robert heinaman, aristotle and the mind-body problem

7/30/2019 Robert Heinaman, Aristotle and the Mind-Body Problem

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Aristotle and the Mind-Body Problem

ROBERT HEINAMAN

In this paper I will argue that Aristotle's position on the mind-body problem

is probably best characterized as dualism. The question of whether dualismis true divides into three questions: Are there immaterial, non-physicalsubstances? Are there non-physical mental events? Are there non-physicalmental properties? Since Aristotle's position is clearer with regard to the

first two issues than the third, I will confine the discussion to an examination

of Aristotle's position on those questions. Section I deals with Aristotle's

commitments in relation to the question about substance and section II

deals with the issue in relation to events. An alternative account of Aristot-

le's position on the second issue is examined and rejected in section III.I will argue that, with reservations, it is plausible to say that Aristotle

accepts the existence ofnon-physical substances. On the question of mental

events, I will argue that Aristotle's position is at odds with both the dualist

and the physicalist views, but since in this case too it is plausible to say that

Aristotle accepts the existence ofnon-physical events, his overall position is

best classified as dualist. The evidence drawn on occurs largely in the

comparatively neglected first book of De Anima.

Many have thought, correctly, that Aristotle's views on the intellectcommit him to some sort of dualism with regard to the rational soul, but

reject this as an accurate representation of his position for other types of

soul - sensitive, nutritive, etc. My argument in section I rests on no

assumptions about the soul peculiar to the intellect. Aristotle's dualism

regarding the soul holds for any kind of soul, including the souls of plants.

However, section II deals only with psychic events which have the soul as a

subject. Digestion and other actualizations of the nutritive soul are not

mental events because the proper subject of digestion, for example, is thebody alone.


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I

What must Aristotle believe in order to hold a dualist view of the soul? Of

course, he must believe that.

(1) the soul is an immaterial entity,but clearly more is required. A materialist might believe that the structure

or shape of some wooden object is an immaterial entity - it is not made out

of matter - without abandoning his materialism. The shape, like weight or

velocity, will count as a physical property, and this the materialist is happyto accept. Similarly, even if Aristotle accepted (1), he might think of the

soul as a kind ofphysical attribute of the body and so not be what we wouldwant to call a dualist. More is needed.

Belief in the possibility of the soul's existence separately from the bodysuffices to make one a dualist, but Aristotle rejects that belief for at least

most types of soul. If Aristotle is committed to dualism, he must be

committed to a weaker version of it which admits that the soul cannot exist

apart from the body.The question of whether Aristotle had some Cartesian concept of con-

sciousness is irrelevant to the issue, as Robinson has pointed out. Amaterialist might accept such a concept while a dualist might reject it.

Nowadays the mind-body problem revolves around the question of

whether psychological entities and laws are reducible to physical entities

and laws (or eliminable altogether). There is no question of Aristotle's

wishing to reduce "psychic laws" to physical laws (or eliminate anything),so the relevant question with regard to Aristotle is: does he reduce psychicentities (such as souls and mental events) to material entities (such as bodies

and physical changes)?The fact that Aristotle considered the soul to be an immaterial entity

irreducible to matter is put beyond doubt by his arguments in De Anima 1. 3

and 4 which purport to prove that the soul is changeless.2In 1.2, 403b25-27, Aristotle had said that the living have been thought to

differ from the non-living in virtue of two characteristics - movement and

perception. Since it is the presence of a soul that distinguishes the livingfrom the non-living, the soul of a living thing should explain why it is able to

move. And it was thought that this explanation would first have to posit thatthe soul moves, and then say that the body of a living thing is caused to move


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by the soul's motion. This account entails materialism, for the soul can

move only if it is a material object.3

Thus, for example, Democritus held the soul to be composed of fine

spherical atoms which move, bump into coarser atoms constituting the

body, and thereby cause it to move. And, of course, since Democritus'

atoms were material objects he had to say that the soul was a material

object.

Aristotle agrees that the soul of a living thing explains why it moves as it

does, but he rejects the suggestion that the soul moves the body in the

manner proposed by Democritus by arguing, in 1.3 and 4, that the soul

cannot change at all.

