ARISTOTLE HYLEMORPHISM AND CONCEPTS OF POTENCY AND ACTUALITY

WHEN EXPLAINING MIND AND THE HUMAN SOUL

Taken from Dr. Erik Sorem’s Master’s Thesis

University College Dublin
2005

I. Two Critical Aristotelian Points

Before beginning our inquiry into the nature of the intellect, it is necessary to first lay

down some crucial concepts. These crucial Aristotelian concepts will not only help in clarifying

the difficult issues involved with understanding the intellect, they will in fact be essential for

understanding the essence of the intellect. The first of the two points is Aristotle’s idea of

actuality and potency. The second point is Aristotle’s treatment of form and matter. We shall

soon see how these two concepts are intimately involved with one another and how they are

essential for understanding the nature of the intellect.

The distinction between actuality and potency most likely arose from the difficulties that

Aristotle had concerning Plato’s doctrine of forms. The problem that Aristotle finds in Plato’s

doctrine is that he ascribes reality only to the forms and denies reality of the sensible world. We

find this doctrine spelled out in Plato’s Timaeus when he asserts the idea that when we think we

see something, we are actually seeing that which is always becoming. Plato concludes that we

cannot say what a thing is on the grounds that the thing is always changing as we try to name it.1

How can a thing be named if it is never a thing for any time? Who can step in the same river

twice?2 Here Plato makes the crucial distinction between that which is and that which is

becoming. For Plato the Form is that which is. The material things, or those things which are

sensible, are merely becoming. The error of Plato, according to Aristotle, is the failure to

1
Plato, Timaeus 49c
2
This comes from Heraclitus’s claim that “It is impossible to step in the same river twice,” meaning that if
something is changing it cannot be the same thing.

1
identify properly between that which is and that which is becoming – which leads to the further

error of denying reality of the sensible world. For Aristotle this dilemma is solved by identifying

‘that which is’ as actuality and ‘that which is merely becoming’ as potency. By doing this,

Aristotle avoided the problem of denying the reality of the sensible world. He viewed the

sensible world as possessing both actuality and potency. He agreed with Plato that matter and

the sensible things are always changing. He also agreed that understanding never changes, not

by persuasion nor any other thing. Furthermore, Aristotle held the belief, like Plato, that

understanding is that which embraces the unchangeable, the Form. However, Aristotle was not

willing to grant Plato’s conclusion - that which always is must exist apart from that which is

always becoming. In short, Aristotle denied that form must exist apart from matter. Aristotle

believed that if one did grant such things, one would eventually end in absurdity. He critiques

and puts forth many arguments against Plato’s position, which can be found in Bk. I Ch. 9 of the

Metaphysics. In this treatment we will not go over these critiques. Rather we will understand that

Aristotle would not conclude that the form or essence existed apart from the sensibles based on

those arguments found in the Metaphysics.

Immanuel Kant had a bit of a different approach when it came to the idea of form and

matter. Kant believed in a Newtonian universe where the sensible world was nothing other than

matter acting under mathematical and physical laws. For Kant, nature does not exist as a

composite of form and matter; therefore, the distinction of actuality and potency within nature is

not to be found in Kant’s doctrine. This is certainly an important distinction to make, and

without it, Kant faces many difficulties in explaining how we come to know. Nevertheless, it is

important to note that Kant does not altogether dismiss the existence of form, but rather he

denies it within nature and simply replaces it within the mind.

2
 Let us return to the solution that Aristotle provides, namely the distinction between

actuality and potency - that which is versus that which is becoming. That which is becoming is

in potency towards being, and that which is being is actuality. According to Aristotle actuality is

prior to potency. Potency is seen always for the sake of some actuality. When Aristotle says in

the Metaphysics, “Further, matter exists in a potential state, just because it may come to its form;

and when it exists actually, then it is in its form,”3 he makes clear that potentiality is for the sake

of actuality.

At this point we can ask ourselves two critical questions. They proceed as follows:

1. Since actuality and potency are principles that hold universally, what part of mind
answers to actuality and what part to potency?

2. Is the intellect a substance, and if so does the intellect exist as a composite of

form and matter?

In answering these questions we will be able to understand how the mind acquires universal

knowledge from sense perception. We will keep both of these questions in mind as we proceed

through each section. After laying all the critical groundwork for each section, we will be able to

answer these two questions with the utmost clarity, which in turn will provide the answer to

whether universal knowledge can be obtained through sense perception.

In considering whether the mind is a substance, we should first turn our thoughts to what

Aristotle’s account of substance is in itself. In contrast to Plato, who viewed substance as merely

the forms, Aristotle understands substance to be both form and matter. For Aristotle, form is that

which forms matter, and matter is that which receives the form. Hence, matter stands to form as

3
Aristotle, Metaphysics 1050a15-17.

3
potency stands to actuality. This is seen when one considers that matter has a potency to be

‘this’ or ‘that’ only according to the form which it will receive. As soon as this distinction is

made, there is no reason to posit forms existing separately. Thus, reality consists in exactly this:

that each object in the world has its own form, or essence by which the form makes the matter to

be what it is. Aristotle focuses more on substance as he says:

Substance, in the truest and primary and most definite sense of the word, is that
which in neither predicable of a subject nor present in a subject: for instance, the
individual man or horse. But in a secondary sense those things are called
substances within which, as species, the primary substances are included; also
those which, as genera, include species. For instance, the individual man is
included in the species ‘man’, and the genus to which the species belongs is
‘animal’; these, therefore – that is to say, the species ‘man’ and the genus
‘animal’ – are termed secondary substances.4

Thus, Aristotle gives us two ways in which we may speak of substance. The first is to speak of

this particular man, such as Callias.5 The second way to speak of substance is to designate the

genus and species. Both in the primary and secondary sense of substance, the form exists in that

subject and not apart from it. That is why we can say that Callias is a rational animal as well as

we can say that “man” is a rational animal. Therefore, the form cannot be a separate substance;

it comes from the very nature of the thing of which it is predicated.

Let us return to the question of whether the intellect is a substance. Certainly, the

intellect can be considered as a thing which has an essence. In this sense the intellect is a

substance.6 However, this does not mean that the intellect is a substance the way Callias is a

substance, i.e. the composite of form and matter. Could it be possible that the mind is more like

4
Aristotle, Categories 2a11-19
5
Aristotle’s speaks of primary substance as a tode ti, i.e. “this particular thing here.”
6
The substance of a thing may be: (i) its essence, or that which makes it what it is. This will ensure that the
substance of a thing is that which remains through change in its properties. In *Aristotle (Metaphysics Z, vii) this
essence becomes more than just the matter, but a unity of matter and form. (ii) That which can exist by itself, or does
not need a subject for existence, in the way that properties need objects; hence (iii) that which bears properties. A
substance is then the subject of predication, that about which things are said as opposed to the things said about it.
(Oxford Dictionary of Philosophy, p. 366).

4
substance in the secondary sense, form that requires no material instantiation? The difference

here is that a person’s intellect is not a genus or species whereas secondary substance is. We will

keep this question in the back of our minds for now and proceed with our inquiry.

Given that we have defined the critical Aristotelian concepts of the four causes, the

doctrine of form and matter combined with the ideas of actuality and potency, I feel confident in

moving our inquiry to the nature of the intellect with greater clarity. Through the course of our

inquiry we will make repeated appeals to these foundational concepts in describing the intellect

and how it comes to know. Finally, in describing the intellect and how we come to know, we

may then return to the question of mind and substance.

II. Knowledge is the Mind becoming the Object Known

In this section we will explore how the intellect comes to knowledge. Through this

exploration we will see that knowledge is the mind becoming the object known. From

understanding this claim we will in turn begin to understand the nature of the mind.

