Therefore, as a surface which is of a
pentagonal shape, is not tetragonal by one shape, and pentagonal by
another---since a tetragonal shape would be superfluous as contained in
the pentagonal---so neither is Socrates a man by one soul, and animal
by another; but by one and the same soul he is both animal and man.
pentagonal shape, is not tetragonal by one shape, and pentagonal by
another---since a tetragonal shape would be superfluous as contained in
the pentagonal---so neither is Socrates a man by one soul, and animal
by another; but by one and the same soul he is both animal and man.
Summa Theologica
But the intellectual principle has "per se" existence and is
subsistent, as was said above ([608]Q[75], A[2]). Therefore it is not
united to the body as its form.
Objection 6: Further, whatever exists in a thing by reason of its
nature exists in it always. But to be united to matter belongs to the
form by reason of its nature; because form is the act of matter, not by
an accidental quality, but by its own essence; otherwise matter and
form would not make a thing substantially one, but only accidentally
one. Therefore a form cannot be without its own proper matter. But the
intellectual principle, since it is incorruptible, as was shown above
([609]Q[75], A[6]), remains separate from the body, after the
dissolution of the body. Therefore the intellectual principle is not
united to the body as its form.
On the contrary, According to the Philosopher, Metaph. viii (Did. vii
2), difference is derived from the form. But the difference which
constitutes man is "rational," which is applied to man on account of
his intellectual principle. Therefore the intellectual principle is the
form of man.
I answer that, We must assert that the intellect which is the principle
of intellectual operation is the form of the human body. For that
whereby primarily anything acts is a form of the thing to which the act
is to be attributed: for instance, that whereby a body is primarily
healed is health, and that whereby the soul knows primarily is
knowledge; hence health is a form of the body, and knowledge is a form
of the soul. The reason is because nothing acts except so far as it is
in act; wherefore a thing acts by that whereby it is in act. Now it is
clear that the first thing by which the body lives is the soul. And as
life appears through various operations in different degrees of living
things, that whereby we primarily perform each of all these vital
actions is the soul. For the soul is the primary principle of our
nourishment, sensation, and local movement; and likewise of our
understanding. Therefore this principle by which we primarily
understand, whether it be called the intellect or the intellectual
soul, is the form of the body. This is the demonstration used by
Aristotle (De Anima ii, 2).
But if anyone says that the intellectual soul is not the form of the
body he must first explain how it is that this action of understanding
is the action of this particular man; for each one is conscious that it
is himself who understands. Now an action may be attributed to anyone
in three ways, as is clear from the Philosopher (Phys. v, 1); for a
thing is said to move or act, either by virtue of its whole self, for
instance, as a physician heals; or by virtue of a part, as a man sees
by his eye; or through an accidental quality, as when we say that
something that is white builds, because it is accidental to the builder
to be white. So when we say that Socrates or Plato understands, it is
clear that this is not attributed to him accidentally; since it is
ascribed to him as man, which is predicated of him essentially. We must
therefore say either that Socrates understands by virtue of his whole
self, as Plato maintained, holding that man is an intellectual soul; or
that intelligence is a part of Socrates. The first cannot stand, as was
shown above ([610]Q[75], A[4]), for this reason, that it is one and the
same man who is conscious both that he understands, and that he senses.
But one cannot sense without a body: therefore the body must be some
part of man. It follows therefore that the intellect by which Socrates
understands is a part of Socrates, so that in some way it is united to
the body of Socrates.
The Commentator held that this union is through the intelligible
species, as having a double subject, in the possible intellect, and in
the phantasms which are in the corporeal organs. Thus through the
intelligible species the possible intellect is linked to the body of
this or that particular man. But this link or union does not
sufficiently explain the fact, that the act of the intellect is the act
of Socrates. This can be clearly seen from comparison with the
sensitive faculty, from which Aristotle proceeds to consider things
relating to the intellect. For the relation of phantasms to the
intellect is like the relation of colors to the sense of sight, as he
says De Anima iii, 5,7. Therefore, as the species of colors are in the
sight, so are the species of phantasms in the possible intellect. Now
it is clear that because the colors, the images of which are in the
sight, are on a wall, the action of seeing is not attributed to the
wall: for we do not say that the wall sees, but rather that it is seen.
Therefore, from the fact that the species of phantasms are in the
possible intellect, it does not follow that Socrates, in whom are the
phantasms, understands, but that he or his phantasms are understood.
Some, however, tried to maintain that the intellect is united to the
body as its motor; and hence that the intellect and body form one thing
so that the act of the intellect could be attributed to the whole. This
is, however, absurd for many reasons. First, because the intellect does
not move the body except through the appetite, the movement of which
presupposes the operation of the intellect. The reason therefore why
Socrates understands is not because he is moved by his intellect, but
rather, contrariwise, he is moved by his intellect because he
understands. Secondly, because since Socrates is an individual in a
nature of one essence composed of matter and form, if the intellect be
not the form, it follows that it must be outside the essence, and then
the intellect is the whole Socrates as a motor to the thing moved.
Whereas the act of intellect remains in the agent, and does not pass
into something else, as does the action of heating. Therefore the
action of understanding cannot be attributed to Socrates for the reason
that he is moved by his intellect. Thirdly, because the action of a
motor is never attributed to the thing moved, except as to an
instrument; as the action of a carpenter to a saw. Therefore if
understanding is attributed to Socrates, as the action of what moves
him, it follows that it is attributed to him as to an instrument. This
is contrary to the teaching of the Philosopher, who holds that
understanding is not possible through a corporeal instrument (De Anima
iii, 4). Fourthly, because, although the action of a part be attributed
to the whole, as the action of the eye is attributed to a man; yet it
is never attributed to another part, except perhaps indirectly; for we
do not say that the hand sees because the eye sees. Therefore if the
intellect and Socrates are united in the above manner, the action of
the intellect cannot be attributed to Socrates. If, however, Socrates
be a whole composed of a union of the intellect with whatever else
belongs to Socrates, and still the intellect be united to those other
things only as a motor, it follows that Socrates is not one absolutely,
and consequently neither a being absolutely, for a thing is a being
according as it is one.
There remains, therefore, no other explanation than that given by
Aristotle---namely, that this particular man understands, because the
intellectual principle is his form. Thus from the very operation of the
intellect it is made clear that the intellectual principle is united to
the body as its form.
The same can be clearly shown from the nature of the human species. For
the nature of each thing is shown by its operation. Now the proper
operation of man as man is to understand; because he thereby surpasses
all other animals. Whence Aristotle concludes (Ethic. x, 7) that the
ultimate happiness of man must consist in this operation as properly
belonging to him. Man must therefore derive his species from that which
is the principle of this operation. But the species of anything is
derived from its form. It follows therefore that the intellectual
principle is the proper form of man.
But we must observe that the nobler a form is, the more it rises above
corporeal matter, the less it is merged in matter, and the more it
excels matter by its power and its operation; hence we find that the
form of a mixed body has another operation not caused by its elemental
qualities. And the higher we advance in the nobility of forms, the more
we find that the power of the form excels the elementary matter; as the
vegetative soul excels the form of the metal, and the sensitive soul
excels the vegetative soul. Now the human soul is the highest and
noblest of forms. Wherefore it excels corporeal matter in its power by
the fact that it has an operation and a power in which corporeal matter
has no share whatever. This power is called the intellect.
It is well to remark that if anyone holds that the soul is composed of
matter and form, it would follow that in no way could the soul be the
form of the body. For since the form is an act, and matter is only in
potentiality, that which is composed of matter and form cannot be the
form of another by virtue of itself as a whole. But if it is a form by
virtue of some part of itself, then that part which is the form we call
the soul, and that of which it is the form we call the "primary
animate," as was said above ([611]Q[75], A[5]).
Reply to Objection 1: As the Philosopher says (Phys. ii, 2), the
ultimate natural form to which the consideration of the natural
philosopher is directed is indeed separate; yet it exists in matter. He
proves this from the fact that "man and the sun generate man from
matter. " It is separate indeed according to its intellectual power,
because the intellectual power does not belong to a corporeal organ, as
the power of seeing is the act of the eye; for understanding is an act
which cannot be performed by a corporeal organ, like the act of seeing.
But it exists in matter so far as the soul itself, to which this power
belongs, is the form of the body, and the term of human generation. And
so the Philosopher says (De Anima iii) that the intellect is separate,
because it is not the faculty of a corporeal organ.
From this it is clear how to answer the Second and Third objections:
since, in order that man may be able to understand all things by means
of his intellect, and that his intellect may understand immaterial
things and universals, it is sufficient that the intellectual power be
not the act of the body.
Reply to Objection 4: The human soul, by reason of its perfection, is
not a form merged in matter, or entirely embraced by matter. Therefore
there is nothing to prevent some power thereof not being the act of the
body, although the soul is essentially the form of the body.
Reply to Objection 5: The soul communicates that existence in which it
subsists to the corporeal matter, out of which and the intellectual
soul there results unity of existence; so that the existence of the
whole composite is also the existence of the soul. This is not the case
with other non-subsistent forms. For this reason the human soul retains
its own existence after the dissolution of the body; whereas it is not
so with other forms.
Reply to Objection 6: To be united to the body belongs to the soul by
reason of itself, as it belongs to a light body by reason of itself to
be raised up. And as a light body remains light, when removed from its
proper place, retaining meanwhile an aptitude and an inclination for
its proper place; so the human soul retains its proper existence when
separated from the body, having an aptitude and a natural inclination
to be united to the body.
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Whether the intellectual principle is multiplied according to the number of
bodies?
Objection 1: It would seem that the intellectual principle is not
multiplied according to the number of bodies, but that there is one
intellect in all men. For an immaterial substance is not multiplied in
number within one species. But the human soul is an immaterial
substance; since it is not composed of matter and form as was shown
above ([612]Q[75], A[5]). Therefore there are not many human souls in
one species. But all men are of one species. Therefore there is but one
intellect in all men.
Objection 2: Further, when the cause is removed, the effect is also
removed. Therefore, if human souls were multiplied according to the
number of bodies, it follows that the bodies being removed, the number
of souls would not remain; but from all the souls there would be but a
single remainder. This is heretical; for it would do away with the
distinction of rewards and punishments.
Objection 3: Further, if my intellect is distinct from your intellect,
my intellect is an individual, and so is yours; for individuals are
things which differ in number but agree in one species. Now whatever is
received into anything must be received according to the condition of
the receiver. Therefore the species of things would be received
individually into my intellect, and also into yours: which is contrary
to the nature of the intellect which knows universals.
Objection 4: Further, the thing understood is in the intellect which
understands. If, therefore, my intellect is distinct from yours, what
is understood by me must be distinct from what is understood by you;
and consequently it will be reckoned as something individual, and be
only potentially something understood; so that the common intention
will have to be abstracted from both; since from things diverse
something intelligible common to them may be abstracted. But this is
contrary to the nature of the intellect; for then the intellect would
seem not to be distinct from the imagination. It seems, therefore, to
follow that there is one intellect in all men.
