Reading notes for Aristotle's De Anima
Michael Taber

(The Fine & Irwin translation, as edited in Cohen, Curd, & Reeve’s Readings in Ancient Greek Philosophy)


Book II

Chapter 1

This chapter contains some general comments about what a psyche is.

412a6-21

The psyche isn't substance in the fullest sense of substance (ousia), namely in the sense in which the bronze sphere is substance. Instead it actualizes matter into a composite, and it's that composite which is substance in the fullest sense.

412a22-27

Aristotle distinguishes between the first and the second actuality of something. What he means is this. Let Alice be ignorant of (but capable of learning about), say, the cause of the winds. Let Betty know the cause of the winds but not be thinking about it now (as she is asleep). And let Cathy know the cause of the winds and be presently explaining the matter to Daphne. Betty has actualized what Alice has as mere potential, yet Cathy is actualizing something which Betty both has actually (in that she actually possesses the knowledge) and has potentially (in that she's not, in her sleep, actualizing that knowledge). So Cathy has actualized her knowledge in two senses, whereas Betty has only the first actualization.

Aristotle's claim here is that psyche is the first actualization. Why is this point worth him making? Well, for starters, the implication of saying that psyche is the first actualization is that the psyche would be not some sort of activity, but the capacity to engage in some sorts of activities; more precisely, not the undeveloped capacity (that would be Alice), but the actualized potential to engage in some sort of activities.

At some point, then, Aristotle will have to tell us which are the relevant activities. He starts on this project at the passage 412b10-413a10, where he says that the psyche of something is the what-it-is-to-be-that-thing, by which he means something like the essential function (the ergon, "peculiar work") of the thing. This, of course, leaves unaddressed the question of which particular activities constitute the psyche of which living things (that is, which particular activities constitute the peculiar workings of which living things). This question will start to be addressed in II.2.

It also leaves open how the psyche actualizes the body; for example, does the psyche actualize the body like the way a sailor sails a ship? If not, then how else? This will come in (the notoriously perplexing) III.5.

412b3-9

What does Aristotle mean by his response to the question "Are the psyche and body one?"

Chapter 2

413b22

Aristotle’s word phantasia is translated by Fine and Irwin (in editions from Hackett Publishing Company) as "appearance" (and see their glossary entry for this term), and by Hamlyn (in Ackrill’s A New Aristotle Reader) as "imagination." It is a difficult word to translate, for it is more interesting than "appearance" but less fancy than what we mean by "imagination." When Aristotle talks of phantasia, he means it not in the sense of what distinguishes poets from mental drudges like the rest of us. He means it in the traditional sense, used even by Descartes, to refer to something like "the ability for at least part of the outside world to appear to you to be a certain way." Something like "the ability to entertain images." So in this sense, Aristotle thinks that a fish must have phantasia, for it must have an image (provided by sense-perception) of the food source towards which it's moving.

413b25-32

Aristotle proceeds to mess up his nice picture by declaring that thought alone is separable (from the body). Furthermore, this seems to land him in the Platonist camp, for it represents a case of a form (the psychic faculty of thought) as being able to exist separately from the world of spatio-temporal particulars. Either Aristotle is right that there is something essentially different about thought (as distinguished from self-feeding, growth, movement, and sensation), or we have to chalk this exception up to Aristotle not being able to throw off the influence of his teacher.

For what it's worth, we can see a similar problem in Aristotle's discussion from Met. XII.5, 6 & 9, where he talks about the divine substance. Here again there is a form which can exist separate from spatio-temporal particulars, and so perhaps represents another bit of residual Platonic.

But then maybe it's the same bit. For what is it that Aristotle takes the divine substance to be doing? Thinking. Which is exactly the exception he's making here at 413bb.25.

Chapter 3

Aristotle gets back into his Aristotelian mode when he says that not much can be said about psyche in general, and that to understand what a psyche is we need to study different sorts of empsyched beings. This approach is what makes Aristotle's mind so well-suited for studying, nay starting, biology.