Aristotle begins the Metaphysics with the following quote, “All men by nature desire to

know.”7 It is this desire that leads man to explore the world and to find out what things really are

like, which is an inquiry into the intelligibility of the world and how it impacts us.

Fundamentally we are concerned with what changes occur within us as we move from ignorance

to knowledge. What becomes of the mind when it attains knowledge of a certain thing? For

example, what happens to the mind when it acquires knowledge of a goat and knows what it is to

be goat? Aristotle explains that for us to have knowledge of a goat the mind must take on the

form of the goat. This means that our minds must become the substance we were seeking to

know. Therefore, the task before us is to find out in what way the mind becomes the substance

we were seeking to know.

7
Aristotle, Metaphysics 980a1.

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 Man, who is a rational animal, may go further than just possessing his own essence. When

he comes to know a certain thing he takes on the essence of that thing, i.e. the form, within his

intellect. In this sense, he possess something more than just his own form, he possess the form

of the object he was contemplating. Gilson puts forth this perplexing matter as follows:

Since these objects are now in the subjects which know them, it must be that the
subjects have in some way become those objects. Thus to know is to be in a new
and richer way than before, since it is essentially to cause to enter into a thing
which is in the first place for itself alone what another thing is in the first place
for itself alone. 8

Mind in knowing a thing becomes the form of that thing and therefore the knower becomes

something more. Aristotle in De Anima shows that there is a special faculty of mind that is able

to grasp this form and understand it. He argues that the sense of sight is distinguished from all

the other senses by its ability to apprehend its object, namely the visible objects. Moreover, not

only is the sense of sight distinguished by its ability to apprehend its object, it is distinguished by

its ability to become its object. As Aristotle says, “that which sees is coloured; for in each case

the sense-organ is capable of receiving the sensible object without its matter. That is why even

when the sensible objects are gone the sensings and the imaginings continue to exist in the sense-

organs.”9 Thus, the eye in seeing becomes colored, that is, it becomes like its object. This same

reasoning applies to all the other senses, each sense being distinguished from one another by its

proper object and its ability to become like the object it was sensing.

What about the higher cognitive realms? Does this same principle apply? Aristotle

argues that since forms and essences are distinct objects themselves there must be some distinct

faculty of the soul that is capable of apprehending these:

8
Etienne Gilson, The Christian Philosophy of St. Thomas Aquinas, p. 224.
9
Aristotle, De Anima 425b22-26.

6
 Since we can distinguish between a magnitude and what it is to be a magnitude,
and between water and what it is to be water, and so in many cases (though not in
all: for in certain cases the thing and its form are identical), flesh and what it is to
be flesh are discriminated either by different faculties, or by the same faculty in
two different states; for flesh necessarily involves matter and is like what is snub-
nosed, a this in this. Now it is by means of the sensitive faculty that we
discriminate the hot and the cold, i.e. the factors which combined in a certain
logos constitute flesh; the essential character of flesh is apprehended by
something different…10

This something different is what Aristotle calls nous, or the mind. Furthermore, the mind when

it grasps essences understands something that has no material aspect whatsoever. For essences

are the forms of composites of form and matter. Here is a very important component in

Aristotle’s doctrine and it is crucial in understanding how knowledge is possible. This is why we

addressed and defined the critical doctrine of form and matter earlier. It is only possible to have

knowledge if things in some way participate in immateriality. This is evident from the fact that

if the world were solely material no one could have understanding at all. For matter is that

which is always changing. How could one know what is always changing? Since it is

impossible to know what is always changing, then knowing must involve the immaterial in some

way.

Aristotle’s doctrine of form and matter admits of this immaterial aspect. As we saw

earlier, the immaterial form is that which forms the matter, and matter is that which receives the

form. We also saw that each object in the world has its own form, or essence and it is the form

that makes the thing be what it is. However, things of the world are not merely forms, they are

composites of form and matter. For this reason we understand that ‘this goat’ is not the same as

the essence of goat. Now what takes place when we understand the essence of goat is that we

separate and lift the form out of its material instantiation. Although Kant’s theory of knowledge

10
Ibid. 429b10-18.

7
does admit of the immaterial in some way, i.e. the a priori categories of the mind, the idea of

immateriality in no way exists outside the mind for him. Therefore, the act of abstracting, that is

the lifting the form out of its material instantiation, is impossible for Kant. As we will soon see,

it will become extremely difficult for Kant to explain how universal knowledge is possible

without the act of abstraction. Given the Aristotelian theory, we avoid many of Kant’s dilemmas

and complications. According to Aristotle the mind through the senses is able to separate and lift

the forms found outside the mind and relocate them within the intellect. The analogy given by

Aristotle in De Anima is quite helpful in understanding how the mind uses the sense organs to

make this happen. He comments:

By a ‘sense’ is meant what has the power of receiving the sensible forms of
things without the matter. This must be conceived of as taking place in the way in
which a piece of wax takes on the impress of a signet-ring without the iron or
gold; we say that what produces the impression is a signet of bronze of bronze or
gold, but its particular metallic constitution makes no difference: in a similar way
the sense is affected by what is coloured or flavoured or sounding, but it is
indifferent what in each case the substance is; what alone matters is what quality
it has, i.e. in what ratio its constituents are combined.11

Thus, the mind uses the sense organs in receiving the object, and in abstracting the mind

possesses the form of that object without its particular matter. This is what is meant by the mind

lifting the form out its material instantiation. Furthermore, the goat, being potentially

intelligible, is only actually intelligible when the mind commits the act of abstraction. In the act

of abstraction the mind understands the form, i.e. goat-form. Therefore, it is not by virtue of this

goat’s matter that it is understood, but by its particular form.

Since form is the non-material aspect of the composite substance, it is therefore manifest

that this must be a condition for which knowledge is possible. This is the first part in answering

the question of whether universal knowledge possible through sense perception. For universal
11
Ibid. 424a18-20.

8
knowledge to be possible via sense perception there must first exist within nature, form and

matter as a composite substance. But what must be said of mind so that it is able to grasp this

non-material aspect of substance? Aristotle answers:

If thinking is like perceiving, it must be either a process in which the soul is acted
upon by what is capable of being thought, or a process different from but
analogous to that. The thinking part of the soul must therefore be, while
impassible, capable of receiving the form of the object; that is, must be
potentially identical in character with its object without being the object. Mind
must be related to what is thinkable, as sense is to what is sensible.
Therefore, since everything is a possible object of thought, mind in order, as
Anaxagoras says, to dominate, that is, to know, must be pure from all admixture;
for the co-presence of what is alien to its nature is a hindrance and a block; it
follows that it too, like the sensitive part, can have no nature of its own, other
than that of having a certain capacity.12

From what Aristotle says we can see that mind, being pure from all admixture, must not be a

bodily organ so as to distort or hinder its ability to think. Aristotle concludes that, “mind is,

before it thinks, not actually any real thing.”13 This is the Aristotelian idea that the soul before it

thinks is a tabula rasa, or a blank slate. The mind before it thinks only has the nature of

potentially thinking and therefore it is nothing actual. The mind becomes actual by being

affected by the world. Objects are imposed on the potential mind and at that moment a new

being is constituted. Mind now becomes something actual. However, if this is to happen then

there must be, as Aristotle suggests, “community of nature between the factors.”14 There must be

something common between the world and the mind. What is common to both is the aspect of

the immaterial, which are the intelligible forms of things. Saint Thomas Aquinas, a perceptive

commentator on Aristotle, addresses this immaterial aspect by saying, “If the intellect were

corporeal, its activity would not reach beyond the order of bodies. So it would understand only

bodies. But this is patently false. For we understand many things which are not corporeal.”15
12
Ibid. 429a15-23.
13
Ibid. 429a 24.
14
Ibid. 429b28.
15
Saint Thomas Aquinas, Summa Contra Gentiles II, 49

9
Furthermore, mind cannot really even understand corporeal things. For corporeal things are

merely potentially intelligible. It is the form of these things which are actually intelligible and

these forms are made actual “by the power of the understanding substance insofar as they are

received in it and are acted upon it.”16 Thomas Aquinas immediately after this statement

concludes, “Therefore every understanding substance must be wholly immune from matter. It

has neither a material part nor is it like the material forms impressed in matter.”17 This recalls

our previous question: In what way is the intellect a substance? As we have just seen the

intellect cannot be a substance by being a composite of form and matter. Nevertheless, the

intellect must still be a form in some way since there is a community between knower and

known. We will return to this problem later, but for now let us suppose the intellect to be a

substance by virtue of it being a form. However, since the intellect is not a composite of matter

and form, it must be a substance in a new sense of the word.

