Aristotle’s De Anima Book III

Chapter 1 – The need for common sense

Since the senses perceive each other’s objects incidentally whenever they are directed at one moment to two different qualities (because they form a unity), and since, the the assertion of the identity of both cannot be the act of either of the senses. . This explains the illusion of sense.

Aristotle asks whether there might be a sixth sense which we happen not to know. He shows that the five special senses have a certain orderly arrangement that makes them a complete set. So it seems reasonable that there exists no sixth sense that we lack and do not know about.

The second part of the chapter takes up the common sensibles and the incidental sensibles (the second and third kinds mentioned in II-6). Aristotle argues that it cannot be by a sixth sense that we sense the commonalities of the five. Rather, we can differentiate the common sensibles because there is a “common sensing” (a together-sensing) by the five. This also explains how we are able to sense the incidentals. The first part of the chapter concerns material and efficient causes (organ and media) although the final cause enters in. The second part is in terms of formal causes. A short part at the end follows from a final cause.

Chapter 2 –

In this chapter many essential linkages are established which are needed for the rest of the Book. Aristotle derives all the following from sensing: We can sense darkness 425b22 images left-over from sense 425b24 a blend, (a voice, a chord, a sauce) The source of pleasure and pain derived from the sense-proportion (vital for the Ethics) We sense that we see we discriminate between the senses (sense that we see, rather than taste or hear) we sense that we see and also hear (when both happen together) the identity of a moment of time the singleness of the one who senses (“we,” the person or animal) 426b19 the sense mean (e.g., of hot/cold) the sense mean taken up into thought (“as it tells (ratios, legei), so it thinks (noein) and senses”)426b22 Also in this chapter: In what exact way the sensible form of thing and organ are one form of one activity. He derives (from voice and harmony) his view that the sense is a proportion. The organ is tuned like a lyre. I need to use the verb “proportioning” for what sensing does:The sensing actively proportions the incoming sense-motion. Sensing is proportioning. Sensing is shown to be a single activity of the five senses in proportion to each other. Aristotle derives the “single sensitive mean” which is later shown to have a major role in thinking.

What functions does the common sense perform in Aristotle’s psychology? (passim, III.1-2)

Chapter 3 – Imagination Distinguished from Sensing (aisthetic), Remembering, Desiring, Thinking (dianoia -discursive).

Here begins Aristotle’s treatment of understanding and thinking. Within his discussion of this topic, and only after a while, does he take up imagination, beginning at 427b27. The chapter falls easily into four parts:

First he distinguishes thinking from sensing. He has just finished discussing sensing.

At 427b15, he says that there is no thinking without “premising” (hupolepsis, ὑπόληψις), and no premising without images. So there is no thinking without images. Hupolepsis (premising) means assuming the truth of something, (which imagination does not). A simple key to this part is that imagination differs from the others in that it can be false and yet not lead us into error, if we don’t premise that what we imagine is so.

From 428a5 to 428b9 he differentiates imagination from other faculties. This part is very confusing to the novice, and can be skimmed. Study it when you are familiar with the whole De Anima.

At 428b10 he defines imagery.

Discuss the nature and importance of imagination (phantasia) in Aristotle’s psychology. Mention the role of this faculty in sensing, remembering, desiring, and thinking. (passim, III.3)

Chapter 4 – What is the Thinking Part and How Does it Work?

The chapter has three parts:

In the first part Aristotle asks certain questions, answers some of them and leaves some of them open.

In the middle section, 429b6 – to 429b21 (from “When the nous has become each knowable thing. . .”) Aristotle leads us through a series of understandings, and then to a conclusion. Since sense faculties are blinded when they become too much like their object, and since this does not happen to the mind, the mind is separable from matter. It allows us to distinguish flesh from what-is-to-be-flesh (actual from potential). Insofar as the realities it knows are capable of being separated from matter, sofar are the powers of mind.

In the third section he answers the questions he had left open:

1) what differentiates the mind? mind is, in a sense, potentially whatever is thinkable though actually it is nothing until it has thought. It is like a writing tablet which has nothing actually written.

2) how can thinking take place? Mind is actual in the same way its objects are –  a) immaterial things are present exactly the way the actually are and b) material things are potentially present – they don’t have mind in them (because mind is in them only insofar as they are capable of being disengaged from matter)

How is thinking similar to sensation? How is it different? (passim, II.12, III.4, 8)

• Just like sensation, thinking involves the object known becoming actual in the knower – and if it is an immaterial object it is fully in the knower, if it is less material it is only that much in the knower. There is a formal intention (potential second act in the knower) and an objective intention (the same act found in both the thing known and the knower)

Chapter 5

It helps to know that Aristotle made no chapter-divisions. The few paragraphs of this brief “chapter” are really the culmination of III-4. So we should be engaged in the train of thought which continues here.

In III-4 he first mentioned Anaxagoras’ universe-nous and then defined our potential nous as able to learn, potentially (capable of) becoming (the forms of) all things. It cannot have any actual form of its own, since it can receive any form. Therefore the potential nous is no actual thing at all before it understands (prin noein, 429a24). Then the potential nous becomes the learned. But to acquire the learned, must there not be (and have been) some learning and understanding? And in the material things the forms are only what III-5 3 can be understood, not understanding. III-4 ends by saying that neither this (potential) nous nor the material things are understanding. The things and nous so far are only understandables, not understanding. Can nature and nous exist just as understandably ordered? Must they not also be an ordering? Now Aristotle continues into our chapter.