Chapter 4

This chapter explores the most basic psyche, the nutritive psyche.

415a26-b1

Note Aristotle's teleology in claiming that everything living reproduces so as to partake of the everlasting as much as possible. He looks around, notices that all forms of life reproduce, and concludes that there must be a universal "urge" (whether felt or unfelt) to reproduce. He does not settle on (or entertain) the more mechanistic explanation that forms of life which don't reproduce die off and so aren't around to be noticed by Aristotle.

415b9-28

Aristotle claims that the psyche is the cause of the body in three ways: it's the efficient cause (the "from which"), the final cause (the "for the sake of which"), and the formal cause (the "by which," here described as "the substance" of the body). Obviously, the psyche can't be the material cause (the "out of which") of the body.

416a3

What does he mean by saying "in accordance with their functions, a plant’s roots correspond to an animal’s head"?

416a9-18

Now that Aristotle has claimed that it's the psyche that is responsible for the ability of a living thing to feed itself and grow, he must counter the view that it's fire that is the essence of feeding and growth. Why might someone think that fire is the source of feeding and growth? Well, fire is, after all, the only element which increases by itself. Effort must be taken to ensure that a fire doesn't feed itself, for except in artificial conditions (like sand pits and wood stoves), fire left on its own will spread. That's fire's nature. The nature of composite things ("everything naturally constituted") involves proportion and limit (note the echo of Pythagoras here), and so an incomposite element like fire isn't up to the job of limiting feeding. Aristotle perhaps is thinking that if there were fire in us which allows us to feed and grow, then that fire would grow out of control, and so consume our very bodies. Interesting.

Chapter 5

This chapter discusses the psyches which have the faculty of perception.

417a2418a7

Spread your fingers out. If it's the job of skin to perceive touch, then why can't you feel your fingers' skin?

Look hard. If your retina is the organ of sight, then why can't you see your retina? Or your optic nerve? Or firings in your optic cortex?

What does your tongue taste like, your nose smell like?

What do your ears sound like? Why do you hear a bell and not the fluttering of your eardrums? (If you say, "But they're the same thing; the bell is the fluttering of the eardrum," then consider how a bell can be two hundred years old without the fluttering of an eardrum being so aged. If you more carefully say, "Well, the sound of the bell is the fluttering of the eardrum," then consider that [i] you've taken the world away from us, for we no longer hear bells, see people, taste chocolate, but we hear middle-C, see colors, taste sweetness. The world of objects has been replaced by a flood of sensations. Further consider that [ii] if the sound of the bell is identical with the fluttering of the eardrum, then the bell makes no sound if there is no eardrum around to flutter.)

What is Aristotle's answer to "why we do not perceive the senses themselves"? (This chapter isn't Aristotle at his clearest, but it has something to do with the actual/potential distinction.)

Chapter 6

This chapter presents Aristotle's account of what the object of perception is. He claims that each sense has a proper object (sometimes rendered "special object," and for those in the market for certainty, these we can be certain of); that there are common objects which can be perceived incidental to perceiving the proper objects; and that I see the son of Diares only incidentally (not incidental by virtue of the son of Diares being a common object, but by virtue of him being incidentally related to the white patch I see from a distance).

A further question, but one not taken up by Aristotle until III.2, is what exact relation is denoted by this "related to." Despite Aristotle's use of the verb "to be" ("if the pale thing is the son of Diares"), the relation can’t be the relation of identity; for then what’s true of the one is true of the other, and so since I see the whiteness more than incidentally, I’d have to see the son of Diares more than incidentally. This is the intriguing question "If what we see isn't things in the world, then just what is the relationship between what we see and the world?" George Berkeley (1685-1753) answers the question most creatively by denying that there is a world; he claims (and argues for the claim) that all that exists (not just all that we can have access to) is perceptions (or minds in which those perceptions inhere).

Chapter 11

This chapter gives Aristotle's account of the sense of touch, and how it differs and doesn't differ from the other senses.