Why does Aristotle reject the possibility of a soul undergoing change? As

Alexander points out,4 it is because the soul is a form, and all forms are

immaterial, and hence changeless.'

The soul, being a form, is not a body6 and hence has no magnitude' and is

not divisible into parts with magnitude. According to De Anima 409al-3


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and the arguments of Physics VI.4 and 10, this excludes the possibility of

the soul's changing.8

The conclusion that the soul is changeless was an important development

in Aristotle's views which is linked to other changes ofposition, for example

in his account ofpleasure. Previously Aristotle had not hesitated to speak of

the soul as the subject ofchange. In the Categories the soul is the substance

which is the proper subject for different kinds of qualities (la25-26, 9b33-

35), and a distinguishing feature of a substance is its capacity to persist

through a change between contraries (4al0-b19). Similarly, the Protrepti-

cus thinks of living as a change undergone by the soul (B80, 83 - Diiring),

and the Topics too speaks of the soul's changing (120b2l-26, l23a15-l7).9

At this stage Aristotle apparently is willing to say that if F and G are

qualities whose proper subject is the soul, then the soul's transition between

F and G is a change in the soul.

By the time he wrote Physics VII, Aristotle was no longer willing to

accept this. There we find a rather strange intermediate position where

some but not all transitions between different qualities of the soul are

changes. The intellectual part of the soul both acquires and uses knowledge

but neither is an alteration - a qualitative change - in the intellect. But this is

not due to any difference between soul and matter, for the perceptive soul

does undergo alterations (244b10- 12, 247a4-17, 248a6-9)10 and some transi-


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tions of state in material objects are not alterations but completions (or

What Aristotle wishes to prove in VII.3 is that alteration

occurs in a subject - soul or matter - only with respect to qualities which are

perceptible. If the qualities in question are not of that kind but are rather

conditions, states or shapes, then the subject - soul or matter - transitingbetween them is not thereby altered. If the qualities are perceptible, then

the subject - body or soul - is altered. Since the intellect is not affected by

sensible qualities, it is only the perceptive part of the soul that suffers

alteration.

Aristotle's ascription of change to the soul in these earlier phases does

not mean that he was then a materialist, any more than in Plato's case."

Rather, by the time he wrote De Anima he had more clearly thought out

what was required of a proper subject of change and had concluded that

such a subject could not lack magnitude. Believing that souls lack magni-

tude he had to conclude that souls are changeless.But why did he come to believe that a subject of change must possess

magnitude? The answer can be found in Physics VI.4, 234b10-20.'z In any

change there is a subject, starting-point and end-point of the change. The

end-point of the change is the newly acquired feature; the starting-point is

the feature lost in the change; and the subject is what persists throughoutthe change, what begins with the starting-point and finishes with the

end-point.

Suppose that a subject is changing from A to B, where B is what the

subject "first" changes into rather than an extreme 6 pEIa@6XXEIto

1tQw'tov). For example, if A is white, take B to be grey rather than black.

Suppose the subject is now engaged in the process ofchanging from A to B.

Then, Aristotle argues, the subject cannot be in A as a whole for then the

subject would be at the starting-point of the change rather than changing.Nor can the subject be in B as a whole for then it would be true that it has


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become B, not that it is becoming B. Since the subject cannot as a whole be

in both A and B or in neither, part of the subject must be in A and part in

B.13 But that means the subject of change, any subject of change, must be

divisible into parts. Since the soul, like any form, is not divisible into parts,it cannot change. Therefore it is immaterial, since for Aristotle all matter is

changeable and divisible. And since there is no question but that Aristotle

considered the soul to be a substance, 14 the soul is an immaterial substance.

But before we can secure the claim that Aristotle is a dualist, a further

question must be addressed: does Aristotle consider the soul to be the

organization of the body ?15For those who think that being an organizationconflicts with being a substance, this possibility is ruled out. But Meta H.2

makes it doubtful that Aristotle agrees. And if artifacts are substances,

their forms are substances, but in many cases such a form will be the

organization of the artifact's material parts. So the interpretation which

understands Aristotle's soul to be the organization of the body which

enables an organism to engage in certain types of behavior cannot be clearlyruled out on this basis. And if the soul were simply the organization of the

body, then it would be far from clear that the soul is a "non-physical" entity.