The next step in the argument is to see how mind can contemplate itself while at the

same time contemplate a particular thing of the world. Locke, Berkeley, and Kant were all early

modern philosophers who where concerned with the same question. It is an important question

for it is dependent on a theory of what the mind actually is. Ultimately, each answer will depend

on what each one thinks the mind to be. For Aristotle, the mind starts off as a blank slate and is

potentially whatever is thinkable. He comments

Have not we already disposed of the difficulty about interaction involving a

common element, when we said that the mind is in a sense potentially whatever is
thinkable, though actually nothing until it has thought? What it thinks must be in
it just as characters may be said to be on a writing table on which as yet nothing
actually stands written: this is exactly what happens with mind.18

16
Saint Thomas Aquinas, De Esse et Essentia, p. 40.
17
Ibid., p.40.
18
Aristotle, De Anima 429a29-430a2.

10
However, as we argued earlier, the actual mind is the form of whatever object it is thinking, apart

from the matter. So if we are to treat the mind itself as an object to be thought about, how should

we think about it given that the actual mind is really the form of the objects it is thinking?

Aristotle argues:

Mind itself is thinkable in exactly the same way as its objects are. For in the case
of objects which involve no matter, what thinks and what is thought are identical;
for understanding and its object are identical. (Why mind is not always thinking
we must consider later.) In the case of those which contain matter each of the
objects of thought is only potentially present. It follows that while they will not
have mind in them (for mind is a potentiality of them only in so far as they are
capable of being disengaged from matter) mind may yet be thinkable.19

Although this passage is quite difficult and perplexing, the argument is simply this: Since the

mind in knowing is the mind becoming the object known, the mind in thinking is identical with

the object being thought. Therefore, to think about the mind is nothing other than to think about

the form of things. Hence, the mind must be understanding itself in the act of contemplating that

thing. For what else is mind then that which is potentially whatever is thinkable? As Jonathan

Lear says, “ For that is all that mind, in thinking is. Thus in all thinking mind is thinkable –

indeed, mind is thought. For understanding and the object are the same.”20 Therefore the mind

must be understanding itself in the act of thinking a certain thing.

Before moving on to the next section, let us recapitulate what we have learned so far in

this section. Among the arguments laid out, we have seen that physical things are composites of

form and matter. Furthermore, physical things can only be understood when a separation occurs

between matter and form, the matter being that which is potentially understood and the form

being that which is actually understood. This is why Aristotle says that it is good to call the soul

19
Ibid. 430a3-7.
20
Jonathan Lear, Aristotle: The Desire to Understand , p. 125.

11
“the place of forms.”21 We have also seen that things are not intelligible of themselves and that it

is immateriality which confers intelligibility. This immateriality is that “community of nature”

between the two factors, namely the mind and the world, which is necessary for such

intelligibility. Given this principle, mind being nothing actual is able to become the actual form

of the object. And since the form of an object is its essence, mind by becoming that form now

possesses the knowledge of that object, knowing what it is to be that particular thing. Moreover,

we have seen how Aristotle solves the dilemma of mind thinking about the world and itself at the

same time by showing us that mind is able to think about itself in the very same way that it

thinks of its objects.

III. The Mind Seen Through the Four Causes

Another essential concept in the Aristotle’s theory is what he calls the Four Causes. The

Four Causes are his way of explaining things. It is often said that we do not think that we know

a thing unless we understand and grasp the ‘why,’ which in turn is to understand the cause. In his

consideration of nature, Aristotle shows that it is necessary for natural science to treat the causes.

After making this point in the Physics, he goes on to identify four causes which must be

considered anytime one attempts to understand nature and change. These causes are the material

cause (that out of which something is made), the formal cause (that into which something is

made), the final or the teleological cause (that for the sake of which something is made), and the

efficient cause or agent cause (that by which something is made).

Aristotle, being a philosopher of nature, deeply concerns himself with change. In observing

nature, he notices that plants, animals, and even humans all undergo change. Furthermore, plants,

animals, and human beings all posses the capability of growth and diminution, which are

processes of change. For Aristotle, understanding nature and change, which in turn is to
21
Aristotle, De Anima 429a27.

12
understand the nature of the things themselves, entails an analysis through the Four Causes.

Since thinking and coming to knowing is a type of change, Aristotle will treat, like he does any

other process of change, this topic through the analysis of its Four Causes. Each one of these

four causes will answer to a specific question concerning the intellect and how it comes to know.

Without an appeal to these four causes it remains impossible to understand what the intellect

truly is. For Immanuel Kant, the task of explaining the nature of the intellect is quite a difficult

matter, if not altogether impossible. In any case, the lack of making these critical distinctions, i.e.

an appeal to the four causes, leaves Kant’s readers puzzled as to what the mind actually is. I will

show that by investigating the mind and its operations through these Four Causes we can avoid

such puzzles. Moreover, how the mind is able to attain universal knowledge through sense

perception will ultimately rest on these four causes, for they will reveal what part of mind is

capable of abstracting and obtaining universal knowledge. As we will soon see, it is the agent

intellect that is, for the most part, responsible for the act of abstraction and obtaining the

universal. However, to completely understand what the agent or active intellect is we must see

how it relates to Aristotle’s Four Causes.

The mind when thinking attempts to move from a state of ignorance to a state of knowledge.

It is important to note that Aristotle distinguishes between coming to know and knowing. He

distinguishes the incomplete action from the complete by calling the first change and the second

actuality. Coming to know involves change, but knowing does not. Therefore, thinking is a type

of change. Like any other type of change, Aristotle proceeds to explain it by investigating its

relation to the Four Causes. As we mentioned earlier, each of these Four Causes will be able to

describe a certain part of the intellect and taken together they form the collective whole for what

we call mind.

13
 a. The Mind Seen through the Material Cause

Looking at how the mind comes to know, we must first look to the material cause of

mind. As we noticed earlier, Aristotle believed that the mind could not be a bodily organ, nor

could it be material in any way. The mind cannot be material for the reason that the matter

would hinder and distort the mind’s ability to think. Furthermore, if the mind were material,

then each time the mind took on a certain form it would literally become that thing of which it

was thinking. Since the mind does not materially become a goat when it apprehends the essence

of goat, the mind cannot be material in any way. This is reiterated by Aristotle when he says,

regarding the mind, that, “it cannot reasonably be regarded as blended with the body; if so, it

would acquire some quality, e.g. warmth or cold, or even have an organ like the sensitive faculty:

as it is, it has none.”22 Nevertheless, this does not mean that the mind does not operate through

that which is material. For the mind makes use of the sense organs in coming to know things, and

every sense organ is indeed material. In coming to know an object we do encounter something

that is material as well as formal. Therefore, it is plausible that we should expect something

material to receive what is material and that which is immaterial to receive that which is not

matter. This is the job that the sense faculties take on. As we saw earlier in Aristotle’s analogy

of the signet ring, the sense organ is likened to the wax and the signet ring to the object. It is the

job of the sense organs to receive the matter and transfer the form to the mind. Thus, although

the mind is not material and possesses nothing material, it does make use of what is material, i.e.

the sense organs. Hence, considering the mind and how it comes to know, there is something

that answers to the material cause and that is the sense organs.

b. The Mind Seen through the Formal Cause

22
Ibid. 429a 24-27.

14
 Let us at this point return to Aristotle’s doctrine of form so that we may treat it in more

detail. In exploring the concept of substantial form more deeply, we may come to understand

how exactly it relates to the mind.