Chapter 12

This chapter draws a lesson about form and matter from the rest of the book. It is an important lesson too, for he uses it in his discussion of thinking in III.4.

424a18-28

Aristotle concludes his discussion of perception by claiming that sensing is the reception of the form of the sensed object without its matter. That the matter isn't communicated can be seen in two ways. First (and this is a point Aristotle doesn't make here), sensing an apple doesn't affect the matter of the apple (and affects the form only in the sense of making that form shared by my perceptual faculty), and certainly doesn't put the whole material apple into my perceptual faculty. Second (and this is left implicit from Aristotle's interest in all sensation requiring a medium), the medium of each instance of sensation acts as a blanket or filter which allows the form but not the matter of the object into my perceptual faculty.

424a33-b19

Aristotle ends his conclusion by distinguishing the perceptual psyche from the first species of psyche which he had discussed, the nutritive psyche, which is had by plants. The nutritive psyche has to be able to be affected by the matter of objects.

To his credit, Aristotle doesn't stop there. He entertains the question "How can something be affected by a perceptual quality (e.g., a smell) without that thing perceiving that quality?" It is a good question, but smell isn't the clearest example he could have used. He uses later the better case of light and darkness. Light and darkness are visual qualities, yet they can affect plants; does that mean that plants must be able to see? This question is especially poignant because of Aristotle's emphasis on the sensory medium; since light and darkness don't directly affect the body, but only the sensory medium (air or water), how can that sensory medium in turn affect, say, a plant unless the plant can see? In other words, if sensing is being affected by a change in a sensory medium, then plants would have to see.

He points out the exception for touch and taste (424b13). What is touched or tasted directly affects a sensory medium, but this sensory medium is the body (the skin or the tongue). So tangible qualities, like hot and cold, cold, can affect plants without the plants being able to sense them. When a heated iron touches a plant it affects the plant by the matter of the iron burning the matter of the plant; form is not sufficient, so this can't be a case of perception.

But this doesn't allow us to explain the case of light and darkness affecting the plant, for there the matter of the source of light need not touch the matter of the plant.

Aristotle doesn't resolve this, and the end of the chapter "looks like a number of lecturer's questions thrown out seriatim by way of challenge" (D. W. Hamlyn, Aristotle's De Anima, Books II and III, Oxford: Clarendon Press, 1968, p.115). But he does suggest in one of his questions that there is something more to sensing than being affected by a perceptual quality. This is a weighty issue, for it involves such questions as "Where in the processing of the visual system does the seeing happen? If in the brain, then in a particular neuron?" and "What exactly happens in the brain of one who understands an explanation of the Pythagorean theorem that doesn't happen in the brain of one who doesn't understand but who nonetheless perceives the words and pictures?" This last goes beyond perception into cognition; the plant is to the perceiver as the mere perceiver is to the knower. This takes us to Book III, where Aristotle takes up the thinking psyche.

Book III

Chapter 3

Aristotle here discusses what phantasia is, and how it differs from perception, belief, and knowledge. This serves as a bridge between his discussions of perception and of thinking.

428a6-17

He adduces four different considerations for why perceiving differs from imaging (which is an appropriately less ambitious word than "imagining"; to image something is for you to have that thing appear to you): at "For perception is...," at "Moreover,...," at "Further,...," and at Again,...." What are the four? Laurels to those getting the fourth (in a way that makes it genuinely different from the rest).

It’s not clear why, but the final sentence repeats the first of the four points.

428a18-24

He gives a reason for phantasia not being knowledge, and two reasons for it not being belief.

428a25-b9

He gives an argument for phantasia not being a combination of belief and perception. The last part (b5-9) of the passage is difficult, but makes sense.

Chapter 4

Now we get squarely to Aristotle's views on the nature of the thinking faculty (intellect, nous).

429a14-18

Although Aristotle seems only to suppose that perception is analogous to thought, he seems go further and to endorse the analogy, at least insofar as thinking requires that the intellect be capable of receiving the form of the object of thought. The analog is said of perception at the opening of II.12.