The characterization of Aristotle as a dualist would be very dubious.

But there is a conclusive objection to this interpretation: in De Anima 1. 4

Aristotle argues that the soul is not the organization of the body.If Aristotle were to express the view that the soul is the organization of

the body, what Greek word would serve for 'organization'? The possibil-


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ities seem to be: iay5 (arrangement), xgtaig or (mixture), k6yog

(proportion), aOv0Eaig (combination), bi60Eaig (state) or iig (condi-

tion). The first word does not occur in De Anima, but the next four do, in I .4

where Aristotle argues that the soul is not a mixture or proportion or

combination of bodily parts.There are three things to be distinguished here. A combination ofbodies

is a juxtaposition of particles of the bodies which leaves the nature of the

original particles intact. For example, I might throw sand and sawdust

together in such a way that particles of sand and sawdust lie next to each

other and are still particles of sand and sawdust. But when two bodies are

mixed they act on one another in such a way that the natures of the original

bodies are altered to a different nature - a kind of chemical reaction takes

place. 16 And the proportion is simply the ratio of the amounts of the mixed

or combined bodies.

If, as Aristotle argues, the soul is not any kind of combination or mixture

or proportion, then it cannot be an organization ofbodily parts. It is useless

to appeal to the notions of arrangement or state or condition and ascribe to

Aristotle the view that one of these terms expresses the type oforganizationof bodily parts with which the soul is to be identified. For in De An. 1.4

(408al-3) Aristotle says that, unlike the soul, it would be correct to identifyhealth or the other bodily virtues with a harmony ofbodily parts. And Meta.

E.19 and 20, after defining a state (bi60Eaig) as an arrangementof what has parts, says that a condition is a kind of state, and giveshealth as an example." So health is an arrangement of bodily parts, a

condition and a state ofthe body; and given De An. 408al-3's contrast of the

soul with health, the conclusion must be that, for Aristotle, the soul is none

ofthese. For every term X that might express the concept oforganization in

Greek, Aristotle denies that the soul is an X of bodily parts. The view thatAristotle considers the soul to be some organization of the body is false.

Further evidence that Aristotle rejects the view that the soul is the

organization of the body is supplied by the fact that although Aristotle

defines the soul as the form of the body, he at times suggests that an

animal's soul is "located primarily" in the heart.'8 This would make no


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sense ifthe soul were the body's organization: a body's organization is not

"located primarily" in any bodily part.The point is put beyond question by Aristotle's insistence (408b20-29)

that the soul is unaffected by (non-fatal) damage to the body of a living

thing.19 If the soul were the organization of the body that constitutes the

living thing's capacity to engage in certain kinds of behavior, then the partof the soul which is an animal's capacity to see would have to comprise the

organization of the animal's eyes. In which case the destruction or cripplingof the eyes of an animal would at the same time destroy that part of the soul,

since the relevant organization would be destroyed. But this is just what

Aristotle rejects: an old man, he says, could see as well as a young man if he

were given a new eye. The damage to the physical eye leaves the soulunaffected. So the relevant part of the soul continues to exist even when the

bodily organization is gone, and hence the soul cannot be that organization.

The soul of a living thing is not an organization ofbodily parts, but rather

something which supervenes on bodily parts when they have been orga-nized in a certain way ptXXov IEg6v 'tL ovQa (ion

eyyLVEiaL tois The point is made with great clarity by

Alexander.2 Aristotle certainly believes that the soul of a living thing is

dependent for its own existence on the existence of bodily parts arranged ina certain way .21But the fact that this organization is a necessary condition

for the soul's existence does not require us to identify it with the soul.

Rather the soul is a dynamis that supervenes on the body

when the organization of matter has reached certain level. From the ac-

count we find in De Generatione Animalium (735al4-17, 736a35-b4) we can

see that different soul-constituting capacities will supervene on the material

organization at different stages of the living thing's development.

