Charlotte Witt
The fact that De Anima is frequently read and taught omitting book 1 suggests a widespread acceptance of the idea that it has nothing important to tell us about Aristotle's views on the soul. To be sure, Aristotle's critical analysis of his predecessors' views of the nature of soul in 1. 2-5 is a goldmine of fascinating information concerning the ideas of soul held by important Presocratics, like
Empedocles and Democritus, and by Plato. In discussing these figures Aristotle is an incisive and witty critic and, like most historians who are also philosophers, he is not always entirely fair to his elders.1
Two characteristics of soul receive extensive discussion in book 1: the soul as the source or origin of motion of the living being and the soul as the seat of perception and cognition. Living or ensouled entities differ from non-living entities by virtue of these two characteristics, and, Aristotle tells us, earlier philosophers held that soul is responsible for them (403b24-8). In the chapters which follow Aristotle presents criticisms of particular explanations of how soul accomplishes these tasks, and what soul must be like in order to do so, but he does not criticize the two characteristics themselves nor their attribution to soul. Not surprisingly then, both topics,
perception and motion, receive extensive discussion later in the De Anima and elsewhere.
Aristotle's purpose is not primarily historical, however, since a discussion of earlier views on a given topic is an integral and important part of his philosophical method, dialectic. In other words, the first book of the De Anima is as intrinsic a part of
Aristotle's project in the treatise as the second two books. For Aristotle does not collect alternative views on the soul merely in order to refute them outright, but rather he is canvassing the opinions of the wise 'in order that we may profit by
whatever is sound in their suggestions and avoid their errors' (403b23-4). The method of dialectic collects and evaluates endoxa—common opinions and the opinions of the wise—in order to shape and direct the inquiry that follows. Book 1 of the De Anima, therefore, is also an important source for our understanding of Aristotle's views on the nature of soul.
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1 For a critical assessment of Aristotle's treatment of the Presocratics see Cherniss (
As we shall see, a careful look at Aristotle's discussions of his predecessors' views in book 1 reveals several interesting and perhaps surprising commitments which have direct consequences for our understanding of Aristotle's own theories concerning the nature of soul, and how the soul is the source or origin of motion and perception.
1935).
2 Perception is also discussed in De Sensu, and motion receives extended analysis in De Motu Animalium. For a fresh translation, commentary, and interpretation of the latter text see Nussbaum (1978).
170 I. Aristotelian Dialectic
There are many reasons a philosopher might find value in a critical discussion of the views of earlier philosophers on a given topic. Today, for example, the refutation of theories other than one's own is customarily included in the theory's presentation and defence, and the theories to be refuted may include the views of historical figures as well as contemporaries. Or one might think it important to survey earlier attempts in order to avoid potential mistakes and pitfalls. Or one might include a historical survey simply as a pedagogical device, as a way of introducing the contours of a philosophical problem to students or readers.
Aristotle has a richer conception of the value of the opinions of the wise for his own philosophical inquiry than the three alternatives listed above. It is stated clearly in his description of the philosophical purpose of dialectic in the Topics:
For the study of the philosophical sciences it [dialectic] is useful, because the ability to puzzle on both sides of a subject will make us detect more easily the truth and error about the several points that arise. (101a35-7.)3
Before we turn to the issues discussed in book 1, however, it is important to have in hand a clearer grasp of what dialectic is for Aristotle. Dialectic is a form of argument or reasoning, according to Aristotle, which uses opinions (or endoxa) as its premisses.
Which are the relevant opinions? Opinions which are accepted 'by everyone or by the majority or by the wise—that is, by all, or by the majority, or by the most notable and reputable of them' (Top. 100b20-2). The first step in a dialectical argument is to collect and organize the endoxa on a given topic; the relevant beliefs are of two basic sorts—
common opinions and the beliefs of the wise.
A dialectical treatment of the opinions of the wise has a negative purpose ('detect error') and a positive purpose ('detect truth'). The sentence from DA I quoted above states the dual purpose of dialectic even more clearly; it is 'to profit from what is sound and to avoid errors'. Dialectic, when it is used in a philosophical investigation, is aimed at ascertaining truth, and the sorting-out of what is true and what is false in the opinions of the wise is an integral part of that process for Aristotle. If this is so, then it follows that Aristotle believed that some of what his philosophical
predecessors thought concerning the soul was true, and so we can profitably read book 1 of De Anima as explaining what Aristotle thought was right in earlier views, as well as explaining what he thought was wrong. Further, we can expect to glean information concerning Aristotle's views from his criticisms of earlier philosophers.
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Aristotle never tells us directly why these two sorts of opinions, as opposed to my eccentric cousin Tom's beliefs, are a good starting point for an investigation. Two
3 Translations from the Topics are adapted from Aristotle (1960).
4 Aristotle's description of endoxa in the Topics lists both common beliefs and the opinions of the wise, but the endoxa in DA 1. 2-5 consist of the opinions of the wise alone. This is consistent with Aristotle's definition of dialectical premisses in the Topics, however, since the definition is stated in the form of a disjunction; the premisses of a dialectical argument need not include endoxa of both sorts.