Objection 5: Further, when the disciple receives knowledge from the
master, it cannot be said that the master's knowledge begets knowledge
in the disciple, because then also knowledge would be an active form,
such as heat is, which is clearly false. It seems, therefore, that the
same individual knowledge which is in the master is communicated to the
disciple; which cannot be, unless there is one intellect in both.
Seemingly, therefore, the intellect of the disciple and master is but
one; and, consequently, the same applies to all men.
Objection 6: Further, Augustine (De Quant. Animae xxxii) says: "If I
were to say that there are many human souls, I should laugh at myself. "
But the soul seems to be one chiefly on account of the intellect.
Therefore there is one intellect of all men.
On the contrary, The Philosopher says (Phys. ii, 3) that the relation
of universal causes to universals is like the relation of particular
causes to individuals. But it is impossible that a soul, one in
species, should belong to animals of different species. Therefore it is
impossible that one individual intellectual soul should belong to
several individuals.
I answer that, It is absolutely impossible for one intellect to belong
to all men. This is clear if, as Plato maintained, man is the intellect
itself. For it would follow that Socrates and Plato are one man; and
that they are not distinct from each other, except by something outside
the essence of each. The distinction between Socrates and Plato would
be no other than that of one man with a tunic and another with a cloak;
which is quite absurd.
It is likewise clear that this is impossible if, according to the
opinion of Aristotle (De Anima ii, 2), it is supposed that the
intellect is a part or a power of the soul which is the form of man.
For it is impossible for many distinct individuals to have one form, as
it is impossible for them to have one existence, for the form is the
principle of existence.
Again, this is clearly impossible, whatever one may hold as to the
manner of the union of the intellect to this or that man. For it is
manifest that, supposing there is one principal agent, and two
instruments, we can say that there is one agent absolutely, but several
actions; as when one man touches several things with his two hands,
there will be one who touches, but two contacts. If, on the contrary,
we suppose one instrument and several principal agents, we might say
that there are several agents, but one act; for example, if there be
many drawing a ship by means of a rope; there will be many drawing, but
one pull. If, however, there is one principal agent, and one
instrument, we say that there is one agent and one action, as when the
smith strikes with one hammer, there is one striker and one stroke. Now
it is clear that no matter how the intellect is united or coupled to
this or that man, the intellect has the precedence of all the other
things which appertain to man; for the sensitive powers obey the
intellect, and are at its service. Therefore, if we suppose two men to
have several intellects and one sense---for instance, if two men had
one eye---there would be several seers, but one sight. But if there is
one intellect, no matter how diverse may be all those things of which
the intellect makes use as instruments, in no way is it possible to say
that Socrates and Plato are otherwise than one understanding man. And
if to this we add that to understand, which is the act of the
intellect, is not affected by any organ other than the intellect
itself; it will further follow that there is but one agent and one
action: that is to say that all men are but one "understander," and
have but one act of understanding, in regard, that is, of one
intelligible object.
However, it would be possible to distinguish my intellectual action
form yours by the distinction of the phantasms---that is to say, were
there one phantasm of a stone in me, and another in you---if the
phantasm itself, as it is one thing in me and another in you, were a
form of the possible intellect; since the same agent according to
divers forms produces divers actions; as, according to divers forms of
things with regard to the same eye, there are divers visions. But the
phantasm itself is not a form of the possible intellect; it is the
intelligible species abstracted from the phantasm that is a form. Now
in one intellect, from different phantasms of the same species, only
one intelligible species is abstracted; as appears in one man, in whom
there may be different phantasms of a stone; yet from all of them only
one intelligible species of a stone is abstracted; by which the
intellect of that one man, by one operation, understands the nature of
a stone, notwithstanding the diversity of phantasms. Therefore, if
there were one intellect for all men, the diversity of phantasms which
are in this one and that one would not cause a diversity of
intellectual operation in this man and that man. It follows, therefore,
that it is altogether impossible and unreasonable to maintain that
there exists one intellect for all men.
Reply to Objection 1: Although the intellectual soul, like an angel,
has no matter from which it is produced, yet it is the form of a
certain matter; in which it is unlike an angel. Therefore, according to
the division of matter, there are many souls of one species; while it
is quite impossible for many angels to be of one species.
Reply to Objection 2: Everything has unity in the same way that it has
being; consequently we must judge of the multiplicity of a thing as we
judge of its being. Now it is clear that the intellectual soul, by
virtue of its very being, is united to the body as its form; yet, after
the dissolution of the body, the intellectual soul retains its own
being. In like manner the multiplicity of souls is in proportion to the
multiplicity of the bodies; yet, after the dissolution of the bodies,
the souls retain their multiplied being.
Reply to Objection 3: Individuality of the intelligent being, or of the
species whereby it understands, does not exclude the understanding of
universals; otherwise, since separate intellects are subsistent
substances, and consequently individual, they could not understand
universals. But the materiality of the knower, and of the species
whereby it knows, impedes the knowledge of the universal. For as every
action is according to the mode of the form by which the agent acts, as
heating is according to the mode of the heat; so knowledge is according
to the mode of the species by which the knower knows. Now it is clear
that common nature becomes distinct and multiplied by reason of the
individuating principles which come from the matter. Therefore if the
form, which is the means of knowledge, is material---that is, not
abstracted from material conditions---its likeness to the nature of a
species or genus will be according to the distinction and
multiplication of that nature by means of individuating principles; so
that knowledge of the nature of a thing in general will be impossible.
But if the species be abstracted from the conditions of individual
matter, there will be a likeness of the nature without those things
which make it distinct and multiplied; thus there will be knowledge of
the universal. Nor does it matter, as to this particular point, whether
there be one intellect or many; because, even if there were but one, it
would necessarily be an individual intellect, and the species whereby
it understands, an individual species.
Reply to Objection 4: Whether the intellect be one or many, what is
understood is one; for what is understood is in the intellect, not
according to its own nature, but according to its likeness; for "the
stone is not in the soul, but its likeness is," as is said, De Anima
iii, 8. Yet it is the stone which is understood, not the likeness of
the stone; except by a reflection of the intellect on itself:
otherwise, the objects of sciences would not be things, but only
intelligible species. Now it happens that different things, according
to different forms, are likened to the same thing. And since knowledge
is begotten according to the assimilation of the knower to the thing
known, it follows that the same thing may happen to be known by several
knowers; as is apparent in regard to the senses; for several see the
same color, according to different likenesses. In the same way several
intellects understand one object understood. But there is this
difference, according to the opinion of Aristotle, between the sense
and the intelligence---that a thing is perceived by the sense according
to the disposition which it has outside the soul ---that is, in its
individuality; whereas the nature of the thing understood is indeed
outside the soul, but the mode according to which it exists outside the
soul is not the mode according to which it is understood. For the
common nature is understood as apart from the individuating principles;
whereas such is not its mode of existence outside the soul. But,
according to the opinion of Plato, the thing understood exists outside
the soul in the same condition as those under which it is understood;
for he supposed that the natures of things exist separate from matter.
Reply to Objection 5: One knowledge exists in the disciple and another
in the master. How it is caused will be shown later on ([613]Q[117],
A[1]).
Reply to Objection 6: Augustine denies a plurality of souls, that would
involve a plurality of species.
__________________________________________________________________
Whether besides the intellectual soul there are in man other souls
essentially different from one another?
Objection 1: It would seem that besides the intellectual soul there are
in man other souls essentially different from one another, such as the
sensitive soul and the nutritive soul. For corruptible and
incorruptible are not of the same substance. But the intellectual soul
is incorruptible; whereas the other souls, as the sensitive and the
nutritive, are corruptible, as was shown above ([614]Q[75], A[6]).
Therefore in man the essence of the intellectual soul, the sensitive
soul, and the nutritive soul, cannot be the same.
Objection 2: Further, if it be said that the sensitive soul in man is
incorruptible; on the contrary, "corruptible and incorruptible differ
generically," says the Philosopher, Metaph. x (Did. ix, 10). But the
sensitive soul in the horse, the lion, and other brute animals, is
corruptible. If, therefore, in man it be incorruptible, the sensitive
soul in man and brute animals will not be of the same "genus. " Now an
animal is so called from its having a sensitive soul; and, therefore,
"animal" will not be one genus common to man and other animals, which
is absurd.
Objection 3: Further, the Philosopher says, Metaph. viii (Did. vii, 2),
that the genus is taken from the matter, and difference from the form.
But "rational," which is the difference constituting man, is taken from
the intellectual soul; while he is called "animal" by reason of his
having a body animated by a sensitive soul. Therefore the intellectual
soul may be compared to the body animated by a sensitive soul, as form
to matter. Therefore in man the intellectual soul is not essentially
the same as the sensitive soul, but presupposes it as a material
subject.
On the contrary, It is said in the book De Ecclesiasticis Dogmatibus
xv: "Nor do we say that there are two souls in one man, as James and
other Syrians write; one, animal, by which the body is animated, and
which is mingled with the blood; the other, spiritual, which obeys the
reason; but we say that it is one and the same soul in man, that both
gives life to the body by being united to it, and orders itself by its
own reasoning. "
I answer that, Plato held that there were several souls in one body,
distinct even as to organs, to which souls he referred the different
vital actions, saying that the nutritive power is in the liver, the
concupiscible in the heart, and the power of knowledge in the brain.
Which opinion is rejected by Aristotle (De Anima ii, 2), with regard to
those parts of the soul which use corporeal organs; for this reason,
that in those animals which continue to live when they have been
divided in each part are observed the operations of the soul, as sense
and appetite. Now this would not be the case if the various principles
of the soul's operations were essentially different, and distributed in
the various parts of the body. But with regard to the intellectual
part, he seems to leave it in doubt whether it be "only logically"
distinct from the other parts of the soul, "or also locally. "
The opinion of Plato might be maintained if, as he held, the soul was
supposed to be united to the body, not as its form, but as its motor.
For it involves nothing unreasonable that the same movable thing be
moved by several motors; and still less if it be moved according to its
various parts. If we suppose, however, that the soul is united to the
body as its form, it is quite impossible for several essentially
different souls to be in one body. This can be made clear by three
different reasons.
In the first place, an animal would not be absolutely one, in which
there were several souls. For nothing is absolutely one except by one
form, by which a thing has existence: because a thing has from the same
source both existence and unity; and therefore things which are
denominated by various forms are not absolutely one; as, for instance,
"a white man. " If, therefore, man were 'living' by one form, the
vegetative soul, and 'animal' by another form, the sensitive soul, and
"man" by another form, the intellectual soul, it would follow that man
is not absolutely one. Thus Aristotle argues, Metaph. viii (Did. vii,
6), against Plato, that if the idea of an animal is distinct from the
idea of a biped, then a biped animal is not absolutely one. For this
reason, against those who hold that there are several souls in the
body, he asks (De Anima i, 5), "what contains them? "---that is, what
makes them one? It cannot be said that they are united by the one body;
because rather does the soul contain the body and make it one, than the
reverse.