The soul is a form and all forms are immaterial entities. But forms can berelated to matter in three ways:

(1) A form which is a structural or physical feature ofmatter, e.g., the form

of an artifact such as a house, or a color, or a certain arrangement of

bodily parts such as health.


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(2) A form which is not an immediate structural or physical feature of

matter but is supervenient and dependent for its existence on immedi-

ate physical features of matter - such as the power of a drug, according

to Alexander, and the soul, according to Aristotle.

(3) A form which does not depend on matter or material features for its

existence.

If Aristotle held the soul to be a form of the third sort he would be a

Cartesian dualist. At most he thinks the intellect is such a form. If Aristotle

held the soul to fall into (1), then there would be at least some plausibility in

labelling him a materialist, despite the fact that the soul would still be an

immaterial substance. I have argued that Aristotle believes the soul to fall

into the second class of forms. Since this makes his position very like that of

present day "emergent dualists", it is, I think, best to classify Aristotle as a

dualist.

So: on the standard account of the dualist-physicalist distinction the

former accepts the existence ofnon-physical entities and the latter does not.

Non-physical entities are explained as being entities irreducible to physicalentities. On this understanding of the issue, Aristotle is a dualist.

But there is a complication in that this account of the physical-non-

physical distinction, and hence of the physicalist-dualist distinction, is

inadequate. Philosophers disagree as to whether a dispositional propertysuch as fragility should be considered a real property distinct from its

physical base - say, the molecular structure ofglass. Suppose Jones believes

dispositions are real properties but rejects the identification of them with

their physical bases. Then Jones might consider fragility to be an emergent

property that supervenes on certain physical states but is irreducible to anyof these material bases. That in no way commits Jones to denying that

fragility is a physical property.

Likewise, the irreducibility of a form of kind (2) need not show that it is

non-physical. Given this unclarity, it also becomes unclear whether 'dualist'

is the correct label to apply to Aristotle's position.

Furthermore, Alexander' compares the soul with the power of a drug

which is not identical to the matter it is found in or to the matter's orga-nization. The comparison suggests that Alexander does not see any radical

break with the physical when the soul supervenes, and there is no evidence

to suggest that Aristotle did either.

Hence, the interpretation of Aristotle as a dualist remains problematicfor two reasons: (i) at least as far as I know, there is no account available


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enabling us to draw a clear distinction between non-physical and physical

emergent entities or, hence, between the dualist and the physicalist; (ii)

even if such an account of the physical-non-physical distinction were or is

available, there is no reason to believe that it or anything like it entered into

Aristotle's thinking about the soul.

II

Aristotle explains what he considers a psychological event to be at the end

of De Anima L 1, 403a3-b19. He begins by asking whether psychic events

belong only to the soul of the living thing or also have the body as a

subject. And from the succeeding lines it is apparent that Aristotle equates

this question to the following one: Is it true that, for any appropriate

predicate F, "the soul (of the living thing) is F" entails "the body is

changing?" Aristotle goes on to claim that with the possible exception of

thinking, the entailment always holds. So, apart, possibly, from thought,

any psychic event involves a bodily change.Aristotle then (403a24-b19) proceeds to say that for at least most psychic

events, there will be a bodily change which is not merely necessary for its

occurrence but serves as the matter of the psychological event which, like a

material substance, is a composite of form and matter. If so, what is the

form of a psychic event? The matter is a change in the body. The form will

be something true of the soul since Aristotle hasjust explained that psychic

events are common to body and soul. It cannot be a change given that that is

the material part of a psychic event and a soul cannot change.Since the formal aspect of a psychic event is a feature of the soul and must

also be an occurrence and not a power or condition of the soul, the only

alternative among the menagerie of Aristotelian beings is an activity in thesense contrasted with change in Meta IX. 6 and EN X.4. So a psychic event,

for Aristotle, is a composite of activity and change. The activity (form)

takes place in the soul of a living thing and the change (matter) occurs in its

body. The composite psychic event is not an activity any more than the

composite human being is a soul.

