Name: Jacob Archambault
Phil 1000—Philosophy of Human Nature
Thomistic article analysis: Prima Pars, Q. 75, art. 1
Prof. Archambault
Q. 75. art. 1: Whether the soul is a body
I. Every soul is a body
(Barbara)
A. Every moved mover is a body1
B. Every soul is a moved mover
(v elim)
i. No soul is an unmoved mover
(a, b, Celarent; c, d, Cesare)
a. Nothing is an unmoved mover
(Modal subalternation)
I) Nothing can be an unmoved mover
(Cesare)
A) Nothing gives to another what it does not have
B) Every unmoved mover gives to another what it does not have2
b. Every soul is something
1
This particular objection contains two separate lines of argument in support of the notion that the soul is moved: the first,
treated in footnote 2, argues that nothing is an unmoved mover; the second, treated here, concedes the existence of an
unmoved mover, but argues that the soul is not one. Since the treatment of the second line of argument presupposes the
solution of the first, the second footnote should be read prior to this one.
Aquinas denies that every moved mover is a body by introducing a distinction between being moved per se, or essentially,
and being moved per accidens—that is, by having a relation to other things that are changed. Aquinas posits that the soul
is not moved per se, but only per accidens. Since its changes of state are tied to the random changes going on around it,
we cannot expect the soul's motion to be perfectly regular.
Next, Aquinas defines “body” as a being that is moved per se. So Aquinas' counterargument can be outlined as follows:
Major premise: Every body is moved per se
Minor premise: No soul is moved per se
Conclusion:
No soul is a body.
Lastly, Aquinas reconstructs the implicit reasoning of behind the objection. Aquinas states that certain ancient natural
philosophers held to this view because they thought that only bodies—beings moved per se—existed. So since they
could not distinguish between potentially and actually having motion, they held that every mover is moved. They
combined this with the thesis that every soul is a mover, from which they concluded that every soul is moved.
Combining this with the thesis that whatever is moved is moved per se, they inferred that every soul is moved per se.
This was combined with the thesis that whatever is moved per se is a body from which they concluded that every soul is
a body.
2
The crucial premise Aquinas denies here can be further analyzed as follows: every mover gives motion; nothing which is
unmoved has motion; So if something is both a mover and unmoved, it both gives motion and does not have motion.
This contradicts the axiom that nothing gives what it does not have, thus entailing that there can be no unmoved mover.
Aquinas responds with a counterargument proving the contradictory of the wider-scope sub-conclusion—against the proof
that nothing can be an unmoved mover, Aquinas argues that something must be an unmoved mover. In the process of
doing so, he shows why the premise “Every unmoved mover gives to another what it does not have” is flawed.
Aquinas does not give the full proof in the context of his response, but instead a) reiterates the crucial premise of the
counterargument—that an infinite regress of moved beings is impossible; and b) refers his reader to the text of the
Aristotle's Physics for the remainder of the proof. The proof can be sketched out as follows. Take some object A, which
is moved by another object B. If B is moved, then it is also moved by something else. It cannot be moved by A, since A
doesn't have any movement to give to B prior to B's moving A. So it has to be moved by another object, C. For the same
reasons, C would have to be moved by D, and so on to infinity. But if this were so—i.e. if every mover were moved, and
if every movement was movement by another—then one would never be able to get back to a first movement that started
the movement of all the others, and thus there would be no movement at all even now. But experience shows us that
there are things that move. Therefore, there must be an unmoved mover.
But if this is so, wouldn't this entail that something would give what it doesn't have—in this case, motion—to another?
Aquinas denies this by denying the premise “nothing which is unmoved has motion.”
Aquinas states that “To be moved is to exit from potency into actuality.” In other words, motion is a) a kind of change in
which b) what is moved moves from a lesser state into a higher state of perfection. So if there is a being which is
absolutely perfect, then that being cannot be moved, since that being cannot exit from its present state to a higher state of
actuality (there isn't one). Aquinas will say elsewhere that such a being has motion virtually, since it has the perfection of
motion within itself, but not actually, since it is not itself subject to motion . So this being (which Aquinas identifies
elsewhere as God) must be able to move others, and therefore have motion, without being moved itself.
c. Every unmoved mover causes and has sempiternal motion
d. No soul causes and has sempiternal motion
ii. Every soul is a mover
(Barbara)
a. Every mover of a body is a mover
b. Every soul is a mover of the body
II. The soul is a body
(Barbara)
A. Whatever is like a body is a body3
B. The soul is like a body
(Modus Ponens)
i. If one being cognizes another, then it is like it
ii. The soul cognizes bodies
III. Every soul is a body
(Barbara)
A. Whatever comes into contact with a body is a body4
B. (Soul comes into contact with the body)
(Barbara)
i. Whatever moves a body comes into contact with it
ii. Soul moves the body.