Secondly, this is proved to be impossible by the manner in which one
thing is predicated of another. Those things which are derived from
various forms are predicated of one another, either accidentally, (if
the forms are not ordered to one another, as when we say that something
white is sweet), or essentially, in the second manner of essential
predication, (if the forms are ordered one to another, the subject
belonging to the definition of the predicate; as a surface is
presupposed to color; so that if we say that a body with a surface is
colored, we have the second manner of essential predication. )
Therefore, if we have one form by which a thing is an animal, and
another form by which it is a man, it follows either that one of these
two things could not be predicated of the other, except accidentally,
supposing these two forms not to be ordered to one another---or that
one would be predicated of the other according to the second manner of
essential predication, if one soul be presupposed to the other. But
both of these consequences are clearly false: because "animal" is
predicated of man essentially and not accidentally; and man is not part
of the definition of an animal, but the other way about. Therefore of
necessity by the same form a thing is animal and man; otherwise man
would not really be the thing which is an animal, so that animal can be
essentially predicated of man.
Thirdly, this is shown to be impossible by the fact that when one
operation of the soul is intense it impedes another, which could never
be the case unless the principle of action were essentially one.
We must therefore conclude that in man the sensitive soul, the
intellectual soul, and the nutritive soul are numerically one soul.
This can easily be explained, if we consider the differences of species
and forms. For we observe that the species and forms of things differ
from one another, as the perfect and imperfect; as in the order of
things, the animate are more perfect than the inanimate, and animals
more perfect than plants, and man than brute animals; and in each of
these genera there are various degrees. For this reason Aristotle,
Metaph. viii (Did. vii, 3), compares the species of things to numbers,
which differ in species by the addition or subtraction of unity. And
(De Anima ii, 3) he compares the various souls to the species of
figures, one of which contains another; as a pentagon contains and
exceeds a tetragon. Thus the intellectual soul contains virtually
whatever belongs to the sensitive soul of brute animals, and to the
nutritive souls of plants.
Therefore, as a surface which is of a
pentagonal shape, is not tetragonal by one shape, and pentagonal by
another---since a tetragonal shape would be superfluous as contained in
the pentagonal---so neither is Socrates a man by one soul, and animal
by another; but by one and the same soul he is both animal and man.
Reply to Objection 1: The sensitive soul is incorruptible, not by
reason of its being sensitive, but by reason of its being intellectual.
When, therefore, a soul is sensitive only, it is corruptible; but when
with sensibility it has also intellectuality, it is incorruptible. For
although sensibility does not give incorruptibility, yet it cannot
deprive intellectuality of its incorruptibility.
Reply to Objection 2: Not forms, but composites, are classified either
generically or specifically. Now man is corruptible like other animals.
And so the difference of corruptible and incorruptible which is on the
part of the forms does not involve a generic difference between man and
the other animals.
Reply to Objection 3: The embryo has first of all a soul which is
merely sensitive, and when this is removed, it is supplanted by a more
perfect soul, which is both sensitive and intellectual: as will be
shown further on ([615]Q[118], A[2], ad 2).
Reply to Objection 4: We must not consider the diversity of natural
things as proceeding from the various logical notions or intentions,
which flow from our manner of understanding, because reason can
apprehend one and the same thing in various ways. Therefore since, as
we have said, the intellectual soul contains virtually what belongs to
the sensitive soul, and something more, reason can consider separately
what belongs to the power of the sensitive soul, as something imperfect
and material. And because it observes that this is something common to
man and to other animals, it forms thence the notion of the "genus";
while that wherein the intellectual soul exceeds the sensitive soul, it
takes as formal and perfecting; thence it gathers the "difference" of
man.
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Whether in man there is another form besides the intellectual soul?
Objection 1: It would seem that in man there is another form besides
the intellectual soul. For the Philosopher says (De Anima ii, 1), that
"the soul is the act of a physical body which has life potentially. "
Therefore the soul is to the body as a form of matter. But the body has
a substantial form by which it is a body. Therefore some other
substantial form in the body precedes the soul.
Objection 2: Further, man moves himself as every animal does. Now
everything that moves itself is divided into two parts, of which one
moves, and the other is moved, as the Philosopher proves (Phys. viii,
5). But the part which moves is the soul. Therefore the other part must
be such that it can be moved. But primary matter cannot be moved (Phys.
v, 1), since it is a being only potentially; indeed everything that is
moved is a body. Therefore in man and in every animal there must be
another substantial form, by which the body is constituted.
Objection 3: Further, the order of forms depends on their relation to
primary matter; for "before" and "after" apply by comparison to some
beginning. Therefore if there were not in man some other substantial
form besides the rational soul, and if this were to inhere immediately
to primary matter; it would follow that it ranks among the most
imperfect forms which inhere to matter immediately.
Objection 4: Further, the human body is a mixed body. Now mingling does
not result from matter alone; for then we should have mere corruption.
Therefore the forms of the elements must remain in a mixed body; and
these are substantial forms. Therefore in the human body there are
other substantial forms besides the intellectual soul.
On the contrary, Of one thing there is but one substantial being. But
the substantial form gives substantial being. Therefore of one thing
there is but one substantial form. But the soul is the substantial form
of man. Therefore it is impossible for there to be in man another
substantial form besides the intellectual soul.
I answer that, If we suppose that the intellectual soul is not united
to the body as its form, but only as its motor, as the Platonists
maintain, it would necessarily follow that in man there is another
substantial form, by which the body is established in its being as
movable by the soul. If, however, the intellectual soul be united to
the body as its substantial form, as we have said above [616](A[1]), it
is impossible for another substantial form besides the intellectual
soul to be found in man.
In order to make this evident, we must consider that the substantial
form differs from the accidental form in this, that the accidental form
does not make a thing to be "simply," but to be "such," as heat does
not make a thing to be simply, but only to be hot. Therefore by the
coming of the accidental form a thing is not said to be made or
generated simply, but to be made such, or to be in some particular
condition; and in like manner, when an accidental form is removed, a
thing is said to be corrupted, not simply, but relatively. Now the
substantial form gives being simply; therefore by its coming a thing is
said to be generated simply; and by its removal to be corrupted simply.
For this reason, the old natural philosophers, who held that primary
matter was some actual being---for instance, fire or air, or something
of that sort---maintained that nothing is generated simply, or
corrupted simply; and stated that "every becoming is nothing but an
alteration," as we read, Phys. i, 4. Therefore, if besides the
intellectual soul there pre-existed in matter another substantial form
by which the subject of the soul were made an actual being, it would
follow that the soul does not give being simply; and consequently that
it is not the substantial form: and so at the advent of the soul there
would not be simple generation; nor at its removal simple corruption,
all of which is clearly false.
Whence we must conclude, that there is no other substantial form in man
besides the intellectual soul; and that the soul, as it virtually
contains the sensitive and nutritive souls, so does it virtually
contain all inferior forms, and itself alone does whatever the
imperfect forms do in other things. The same is to be said of the
sensitive soul in brute animals, and of the nutritive soul in plants,
and universally of all more perfect forms with regard to the imperfect.
Reply to Objection 1: Aristotle does not say that the soul is the act
of a body only, but "the act of a physical organic body which has life
potentially"; and that this potentiality "does not reject the soul. "
Whence it is clear that when the soul is called the act, the soul
itself is included; as when we say that heat is the act of what is hot,
and light of what is lucid; not as though lucid and light were two
separate things, but because a thing is made lucid by the light. In
like manner, the soul is said to be the "act of a body," etc. , because
by the soul it is a body, and is organic, and has life potentially. Yet
the first act is said to be in potentiality to the second act, which is
operation; for such a potentiality "does not reject"---that is, does
not exclude---the soul.
Reply to Objection 2: The soul does not move the body by its essence,
as the form of the body, but by the motive power, the act of which
presupposes the body to be already actualized by the soul: so that the
soul by its motive power is the part which moves; and the animate body
is the part moved.
Reply to Objection 3: We observe in matter various degrees of
perfection, as existence, living, sensing, and understanding. Now what
is added is always more perfect. Therefore that form which gives matter
only the first degree of perfection is the most imperfect; while that
form which gives the first, second, and third degree, and so on, is the
most perfect: and yet it inheres to matter immediately.
Reply to Objection 4: Avicenna held that the substantial forms of the
elements remain entire in the mixed body; and that the mixture is made
by the contrary qualities of the elements being reduced to an average.
But this is impossible, because the various forms of the elements must
necessarily be in various parts of matter; for the distinction of which
we must suppose dimensions, without which matter cannot be divisible.
Now matter subject to dimension is not to be found except in a body.
But various bodies cannot be in the same place. Whence it follows that
elements in the mixed body would be distinct as to situation. And then
there would not be a real mixture which is in respect of the whole; but
only a mixture apparent to sense, by the juxtaposition of particles.
Averroes maintained that the forms of elements, by reason of their
imperfection, are a medium between accidental and substantial forms,
and so can be "more" or "less"; and therefore in the mixture they are
modified and reduced to an average, so that one form emerges from them.
But this is even still more impossible. For the substantial being of
each thing consists in something indivisible, and every addition and
subtraction varies the species, as in numbers, as stated in Metaph.
viii (Did. vii, 3); and consequently it is impossible for any
substantial form to receive "more" or "less. " Nor is it less impossible
for anything to be a medium between substance and accident.
Therefore we must say, in accordance with the Philosopher (De Gener. i,
10), that the forms of the elements remain in the mixed body, not
actually but virtually. For the proper qualities of the elements
remain, though modified; and in them is the power of the elementary
forms. This quality of the mixture is the proper disposition for the
substantial form of the mixed body; for instance, the form of a stone,
or of any sort of soul.
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Whether the intellectual soul is properly united to such a body?
Objection 1: It would seem that the intellectual soul is improperly
united to such a body. For matter must be proportionate to the form.
But the intellectual soul is incorruptible. Therefore it is not
properly united to a corruptible body.
Objection 2: Further, the intellectual soul is a perfectly immaterial
form; a proof whereof is its operation in which corporeal matter does
not share. But the more subtle is the body, the less has it of matter.
Therefore the soul should be united to a most subtle body, to fire, for
instance, and not to a mixed body, still less to a terrestrial body.
Objection 3: Further, since the form is the principle of the species,
one form cannot produce a variety of species. But the intellectual soul
is one form. Therefore, it should not be united to a body which is
composed of parts belonging to various species.
Objection 4: Further, what is susceptible of a more perfect form should
itself be more perfect. But the intellectual soul is the most perfect
of souls. Therefore since the bodies of other animals are naturally
provided with a covering, for instance, with hair instead of clothes,
and hoofs instead of shoes; and are, moreover, naturally provided with
arms, as claws, teeth, and horns; it seems that the intellectual soul
should not have been united to a body which is imperfect as being
deprived of the above means of protection.