The end of De An. 1.1 shows that there are only two possibilities: an

activity such as seeing red must be either the form of a psychological event

or a composite of form and matter where the matter is a bodily change. Butthe second alternative is not possible.

Aristotle believes that a change necessarily occupies a period of time

(Phys. 234a24-31) because it is itself divisible into temporal parts with

"magnitude". This structure of a change is determined by the analogous


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a bodily change - C. Then there are two possibilities. Suppose t is the first

moment of activity A. Either (1) t is a limit of the time occupied by C - at t

and prior to t C does not exist but for a period of time of which t is the first

limit it does exist; or (2) C begins to exist before t.

On (1), "all" of the temporally indivisible activity A exists at t but C does

not. Therefore C could not constitute A.

On (2), since C exists before t and moments are not next to one another,

there will be a period of time occupied by C prior to t. Now if C is the

material part of the activity, then the time needed for the change to come to

be from the last moment of the period ofrest until t will also be time needed

for the activity's coming to be. If the change constitutes the activity in the

way Socrates' flesh and bones constitute Socrates, then the stages of the

change's coming to up until t will be stages of the activity's coming to

be, just as stages of Socrates' body coming to be are stages of Socrates'

coming to be. And the time necessary for the stages of the change prior to t

to pass by will also be time necessary for the activity to come to be. So

contrary to EN 1174b9-14, there will be no difference on this score between

change and activity.

Since, then, an activity cannot be a composite the matter of which is a

bodily change, the only alternative is that an activity is the formal aspect of a

psychological occurrence, i.e. it is that part of a psychological occurrence

the proper subject of which is the soul.

Not only do activities occur in souls, they occur only in souls. This claim

receives support from the examples of activities listed by Aristotle which

are all psychic occurrences: thinking, perceiving, living, living well, plea-sure.24 And the clear implication of EN 1173b7-13 is that the soul is the

subject even of activities that are bodily pleasures. Further, a soul has no

magnitude and it is certain at least that the nature ofan activity is not such asto demand that its proper subject be an entity possessing magnitude. Phys.

VI. 4's argument that the subject of a change possesses magnitude rests on a

distinctive feature ofchange: it has a path with starting-point and end-point

(and intermediate points) which are specifically different. And it is conse-

quently argued that - ifA and B are two such features on a path ofchange -

then since a changing subject cannot be A as a whole or B as a whole, part of


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the subject must be A and another part B. But an activity has no path.

There is no distance from one quality, quantity or place to another covered

by the subject of an activity. So VI.4's argument cannot be applied to derive

the conclusion that the subject of an activity possesses magnitude."

Furthermore, the indivisibility of the subject of an activity may be neces-

sary given Aristotle's view that a change, its subject and time are all alike

divisible or indivisible (Phys.. 235a13-b5), whereas the time of an activity

may be indivisible (EN 1174a14-19, b7-14). For this may imply that the

subject of an activity cannot be necessarily divisible, as any material object

is.

Many will object that activities cannot be restricted to psychic events

because, e.g., walking and housebuilding must (or can) be counted as

activities. One motivation for this view is the "tense-test" according to

which Xing is an activity if "A is Xing" entails "A has Xed". But on

Aristotle's own view (Phys. VI.6) "A is walking" entails "A has walked".

Again, activities are ends, but people may walk for its own sake, and in that

case it is an activity.I cannot fully reply to this objection here, but it rests on a misunder-

standing of Aristotle's distinction, including the failure to appreciate that

activities and changes fall under hierarchies of species and genera just asitems in other categories do (Phys.. V.4). Aristotle is drawing a distinction

between mutually exclusive classes of beings, not between verbs or verb-

phrases. Nor is the distinction based on a grammatical difference.

In Phys. VI. 6 Aristotle argues that it may be simultaneously true that A is

changing and A has changed, but this does not mean at all that a change is

an activity. Suppose A changes place from B to E in time t1 to t4.