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reasons come to mind: (i) they are opinions which will have to be addressed by our theory since they are either very widespread or very influential; (ii) they are more likely than other opinions, those of a crackpot or the stupid, to be true or partly true or enlightening.
Step two in a dialectical argument is to develop the puzzles or difficulties (aporiai) surrounding the endoxa we have collected. It is clear from the following passage from the Metaphysics that Aristotle thinks that this is a crucial step towards an adequate theory:
For those who wish to get clear of difficulties it is advantageous to state the
difficulties well; for the subsequent free play of thought implies the solution of the previous difficulties, and it is not possible to untie a knot which one does not know.
But the difficulty of our thinking points to a knot in the object; for in so far as our thought is in difficulties, it is in like case with those who are tied up; for in either case it is impossible to go forward. Therefore one should have surveyed all the difficulties beforehand, both for the reasons we have stated and because people who inquire without first stating the difficulties are like those who do not know where they have to go; besides, a person does not otherwise know even whether he has found what he is looking for or not; for the end is not clear to such a person, while to him who has first discussed the difficulties it is clear. Further, he who has heard all the contending arguments, as if they were the parties to the case, must be in a better position for judging. (995a27-b4.)5
The survey of difficulties or puzzles concerning a given topic consists in part of a statement of difficulties concerning the endoxa (the beliefs of the wise or the many), and in part in the development of any additional difficulties surrounding the issue whether they directly involve the endoxa or not.
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II. The Soul as Origin of Motion
The purpose of the critical phase of dialectic is twofold: it offers a glimpse of the end or goal of the investigation just as the negative of a photograph outlines a positive image, and it also helps one decide which theory is adequate or most adequate in relation to the array of puzzles and problems.
Aristotle's most sustained and complex dialectical treatment of his predecessors' views concerns their idea that the soul is the origin of the animal's motion by itself moving. Near the beginning of DA 1. 2, Aristotle states very succinctly the position that he will criticize in the following chapter:
Some say that what originates movement is both pre-eminently and primarily soul;
believing that what is not itself moved cannot originate movement in another, they arrived at the view that soul belongs to the class of things in movement. (403b28-31.)7
5 Translations from the Metaphysics are adapted from Aristotle (
1984).
6 In DA 1 Aristotle develops aporiai of both sorts: in ch. 1 he presents a series of puzzles concerning soul in his own terminology, and in chs. 2-5 he develops the puzzles which arise from a consideration of the endoxa concerning soul.
7 Translations from De Anima are adapted from Aristotle (1984).
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He attributes this view to a heterogeneous group of thinkers: the atomists Democritus and Leucippus, who identified soul with spherical, fiery atoms; the Pythagoreans, who apparently considered the swirling, tiny particles sometimes visible in a sunbeam to be soul; the Platonists, who defined soul as a self-mover; and Anaxagoras, who said that mind (nous) moves the whole (403b31-404b6). Given that this list includes philosophers with clearly materialist theories of soul, like
Democritus, and philosophers with clearly dualist theories, like Anaxagoras, who sharply distinguished mind from everything else in the cosmos, and some thinkers whose views are more difficult to classify in these terms, like Plato and the
Pythagoreans, we need to determine exactly what the view is which Aristotle attributes to them all.8
(i)
The argument which these diverse thinkers share runs as follows:
the soul is the primary origin of motion of the animal;
(ii) only something in motion can originate motion in another; therefore, (iii) the soul moves.
Aristotle portrays his predecessors as believing (i) and (ii) and therefore accepting (iii) (403b29-30). His position, in contrast, is to accept (i) but to reject (ii) and hence the inference to (iii). Aristotle's acceptance of (i), the idea that the soul is the origin of motion of the animal, is clear from the fact that he never challenges it in his criticisms of earlier philosophers, and from the fact that it is mentioned prominently in his own account of animal motion later in De Anima (432a15-19). Additional evidence of Aristotle's acceptance of (i) can be found in his criticism of the theory that the soul is a harmonia of the body: 'the power of originating movement cannot belong to a
harmonia, while all concur in regarding this pretty well as a principal attribute of soul' (407b34-408a1). In addition to rejecting the argument just outlined, Aristotle also argues vigorously against the plausibility of (iii), the position that it makes sense to attribute motion to the soul.
Why does Aristotle reject premiss (ii) of the argument to the conclusion that the soul moves? His rejection of (ii) is easy to miss since it is accomplished in a sentence: 'We have already pointed out that there is no necessity that what originates movement should itself be moved' (406a3-4). Most commentators take Aristotle's reference to be to a section of his argument for the prime mover, an unmoved origin of all motion, in Ph. 8. 5. There Aristotle argues that it is not necessary that everything that causes motion should itself be moving (256b27-257a32). He considers two possibilities. Either the cause x moves in the same way as the motion it causes y, or cause x moves in a different way from the motion it causes. Suppose that x is heating y. All that is
required in order for x to heat y is that x be hot; it need not be undergoing the motion
8 Aristotle here attributes a materialist account of soul to both the Pythagoreans and Plato, whom we would tend to identify as early dualists. Whether or not Aristotle thought of a particular theory of soul as materialist or not is difficult to determine from DA 1, since he uses the word 'incorporeal' as a comparative term, and it seems to refer to more or less refined matter rather than to contrast a material with an immaterial notion of soul. See 409b20 ff. and Hicks's note ad loc. in Aristotle (1907).