As we discussed earlier, for Aristotle the form is that which forms the matter. However,

given this basic meaning, it may sound as if form is merely the shape, outline, or contour of a

thing. It should be noted that Aristotle’s doctrine of form is much more than just this superficial

meaning. For Aristotle, form or eidos, is something more than just an exterior shape of a thing, it

is an internal principle which guides and determines the potential matter. Moreover, eidos is that

which constitutes the very foundation of thing. It is the origin of a thing’s identity and a

determining cause of what that thing is to be. Eidos is a thing’s intrinsic essence, for it actualizes

a thing’s matter and gives it ‘whatness’ from within. This is why Aristotle equates eidos with

ousia. The form, according to Aristotle, is the essence of the individual and its ‘beingness’, and

it is what makes the potential matter something concrete and particular, different form all other

things - that what individuates matter.

It is interesting to see how Aristotle makes use of his idea of substantial form with

regards to the soul. Aristotle defines soul in the second book of De Anima, where he says,

“Hence the soul must be a substance in the sense of the form of a natural body having life

potentially within it.”23 Aristotle goes on to say that “substance is actuality, and thus soul is the

actuality of the body as above characterized.”24 Now there are two ways in which we can speak

of actuality: one with regard to the possession of knowledge and the other with regard to the

exercise of knowledge. Aristotle informs us that the soul is obviously the first type of actuality,

that which corresponds to the possession of knowledge. He comments, “for both sleeping and

23
Ibid. 412a20-21.
24
Ibid. 412a22-23.

15
waking presuppose the existence of soul, and of these waking corresponds to actual knowing,

sleeping to knowledge possessed but not employed, and, in the history of the individual,

knowledge comes before its employment.”25 Therefore, it follows that the phenomena of life,

such as walking, speaking, thinking, and desiring presuppose the existence of a first act, which

Aristotle has defined as the soul, i.e. the form of a natural body. Whereas actuality in the second

sense involves those activities which follow from the soul, and those activities must presuppose

the existence of the form of a natural body, which is actuality in the first sense. Thus, Aristotle

concludes that, “This is why the soul is the first grade of actuality of a natural body having life

potentially in it.”26

The composite substance of form and matter is a natural body endowed with life, and the

principle of this life is soul. According to Aristotle the body cannot be the soul, for the body is

not life but what has life. The body then is matter for the soul, while the soul is the form or

actuality of the body. Hence, the soul is act of the body that possesses life in potency. The

argument for this claim is: that which is the first principle of living is the act and form of living

bodies. But the soul is the first principle of living in those things which live. Therefore, soul

must be the act and form of living body. The body, composed of its various organs, does

actualize itself through these organs; but, as we have seen, this activity is an actuality of the

second order and it necessarily presupposes the form of the body, that which is the first actuality.

Through the soul, i.e. the form of the body, the various organs are guided, determined and grow

into an individual substance. The soul moulds the body and its organs into a self-subsistent

living being which we call the human being. It is by the soul, the form of the human being, that

all other actualizations occur. As Aristotle says, “it is by the soul by or with which primarily we

25
Ibid. 412a24-28.
26
Ibid. De Anima 412a29-30.

16
live, perceive, and think: - it follows that the soul must be a ratio or formulable essence, not a

matter.”27

Now there are three types of soul: Vegetative soul, Animal soul, and Human soul. The

vegetative souls belong to plants and they are capable of nourishing themselves and capable of

reproduction. The animal soul has what we call a ‘sensitive soul’ and it is not only capable of

nourishing and reproduction, it is capable of sensing. Lastly, we have the human soul, which is a

higher kind of soul. Not only does the human soul unite in itself the powers of the lower souls, it

rises above by the possession of nous or Reason. It should be noted that Aristotle does not

believe that human beings posses three souls, but rather one soul with three sets of powers and its

highest power is that of reason. Thus, in one sense, the formal cause that answers to the question

of what is mind, is the human soul.

Michael Frede comments that “Aristotle thinks that there is no reason to treat mental

functions, things like desiring, thinking, and believing, any differently than the ordinary living

function.”28 He goes on to say that Aristotle “refuses to divide the things animate objects can do

into two classes, namely into those things which the body is made to do by the soul and those

thing which the soul does itself.”29 Aristotle stands diametrically opposed to Cartesian dualism

on this point. For Aristotle does not believe that there are two separate substances, one of mind

and the other body, whereby the mind animates the body. The moderns, including Descartes and

Kant, believe that body is somewhat like a machine subject to the laws of physics and mind is

somehow involved with that machine. How they explain the mind’s interactions with body is

quite a difficult matter for them, if not impossible. Aristotle does not have this problem.

Although the mind is not the body, Aristotle maintains that they remain united through one

27
Ibid. 414a13-15.
28
Michael Frede, “On Aristotle’s Conception of the Soul.” Essays on Aristotle’s De Anima. (Oxford: 1992), p.96.
29
Ibid.

17
substantial form, i.e. the human soul. Gilson makes an important distinction when he says the

mind, “is the power which constitutes the human soul in its own degree of perfection, and yet,

properly speaking, the human soul is not an intellect.”30

We have seen that the formal cause of mind is the human soul; however, the mind is not

strictly the human soul, it is a power that distinguishes the human soul from all others. We have

also seen that mind cannot be a separate substance that merely animates the body, since then we

would have two substances. Returning to the question of whether the intellect is a substance, we

find that it is not a substance in the traditional way Aristotle uses the word. As Aristotle says,

substance in the truest sense is that which is neither present in nor predicable of a subject.31 The

intellect is not substance in this sense, because the mind does need a subject for its existence, that

is, a particular man to which the intellect may be attributed. Furthermore, the mind cannot be a

primary substance for the reason that it is not a composite of matter and form, which is the

criterion that Aristotle gives for something to be a primary substance. Nor is the mind a genus or

species as we find secondary substances to be. Thus, we must conclude that if mind is to be a

substance, it cannot be a substance according to these traditional uses of the word.

The intellect is a form, meaning that it is an essence; therefore, it can be considered as a

substance insofar as it has a specific nature. Yet this form is a form that has no matter.