Summary
The order of St. Thomas' response is as follows: first, he defines soul; then he supports this
definition with an example; third, he distinguishes the operations of the soul; fourth, he assigns a cause
to the error of those who hold that the soul is a body; fifth, he refutes that error.
St. Thomas defines soul as first principle of life in those beings among us that are living. The
Latin word for “soul” is “anima”. Thus, Thomas says, we call living things “animate” and non-living
beings “inanimate.”
We come to know what kind of entity a being is via its activities, or operations. The chief
operations of the soul are two: motion and cognition. Both of these words have wider meanings in
Thomas' vocabulary than they do in ours.
Thomas uses the word “motion” to signify not only change of place, but also just about any
change whatsoever, including the growth of plants and the changes in attitude or emotional state. In
English, we use the word in a way closer to Thomas' definition when we say, for instance, that a film
“moved me to tears.” This English usage also captures another important sense of Thomas' notion of
movement: that movement is always primarily on account of another being e.g. the film moved me. In
other words, Thomas tends to thinks of motion primarily as an elicitation, and only secondarily as selfmovement. This gives an additional reason for searching for a principle of movement in beings as
opposed to resting content with the notion that the movement of entities is essentially spontaneous.
For Thomas, “cognition” signifies nothing particularly scientific, and nothing peculiar to human
beings. Taken broadly, “cognition” signifies any kind of mental operation performed by a sensate being.
We might use words like “awareness,” “acquaintance” or “recognition” to signify something similarly
basic.
Since we know the soul via its operations; and since the operations of the soul are motion and
cognition, the most straightforward way for our knowledge of the soul to fail would be to misconstrue
or misidentify the source of these operations. Hence why a) the objections that Thomas forges are all
3
St. Thomas denies that Everything that is like a body must be a body. The objector presupposes that the only way for there
to be a likeness between two things—in this argument, a cognizer and what it cognizes—is for the one to be the other.
For instance, if something is like a rock, then it must be a rock. As in footnote two above, St. Thomas has recourse to the
distinction between potency and actuality. A cognizer is not like what it cognizes by actually being the things that it
cognizes, but by potentially containing within itself the things that it cognizes. Thus, there remains a likeness between
body and soul without the soul's being corporeal.
4
St. Thomas denies this premise. There are two kinds of contact: of quantitative and virtual. Only for the former kind is it
necessary that the agent of change be a body.
concerned with one of these two operations: if the peculiar operations of the soul could only be
performed by bodies, then the soul itself would have to be a body; and b) Thomas associates the
identification of soul and body on the part of certain ancient philosophers with a failure to transcend
imagination: these philosophers all thought of the soul as the cause or principle of the above mentioned
operations, but they could not conceive of anything that wasn't a body, and thus had to regard the soul
as a body.
Thomas' argument against the identification of soul and body is carried out in three parts: first,
he argues against the identification of the soul with any “principle of life” and defines it more
specifically as first principle of life; second, he shows that body taken generally cannot be a first
principle of life; third, he shows that the soul cannot be a body at all.
In his argument against the identification of soul and body, Thomas first refutes the notion that
any principle of any vital operation indiscriminately could be a soul. This would lead to many
absurdities: for instance, my eye would be a soul, since it is a principle of the vital operation of vision;
for similar reasons, my heart, brain, kidneys, and stomach, lungs, etc. would also be souls, which would
also entail that I have a lot more souls than I thought. So it is necessary that the soul be not just any
principle of life, but a first principle
Next, Aquinas refutes the identification of soul and body in general via the following modus
tollens: if every body were a soul, then it would follow that every body were living—in other words,
there would be no distinction between animate and inanimate bodies; but not every body is living.
Therefore, not every body is a soul. So if the soul is a body, it can't be just any body.
Lastly, Thomas refutes the identification of the soul with some particular body, such as the heart.
Today, many philosophers and scientists do this when they construe the brain as the source of all
human activity and identify the soul with the brain. Thomas' argument is as follows.
To be a soul is to be a first principle of life of an entity. And to be first principle of life of a
corporeal entity is to be the act of a body. So if the soul were the act of some body (e.g. Socrates), and
were also some part of that body (e.g. his brain), then, since the soul is the act of a body, and the brain
is also a living body, we would be forced to ask again, “What is the principle of life of the brain?” In
other words, answering the question “what is the soul of this body?” by pointing to another body
doesn't answer our question: it just displaces it. So it is impossible to genuinely answer the question
“What is the soul of a human?” by pointing to some physical part of the human being. Thus, the root
principle of life in a human being cannot be a body.