Aristotle thinks that there are infinitely many points (or places) along the

path B-E to which A can be said to be changing in the course of tct4. VI.6's

claim is that ifwe pick out one of these, say the change from B to D, then


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when A is changing from B to D, A has changed a different change, say from

B to C (and infinitely many others).This does not show that change is an activity for two reasons. (i) In the

"tense-test" it must be the same change that is referred to by the presentand the perfect (Phys. 231b28-232al), but in VI.6 different changes are

referred to by the present and perfect. (ii) The tense-test, properly under-

stood, does not state that the truth ofone statement is or is not simultaneous

with the truth of another statement. Rather it asserts that non-linguisticstates of affairs (or events) are or are not simultaneous. In VI.6 "A is

changing" and "A has changed" may be simultaneously true statements,

but the relevant point is that the state of affairs referred to by the second

is earlier than the event referred to by the first (236b34, 237b5).Here it is also essential to bear in mind that just as "A's walking"and "A's

walking from B to D" denote the same being, so "A is walking" and "A is

walking from B to D" both refer to the same being. And we have already

seen that it is impossible for the same thing to be an activity and a change.Note too that housebuilding (or walking), like changes and unlike activ-

ities, (1) can be fast or slow, and so (2) must occupy time; (3) is divisible into

parts specifically different from each other and the whole (cf. Phys. VI.4,

EN X . 4) ; (4) has a divisible path with different starting- and end-points; (5)ends with an old feature lost and a new feature deposited in the subject of

change; (6) has an end - the house - distinct from itself and so (7) is not

indefinitely continuable; (8) depends for its species on what happens later:

if no house results it wasn't housebuilding after all. Furthermore, these

characteristics of housebuilding (or walking) are unrelated to the questionof whether the housebuilder engaged in housebuilding for its own sake or as

a means to an end. For example, Jones' housebuilding for its own sake

cannot bring it about that his housebuilding need not occupy time or isindivisible into specifically different stages.26 As Aristotle explains in Meta.

IX.6, the end (in the relevant sense) of walking is a limit ofthe walk. Since


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walking and housebuilding cannot be their own limits they cannot be ends in

the relevant sense.

Now in order to see that the above interpretation of a psychic event fits

Aristotle's text, one has to take into consideration an ambiguity in terms

referring to psychic events. This ambiguity corresponds to the ambiguity of

terms referring to substances which are composites of form and matter. In

the Metaphysics terms such as 'man' and 'horse' are used either to refer to

the form on its own, i.e., in these cases, the soul, or to the composite of form

and matter." Similarly for psychological terms such as 'perception' and

'anger': they refer to composites of form (activity) and matter (change) but

can also be understood to refer to the activity alone. And this is what 'anger'

denotes when the dialectician defines anger as the desire to return pain for

pain (403a30-31). Omitted is any reference to the matter of the composite -a bodily change - which must be taken into consideration by the natural

scientist who studies anger. (The same ambiguity will apply to 'desire').28


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At the end of Book II (424b16-18) Aristotle says that smelling is some-

thing over and above undergoing a change (1tOXELVTL), i.e. over and

above the matter of smelling, viz. perceiving (16 pv oO.ta08aL xai

aLo6dveo6aL). 'Perceiving' here refers to the formal aspect of the per-

ception apart from the change in the body of the smeller. It must do so if it

states the formal aspect of the perception. For if 'perception' here denoted

a composite, then perception could not be what smelling is over and above

(napa) a bodily change.

So a typical psychological event is a change in the body as well as an

activity, just as Socrates is flesh and bones as well as a soul. Perception,

recollection, anger, fear and shame (e.g.) are bodily (awpaIix6v) events

(De An. 427a27, Parva Nat. 453al4-15, 26, EN l128b13-l5), unlike think-

ing which is not a bodily actuality (De An. 427a26-27, De Gen. Anim.

736b21-29, EN 1117b28-31), even if it requires one (viz. imagination) in

order to occur in human beings. 21 So while Aristotle disagrees with the

materialist in holding a psychological event to be not reducible to a bodily

change, he also disagrees with the dualist in holding a psychological event to

be a bodily event, for the matter of such an event is a physical change.