On the contrary, The Philosopher says (De Anima ii, 1), that "the soul
is the act of a physical organic body having life potentially. "
I answer that, Since the form is not for the matter, but rather the
matter for the form, we must gather from the form the reason why the
matter is such as it is; and not conversely. Now the intellectual soul,
as we have seen above ([617]Q[55], A[2]) in the order of nature, holds
the lowest place among intellectual substances; inasmuch as it is not
naturally gifted with the knowledge of truth, as the angels are; but
has to gather knowledge from individual things by way of the senses, as
Dionysius says (Div. Nom. vii). But nature never fails in necessary
things: therefore the intellectual soul had to be endowed not only with
the power of understanding, but also with the power of feeling. Now the
action of the senses is not performed without a corporeal instrument.
Therefore it behooved the intellectual soul to be united to a body
fitted to be a convenient organ of sense.
Now all the other senses are based on the sense of touch. But the organ
of touch requires to be a medium between contraries, such as hot and
cold, wet and dry, and the like, of which the sense of touch has the
perception; thus it is in potentiality with regard to contraries, and
is able to perceive them. Therefore the more the organ of touch is
reduced to an equable complexion, the more sensitive will be the touch.
But the intellectual soul has the power of sense in all its
completeness; because what belongs to the inferior nature pre-exists
more perfectly in the superior, as Dionysius says (Div. Nom. v).
Therefore the body to which the intellectual soul is united should be a
mixed body, above others reduced to the most equable complexion. For
this reason among animals, man has the best sense of touch. And among
men, those who have the best sense of touch have the best intelligence.
A sign of which is that we observe "those who are refined in body are
well endowed in mind," as stated in De Anima ii, 9.
Reply to Objection 1: Perhaps someone might attempt to answer this by
saying that before sin the human body was incorruptible. This answer
does not seem sufficient; because before sin the human body was
immortal not by nature, but by a gift of Divine grace; otherwise its
immortality would not be forfeited through sin, as neither was the
immortality of the devil.
Therefore we answer otherwise by observing that in matter two
conditions are to be found; one which is chosen in order that the
matter be suitable to the form; the other which follows by force of the
first disposition. The artisan, for instance, for the form of the saw
chooses iron adapted for cutting through hard material; but that the
teeth of the saw may become blunt and rusted, follows by force of the
matter itself. So the intellectual soul requires a body of equable
complexion, which, however, is corruptible by force of its matter. If,
however, it be said that God could avoid this, we answer that in the
formation of natural things we do not consider what God might do; but
what is suitable to the nature of things, as Augustine says (Gen. ad
lit. ii, 1). God, however, provided in this case by applying a remedy
against death in the gift of grace.
Reply to Objection 2: A body is not necessary to the intellectual soul
by reason of its intellectual operation considered as such; but on
account of the sensitive power, which requires an organ of equable
temperament. Therefore the intellectual soul had to be united to such a
body, and not to a simple element, or to a mixed body, in which fire
was in excess; because otherwise there could not be an equability of
temperament. And this body of an equable temperament has a dignity of
its own by reason of its being remote from contraries, thereby
resembling in a way a heavenly body.
Reply to Objection 3: The parts of an animal, for instance, the eye,
hand, flesh, and bones, and so forth, do not make the species; but the
whole does, and therefore, properly speaking, we cannot say that these
are of different species, but that they are of various dispositions.
This is suitable to the intellectual soul, which, although it be one in
its essence, yet on account of its perfection, is manifold in power:
and therefore, for its various operations it requires various
dispositions in the parts of the body to which it is united. For this
reason we observe that there is a greater variety of parts in perfect
than in imperfect animals; and in these a greater variety than in
plants.
Reply to Objection 4: The intellectual soul as comprehending
universals, has a power extending to the infinite; therefore it cannot
be limited by nature to certain fixed natural notions, or even to
certain fixed means whether of defence or of clothing, as is the case
with other animals, the souls of which are endowed with knowledge and
power in regard to fixed particular things. Instead of all these, man
has by nature his reason and his hands, which are "the organs of
organs" (De Anima iii), since by their means man can make for himself
instruments of an infinite variety, and for any number of purposes.
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Whether the intellectual soul is united to the body through the medium of
accidental dispositions?
Objection 1: It would seem that the intellectual soul is united to the
body through the medium of accidental dispositions. For every form
exists in its proper disposed matter. But dispositions to a form are
accidents. Therefore we must presuppose accidents to be in matter
before the substantial form; and therefore before the soul, since the
soul is a substantial form.
Objection 2: Further, various forms of one species require various
parts of matter. But various parts of matter are unintelligible without
division in measurable quantities. Therefore we must suppose dimensions
in matter before the substantial forms, which are many belonging to one
species.
Objection 3: Further, what is spiritual is connected with what is
corporeal by virtual contact. But the virtue of the soul is its power.
Therefore it seems that the soul is united to the body by means of a
power, which is an accident.
On the contrary, Accident is posterior to substance, both in the order
of time and in the order of reason, as the Philosopher says, Metaph.
vii (Did. vi, 1). Therefore it is unintelligible that any accidental
form exist in matter before the soul, which is the substantial form.
I answer that, If the soul were united to the body, merely as a motor,
there would be nothing to prevent the existence of certain dispositions
mediating between the soul and the body; on the contrary, they would be
necessary, for on the part of the soul would be required the power to
move the body; and on the part of the body, a certain aptitude to be
moved by the soul.
If, however, the intellectual soul is united to the body as the
substantial form, as we have already said above [618](A[1]), it is
impossible for any accidental disposition to come between the body and
the soul, or between any substantial form whatever and its matter. The
reason is because since matter is in potentiality to all manner of acts
in a certain order, what is absolutely first among the acts must be
understood as being first in matter. Now the first among all acts is
existence. Therefore, it is impossible for matter to be apprehended as
hot, or as having quantity, before it is actual. But matter has actual
existence by the substantial form, which makes it to exist absolutely,
as we have said above [619](A[4]). Wherefore it is impossible for any
accidental dispositions to pre-exist in matter before the substantial
form, and consequently before the soul.
Reply to Objection 1: As appears from what has been already said
[620](A[4]), the more perfect form virtually contains whatever belongs
to the inferior forms; therefore while remaining one and the same, it
perfects matter according to the various degrees of perfection. For the
same essential form makes man an actual being, a body, a living being,
an animal, and a man. Now it is clear that to every "genus" follow its
own proper accidents. Therefore as matter is apprehended as perfected
in its existence, before it is understood as corporeal, and so on; so
those accidents which belong to existence are understood to exist
before corporeity; and thus dispositions are understood in matter
before the form, not as regards all its effects, but as regards the
subsequent effect.
Reply to Objection 2: Dimensions of quantity are accidents consequent
to the corporeity which belongs to the whole matter. Wherefore matter,
once understood as corporeal and measurable, can be understood as
distinct in its various parts, and as receptive of different forms
according to the further degrees of perfection. For although it is
essentially the same form which gives matter the various degrees of
perfection, as we have said (ad 1), yet it is considered as different
when brought under the observation of reason.
Reply to Objection 3: A spiritual substance which is united to a body
as its motor only, is united thereto by power or virtue. But the
intellectual soul is united by its very being to the body as a form;
and yet it guides and moves the body by its power and virtue.
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Whether the soul is united to the animal body by means of a body?
Objection 1: It seems that the soul is united to the animal body by
means of a body. For Augustine says (Gen. ad lit. vii, 19), that "the
soul administers the body by light," that is, by fire, "and by air,
which is most akin to a spirit. " But fire and air are bodies. Therefore
the soul is united to the human body by means of a body.
Objection 2: Further, a link between two things seems to be that thing
the removal of which involves the cessation of their union. But when
breathing ceases, the soul is separated from the body. Therefore the
breath, which is a subtle body, is the means of union between soul and
body.
Objection 3: Further, things which are very distant from one another,
are not united except by something between them. But the intellectual
soul is very distant from the body, both because it is incorporeal, and
because it is incorruptible. Therefore it seems to be united to the
body by means of an incorruptible body, and such would be some heavenly
light, which would harmonize the elements, and unite them together.
On the contrary, The Philosopher says (De Anima ii, 1): "We need not
ask if the soul and body are one, as neither do we ask if wax and its
shape are one. " But the shape is united to the wax without a body
intervening. Therefore also the soul is thus united to the body.
I answer that, If the soul, according to the Platonists, were united to
the body merely as a motor, it would be right to say that some other
bodies must intervene between the soul and body of man, or any animal
whatever; for a motor naturally moves what is distant from it by means
of something nearer.
If, however, the soul is united to the body as its form, as we have
said [621](A[1]), it is impossible for it to be united by means of
another body. The reason of this is that a thing is one, according as
it is a being. Now the form, through itself, makes a thing to be actual
since it is itself essentially an act; nor does it give existence by
means of something else. Wherefore the unity of a thing composed of
matter and form, is by virtue of the form itself, which by reason of
its very nature is united to matter as its act. Nor is there any other
cause of union except the agent, which causes matter to be in act, as
the Philosopher says, Metaph. viii (Did. vii, 6).
From this it is clear how false are the opinions of those who
maintained the existence of some mediate bodies between the soul and
body of man. Of these certain Platonists said that the intellectual
soul has an incorruptible body naturally united to it, from which it is
never separated, and by means of which it is united to the corruptible
body of man. Others said that the soul is united to the body by means
of a corporeal spirit. Others said it is united to the body by means of
light, which, they say, is a body and of the nature of the fifth
essence; so that the vegetative soul would be united to the body by
means of the light of the sidereal heaven; the sensible soul, by means
of the light of the crystal heaven; and the intellectual soul by means
of the light of the empyrean heaven. Now all this is fictious and
ridiculous: for light is not a body; and the fifth essence does not
enter materially into the composition of a mixed body (since it is
unchangeable), but only virtually: and lastly, because the soul is
immediately united to the body as the form to matter.
Reply to Objection 1: Augustine speaks there of the soul as it moves
the body; whence he uses the word "administration. " It is true that it
moves the grosser parts of the body by the more subtle parts. And the
first instrument of the motive power is a kind of spirit, as the
Philosopher says in De causa motus animalium (De mot. animal. x).
Reply to Objection 2: The union of soul and body ceases at the
cessation of breath, not because this is the means of union, but
because of the removal of that disposition by which the body is
disposed for such a union. Nevertheless the breath is a means of
moving, as the first instrument of motion.
Reply to Objection 3: The soul is indeed very distant from the body, if
we consider the condition of each separately: so that if each had a
separate existence, many means of connection would have to intervene.
But inasmuch as the soul is the form of the body, it has not an
existence apart from the existence of the body, but by its own
existence is united to the body immediately. This is the case with
every form which, if considered as an act, is very distant from matter,
which is a being only in potentiality.
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Whether the soul is in each part of the body?
Objection 1: It would seem that the whole soul is not in each part of
the body; for the Philosopher says in De causa motus animalium (De mot.
animal. x): "It is not necessary for the soul to be in each part of the
body; it suffices that it be in some principle of the body causing the
other parts to live, for each part has a natural movement of its own. "
Objection 2: Further, the soul is in the body of which it is the act.
But it is the act of an organic body. Therefore it exists only in an
organic body. But each part of the human body is not an organic body.