Therefore, if the intellect is a substance, it is something more like what Thomas Aquinas calls

‘simple substances,’32 forms which exist apart from matter - pure essences. Among simple

30
Etienne Gilson, The Christian Philosophy of St. Thomas Aquinas, p. 207.
31
Aristotle, Categories 2a11.
32
“The essences of complex and simple substances differ in that the essence of the complex is not form alone but is
composed of form and matter, whereas the essence of simple substance is form alone. Two other differences flow
from this. One is that the essence of complex substance can be signified either as a whole or as a part, which befalls
it on account of the designation of matter, as has been said. Therefore it is not in just any way that the essence of the
complex thing is predicated of it, for it cannot be said that man is his quiddity. But the essence of the simple thing,
which is its form, can be signified only as a whole, since there is nothing apart from form that might be the recipient
of form; that is why Avicenna said that ‘the quiddity of the simple is the simple thing itself’ because there is nothing
else receiving it.” (Saint Thomas Aquinas, De Esse et Essentia, p. 41)

18
substances, Aquinas designates the pure intelligences, or what are also known as the angels. The

difference here is that although the human intellect is immaterial, it operates through a material

body, whereas the pure intelligences do not. Keeping this in mind, we may call the intellect a

simple substance. However, it is more proper to reserve the title ‘substance’ for the human

person and to consider the intellect as a power of that substance, the power of the human soul

that operates like the other lower living functions, but rises above by its ability to think.33

c. The Mind Seen through the Final Cause

The final cause can be understood as the formal cause, differing only insofar as it carries

the notion of purpose with it, or as Aristotle says ‘that for the sake of which.’ He calls attention

to the final cause, telos, in his consideration of nature. He states that, “action for an end is

present in things which come to be and are by nature.”34 When we consider things in nature that

are born and grow, it is natural to ask the question “toward what do they grow?” Joseph Owens

asks the same question. “That which is born starts as something and advances or grows toward

something. Toward what, then does it grow? Not toward that from which it came, but toward

that to which it advances.”35 That to which something advances is a thing’s end and perfection.

As we have already discussed, form (eidos), is the principle of growth and it constitutes the very

foundation of thing. It is its intrinsic essence, actualizing and giving ‘whatness’ from within.

33
“In accordance with what has been already shown (54, 3; 77, 1) it is necessary to say that the intellect is a power
of the soul, and not the very essence of the soul. For then alone the essence of that which operates is the immediate
principle of operation, when operation itself is its being: for as power is to operation as its act, so is the essence to
being. But in God alone His action of understanding is His very Being. Wherefore in God alone is His intellect His
essence: while in other intellectual creatures, the intellect is power.” (Saint Thomas Aquinas, Summa Theologica,
Q.79, Art. 1)
34
Aristotle, Physics 199a7.
35
Joseph Owens “Aristotelian Ethics, Medicine, and the Changing Nature of Man,” Aristotle: The Collected Papers
of Joseph Owens, ed. John R. Catan (Albany: State University of New York Press, 1981), p. 173.

19
The full actualization of the potential of the thing, whereby a thing’s essence is fully realized is

what Aristotle calls entelechy. Thus, telos refers to the fulfillment of eidos, which is – entelechy.

Since we find these terms within nature universally, they must also apply to the mind as

well. Fran O’Rourke comments that, “These various terms reveal distinct nuances of the same

reality, substantial form in its various stages of potency and actualization, development and

completion.”36 The intellect also develops through various stages of potency and actualization.

We have seen that the intellect exists as a pure form; however, as a pure form it still remains a

potency to receive the objects of thought. Like any other thing within nature, the mind’s

actualization and fulfillment is guided by its telos. The mind’s telos (perfection) is to think itself,

which is simply to think the forms of intelligibles. This is the mind’s most developed state -

active thinking. Since the mind is in no way material, we do not find it growing like physical

objects in nature. Nevertheless, we do see the mind moving, moving from potency to actuality.

The intellect moves towards its full realization, towards its end, not its beginning; hence, its

actualization and fulfillment must be guided by its telos. However, it is important to note that

although it is the nature of the intellect to be thinking the forms of intelligible objects, it still

remains a potency. For the mind is potentially all things thinkable. Thus, for the mind to be fully

actualized, it must be engaged in the activity of thinking all things. Yet, we only find this to be

true of God, who is self-thinking thought and pure actuality.37 The human intellect is an image

and a likeness to the divine mind, but it falls short in that it has much potency. Even if the

intellect could actively think all things, it would still contain potency; for the existence that it has

36
Fran O’Rourke, “Aristotle and the Metaphysics of Evolution,” The Review of Metaphysics 58 (September 2004):
17.
37
“Since therefore God has nothing in Him of potentiality, but is pure act, His intellect and its object are altogether
the same; so that He neither is without the intelligible species, as is the case with our intellect when it understands
potentially; nor does the intelligible species differ from the substance of the divine intellect, as it differs in our
intellect when it understands actually; but the intelligible species itself is the divine intellect itself, and thus God
understands Himself through Himself.” (Saint Thomas Aquinas, Summa Theologica, Q.14, Art.2)

20
is received and therefore human intellect will always lack the perfection of full actuality.38

God’s existence, on the other hand, is not caused, nor is it received from another; therefore his

essence and existence are one and the same.39 In this, God is the utmost perfection and full

actuality, containing no potency whatsoever. Granted that we can never obtain complete

actuality and full perfection, our intellects still have an end suitable to the nature it has been

given. This end is the intellect’s telos, to receive the intelligible objects of the world and to

become the forms of those objects in active contemplation, or as F.L. van Becelaere says, to be

“a faithful mirror of the external universe, that mirrors itself in it ideally and immaterially.”40

d. The Mind Seen through the Efficient Cause

There is a further dilemma that we must now address. It appears inadequate that

understanding should be completely explained by the mere fact that the mind is able to receive

intelligible forms of objects. For external objects cannot determine thought in the same way as it

determines sensation and the tabula rasa by itself alone is powerless. Furthermore, objects

cannot by means of the sensations they produce, give rise to an impression in us which gives

them a mode of being different in kind and superior (abstract) to that which really belongs to

them (particular, concrete). If this were so, we would have a cause producing an effect greater

than itself, which is absurd. Lear comments on this by saying that, “there is too much

potentiality around to explain how active contemplating occurs. There is the potentiality for
38
“Intelligences whose essence and existence differ, though their essence is without matter…their existence is not
absolute, but received, therefore finite and limited to the capacity of the receiving nature.” (Saint Thomas Aquinas,
De Esse et Essentia, p. 44)
39
“Existence is that which makes every form or nature actual; for goodness and humanity are spoken of as actual,
only because they are spoken of as existing. Therefore existence must be compared to essence, if the latter is a
distinct reality, as actuality to potentiality. Therefore, since in God there is no potentiality, as shown above (1), it
follows that in Him essence does not differ from existence. Therefore His essence is His existence.” (Saint Thomas
Aquinas, Summa Theologica, Q.3, Art.4)
40
F.L. van Becelaere , “A Summary Exposition of Saint Thomas Aquinas’ Theory of Knowledge,” The
Philosophical Review Vol. 6, No. 12 (November 1903): 627.

21
contemplating and the potentiality for being understood, but how can one get an actuality, active

thinking, from these two potentialities alone? One cannot.”41 Therefore, there must be something

else besides the external objects which act upon my intelligence. In other words, there must be

an efficient cause which is responsible for the mind moving from potentiality to actuality.

Aristotle in De Anima says,

Since in every class of things, as in nature as a whole, we find two factors involved,
(1) a matter which is potentially all the particulars included in the class, (2) a cause
which is productive in the sense that it makes them all (the latter standing to the
former, as e.g. an art to its material), these distinct elements must likewise be found
within the soul.42

From the above passage we see that Aristotle is making a connection between mind and nature.