The relation between the change and activity composing a psychic event

can be causal. Which way the causal relation runs will vary with the type ofthe psychic event. Thus, at De An. 408b15-18 Aristotle says that in the case

of recollection the change occurring in the body may be caused by the soul,

i.e., I suggest, by the form of recollection, an activity occurring in the soul.

On the other hand, in the case ofperception the causal chain must proceedin the opposite direction - a sequence of changes in the body leads to the

occurrence of an activity in the soul. Similarly, Parva Nat. 436b6-7 says that

perception comes to be in the soul via the body. 30

It is in this way that, in the case of psychic events, the soul is an efficientcause ofbodily events. David Charles3' has objected that the soul cannot be

an efficient cause of physical events because any such cause must have

extension and magnitude and be divisible. A mover moves another thing

only if it comes into contact with the moved object. Given Aristotle's

definition of contact,32 only a material object can have contact, and that


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with another material object. So a mover, like a moved object, must have

extension and magnitude. The soul lacks magnitude and extension, and

therefore it cannot be a mover, or at least can be one only incidentally in

virtue of existing in matter which is, properly, a mover.But Aristotle believes only that whatever moves an object naturally

must do so by coming into contact with it and hence itself suffers a

reaction from the moved object (Phys. 20la24-25, 198a27-29, 202a3-9, De

Gen. Anim. 768b15-25). And as Aristotle points out in De Anima (406b24-

25), it is precisely not in this way that the soul moves the body but "through

choice and thought". Aristotle does not elaborate, but since he is explicitly

ruling out the soul's changing being a cause of the animal's motion, 'choice'

and `thought' can only refer to activities (or perhaps sequences ofactivities):choice and thought must be actualities and there is no other kind of actuality

that is an occurrence available in Aristotle's ontology.33

Further, De Gen. et. Corr. distinguishes two types of efficient cause. In

every case the moved object will be a physical magnitude, but only certain

movers properly touch the moved object, viz. those which themselves have

position and magnitude (322b32-323al, 5, 10-12; cf. De Gen. Anim.

768b15-25). In these cases the mover will be a moved mover because it will

in turn be acted on by the moved object. So if A moves B in this way, both Aand B have magnitude, and A will touch B and B will touch A, and A will

move B and B will move A.

But sometimes the mover A is without magnitude, and then A will

"touch" B but not be touched or, hence, moved by B in return (ia bi

1tOLEL1ta8f] 6vIa - 328a22; cf. 323a13-34, De An. 406a3-4, Phys. 258al8-

This describes the relation between soul and body demanded byAristotle's account of self-motion in Phys. VIII.5. The soul is immaterial

and withoutmagnitude and hence cannot be touched by the body which it

moves. And so it cannot be moved in return, and hence is an unmoved

mover.

So it is clear that Aristotle does not believe that only material bodies can

be efficient causes of change.


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III

To close I will consider a possible objection to my conclusion that what a

psychic event is over and above a physical change is an activity. For

according to one popular view Aristotle is a functionalist , and on this view

a mental event is, in addition to a material change, a certain functional

characteristic; or perhaps rather the material change which is (alone) the

mental event has such a characteristic. According to functionalism a certain

type ofmental event is to be defined in terms of its causal role, specifically in

terms of its causal relations to sensory input, behavioral output, and other

mental states. This would allow Aristotle to give a materialist account ofpsychological events for a physical event may have such a causal role. But

whether the causal role is counted as a physical or non-physical property, it

will be a disposition of the material change which is the matter ofthe psychicevent and not, as I claimed, an activity. Hence, the form of a psychic event

is not an activity possibly causing or caused by the bodily change but the

causal role of that change.It should be noted, to begin with, that there is no evidence that Aristotle

shares the belief which is one of the main motivations of functionalism, viz.the belief that the same mental state can have different physical real-

izations. For example, different species of animal can, it is said, have the

same mental state even though its physical realization will differ in the

different species. And then it is concluded that a type of mental event

cannot be identified with a type of physical event. On the other hand,

functionalism easily handles this possibility of multiple realizations.