Therefore the whole soul is not in each part.
Objection 3: Further, the Philosopher says (De Anima. ii, 1) that the
relation of a part of the soul to a part of the body, such as the sight
to the pupil of the eye, is the same as the relation of the soul to the
whole body of an animal.
subsistent, as was said above ([608]Q[75], A[2]). Therefore it is not
united to the body as its form.
Objection 6: Further, whatever exists in a thing by reason of its
nature exists in it always. But to be united to matter belongs to the
form by reason of its nature; because form is the act of matter, not by
an accidental quality, but by its own essence; otherwise matter and
form would not make a thing substantially one, but only accidentally
one. Therefore a form cannot be without its own proper matter. But the
intellectual principle, since it is incorruptible, as was shown above
([609]Q[75], A[6]), remains separate from the body, after the
dissolution of the body. Therefore the intellectual principle is not
united to the body as its form.
On the contrary, According to the Philosopher, Metaph. viii (Did. vii
2), difference is derived from the form. But the difference which
constitutes man is "rational," which is applied to man on account of
his intellectual principle. Therefore the intellectual principle is the
form of man.
I answer that, We must assert that the intellect which is the principle
of intellectual operation is the form of the human body. For that
whereby primarily anything acts is a form of the thing to which the act
is to be attributed: for instance, that whereby a body is primarily
healed is health, and that whereby the soul knows primarily is
knowledge; hence health is a form of the body, and knowledge is a form
of the soul. The reason is because nothing acts except so far as it is
in act; wherefore a thing acts by that whereby it is in act. Now it is
clear that the first thing by which the body lives is the soul. And as
life appears through various operations in different degrees of living
things, that whereby we primarily perform each of all these vital
actions is the soul. For the soul is the primary principle of our
nourishment, sensation, and local movement; and likewise of our
understanding. Therefore this principle by which we primarily
understand, whether it be called the intellect or the intellectual
soul, is the form of the body. This is the demonstration used by
Aristotle (De Anima ii, 2).
But if anyone says that the intellectual soul is not the form of the
body he must first explain how it is that this action of understanding
is the action of this particular man; for each one is conscious that it
is himself who understands. Now an action may be attributed to anyone
in three ways, as is clear from the Philosopher (Phys. v, 1); for a
thing is said to move or act, either by virtue of its whole self, for
instance, as a physician heals; or by virtue of a part, as a man sees
by his eye; or through an accidental quality, as when we say that
something that is white builds, because it is accidental to the builder
to be white. So when we say that Socrates or Plato understands, it is
clear that this is not attributed to him accidentally; since it is
ascribed to him as man, which is predicated of him essentially. We must
therefore say either that Socrates understands by virtue of his whole
self, as Plato maintained, holding that man is an intellectual soul; or
that intelligence is a part of Socrates. The first cannot stand, as was
shown above ([610]Q[75], A[4]), for this reason, that it is one and the
same man who is conscious both that he understands, and that he senses.
But one cannot sense without a body: therefore the body must be some
part of man. It follows therefore that the intellect by which Socrates
understands is a part of Socrates, so that in some way it is united to
the body of Socrates.
The Commentator held that this union is through the intelligible
species, as having a double subject, in the possible intellect, and in
the phantasms which are in the corporeal organs. Thus through the
intelligible species the possible intellect is linked to the body of
this or that particular man. But this link or union does not
sufficiently explain the fact, that the act of the intellect is the act
of Socrates. This can be clearly seen from comparison with the
sensitive faculty, from which Aristotle proceeds to consider things
relating to the intellect. For the relation of phantasms to the
intellect is like the relation of colors to the sense of sight, as he
says De Anima iii, 5,7. Therefore, as the species of colors are in the
sight, so are the species of phantasms in the possible intellect. Now
it is clear that because the colors, the images of which are in the
sight, are on a wall, the action of seeing is not attributed to the
wall: for we do not say that the wall sees, but rather that it is seen.
Therefore, from the fact that the species of phantasms are in the
possible intellect, it does not follow that Socrates, in whom are the
phantasms, understands, but that he or his phantasms are understood.
Some, however, tried to maintain that the intellect is united to the
body as its motor; and hence that the intellect and body form one thing
so that the act of the intellect could be attributed to the whole. This
is, however, absurd for many reasons. First, because the intellect does
not move the body except through the appetite, the movement of which
presupposes the operation of the intellect. The reason therefore why
Socrates understands is not because he is moved by his intellect, but
rather, contrariwise, he is moved by his intellect because he
understands. Secondly, because since Socrates is an individual in a
nature of one essence composed of matter and form, if the intellect be
not the form, it follows that it must be outside the essence, and then
the intellect is the whole Socrates as a motor to the thing moved.
Whereas the act of intellect remains in the agent, and does not pass
into something else, as does the action of heating. Therefore the
action of understanding cannot be attributed to Socrates for the reason
that he is moved by his intellect. Thirdly, because the action of a
motor is never attributed to the thing moved, except as to an
instrument; as the action of a carpenter to a saw. Therefore if
understanding is attributed to Socrates, as the action of what moves
him, it follows that it is attributed to him as to an instrument. This
is contrary to the teaching of the Philosopher, who holds that
understanding is not possible through a corporeal instrument (De Anima
iii, 4). Fourthly, because, although the action of a part be attributed
to the whole, as the action of the eye is attributed to a man; yet it
is never attributed to another part, except perhaps indirectly; for we
do not say that the hand sees because the eye sees. Therefore if the
intellect and Socrates are united in the above manner, the action of
the intellect cannot be attributed to Socrates. If, however, Socrates
be a whole composed of a union of the intellect with whatever else
belongs to Socrates, and still the intellect be united to those other
things only as a motor, it follows that Socrates is not one absolutely,
and consequently neither a being absolutely, for a thing is a being
according as it is one.
There remains, therefore, no other explanation than that given by
Aristotle---namely, that this particular man understands, because the
intellectual principle is his form. Thus from the very operation of the
intellect it is made clear that the intellectual principle is united to
the body as its form.
The same can be clearly shown from the nature of the human species. For
the nature of each thing is shown by its operation. Now the proper
operation of man as man is to understand; because he thereby surpasses
all other animals. Whence Aristotle concludes (Ethic. x, 7) that the
ultimate happiness of man must consist in this operation as properly
belonging to him. Man must therefore derive his species from that which
is the principle of this operation. But the species of anything is
derived from its form. It follows therefore that the intellectual
principle is the proper form of man.
But we must observe that the nobler a form is, the more it rises above
corporeal matter, the less it is merged in matter, and the more it
excels matter by its power and its operation; hence we find that the
form of a mixed body has another operation not caused by its elemental
qualities. And the higher we advance in the nobility of forms, the more
we find that the power of the form excels the elementary matter; as the
vegetative soul excels the form of the metal, and the sensitive soul
excels the vegetative soul. Now the human soul is the highest and
noblest of forms. Wherefore it excels corporeal matter in its power by
the fact that it has an operation and a power in which corporeal matter
has no share whatever. This power is called the intellect.
It is well to remark that if anyone holds that the soul is composed of
matter and form, it would follow that in no way could the soul be the
form of the body. For since the form is an act, and matter is only in
potentiality, that which is composed of matter and form cannot be the
form of another by virtue of itself as a whole. But if it is a form by
virtue of some part of itself, then that part which is the form we call
the soul, and that of which it is the form we call the "primary
animate," as was said above ([611]Q[75], A[5]).
Reply to Objection 1: As the Philosopher says (Phys. ii, 2), the
ultimate natural form to which the consideration of the natural
philosopher is directed is indeed separate; yet it exists in matter. He
proves this from the fact that "man and the sun generate man from
matter. " It is separate indeed according to its intellectual power,
because the intellectual power does not belong to a corporeal organ, as
the power of seeing is the act of the eye; for understanding is an act
which cannot be performed by a corporeal organ, like the act of seeing.
But it exists in matter so far as the soul itself, to which this power
belongs, is the form of the body, and the term of human generation. And
so the Philosopher says (De Anima iii) that the intellect is separate,
because it is not the faculty of a corporeal organ.
From this it is clear how to answer the Second and Third objections:
since, in order that man may be able to understand all things by means
of his intellect, and that his intellect may understand immaterial
things and universals, it is sufficient that the intellectual power be
not the act of the body.
Reply to Objection 4: The human soul, by reason of its perfection, is
not a form merged in matter, or entirely embraced by matter. Therefore
there is nothing to prevent some power thereof not being the act of the
body, although the soul is essentially the form of the body.
Reply to Objection 5: The soul communicates that existence in which it
subsists to the corporeal matter, out of which and the intellectual
soul there results unity of existence; so that the existence of the
whole composite is also the existence of the soul. This is not the case
with other non-subsistent forms. For this reason the human soul retains
its own existence after the dissolution of the body; whereas it is not
so with other forms.
Reply to Objection 6: To be united to the body belongs to the soul by
reason of itself, as it belongs to a light body by reason of itself to
be raised up. And as a light body remains light, when removed from its
proper place, retaining meanwhile an aptitude and an inclination for
its proper place; so the human soul retains its proper existence when
separated from the body, having an aptitude and a natural inclination
to be united to the body.
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Whether the intellectual principle is multiplied according to the number of
bodies?
Objection 1: It would seem that the intellectual principle is not
multiplied according to the number of bodies, but that there is one
intellect in all men. For an immaterial substance is not multiplied in
number within one species. But the human soul is an immaterial
substance; since it is not composed of matter and form as was shown
above ([612]Q[75], A[5]). Therefore there are not many human souls in
one species. But all men are of one species. Therefore there is but one
intellect in all men.
Objection 2: Further, when the cause is removed, the effect is also
removed. Therefore, if human souls were multiplied according to the
number of bodies, it follows that the bodies being removed, the number
of souls would not remain; but from all the souls there would be but a
single remainder. This is heretical; for it would do away with the
distinction of rewards and punishments.
Objection 3: Further, if my intellect is distinct from your intellect,
my intellect is an individual, and so is yours; for individuals are
things which differ in number but agree in one species. Now whatever is
received into anything must be received according to the condition of
the receiver. Therefore the species of things would be received
individually into my intellect, and also into yours: which is contrary
to the nature of the intellect which knows universals.
Objection 4: Further, the thing understood is in the intellect which
understands. If, therefore, my intellect is distinct from yours, what
is understood by me must be distinct from what is understood by you;
and consequently it will be reckoned as something individual, and be
only potentially something understood; so that the common intention
will have to be abstracted from both; since from things diverse
something intelligible common to them may be abstracted. But this is
contrary to the nature of the intellect; for then the intellect would
seem not to be distinct from the imagination. It seems, therefore, to
follow that there is one intellect in all men.
Objection 5: Further, when the disciple receives knowledge from the
master, it cannot be said that the master's knowledge begets knowledge
in the disciple, because then also knowledge would be an active form,
such as heat is, which is clearly false. It seems, therefore, that the
same individual knowledge which is in the master is communicated to the
disciple; which cannot be, unless there is one intellect in both.