In nature we find that all substances are composites of matter and form, matter standing to form

as potentiality does to actuality. Since we find these distinctions to be universally applicable

within nature, they must also apply to mind as well. Aristotle realizes that within nature form is

that which makes the potential matter to be what it is. Therefore, there must be some cause

attributed to mind which also makes the potential something actual. Aristotle goes on to say,

And in fact mind as we have described it is what it is by virtue of becoming all

things, while there is another which is what it is by virtue of making all things:
this is a sort of positive state like light; for in a sense light makes potential
colours into actual colours.
Mind in this sense of it is separable, impassible, unmixed, since it is in its
essential nature activity (for always the active is superior to the passive factor, the
originating force to the matter which it forms).
Actual knowledge is identical with its object: in the individual, potential
knowledge is in time prior to actual knowledge, but in the universe as a whole it
is not prior even in time. Mind is not at one time knowing and at another not.
When mind is set free from its present conditions it appears as just what it is and
nothing more: this alone is immortal and eternal (we do not, however, remember
its former activity because, while mind in this sense is impassible, mind as
passive is destructible), and without it nothing thinks.43

41
Jonathan Lear, Aristotle: The Desire to Understand, p. 135.
42
Aristotle, De Anima 430a10-14.
43
Ibid. 430a14-25.

22
Aristotle is arguing that mind is, by virtue of becoming all things, in a state of potency. But only

that which is in a state of actuality can bring what is in potency to act.44 Therefore there must be

an active power which makes the forms of sensible things intelligible in act. The sensation of

objects acting in cooperation with a special spiritual power within us, which "is a sort of positive

state like light”45 must shine upon the sense data, making them capable of knowledge. Such a

creative power has been named the active intellect (intellectus agens) or agent intellect.46

Although Aristotle never uses the name intellectus agens or agent intellect, we do find that he

has introduced another aspect of mind so as to distinguish the passive mind from that which

‘makes’ all things, which he calls nous poiētikos.

At this point let us recall the question put forth earlier. What part of mind answers to

actuality and what part to potency? The part of mind that answers to the question of potency is

called the potential intellect or the intellectus possibilis. This is the part of the mind that is

capable of knowing, but not yet actualized. It is the mind that begins as a sort of tabula rasa, a

pure potency to know. However, as we have just seen, there must be a power of mind which is

capable of bringing what is in potency into act. The part of the mind which answers to actuality

and brings what is in potency into act is called the agent intellect or the intellectus agens. This is

the maker mind. This ‘making’ that Aristotle speaks of is not so much a making in the sense of a

productive activity, but rather it is a causal responsibility in reference to form. The example that

he uses is one of light. For light is the cause of an object being seen. Without light an object and

its colours are in a mere state of potency to be seen. Thus, it is light that makes actual what is

only potentially visible. Likewise, there is an aspect to mind which makes the potentially

44
Aristotle’s arguments for actuality being prior to potency and that which brings potency into act are given in
Metaphysics IX ch. 8.
45
Aristotle, De Anima 430a15.
46
The Agent Intellect is what Saint Thomas Aquinas called and understood as the active intellect.

23
intelligible form actual. The active mind not only makes that form actual, it makes it superior

(abstract) to that which really belongs to them (particular, concrete). Lear agrees by saying,

“The ‘making’ is explicable in terms of the causal responsibility of form at the highest level of

actuality for form at lower levels of actuality and potentiality.”47 Therefore it is not merely by

means of objects and the sensations that they produce that give rise to form in a superior state,

but it is by this active principle of mind, what is known as the agent intellect - that power of the

intellect which is analogous to light.

IV. The Agent Intellect

a. The Agent Intellect and the Analogy of Light

As we have seen, Aristotle has created an analogy between the active intellect and light.

However, if we are to understand this analogy properly, it is important to see how Aristotle views

light itself. We find Aristotle’s views on light in De Anima Bk. II Ch. 7 where he says,

Light is the activity – the activity of what is transparent so far forth as it has in it
the determinate power of becoming transparent; where this power is present, there
is also the potentiality of the contrary, viz. darkness. Light is as it were the proper
colour of what is transparent, and exists whenever the potentially transparent is
excited to actuality by the influence of fire or something resembling ‘the
uppermost body’; for fire too contains something which is one and the same with
the substance in question.48

For Aristotle whatever is visible is color and light is that which makes the potential color actual,

or in other words, as Aristotle says, “it is only in light that the colour of a thing is seen.”49

However, as is the case with all perceptions, a medium is necessary. Aristotle says that,

The following experiment makes the necessity of a medium clear. If what has
colour is placed in immediate contact with the eye, it cannot be seen. Colour sets

47
Jonathan Lear, Aristotle: The Desire to Understand, p. 137.
48
Aristotle, De Anima 418b9-13.
49
Ibid. 418b2-3.

24
 in movement not the sense organ but what is transparent, e.g. the air, and that,
extending continuously from the object of the organ, sets the latter in movement.50

The medium must have the capability to take on the forms of objects and transfer them to the

sense organs. For Aristotle, this medium must be what is transparent. Furthermore, the

transparent is what is visible, not in virtue of itself, but “rather owing its visibility to the colour

of something else.”51 The transparent has the potency to take on color and forms and transfer

them from the object to the mind. However, this transparent medium must be actualized

somehow. The actualization that is necessary for it is light. This is why Aristotle calls light the

activity of what is transparent. Moreover, light is the proper color of the transparent and it

“exists whenever the potentially transparent is excited to actuality.”52 Thus, for Aristotle, light is

simply the actual transparent and nothing else.

Michael V. Wedin comments on how this analogy is carried over to the doctrine of

mind. He says, “it is in the nature of the actually transparent that it change from one colour to

another. Analogously, it is in the nature of an actually contemplating mind that its object

change. Indeed, this a requirement productive mind is tailored to fit.”53 The mind is like the

transparent in that it has the potency to take on different forms. As we have seen, the mind when

thinking becomes the form of the object it is contemplating, just as the transparent becomes a

certain color when actualized. Although the transparent medium needs to be engaged by fire, the

sun, or something of the like, the cause of the visible is more properly found within the

transparent itself, whereby its activity is understood as light. From this consideration there

appears to be a dual nature to the transparent. In one sense it is that which is capable of being

certain colors, while in another way it is that which actualizes. Does this not sound similar to the
50
Ibid. 418a11-15.
51
Ibid. 418b5-6.
52
Ibid. 418b12.
53
Michael V. Wedin, “Tracking Aristotle’s Nous.” Aristotle’s De Anima in Focus (London: 1993) p.140.

25
case of mind? There is that aspect of the intellect that is capable of becoming any of the forms it

thinks, while at the same time there is that characteristic of the intellect which actualizes that

form within the potential intellect. The interesting point of the analogy is that in both cases, one

and the same thing, i.e. the intellect and the transparent, possess a sort of dual nature, one which

admits of a potency and the other, an activity as the power to actualize. Another similarity worth

considering is that the transparent is not visible per se, but rather it is visible in virtue of some

color. As Wedin comments, “light never occurs without some colour or other and that it itself is

visible insofar as a given colour is visible. Analogous points hold for productive mind and its

objects.”54 The mind in a similar sense never occurs without an object, or in other words, as

Aristotle says, “the mind is in a sense is potentially whatever is thinkable, though actually

nothing until it has thought.”55 Therefore, the mind itself is only visible insofar as it is thinking a

given object.

At this point we may wonder if it is the mind thinking that is actualized or the object

thought. Given the analogy of light, we find that when the light shines on an object, my seeing

and the object seen are actualized together. Although they possess different modes of being,

they are but one actuality. For Aristotle the same applies to the mind and the object of thought.

Since mind when thinking becomes the object thought, it is as L.A. Kosman says, “the subject

thinking and the object being thought are one and the same; the actuality of the one is the same

entity as the actuality of the other.”56 Thus, the agent intellect, that power of the mind that is

likened to light, is responsible for the actualization of mind thinking and the object being

thought.

54
Ibid. p.141.
55
Aristotle, De Anima 429a30.
56
L.A. Kosman, “What does the Maker Mind Make?” Essays on Aristotle’s De Anima. (Oxford: 1992) p.346.