It is true that Aristotle allows that the same psychological event may be

found in different species of animal (Hist. Anim. 588a15f. ; cf. De Part.Anim. 639a15-22, 645b3-6) but nothing he says suggests that he believes

that the physical basis of the same psychological state will vary. It may be

that he thought, e.g., that boiling blood is the physical basis of anger in

every species of animal that can experience anger.There are good reasons to reject the view that Aristotle is a functionalist.

To begin with, for the functionalist the only essential features of a psycho-

logical event are its functional features. Thus, while brain matter may in


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fact realize pain in man, it is possible that eventually some synthetic

material should come to play the causal role ofpain, and then the syntheticmaterial would realize pain. Generally, it is an essential feature of function-

alism that it allows the same psychological state to be realized in different

types of matter or event. Aristotle rejects this. At the close ofDe An. I.1 he

says that it is part of the definition ofanger that it is boiling blood. 36 He does

not say that it is in part matter which must have features enabling it to play

the causal role of anger. Similarly, fear is defined as refrigeration (De Part.

Anim. 667al2-19, 692a24-25, Rhet. 1389b32), i.e. as being that specific typeof change, not merely as whatever type of change has certain causal

features.

Further, suppose one accepts, as I do, Richard Sorabji's interpretation 31according to which the vision of a red object consists in, as far as its matter is

concerned, the eye-jelly becoming red. Could this specific type of changenot be necessary for the perception of red? Could the matter ofseeing red,

for Aristotle, be a change to yellow, green or any other sensible quality?

No, because Aristotle thinks that the perception of a sensible qualityinvolves the sense organ becoming like the perceived quality (De An.

418a3-6, 422a7, b14-16, 423b27-424a2, 424a7-10, 17-18, 425b22-24). If so,

the specific change of becoming red is necessary for the perception of red,and a similar point applies to the rest of the five senses: the organ must

acquire the specific quality perceived. Contrary to a functionalist view,

Aristotle considers specific types of perception to be tied down to specific

types of bodily change.

Secondly, Aristotle allows that one's body can be in the same condition as

it is when one is in a certain psychological state but not be in that psycholog-ical state (De An. 403a21-22). This is incompatible with a materialistic

functionalism for aphysical

statewhich realizes a certain psychologicalstate in human beings cannot fail to have the functional features which

make it the realization of that psychological state when it exists in a person.

Thirdly, if we look at some of the formal definitions of psychologicalevents given by Aristotle, they often fail to conform to the functionalist

style of definition. For example, in Rhet. 11.3 Aristotle first defines growingcalm as the quieting of anger and then explains what can cause it.

Consider the psychological occurrence of theoretical contemplation. A

typical

cause of this event will be the theoreticalknowledge

which is the


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potentiality for that actuality, just as knowledge of the art ofhousebuildingis a cause of its actuality of housebuilding (Meta. 1032b21-23, De Gen.

Anim. 730b15-19, De Gen. et Corr. 324a35-bl, 335b32-33). But Aristotle

rules out defining the actuality in terms of the potentiality (Meta. 1049b12-

17, De An. 415a18-20). So not all of the typical causes ofcontemplation are

used to define it, and a parallel point holds for any psychological occur-

rence. Again, when Aristotle says at EN 1177b2 that nothing comes to be

from contemplation apart from the contemplation itself, this means at least

that the definition of contemplation will not incorporate any statement

asserting that it causes certain effects. Nor could any final causes be re-

ferred to in a definition of contemplation. So the psychological event of

contemplation is not functionally defined by Aristotle, and therefore hecannot have wanted, in general, to give a functional account of mental

events.

Finally, a functional characteristic is a quality - a disposition - whereas a

psychological event is an event, falling into the category of doing (1tOLELV)or suffering Aristotle can no more allow an event to be consti-

tuted by a quality than he can allow a substance to be constituted out of

qualities (De An 410al3-22; Meta. 1038b23-27, 1039a30-32, 1070b2-4,

1073a36, 1086b37-1087a4, 1088b2-4; cf. Phys. 265al5-16). The form of anevent must be an event, just as the form of a substance must be a

substance. 31

University College London

robert heinaman, aristotle and the mind-body problem

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