Q[78] A[1] OTC Para. 1/1

 On the contrary, The Philosopher says (De Anima ii, 3), "The  powers are 
the vegetative, the sensitive, the appetitive, the locomotion, and the 
intellectual."

Aquin.: SMT FP Q[78] A[1] Body Para. 1/4

 I answer that, There are five genera of powers of the soul, as above 
numbered. Of these, three are called souls, and four are called modes of 
living. The reason of this diversity lies in the various souls being 
distinguished accordingly as the operation of the soul transcends the 
operation of the corporeal nature in various ways; for the whole 
corporeal nature is subject to the soul, and is related to it as its 
matter and instrument. There exists, therefore, an operation of the soul 
which so far exceeds the corporeal nature that it is not even performed 
by any corporeal organ; and such is the operation of the "rational soul." 
Below this, there is another operation of the soul, which is indeed 
performed through a corporeal organ, but not through a corporeal quality, 
and this is the operation of the "sensitive soul"; for though hot and 
cold, wet and dry, and other such corporeal qualities are required for 
the work of the senses, yet they are not required in such a way that the 
operation of the senses takes place by virtue of such qualities; but only 
for the proper disposition of the organ. The lowest of the operations of 
the soul is that which is performed by a corporeal organ, and by virtue 
of a corporeal quality. Yet this transcends the operation of the 
corporeal nature; because the movements of bodies are caused by an 
extrinsic principle, while these operations are from an intrinsic 
principle; for this is common to all the operations of the soul; since 
every animate thing, in some way, moves itself. Such is the operation of 
the "vegetative soul"; for digestion, and what follows, is caused 
instrumentally by the action of heat, as the Philosopher says (De Anima 
ii, 4).

Aquin.: SMT FP Q[78] A[1] Body Para. 2/4

 Now the powers of the soul are distinguished generically by their 
objects. For the higher a power is, the more universal is the object to 
which it extends, as we have said above (Q[77], A[3], ad 4). But the 
object of the soul's operation may be considered in a triple order. For 
in the soul there is a power the object of which is only the body that is 
united to that soul; the powers of this genus are called "vegetative" for 
the vegetative power acts only on the body to which the soul is united. 
There is another genus in the powers of the soul, which genus regards a 
more universal object---namely, every sensible body, not only the body to 
which the soul is united. And there is yet another genus in the powers of 
the soul, which genus regards a still more universal object---namely, not 
only the sensible body, but all being in universal. Wherefore it is 
evident that the latter two genera of the soul's powers have an operation 
in regard not merely to that which is united to them, but also to 
something extrinsic. Now, since whatever operates must in some way be 
united to the object about which it operates, it follows of necessity 
that this something extrinsic, which is the object of the soul's 
operation, must be related to the soul in a twofold manner. First, 
inasmuch as this something extrinsic has a natural aptitude to be united 
to the soul, and to be by its likeness in the soul. In this way there are 
two kinds of powers ---namely, the "sensitive" in regard to the  less 
common object---the sensible body; and the "intellectual," in regard to 
the most common object---universal being. Secondly, forasmuch as the soul 
itself has an inclination and tendency to the something extrinsic. And in 
this way there are again two kinds of powers in the soul: one---the 
"appetitive"---in respect of which the soul is referred to something 
extrinsic as to an end, which is first in the intention; the other---the 
"locomotive" power---in respect of which the soul is referred to 
something extrinsic as to the term of its operation and movement; for 
every animal is moved for the purpose of realizing its desires and 
intentions.

Aquin.: SMT FP Q[78] A[1] Body Para. 3/4

 The modes of living are distinguished according to the degrees of living 
things. There are some living things in which there exists only 
vegetative power, as the plants. There are others in which with the 
vegetative there exists also the sensitive, but not the locomotive power; 
such as immovable animals, as shellfish. There are others which besides 
this have locomotive powers, as perfect animals, which require many 
things for their life, and consequently movement to seek necessaries of 
life from a distance. And there are some living things which with these 
have intellectual power---namely, men. But the appetitive power does not 
constitute a degree of living things; because wherever there is sense 
there is also appetite (De Anima ii, 3).

Aquin.: SMT FP Q[78] A[1] Body Para. 4/4

 Thus the first two objectives are hereby solved.

Aquin.: SMT FP Q[78] A[1] R.O. 3 Para. 1/1

 Reply OBJ 3: The "natural appetite" is that inclination which each thing 
has, of its own nature, for something; wherefore by its natural appetite 
each power desires something suitable to itself. But the "animal 
appetite" results from the form apprehended; this sort of appetite 
requires a special power of the soul---mere apprehension does not 
suffice. For a thing is desired as it exists in its own nature, whereas 
in the apprehensive power it exists not according to its own nature, but 
according to its likeness. Whence it is clear that sight desires 
naturally a visible object for the purpose of its act only---namely, for 
the purpose of seeing; but the animal by the appetitive power desires the 
thing seen, not merely for the purpose of seeing it, but also for other 
purposes. But if the soul did not require things perceived by the senses, 
except on account of the actions of the senses, that is, for the purpose 
of sensing them; there would be no need for a special genus of appetitive 
powers, since the natural appetite of the powers would suffice.

Aquin.: SMT FP Q[78] A[1] R.O. 4 Para. 1/1

 Reply OBJ 4: Although sense and appetite are principles of movement in 
perfect animals, yet sense and appetite, as such, are not sufficient to 
cause movement, unless another power be added to them; for immovable 
animals have sense and appetite, and yet they have not the power of 
motion. Now this motive power is not only in the appetite and sense as 
commanding the movement, but also in the parts of the body, to make them 
obey the appetite of the soul which moves them. Of this we have a sign in 
the fact that when the members are deprived of their natural disposition, 
they do not move in obedience to the appetite.