26
 In De Anima, starting at 417a 21, Aristotle makes a further distinction between potency

and actuality. He tells us that there are different senses in which we can speak of what is

potential and actual. He begins by speaking of man as a knower. In the first sense we can say

that man is a knower because he falls under the class of beings who are capable of knowing;

however, he has not come to know anything as of yet. We can designate this type as first

potentiality. As man then begins to learn, he makes a qualitative change and actualizes himself

as a being who knows. This qualitative change to man as knower is an example of first

actualization. The second sense in which we can speak of potency and actuality can be found in

the man who possesses knowledge, such as a grammarian, yet he may not exercise that

knowledge. We can say that grammarian who possesses such knowledge is in a state of potency

for he has the ability to recall the grammatical forms to his mind, but they are not present in his

mind until he recalls them. When he exercises his knowledge he moves from second potentiality

to second actuality. In both examples man is potentially a knower; however, as Aristotle

distinguishes, one is a knower “by change of quality, i.e. repeated transitions form one state to its

opposite under instruction, the other by the transition form the inactive possession of sense or

grammar to their active exercise. The two kinds of transition are distinct.”57

So how does this exactly relate to nous and in what sense does the active intellect cause

actuality? As we have seen, the active intellect makes both the potential intellect and the object

of thought actual. However, is this actuality in the first sense or the second? When comparing

the analogy of light to the mind, we may be tempted to say that the actuality we are speaking of

is only actuality in the first sense. Kosman points out this same temptation, saying

Since, as we read earlier in the De Anima, colour is the visible, it follows that in
making what is potentially a colour actually a colour, light is making what is
potentially visible actually visible. And since visibility is itself a first actuality,
57
Aristotle, De Anima 417a31- 417b1.

27
 that is, a realized structure of potentiality relative to the further actuality of being
seen, light brings into being a first actuality: it makes things visible.58

The difficulty arises when we recall our discussion on the mind becoming the object known.

When the mind and the object become one in form, this implies an actualization in the second

sense, since the mind only becomes identical with the object known in the active exercise of

contemplating. Therefore, it appears that the active intellect is responsible for actualization in

the second sense. Is this a difficulty within Aristotle’s analogy? Kosman suggests that this is

only a difficulty “if we assume that light cannot serve to effect both actualizations.”59 Kosman’s

reason for asserting that light can effect both actualizations is rooted in his understanding of

what Aristotle took from the Platonic dialogues in regards to the theory of perception. In the

Republic Book VI, Plato says

Sight may be present in the eyes, and the one who has it may try to use it, and
colors may be present in things, but unless a third kind of thing is present, which
is naturally adapted for this very purpose, you know that sight will see nothing,
and the colors will remain unseen.
What kind of thing do you mean?
I mean what you call light.
You’re right.
Then it isn’t an insignificant kind of link that connects the sense of sight and the
power to be seen – it is a more valuable link than any other linked things have
got.60

What Kosman points out from this discussion is that, according to Plato, light creates the powers

of vision. Plato emphasizes that without light, which is in turn the good, the world remains

unintelligible and cannot be seen. From this Kosman says, “Light is pictured as linking together

entities which are Aristotelian first actualities.”61 However, Plato continues his discussion by

saying, “You know that, when we turn our eyes to things whose colors are no longer in the light

58
L.A. Kosman, “What does the Maker Mind Make?” Essays on Aristotle’s De Anima. (Oxford: 1992) p.346.
59
Ibid. p.349.
60
Plato, Republic 507d.
61
L.A. Kosman, “What does the Maker Mind Make?” Essays on Aristotle’s De Anima. (Oxford: 1992) p.350.

28
of day but in the gloom of night, the eyes are dimmed and seem nearly blind, as if clear vision

were no longer in them.”62 Drawing from Plato’s theory, we can understand that light not only

actualizes in the first sense, creating powers of vision, but it also makes visibility itself actual.

According to this view, light actualizes from first actuality to second actuality. It makes seeing

actual and the visible actual. From this Kosman concludes

We might thus save, with hints from Plato, the consistency of what initially
seemed two conflicting Aristotelian views of light by stressing the primacy of
second actuality to first actuality, the consequent primacy of the actualization
from first actuality to second actuality, and the logical dependency on that
actualization of the secondary actualization from first potentiality to first
actuality.63

Applying this interpretation to the active intellect, we should move our emphasis from the

view that the active intellect makes both the potential intellect and what is potentially an

object of thought, according to first potentiality, into actuality in the first sense. The

focus should rather be on the fact that the agent intellect “effects the actualization of nous

in the actual activity of thinking, that is, because it brings about the realization of second-

actuality thought.”64 The active intellect’s primary role is illuminating the potential

intellect and the potential object of thought, actualizing both into one form in the activity

of thinking, which is a move from first actuality to second actuality. As Kosman says, “it

is actual thinking, that is, second-actuality thinking, that the maker mind brings into

being.”65 Thus, the primacy of actualization with regard to the active intellect is from first

actuality to second actuality, not from first potentiality to first actuality.

b. The Agent Intellect and Universals

62
Plato, Republic 508 c.
63
L.A. Kosman, “What does the Maker Mind Make?” Essays on Aristotle’s De Anima. (Oxford: 1992) p.350.
64
Ibid. p.350.
65
Ibid. p.350.

29
 We have explored Aristotle’s theory of the intellect in depth and we have come to

understand the nature of the intellect according to Aristotle. We have come to understand that

the intellect exists as a form and it is not mixed with matter. It has been argued that the mind,

although one, possesses two powers, a power to receive (the potential intellect) and a power to

make (the agent intellect). This power to make is the power to make what is potentially

intelligible actual by an extraordinary spiritual power likened to light. The effect of such a

spiritual power is the act of abstraction, whereby the intellect separates the form from its matter

and gives it a mode superior in kind – the mode of the universal. As we shall soon see, it is only

in this mode of existence that anything at all is intelligible. It is my purpose to show how the

agent intellect is involved with this process and how it is the key to answering how universal

knowledge is possible through the sense perception.

Not only is the agent intellect able to make intelligible in act the intelligible which

objects contain in potency, its most distinctive mark is its ability to apprehend and discern the

universal among the particulars. The active intellect by apprehending and discerning the

universal among the particulars is committing an act of abstraction. Since for Aristotle the

sensible and the intelligible are one in substance, the process of separating the intelligible form

from the sensible object is called abstraction. The intellect disengages form as instantiated in

matter (abstracting), and then it makes a second act, apprehending not only the form, but also

understanding it as realized in a number of other similar individuals. Hence, the agent intellect

or intellectus agens apprehends ‘the one in many’ which is the universal. Therefore, the agent

intellect should be seen as that operation which provides the potential intellect with not only the

intelligible but the universal as well. The passive intellect remains a power of the sensible order

30
because it only receives, whereas the agent intellect’s characteristic mark is the power to

apprehend the universal.

It is only by means of the universal that we have knowledge. With regard to the senses

there is no knowledge. There is simply the perceiving of accidents which are either appropriate

to each sense, like color to the sense of sight, or common to all the senses. Accidents which are

common to all are things like movement, rest, number, figure, and magnitude. Aristotle

rightfully calls such things common sensibles for the reason that they are not particular to any

one sense. Both common sensibles and proper sensibles have been called accidental forms,

which stands in contrast to the substantial forms. The senses are what grasp the accidental forms

such as colors, smells and shapes, while it is the intellect that grasps the substantial forms. The

substantial form is the proper object of human knowledge. As we discussed earlier, material

things found within nature are substances that are composed of both form and matter. However,

matter and the individuality of matter cannot be grasped by the intellect. Anthony Kenny deals

with this same idea when he says:

The intellect can grasp what makes Socrates a man, but not what makes him Socrates;
it can grasp his form but not his matter; or rather, more strictly, it grasps his nature by
grasping the form plus the fact that the form must be embodied in some matter or
other of the right kind. But because it is matter which is the principle of individuation,
the form which is grasped by the intellect is universal, unlike the individual accidental
forms which are the objects of sense-perception.66