Seemingly, therefore, the intellect of the disciple and master is but
one; and, consequently, the same applies to all men.
Objection 6: Further, Augustine (De Quant. Animae xxxii) says: "If I
were to say that there are many human souls, I should laugh at myself. "
But the soul seems to be one chiefly on account of the intellect.
Therefore there is one intellect of all men.
On the contrary, The Philosopher says (Phys. ii, 3) that the relation
of universal causes to universals is like the relation of particular
causes to individuals. But it is impossible that a soul, one in
species, should belong to animals of different species. Therefore it is
impossible that one individual intellectual soul should belong to
several individuals.
I answer that, It is absolutely impossible for one intellect to belong
to all men. This is clear if, as Plato maintained, man is the intellect
itself. For it would follow that Socrates and Plato are one man; and
that they are not distinct from each other, except by something outside
the essence of each. The distinction between Socrates and Plato would
be no other than that of one man with a tunic and another with a cloak;
which is quite absurd.
It is likewise clear that this is impossible if, according to the
opinion of Aristotle (De Anima ii, 2), it is supposed that the
intellect is a part or a power of the soul which is the form of man.
For it is impossible for many distinct individuals to have one form, as
it is impossible for them to have one existence, for the form is the
principle of existence.
Again, this is clearly impossible, whatever one may hold as to the
manner of the union of the intellect to this or that man. For it is
manifest that, supposing there is one principal agent, and two
instruments, we can say that there is one agent absolutely, but several
actions; as when one man touches several things with his two hands,
there will be one who touches, but two contacts. If, on the contrary,
we suppose one instrument and several principal agents, we might say
that there are several agents, but one act; for example, if there be
many drawing a ship by means of a rope; there will be many drawing, but
one pull. If, however, there is one principal agent, and one
instrument, we say that there is one agent and one action, as when the
smith strikes with one hammer, there is one striker and one stroke. Now
it is clear that no matter how the intellect is united or coupled to
this or that man, the intellect has the precedence of all the other
things which appertain to man; for the sensitive powers obey the
intellect, and are at its service. Therefore, if we suppose two men to
have several intellects and one sense---for instance, if two men had
one eye---there would be several seers, but one sight. But if there is
one intellect, no matter how diverse may be all those things of which
the intellect makes use as instruments, in no way is it possible to say
that Socrates and Plato are otherwise than one understanding man. And
if to this we add that to understand, which is the act of the
intellect, is not affected by any organ other than the intellect
itself; it will further follow that there is but one agent and one
action: that is to say that all men are but one "understander," and
have but one act of understanding, in regard, that is, of one
intelligible object.
However, it would be possible to distinguish my intellectual action
form yours by the distinction of the phantasms---that is to say, were
there one phantasm of a stone in me, and another in you---if the
phantasm itself, as it is one thing in me and another in you, were a
form of the possible intellect; since the same agent according to
divers forms produces divers actions; as, according to divers forms of
things with regard to the same eye, there are divers visions. But the
phantasm itself is not a form of the possible intellect; it is the
intelligible species abstracted from the phantasm that is a form. Now
in one intellect, from different phantasms of the same species, only
one intelligible species is abstracted; as appears in one man, in whom
there may be different phantasms of a stone; yet from all of them only
one intelligible species of a stone is abstracted; by which the
intellect of that one man, by one operation, understands the nature of
a stone, notwithstanding the diversity of phantasms. Therefore, if
there were one intellect for all men, the diversity of phantasms which
are in this one and that one would not cause a diversity of
intellectual operation in this man and that man. It follows, therefore,
that it is altogether impossible and unreasonable to maintain that
there exists one intellect for all men.
Reply to Objection 1: Although the intellectual soul, like an angel,
has no matter from which it is produced, yet it is the form of a
certain matter; in which it is unlike an angel. Therefore, according to
the division of matter, there are many souls of one species; while it
is quite impossible for many angels to be of one species.
Reply to Objection 2: Everything has unity in the same way that it has
being; consequently we must judge of the multiplicity of a thing as we
judge of its being. Now it is clear that the intellectual soul, by
virtue of its very being, is united to the body as its form; yet, after
the dissolution of the body, the intellectual soul retains its own
being. In like manner the multiplicity of souls is in proportion to the
multiplicity of the bodies; yet, after the dissolution of the bodies,
the souls retain their multiplied being.
Reply to Objection 3: Individuality of the intelligent being, or of the
species whereby it understands, does not exclude the understanding of
universals; otherwise, since separate intellects are subsistent
substances, and consequently individual, they could not understand
universals. But the materiality of the knower, and of the species
whereby it knows, impedes the knowledge of the universal. For as every
action is according to the mode of the form by which the agent acts, as
heating is according to the mode of the heat; so knowledge is according
to the mode of the species by which the knower knows. Now it is clear
that common nature becomes distinct and multiplied by reason of the
individuating principles which come from the matter. Therefore if the
form, which is the means of knowledge, is material---that is, not
abstracted from material conditions---its likeness to the nature of a
species or genus will be according to the distinction and
multiplication of that nature by means of individuating principles; so
that knowledge of the nature of a thing in general will be impossible.
But if the species be abstracted from the conditions of individual
matter, there will be a likeness of the nature without those things
which make it distinct and multiplied; thus there will be knowledge of
the universal. Nor does it matter, as to this particular point, whether
there be one intellect or many; because, even if there were but one, it
would necessarily be an individual intellect, and the species whereby
it understands, an individual species.
Reply to Objection 4: Whether the intellect be one or many, what is
understood is one; for what is understood is in the intellect, not
according to its own nature, but according to its likeness; for "the
stone is not in the soul, but its likeness is," as is said, De Anima
iii, 8. Yet it is the stone which is understood, not the likeness of
the stone; except by a reflection of the intellect on itself:
otherwise, the objects of sciences would not be things, but only
intelligible species. Now it happens that different things, according
to different forms, are likened to the same thing. And since knowledge
is begotten according to the assimilation of the knower to the thing
known, it follows that the same thing may happen to be known by several
knowers; as is apparent in regard to the senses; for several see the
same color, according to different likenesses. In the same way several
intellects understand one object understood. But there is this
difference, according to the opinion of Aristotle, between the sense
and the intelligence---that a thing is perceived by the sense according
to the disposition which it has outside the soul ---that is, in its
individuality; whereas the nature of the thing understood is indeed
outside the soul, but the mode according to which it exists outside the
soul is not the mode according to which it is understood. For the
common nature is understood as apart from the individuating principles;
whereas such is not its mode of existence outside the soul. But,
according to the opinion of Plato, the thing understood exists outside
the soul in the same condition as those under which it is understood;
for he supposed that the natures of things exist separate from matter.
Reply to Objection 5: One knowledge exists in the disciple and another
in the master. How it is caused will be shown later on ([613]Q[117],
A[1]).
Reply to Objection 6: Augustine denies a plurality of souls, that would
involve a plurality of species.
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Whether besides the intellectual soul there are in man other souls
essentially different from one another?
Objection 1: It would seem that besides the intellectual soul there are
in man other souls essentially different from one another, such as the
sensitive soul and the nutritive soul. For corruptible and
incorruptible are not of the same substance. But the intellectual soul
is incorruptible; whereas the other souls, as the sensitive and the
nutritive, are corruptible, as was shown above ([614]Q[75], A[6]).
Therefore in man the essence of the intellectual soul, the sensitive
soul, and the nutritive soul, cannot be the same.
Objection 2: Further, if it be said that the sensitive soul in man is
incorruptible; on the contrary, "corruptible and incorruptible differ
generically," says the Philosopher, Metaph. x (Did. ix, 10). But the
sensitive soul in the horse, the lion, and other brute animals, is
corruptible. If, therefore, in man it be incorruptible, the sensitive
soul in man and brute animals will not be of the same "genus. " Now an
animal is so called from its having a sensitive soul; and, therefore,
"animal" will not be one genus common to man and other animals, which
is absurd.
Objection 3: Further, the Philosopher says, Metaph. viii (Did. vii, 2),
that the genus is taken from the matter, and difference from the form.
But "rational," which is the difference constituting man, is taken from
the intellectual soul; while he is called "animal" by reason of his
having a body animated by a sensitive soul. Therefore the intellectual
soul may be compared to the body animated by a sensitive soul, as form
to matter. Therefore in man the intellectual soul is not essentially
the same as the sensitive soul, but presupposes it as a material
subject.
On the contrary, It is said in the book De Ecclesiasticis Dogmatibus
xv: "Nor do we say that there are two souls in one man, as James and
other Syrians write; one, animal, by which the body is animated, and
which is mingled with the blood; the other, spiritual, which obeys the
reason; but we say that it is one and the same soul in man, that both
gives life to the body by being united to it, and orders itself by its
own reasoning. "
I answer that, Plato held that there were several souls in one body,
distinct even as to organs, to which souls he referred the different
vital actions, saying that the nutritive power is in the liver, the
concupiscible in the heart, and the power of knowledge in the brain.
Which opinion is rejected by Aristotle (De Anima ii, 2), with regard to
those parts of the soul which use corporeal organs; for this reason,
that in those animals which continue to live when they have been
divided in each part are observed the operations of the soul, as sense
and appetite. Now this would not be the case if the various principles
of the soul's operations were essentially different, and distributed in
the various parts of the body. But with regard to the intellectual
part, he seems to leave it in doubt whether it be "only logically"
distinct from the other parts of the soul, "or also locally. "
The opinion of Plato might be maintained if, as he held, the soul was
supposed to be united to the body, not as its form, but as its motor.
For it involves nothing unreasonable that the same movable thing be
moved by several motors; and still less if it be moved according to its
various parts. If we suppose, however, that the soul is united to the
body as its form, it is quite impossible for several essentially
different souls to be in one body. This can be made clear by three
different reasons.
In the first place, an animal would not be absolutely one, in which
there were several souls. For nothing is absolutely one except by one
form, by which a thing has existence: because a thing has from the same
source both existence and unity; and therefore things which are
denominated by various forms are not absolutely one; as, for instance,
"a white man. " If, therefore, man were 'living' by one form, the
vegetative soul, and 'animal' by another form, the sensitive soul, and
"man" by another form, the intellectual soul, it would follow that man
is not absolutely one. Thus Aristotle argues, Metaph. viii (Did. vii,
6), against Plato, that if the idea of an animal is distinct from the
idea of a biped, then a biped animal is not absolutely one. For this
reason, against those who hold that there are several souls in the
body, he asks (De Anima i, 5), "what contains them? "---that is, what
makes them one? It cannot be said that they are united by the one body;
because rather does the soul contain the body and make it one, than the
reverse.