Why does Aristotle distinguish between the agent and possible intellects? Do these both exist in individual souls? Is either or both immaterial? Does Aristotle think that either of them can exist apart from the body? (III.4-5)

Chapter 6

This chapter is about the objects of understanding. According to the programme laid out at the start of II-4, Aristotle began his treatment of nous with the potentiality, has then moved to the activity, and will now discuss the objects.

The objects are first those of nature up to: 430b6; then the objects of mathematics until 430b24 where objects that are “indivisible not quantitatively but in form” are taken up, i.e., substances, the kind of objects distinguished in metaphysics (“But if there is anything . . . which has no opposite. . . ..”).

The chapter is about different kinds of thought-unities. First he discusses unity by combining, then indivisibility in the mathematical continuity, then the unity of a substance.

How does Aristotle explain the possibility of error in sensation and in thinking? (II.6, III.3, 6)

Chapter 7

In this chapter Aristotle puts sensing and thinking together in one continuity including much of what has been built so far. He shows the continuation of sensing into action, and how thinking functions in the continuation to action. He explains the combinations among the five senses and among thoughts in relation to good and bad, pursuit and avoidance in both practice and theory.

The previous chapter (III-6) was about the thought-objects. He said that single grasps were certain; only combinations can be true or false. We have not yet seen how sensing and thinking combine the single images and thoughts. This chapter shows it.

In reading the chapter it helps to know that the proportions in this chapter (“as white is to sweet, so …”) apply both among the five senses and between sense and thought.

The chapter also shows why thinking requires images. This is because the five kinds of sense-motion continue to a single active “mean” between them all. This “sensuous mean” combines single sensations by giving them proportional relations. In proportioning the senses, this sense-mean also functions to proportion and combine the single thoughts. Since we get our thoughts from sensations, and since their combination is “marked out” there, Aristotle holds that we have to use the sense-images in our thinking.

The sensuous mean continues into desire and action. In action the human practical thinking can play a role. Chapters III-9-11 will then take up locomotion and action more exactly. The chapter provides the continuity across all the previous sections, and also the continuity from them to the next section of the De Anima.

I remind you that some translators use the English “sensing,” others use “perceiving” but they mean the same thing and translate the same word (aisthesis).

Chapter 8

Aristotle calls the chapter a “summary.” It deals with the argument he repeated throughout the sensation chapters that the sense is potentially all sensibles, or is actually the one that just now activates it. Also covered is the analogous argument about nous. In our chapter he says explicitly that we learn the thought-forms only from sense. The summary ends where III-7 had just arrived, with the reason why thought requires images. However, there is something new at each point.

Chapter 9

It helps to know from the start, that in this chapter Aristotle does not tell us what causes locomotion. Rather, he shows that no single soul-part (soul function) is always sufficient to cause motion alone. In the next chapter we will see that locomotion is caused when certain soul-parts are in a certain relationship.

Humans are of course animals, so that animal locomotion includes human locomotion. Humans are not necessarily moved by desire alone, since reasoning can stop them. And reasoning alone without desire is also not enough to move us.

As usual when taking up a new function, Aristotle shows that it is not accounted for by those he has already considered. i.e., not nutrizing, not sense as such, not thinking alone, and not always even desire + reason, since a more immediate desire can stop it.

Chapter 10

As always, an activity is caused by a soul-power and is defined by its object. The chapter moves to define a single source of locomotion, not two. Practical nous is not another power that causes movement; rather it provides one kind of object. There is only one power, the desire-power, but Aristotle defines different kinds of desire depending upon its various objects.

How is self-movement possible? Is this faculty common to all animals? (III.9-10)

Chapter 11

III-11 is about the different kinds of objects of desire and motion which different kinds of animals have. Aristotle uses the distinction he just made between two kinds of imagination, calculative or sensitive (ἢ λογιστικὴ ἢ αἰσθητική). Objects of desire and motion always involve one of these two kinds of imagination. A desired condition is one which does not obtain; it has to be imagined.

He begins with the sensuous kind of imagination. He is first concerned with animals that have only one sense, the sense of touch. Such animals do not have locomotion. They remain in place but do move. Aristotle says they have “indefinite” motion and imagination, whereas those with more than one sense have “definite” imagination and motion. We will see what this means.

Then he turns to the kind of imagination and desire-object which is formed with the participation of the practical nous. When a choice must be made, a single combined image of the alternatives is created by practical nous, so that they can be weighed. He arrives at just three possible conflicts between alternative objects of desire.

Chapter 12

In III-12 and III-13 Aristotle draws together and answers some questions he had left open. In II-2 he promised to tell us later the causes why sensing defines animals and why the touch sense is necessary before any other senses. In III-1 and 2 he showed that the senses must join but did not say where, only that it cannot be at a sixth organ. Now he can show how these things are all causally connected. By “cause” he means all four kinds of answers to the question “why?” Most of what is said here has been said earlier, but it is exciting to see Aristotle giving the inherent reasons, the internal connections, showing that it all fits together, and why it does.

Chapter 13

Aristotle continues to fill in the chain of causes which he began in III-12. He gives two reasons why a body that senses cannot be simple, i.e., made of one element. It must be solid and it must be a mean between all four tangible qualities. He shows where the five senses join and why they have to join there. Then he fills in why the very being, definition, and composition of an animal’s whole body is the sense of touch.