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of becoming hot. Nor is it a necessary condition of the possibility of x heating y that x be undergoing some other type of motion (e.g. locomotion) or even that x be capable of undergoing some other type of motion. There is no logical requirement that x move or be capable of undergoing motion for x to be the cause of y's motion. So the fact that the soul is the origin or cause of the animal's motion does not warrant the inference that the soul moves.
In the Physics Aristotle argued that there is no requirement in principle that a cause or origin of motion itself move. But thus far he has given us no reason to question the idea, which he attributes to several pre-Socratics and Plato, that the soul in fact does move when it causes the animal to move. He has given us no reason to question the truth of the conclusion of the argument we have been considering. Aristotle's
criticisms of this idea can be divided into two sorts: he objects in general terms drawn from his own theory of motion to the coherence of the idea that the soul moves (406a12-406b15), and he also objects in detail to the particular theories of Democritus and Plato (406b15-407b26).
Aristotle begins his criticism of the idea that the soul moves, or that movement is an attribute of soul, by making an important distinction between two ways in which an entity is moved: by virtue of itself and by virtue of something else. For example, a ship under sail moves by virtue of itself, but the crew moves by virtue of the ship's motion. Of course, a member of the crew could also walk about the ship, and in this case he would be moving in virtue of himself, or by virtue of a movement proper to himself. Aristotle's position is that the soul does not move by virtue of itself, in contrast to both the ship and the crew, each of which is capable of moving by virtue of itself. By drawing this distinction, he leaves open the possibility that the soul could move by virtue of the movement of something else, namely the body. More
importantly, however, he uses the distinction to pave the way for another point concerning the question of what motion is natural for the soul.
As we saw in Aristotle's example of ship and sailor, there is a close connection between the idea that an entity moves by virtue of itself, and the idea that there is a kind of motion proper or natural to it. Ships sail and humans walk. What kind of motion is proper or natural to soul? In order to understand the way that Aristotle approaches this question it is helpful to remember that he construes the term 'motion' broadly; it covers locomotion, alteration, diminution, and growth (406a12-13). Now each of these species of motion involves place (topos). Locomotion, alteration, diminution, or growth all occur somewhere, at some location. But, if one of these forms of motion is proper to the soul, then soul must have a location or place, and Aristotle thinks that this idea is implausible. He does not tell us explicitly why it is implausible, but he does provide an explanation of his point by means of the example of a colour, an attribute. The attribute does not have location, he says, but rather the body in which the attribute inheres has location. So the attribute does not move by virtue of itself but rather by virtue of the body, which, having a location, can undergo locomotion or one of the other species of motion. There is no motion
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proper to colours, although there is to coloured bodies. Similarly, soul does not have a location in virtue of itself, although it may have one by virtue of the body with which it is associated.
Aristotle denies that the soul can move in virtue of itself, and that it has a distinctive location of its own. The illustration of the first point, ship and sailor, suggests that he thinks of the soul as a part of, or contained within the body; the soul is carried along when the body moves just as the sailor is carried along by the ship. He does not explain here why the soul cannot move in virtue of itself. The imagery of parts and containment suggests that the soul is a material entity transported like cargo in the body. On the other hand, since, as we shall see below, Aristotelian matter by
definition has a natural tendency to move we might take Aristotle's point to be that the soul just is not the sort of thing that can move by virtue of itself, that is to say, it is not matter or material. But if the latter is the case, then how are we to think of the soul as being carried along by the body?
The soul does not have a location, and hence is not capable of motion by virtue of itself by analogy with an attribute like colour. This comparison suggests that
Aristotle does think of the soul as just not being the sort of thing that can move, that is, as not being a material thing. For a colour does not have a location, and so does not move by virtue of itself because of the sort of thing it is, because it is not a
material body. The colour has a location and moves only in virtue of something else, namely the location and movement of the body in which it inheres. Here the
relationship is not one of parts to wholes, or contents to container, but rather of inherent to subject (Cat. 1a24-5). The analogy between soul and an attribute is helpful because it suggests that Aristotle is not thinking of soul in terms of a special sort of matter, itself incapable of motion, that resides within an ordinary material body and is carried about by it. The comparison suggests instead that souls, like attributes, just
relationship is not one of parts to wholes, or contents to container, but rather of inherent to subject (Cat. 1a24-5). The analogy between soul and an attribute is helpful because it suggests that Aristotle is not thinking of soul in terms of a special sort of matter, itself incapable of motion, that resides within an ordinary material body and is carried about by it. The comparison suggests instead that souls, like attributes, just