Secondly, this is proved to be impossible by the manner in which one
thing is predicated of another. Those things which are derived from
various forms are predicated of one another, either accidentally, (if
the forms are not ordered to one another, as when we say that something
white is sweet), or essentially, in the second manner of essential
predication, (if the forms are ordered one to another, the subject
belonging to the definition of the predicate; as a surface is
presupposed to color; so that if we say that a body with a surface is
colored, we have the second manner of essential predication. )
Therefore, if we have one form by which a thing is an animal, and
another form by which it is a man, it follows either that one of these
two things could not be predicated of the other, except accidentally,
supposing these two forms not to be ordered to one another---or that
one would be predicated of the other according to the second manner of
essential predication, if one soul be presupposed to the other. But
both of these consequences are clearly false: because "animal" is
predicated of man essentially and not accidentally; and man is not part
of the definition of an animal, but the other way about. Therefore of
necessity by the same form a thing is animal and man; otherwise man
would not really be the thing which is an animal, so that animal can be
essentially predicated of man.
Thirdly, this is shown to be impossible by the fact that when one
operation of the soul is intense it impedes another, which could never
be the case unless the principle of action were essentially one.
We must therefore conclude that in man the sensitive soul, the
intellectual soul, and the nutritive soul are numerically one soul.
This can easily be explained, if we consider the differences of species
and forms. For we observe that the species and forms of things differ
from one another, as the perfect and imperfect; as in the order of
things, the animate are more perfect than the inanimate, and animals
more perfect than plants, and man than brute animals; and in each of
these genera there are various degrees. For this reason Aristotle,
Metaph. viii (Did. vii, 3), compares the species of things to numbers,
which differ in species by the addition or subtraction of unity. And
(De Anima ii, 3) he compares the various souls to the species of
figures, one of which contains another; as a pentagon contains and
exceeds a tetragon. Thus the intellectual soul contains virtually
whatever belongs to the sensitive soul of brute animals, and to the
nutritive souls of plants.
Therefore, as a surface which is of a
pentagonal shape, is not tetragonal by one shape, and pentagonal by
another---since a tetragonal shape would be superfluous as contained in
the pentagonal---so neither is Socrates a man by one soul, and animal
by another; but by one and the same soul he is both animal and man.
Reply to Objection 1: The sensitive soul is incorruptible, not by
reason of its being sensitive, but by reason of its being intellectual.
When, therefore, a soul is sensitive only, it is corruptible; but when
with sensibility it has also intellectuality, it is incorruptible. For
although sensibility does not give incorruptibility, yet it cannot
deprive intellectuality of its incorruptibility.
Reply to Objection 2: Not forms, but composites, are classified either
generically or specifically. Now man is corruptible like other animals.
And so the difference of corruptible and incorruptible which is on the
part of the forms does not involve a generic difference between man and
the other animals.
Reply to Objection 3: The embryo has first of all a soul which is
merely sensitive, and when this is removed, it is supplanted by a more
perfect soul, which is both sensitive and intellectual: as will be
shown further on ([615]Q[118], A[2], ad 2).
Reply to Objection 4: We must not consider the diversity of natural
things as proceeding from the various logical notions or intentions,
which flow from our manner of understanding, because reason can
apprehend one and the same thing in various ways. Therefore since, as
we have said, the intellectual soul contains virtually what belongs to
the sensitive soul, and something more, reason can consider separately
what belongs to the power of the sensitive soul, as something imperfect
and material. And because it observes that this is something common to
man and to other animals, it forms thence the notion of the "genus";
while that wherein the intellectual soul exceeds the sensitive soul, it
takes as formal and perfecting; thence it gathers the "difference" of
man.
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Whether in man there is another form besides the intellectual soul?
Objection 1: It would seem that in man there is another form besides
the intellectual soul. For the Philosopher says (De Anima ii, 1), that
"the soul is the act of a physical body which has life potentially. "
Therefore the soul is to the body as a form of matter. But the body has
a substantial form by which it is a body. Therefore some other
substantial form in the body precedes the soul.
Objection 2: Further, man moves himself as every animal does. Now
everything that moves itself is divided into two parts, of which one
moves, and the other is moved, as the Philosopher proves (Phys. viii,
5). But the part which moves is the soul. Therefore the other part must
be such that it can be moved. But primary matter cannot be moved (Phys.
v, 1), since it is a being only potentially; indeed everything that is
moved is a body. Therefore in man and in every animal there must be
another substantial form, by which the body is constituted.
Objection 3: Further, the order of forms depends on their relation to
primary matter; for "before" and "after" apply by comparison to some
beginning. Therefore if there were not in man some other substantial
form besides the rational soul, and if this were to inhere immediately
to primary matter; it would follow that it ranks among the most
imperfect forms which inhere to matter immediately.
Objection 4: Further, the human body is a mixed body. Now mingling does
not result from matter alone; for then we should have mere corruption.
Therefore the forms of the elements must remain in a mixed body; and
these are substantial forms. Therefore in the human body there are
other substantial forms besides the intellectual soul.
On the contrary, Of one thing there is but one substantial being. But
the substantial form gives substantial being. Therefore of one thing
there is but one substantial form. But the soul is the substantial form
of man. Therefore it is impossible for there to be in man another
substantial form besides the intellectual soul.
I answer that, If we suppose that the intellectual soul is not united
to the body as its form, but only as its motor, as the Platonists
maintain, it would necessarily follow that in man there is another
substantial form, by which the body is established in its being as
movable by the soul. If, however, the intellectual soul be united to
the body as its substantial form, as we have said above [616](A[1]), it
is impossible for another substantial form besides the intellectual
soul to be found in man.
In order to make this evident, we must consider that the substantial
form differs from the accidental form in this, that the accidental form
does not make a thing to be "simply," but to be "such," as heat does
not make a thing to be simply, but only to be hot. Therefore by the
coming of the accidental form a thing is not said to be made or
generated simply, but to be made such, or to be in some particular
condition; and in like manner, when an accidental form is removed, a
thing is said to be corrupted, not simply, but relatively. Now the
substantial form gives being simply; therefore by its coming a thing is
said to be generated simply; and by its removal to be corrupted simply.
For this reason, the old natural philosophers, who held that primary
matter was some actual being---for instance, fire or air, or something
of that sort---maintained that nothing is generated simply, or
corrupted simply; and stated that "every becoming is nothing but an
alteration," as we read, Phys. i, 4. Therefore, if besides the
intellectual soul there pre-existed in matter another substantial form
by which the subject of the soul were made an actual being, it would
follow that the soul does not give being simply; and consequently that
it is not the substantial form: and so at the advent of the soul there
would not be simple generation; nor at its removal simple corruption,
all of which is clearly false.
Whence we must conclude, that there is no other substantial form in man
besides the intellectual soul; and that the soul, as it virtually
contains the sensitive and nutritive souls, so does it virtually
contain all inferior forms, and itself alone does whatever the
imperfect forms do in other things. The same is to be said of the
sensitive soul in brute animals, and of the nutritive soul in plants,
and universally of all more perfect forms with regard to the imperfect.
Reply to Objection 1: Aristotle does not say that the soul is the act
of a body only, but "the act of a physical organic body which has life
potentially"; and that this potentiality "does not reject the soul. "
Whence it is clear that when the soul is called the act, the soul
itself is included; as when we say that heat is the act of what is hot,
and light of what is lucid; not as though lucid and light were two
separate things, but because a thing is made lucid by the light. In
like manner, the soul is said to be the "act of a body," etc. , because
by the soul it is a body, and is organic, and has life potentially. Yet
the first act is said to be in potentiality to the second act, which is
operation; for such a potentiality "does not reject"---that is, does
not exclude---the soul.
Reply to Objection 2: The soul does not move the body by its essence,
as the form of the body, but by the motive power, the act of which
presupposes the body to be already actualized by the soul: so that the
soul by its motive power is the part which moves; and the animate body
is the part moved.
Reply to Objection 3: We observe in matter various degrees of
perfection, as existence, living, sensing, and understanding. Now what
is added is always more perfect. Therefore that form which gives matter
only the first degree of perfection is the most imperfect; while that
form which gives the first, second, and third degree, and so on, is the
most perfect: and yet it inheres to matter immediately.
Reply to Objection 4: Avicenna held that the substantial forms of the
elements remain entire in the mixed body; and that the mixture is made
by the contrary qualities of the elements being reduced to an average.
But this is impossible, because the various forms of the elements must
necessarily be in various parts of matter; for the distinction of which
we must suppose dimensions, without which matter cannot be divisible.
Now matter subject to dimension is not to be found except in a body.
But various bodies cannot be in the same place. Whence it follows that
elements in the mixed body would be distinct as to situation. And then
there would not be a real mixture which is in respect of the whole; but
only a mixture apparent to sense, by the juxtaposition of particles.
Averroes maintained that the forms of elements, by reason of their
imperfection, are a medium between accidental and substantial forms,
and so can be "more" or "less"; and therefore in the mixture they are
modified and reduced to an average, so that one form emerges from them.
But this is even still more impossible. For the substantial being of
each thing consists in something indivisible, and every addition and
subtraction varies the species, as in numbers, as stated in Metaph.
viii (Did. vii, 3); and consequently it is impossible for any
substantial form to receive "more" or "less. " Nor is it less impossible
for anything to be a medium between substance and accident.
Therefore we must say, in accordance with the Philosopher (De Gener. i,
10), that the forms of the elements remain in the mixed body, not
actually but virtually. For the proper qualities of the elements
remain, though modified; and in them is the power of the elementary
forms. This quality of the mixture is the proper disposition for the
substantial form of the mixed body; for instance, the form of a stone,
or of any sort of soul.
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Whether the intellectual soul is properly united to such a body?
Objection 1: It would seem that the intellectual soul is improperly
united to such a body. For matter must be proportionate to the form.
But the intellectual soul is incorruptible. Therefore it is not
properly united to a corruptible body.
Objection 2: Further, the intellectual soul is a perfectly immaterial
form; a proof whereof is its operation in which corporeal matter does
not share. But the more subtle is the body, the less has it of matter.
Therefore the soul should be united to a most subtle body, to fire, for
instance, and not to a mixed body, still less to a terrestrial body.
Objection 3: Further, since the form is the principle of the species,
one form cannot produce a variety of species. But the intellectual soul
is one form. Therefore, it should not be united to a body which is
composed of parts belonging to various species.
Objection 4: Further, what is susceptible of a more perfect form should
itself be more perfect. But the intellectual soul is the most perfect
of souls. Therefore since the bodies of other animals are naturally
provided with a covering, for instance, with hair instead of clothes,
and hoofs instead of shoes; and are, moreover, naturally provided with
arms, as claws, teeth, and horns; it seems that the intellectual soul
should not have been united to a body which is imperfect as being
deprived of the above means of protection.
On the contrary, The Philosopher says (De Anima ii, 1), that "the soul
is the act of a physical organic body having life potentially. "
I answer that, Since the form is not for the matter, but rather the
matter for the form, we must gather from the form the reason why the
matter is such as it is; and not conversely. Now the intellectual soul,
as we have seen above ([617]Q[55], A[2]) in the order of nature, holds
the lowest place among intellectual substances; inasmuch as it is not
naturally gifted with the knowledge of truth, as the angels are; but
has to gather knowledge from individual things by way of the senses, as
Dionysius says (Div. Nom. vii). But nature never fails in necessary
things: therefore the intellectual soul had to be endowed not only with
the power of understanding, but also with the power of feeling. Now the
action of the senses is not performed without a corporeal instrument.