Forms existing in matter are only potentially intelligible to the mind. Not until the agent intellect

abstracts those forms, disengaging them from their matter and relocates them within the possible

intellect with a universal status, does the form become intelligible in act. So how is that the

mind understands particulars and individuals when we have just said that only form in the status

66
Anthony Kenny, The Legacy of Wittgenstein (Oxford: 1984), p.67.

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of the universal is intelligible? Here is what Saint Thomas Aquinas has to say about this

problem:

Our intellect cannot have direct and primary knowledge of individual material objects.
The reason is that the principle of individuation of material objects is individual
matter; and our intellect understands by abstracting ideas from such matter. But what
is abstracted from individual matter is universal. So our intellect is not directly
capable of knowing anything which is not universal.67

We cannot have direct knowledge of particular and individual objects.68 Therefore, it is only by

means of the universal that we have knowledge of individual material objects, or as Kenny says,

“It is by linking universal intellectual ideas with sensory experience that we know individuals

and are capable of forming singular propositions such as ‘Socrates is a man’.”69 Socrates as an

individual is unintelligible because the form ‘rational animal’ (the intelligible) exists within

matter. It is only when the agent intellect creates the universal and places Socrates under that

intelligible form, i.e. rational animal, does Socrates himself become intelligible to the mind. The

reason why I say that the agent intellect creates the universal is that the universal exists nowhere

else but in the mind. The universal is not the same as form; therefore, the universal cannot be

something that exists outside the mind in the physical world. In fact, the universal is not even

the same as the disembodied or de-individuated form. The universal is something different and

superior.

Saint Thomas Aquinas, who developed with meticulous detail Aristotle’s theory of

abstraction and universals, makes several distinctions concerning how abstraction is made. First

and foremost Aquinas observes that the sense organs receive sensible objects and he designates

these under the ‘sensible species.’ Now whatever is received is always received according to the
67
Saint Thomas Aquinas, Summa Theologica, Part I, Question 86, Article I.
68
Aristotle comments on knowledge and its proper object in De Anima where he says, “What actual sensation
apprehends is individuals, while what knowledge apprehends is universals, and these are in a sense within the soul.”
(De Anima 417b23-25)
69
Anthony Kenny, The Legacy of Wittgenstein (Oxford: 1984), p.70.

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mode of the recipient. Thus, the physical objects received by the sense organs must be received

according to a material species since the sense organs are themselves material. Received

materially these objects are always individuated, since matter is the principle of individuation.

However, this is not enough for knowledge. There must be a series of repeated sensations70 of

the sensible species received, after which the imagination forms a new species. St. Thomas calls

this species the phantasma and it is also individuated on the grounds that the imagination71 deals

with a material organ as well. St. Thomas notes that phantasma is what is potentially

intelligible. The phantasma is nothing other than a sense image, 72the physical likenesses of an

object sensed, imprinted on the sense organs. Aquinas tells us that it is like the object sensed

because it possesses the same form.73 However, its species remains potentially intelligible until

the agent intellect goes to work and makes that species actually intelligible. The agent intellect,

which is an intelligible light, must illuminate the phantasma, abstracting the form and thereby

creating the intelligible species. Since the intellect is not material, the mode of its reception

cannot be material. Hence, the process of the agent intellect abstracting the intelligible species

should really be viewed as a dematerializing of the phantasma. However, this is still not

enough for the mind to possess the universal. Francis P. Clarke comments on the universal:

70
“So out of sense-perception comes to be what we call memory, and out of frequently repeated memories of the
same thing develops experience; for a number of memories constitute a single experience. From experience again –
i.e. from the universal now stabilized in its entirety within the soul, the one besides the many which is a single
identity within them all – originate the skill of the craftsman and the knowledge of the man of science…these states
are neither innate in a determinate form, nor developed from other higher states of knowledge, but from sense-
perception. It is like a rout in battle stopped by first one man making a stand and then another, until the original
formation has been restored. The soul is so constituted as to be capable of this process.” (Posterior Analytics 100a5-
14)
71
Aristotle says that imagination “is different from either perceiving or discursive thinking, though it is not found
without sensation, or judgment without it.” (De Anima 427b15-17)
72
Aristotle believes that intellect always thinks through images. He states, “To the thinking soul images serve as if
they were contents of perception…that is why the soul never thinks without an image.” (De Anima 431a14-16)
73
This is to be found in Aristotle as well when he says, “The faculty of thinking then thinks the forms in the images”
(De Anima 431b3). He goes on to say that, “when the mind is actively aware of anything it is necessarily aware of it
along with an image; for images are like sensuous contents except in that they contain no matter.” (De Anima 432a8-
10).

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 It is not identical to the “dematerialized” or the “de-individuated”; for the intelligible
species is such, but it is not universal. Nor is it a characteristic of the concept simply
as expressing the quiddity or nature or essence. It is manifest only in the act of
predication; to be universal is to be predicable of many. It is thus a logical relation: for
it is a concern of logic to consider the acts of reason as such. And if a concept is said
to be universal it is only because it has the quality of being predicable.74

From what has been said, we see that the universal is not simply the possession of a form

abstracted from its matter. Neither is it that which merely represents an essence or nature. There

is no doubt that these are all aspects which belong to the universal and without which we could

not possess the universal. However, it should be understood that the existence of the universal is

superior by the very fact that it encompasses all which we have mentioned plus the ability to

exist in the act of predication.75 Not only is the universal superior by being the ‘one predicated

of many,’ it is superior by the fact that the many is only intelligible by the one. In other words,

without universal knowledge we couldn’t have the knowledge of its particulars. Without the

universal ‘rational animal’ we would be unable to understand the nature of Socrates, that

Socrates is a man. As we have seen, it would be completely impossible to have knowledge of

particular or individual objects whatsoever apart from the possession of the universal.

Therefore, it is only by means of the universal that we have knowledge.

How universal knowledge is obtained has been put forth in detail with the help of Aristotle’s

theory and the refinements provided by Aquinas. First, we have seen that it is necessary that

physical objects exist as composites of form and matter. Furthermore, if there is to be universal

74
Francis P. Clarke, “St. Thomas on Universals,” The Journal of Philosophy 59 (1962): 724.
75
Aristotle’s qualifications for something to be universal are as follows:
(1) “By the term ‘universal’ I mean that which is of such a nature as to be predicated of many subjects, by
‘individual’ that which is not thus predicated. Thus ‘man’ is a universal, ‘Callias’ an individual.” (On
Interpretation 17a38-40) “Substance means that which is not predicable of a subject, but the universal is
predicable of some subject always.” (Metaphysics 1038b15)
(2) “The universal is common, since that is called universal which is such as belong to more than one thing”
(Metaphysics 1038b 11). “For this is just what we mean by the individual – the numerically one, and by the
universal we mean that which is predicable of the individuals.” (Metaphysics 999b34 – 1000a1)

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knowledge there must be form involved. Second, there must be a potential intellect capable of

receiving and storing these forms (the intelligibles). Since physical objects are material their

mode of reception must be material as well. This requires that we have material sense organs

capable of sensing physical objects. Out of these sense perceptions comes to be a memory.

However, Aristotle tells us that this memory requires a presentation or what he calls the

phantasia.76 From here the agent intellect must shine upon the phantasia, illumine and abstract

the intelligible form from the sensible organ (the imagination), and thereby create the universal –

the one predicated of many. Thus, universal knowledge can be obtained through sense

perception in cooperation with that special divine power of intellect which we call the agent

intellect.

76
Phantasma is the word St. Thomas Aquinas uses for imagination, whereas phantasia is the word Aristotle uses.
Aristotle says that, “As sight is the most highly developed senses, the name phantasia (imagination) has been
formed from phaos (light) because it is not possible to see without light.” (De Anima 429a1)

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