Whether the Human Soul Is Something Subsistent?
Objection 1: It would seem that the human soul is not something
subsistent. For that which subsists is said to be "this particular
thing." Now "this particular thing" is said not of the soul, but of
that which is composed of soul and body. Therefore the soul is not
something subsistent.
Obj. 2: Further, everything subsistent operates. But the soul does
not operate; for, as the Philosopher says (De Anima i, 4), "to say
that the soul feels or understands is like saying that the soul
weaves or builds." Therefore the soul is not subsistent.
Obj. 3: Further, if the soul were subsistent, it would have some
operation apart from the body. But it has no operation apart from the
body, not even that of understanding: for the act of understanding
does not take place without a phantasm, which cannot exist apart from
the body. Therefore the human soul is not something subsistent.
_On the contrary,_ Augustine says (De Trin. x, 7): "Who understands
that the nature of the soul is that of a substance and not that of a
body, will see that those who maintain the corporeal nature of the
soul, are led astray through associating with the soul those things
without which they are unable to think of any nature--i.e. imaginary
pictures of corporeal things." Therefore the nature of the human
intellect is not only incorporeal, but it is also a substance, that
is, something subsistent.
_I answer that,_ It must necessarily be allowed that the principle of
intellectual operation which we call the soul, is a principle both
incorporeal and subsistent. For it is clear that by means of the
intellect man can have knowledge of all corporeal things. Now whatever
knows certain things cannot have any of them in its own nature;
because that which is in it naturally would impede the knowledge of
anything else. Thus we observe that a sick man's tongue being vitiated
by a feverish and bitter humor, is insensible to anything sweet, and
everything seems bitter to it. Therefore, if the intellectual
principle contained the nature of a body it would be unable to know
all bodies. Now every body has its own determinate nature. Therefore
it is impossible for the intellectual principle to be a body. It is
likewise impossible for it to understand by means of a bodily organ;
since the determinate nature of that organ would impede knowledge of
all bodies; as when a certain determinate color is not only in the
pupil of the eye, but also in a glass vase, the liquid in the vase
seems to be of that same color.
Therefore the intellectual principle which we call the mind or the
intellect has an operation _per se_ apart from the body. Now only that
which subsists can have an operation _per se._ For nothing can operate
but what is actual: for which reason we do not say that heat imparts
heat, but that what is hot gives heat. We must conclude, therefore,
that the human soul, which is called the intellect or the mind, is
something incorporeal and subsistent.
Reply Obj. 1: "This particular thing" can be taken in two senses.
Firstly, for anything subsistent; secondly, for that which subsists,
and is complete in a specific nature. The former sense excludes the
inherence of an accident or of a material form; the latter excludes
also the imperfection of the part, so that a hand can be called "this
particular thing" in the first sense, but not in the second.
Therefore, as the human soul is a part of human nature, it can indeed
be called "this particular thing," in the first sense, as being
something subsistent; but not in the second, for in this sense, what
is composed of body and soul is said to be "this particular thing."
Reply Obj. 2: Aristotle wrote those words as expressing not his own
opinion, but the opinion of those who said that to understand is to
be moved, as is clear from the context. Or we may reply that to
operate _per se_ belongs to what exists _per se._ But for a thing to
exist _per se,_ it suffices sometimes that it be not inherent, as an
accident or a material form; even though it be part of something.
Nevertheless, that is rightly said to subsist _per se,_ which is
neither inherent in the above sense, nor part of anything else. In
this sense, the eye or the hand cannot be said to subsist _per se_;
nor can it for that reason be said to operate _per se._ Hence the
operation of the parts is through each part attributed to the whole.
For we say that man sees with the eye, and feels with the hand, and
not in the same sense as when we say that what is hot gives heat by
its heat; for heat, strictly speaking, does not give heat. We may
therefore say that the soul understands, as the eye sees; but it is
more correct to say that man understands through the soul.
Reply Obj. 3: The body is necessary for the action of the intellect,
not as its origin of action, but on the part of the object; for the
phantasm is to the intellect what color is to the sight. Neither
does such a dependence on the body prove the intellect to be
non-subsistent; otherwise it would follow that an animal is
non-subsistent, since it requires external objects of the senses
in order to perform its act of perception.
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