Therefore it behooved the intellectual soul to be united to a body
fitted to be a convenient organ of sense.
Now all the other senses are based on the sense of touch. But the organ
of touch requires to be a medium between contraries, such as hot and
cold, wet and dry, and the like, of which the sense of touch has the
perception; thus it is in potentiality with regard to contraries, and
is able to perceive them. Therefore the more the organ of touch is
reduced to an equable complexion, the more sensitive will be the touch.
But the intellectual soul has the power of sense in all its
completeness; because what belongs to the inferior nature pre-exists
more perfectly in the superior, as Dionysius says (Div. Nom. v).
Therefore the body to which the intellectual soul is united should be a
mixed body, above others reduced to the most equable complexion. For
this reason among animals, man has the best sense of touch. And among
men, those who have the best sense of touch have the best intelligence.
A sign of which is that we observe "those who are refined in body are
well endowed in mind," as stated in De Anima ii, 9.
Reply to Objection 1: Perhaps someone might attempt to answer this by
saying that before sin the human body was incorruptible. This answer
does not seem sufficient; because before sin the human body was
immortal not by nature, but by a gift of Divine grace; otherwise its
immortality would not be forfeited through sin, as neither was the
immortality of the devil.
Therefore we answer otherwise by observing that in matter two
conditions are to be found; one which is chosen in order that the
matter be suitable to the form; the other which follows by force of the
first disposition. The artisan, for instance, for the form of the saw
chooses iron adapted for cutting through hard material; but that the
teeth of the saw may become blunt and rusted, follows by force of the
matter itself. So the intellectual soul requires a body of equable
complexion, which, however, is corruptible by force of its matter. If,
however, it be said that God could avoid this, we answer that in the
formation of natural things we do not consider what God might do; but
what is suitable to the nature of things, as Augustine says (Gen. ad
lit. ii, 1). God, however, provided in this case by applying a remedy
against death in the gift of grace.
Reply to Objection 2: A body is not necessary to the intellectual soul
by reason of its intellectual operation considered as such; but on
account of the sensitive power, which requires an organ of equable
temperament. Therefore the intellectual soul had to be united to such a
body, and not to a simple element, or to a mixed body, in which fire
was in excess; because otherwise there could not be an equability of
temperament. And this body of an equable temperament has a dignity of
its own by reason of its being remote from contraries, thereby
resembling in a way a heavenly body.
Reply to Objection 3: The parts of an animal, for instance, the eye,
hand, flesh, and bones, and so forth, do not make the species; but the
whole does, and therefore, properly speaking, we cannot say that these
are of different species, but that they are of various dispositions.
This is suitable to the intellectual soul, which, although it be one in
its essence, yet on account of its perfection, is manifold in power:
and therefore, for its various operations it requires various
dispositions in the parts of the body to which it is united. For this
reason we observe that there is a greater variety of parts in perfect
than in imperfect animals; and in these a greater variety than in
plants.
Reply to Objection 4: The intellectual soul as comprehending
universals, has a power extending to the infinite; therefore it cannot
be limited by nature to certain fixed natural notions, or even to
certain fixed means whether of defence or of clothing, as is the case
with other animals, the souls of which are endowed with knowledge and
power in regard to fixed particular things. Instead of all these, man
has by nature his reason and his hands, which are "the organs of
organs" (De Anima iii), since by their means man can make for himself
instruments of an infinite variety, and for any number of purposes.
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Whether the intellectual soul is united to the body through the medium of
accidental dispositions?
Objection 1: It would seem that the intellectual soul is united to the
body through the medium of accidental dispositions. For every form
exists in its proper disposed matter. But dispositions to a form are
accidents. Therefore we must presuppose accidents to be in matter
before the substantial form; and therefore before the soul, since the
soul is a substantial form.
Objection 2: Further, various forms of one species require various
parts of matter. But various parts of matter are unintelligible without
division in measurable quantities. Therefore we must suppose dimensions
in matter before the substantial forms, which are many belonging to one
species.
Objection 3: Further, what is spiritual is connected with what is
corporeal by virtual contact. But the virtue of the soul is its power.
Therefore it seems that the soul is united to the body by means of a
power, which is an accident.
On the contrary, Accident is posterior to substance, both in the order
of time and in the order of reason, as the Philosopher says, Metaph.
vii (Did. vi, 1). Therefore it is unintelligible that any accidental
form exist in matter before the soul, which is the substantial form.
I answer that, If the soul were united to the body, merely as a motor,
there would be nothing to prevent the existence of certain dispositions
mediating between the soul and the body; on the contrary, they would be
necessary, for on the part of the soul would be required the power to
move the body; and on the part of the body, a certain aptitude to be
moved by the soul.
If, however, the intellectual soul is united to the body as the
substantial form, as we have already said above [618](A[1]), it is
impossible for any accidental disposition to come between the body and
the soul, or between any substantial form whatever and its matter. The
reason is because since matter is in potentiality to all manner of acts
in a certain order, what is absolutely first among the acts must be
understood as being first in matter. Now the first among all acts is
existence. Therefore, it is impossible for matter to be apprehended as
hot, or as having quantity, before it is actual. But matter has actual
existence by the substantial form, which makes it to exist absolutely,
as we have said above [619](A[4]). Wherefore it is impossible for any
accidental dispositions to pre-exist in matter before the substantial
form, and consequently before the soul.
Reply to Objection 1: As appears from what has been already said
[620](A[4]), the more perfect form virtually contains whatever belongs
to the inferior forms; therefore while remaining one and the same, it
perfects matter according to the various degrees of perfection. For the
same essential form makes man an actual being, a body, a living being,
an animal, and a man. Now it is clear that to every "genus" follow its
own proper accidents. Therefore as matter is apprehended as perfected
in its existence, before it is understood as corporeal, and so on; so
those accidents which belong to existence are understood to exist
before corporeity; and thus dispositions are understood in matter
before the form, not as regards all its effects, but as regards the
subsequent effect.
Reply to Objection 2: Dimensions of quantity are accidents consequent
to the corporeity which belongs to the whole matter. Wherefore matter,
once understood as corporeal and measurable, can be understood as
distinct in its various parts, and as receptive of different forms
according to the further degrees of perfection. For although it is
essentially the same form which gives matter the various degrees of
perfection, as we have said (ad 1), yet it is considered as different
when brought under the observation of reason.
Reply to Objection 3: A spiritual substance which is united to a body
as its motor only, is united thereto by power or virtue. But the
intellectual soul is united by its very being to the body as a form;
and yet it guides and moves the body by its power and virtue.
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Whether the soul is united to the animal body by means of a body?
Objection 1: It seems that the soul is united to the animal body by
means of a body. For Augustine says (Gen. ad lit. vii, 19), that "the
soul administers the body by light," that is, by fire, "and by air,
which is most akin to a spirit. " But fire and air are bodies. Therefore
the soul is united to the human body by means of a body.
Objection 2: Further, a link between two things seems to be that thing
the removal of which involves the cessation of their union. But when
breathing ceases, the soul is separated from the body. Therefore the
breath, which is a subtle body, is the means of union between soul and
body.
Objection 3: Further, things which are very distant from one another,
are not united except by something between them. But the intellectual
soul is very distant from the body, both because it is incorporeal, and
because it is incorruptible. Therefore it seems to be united to the
body by means of an incorruptible body, and such would be some heavenly
light, which would harmonize the elements, and unite them together.
On the contrary, The Philosopher says (De Anima ii, 1): "We need not
ask if the soul and body are one, as neither do we ask if wax and its
shape are one. " But the shape is united to the wax without a body
intervening. Therefore also the soul is thus united to the body.
I answer that, If the soul, according to the Platonists, were united to
the body merely as a motor, it would be right to say that some other
bodies must intervene between the soul and body of man, or any animal
whatever; for a motor naturally moves what is distant from it by means
of something nearer.
If, however, the soul is united to the body as its form, as we have
said [621](A[1]), it is impossible for it to be united by means of
another body. The reason of this is that a thing is one, according as
it is a being. Now the form, through itself, makes a thing to be actual
since it is itself essentially an act; nor does it give existence by
means of something else. Wherefore the unity of a thing composed of
matter and form, is by virtue of the form itself, which by reason of
its very nature is united to matter as its act. Nor is there any other
cause of union except the agent, which causes matter to be in act, as
the Philosopher says, Metaph. viii (Did. vii, 6).
From this it is clear how false are the opinions of those who
maintained the existence of some mediate bodies between the soul and
body of man. Of these certain Platonists said that the intellectual
soul has an incorruptible body naturally united to it, from which it is
never separated, and by means of which it is united to the corruptible
body of man. Others said that the soul is united to the body by means
of a corporeal spirit. Others said it is united to the body by means of
light, which, they say, is a body and of the nature of the fifth
essence; so that the vegetative soul would be united to the body by
means of the light of the sidereal heaven; the sensible soul, by means
of the light of the crystal heaven; and the intellectual soul by means
of the light of the empyrean heaven. Now all this is fictious and
ridiculous: for light is not a body; and the fifth essence does not
enter materially into the composition of a mixed body (since it is
unchangeable), but only virtually: and lastly, because the soul is
immediately united to the body as the form to matter.
Reply to Objection 1: Augustine speaks there of the soul as it moves
the body; whence he uses the word "administration. " It is true that it
moves the grosser parts of the body by the more subtle parts. And the
first instrument of the motive power is a kind of spirit, as the
Philosopher says in De causa motus animalium (De mot. animal. x).
Reply to Objection 2: The union of soul and body ceases at the
cessation of breath, not because this is the means of union, but
because of the removal of that disposition by which the body is
disposed for such a union. Nevertheless the breath is a means of
moving, as the first instrument of motion.
Reply to Objection 3: The soul is indeed very distant from the body, if
we consider the condition of each separately: so that if each had a
separate existence, many means of connection would have to intervene.
But inasmuch as the soul is the form of the body, it has not an
existence apart from the existence of the body, but by its own
existence is united to the body immediately. This is the case with
every form which, if considered as an act, is very distant from matter,
which is a being only in potentiality.
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Whether the soul is in each part of the body?
Objection 1: It would seem that the whole soul is not in each part of
the body; for the Philosopher says in De causa motus animalium (De mot.
animal. x): "It is not necessary for the soul to be in each part of the
body; it suffices that it be in some principle of the body causing the
other parts to live, for each part has a natural movement of its own. "
Objection 2: Further, the soul is in the body of which it is the act.
But it is the act of an organic body. Therefore it exists only in an
organic body. But each part of the human body is not an organic body.
Therefore the whole soul is not in each part.
Objection 3: Further, the Philosopher says (De Anima. ii, 1) that the
relation of a part of the soul to a part of the body, such as the sight
to the pupil of the eye, is the same as the relation of the soul to the
whole body of an animal.