429a19-29

This passage is not only crucial for Aristotle's account of the psyche, but the point it makes is hugely influential in the history of theorizing about the mind, its relation to the brain, and its ability to attain knowledge.

Aristotle holds that because everything can come to be known by the cognitive psyche (nothing in the cosmos need remain locked away from us), the intellect must have no nature. It is pure potentiality. For if the intellect had an actual nature, a form of its own, that nature would interrupt the ability of the intellect to receive the forms of some objects. The slate has to be blank (actually blank, though potentially full; cf. 430a1) in order for everything to be legibly written on it.

It won't be until Kant's Critique of Pure Reason (1781 and 1787) that someone proposes in any detail that the mind is hardwired to think with certain categories (like space, time, causality, substance), with the consequence that anything not conforming to those categories couldn't be an object of thought for us. Aristotle is more optimistic about the ability of the intellect to know everything in principle.

But that's not all. Aristotle draws out the implication that if the intellect is to be characterless so as to be able to take on the character of anything it thinks about, then it cannot "be mixed with the body." This is reminiscent of 413b24-31, where he had said that the intellect alone is separable (from the body? from the organism, including the rest of the psyche?).

Despite this precedent, this poses no small problem for Aristotle's general account of the psyche in II.1: "The psyche must, then, be substance qua form of a natural body which has life potentially...The psyche, therefore, will be the actuality of a body of this kind." If the psyche is form and actuality, then how can the intellect (part of the psyche, after all) be formless and pure potentiality?

Second, even if Aristotle adjusts his general account of what a psyche is, then, given his association of matter with potentiality and form with actuality (412a9), it stands to reason that if the intellect is without form, it's without actuality. But then if it's potentiality, wouldn't it have to be material?

Third, Aristotle believes that even matter has a form, though a lower level form than that of which the matter is matter. For example, a lump of bronze has the form of being a certain ratio of the four elements, even before the sculptor induces the higher level form of sphericality onto the lump. Since matter has some form, that limits the potential it has. Bronze could never become food, for instance. And even the element of water could never become fire. But even if Aristotle responds to the second point above with the claim that the intellect is purer potentiality then anything material could ever be, wouldn't it follow that when the intellect isn't thinking, it vanishes into the void (since it has no nature of its own)? To call this counter-intuitive would be too gentle.

429a29-b9

Aristotle notes two ways in which perception differs from thought, and they both involve perception being, and thought not being, separate from the body. (1) Only thought isn't worsened by having an intense object. (2) The intellect can think by itself, but the perceptual faculties require an external object. (And lest you object that it's possible to imagine an object that's not present, remember that Aristotle has already given not one, but four reasons for holding that imaging is distinct from perception [428a5-16].)

429b23-430a9

Aristotle poses and responds to two questions about his view of what the intellect is. (1) If x can act on y only in virtue of some similarity between them (for example, rain can act on a seed only if they are both material objects and only if they exist at the same time and place), then how can actual objects of thought act on a completely non-actual intellect? (2) Can the intellect think about itself? (Given what Aristotle has said in this chapter, why might this second question be a special challenge for him?)

He provides an answer to each in the second half of the passage. What are his answers?

Chapter 5

This is where Aristotle introduces the distinction between the passive intellect and the active (or producing) intellect. It represents a fast break from the previous chapter's analogy between perception and thought (cf. 429a14-18). In fact, it is surprising that the account of thinking in III.4 is so bereft of any hint of there being two intellects, or, at the very least, two aspects of the intellect. An example of this puzzlement is that where before he had said that the intellect has no nature and is only potential (429a21), he now commits himself to saying that there is an intellect which is pure activity, and so is pure form and has a full nature (activity, form, and nature all being linked in Aristotle's metaphysics). This new wrinkle can't simply be appended onto III.4, for it's incompatible with much of III.4.

Any ideas?

Chapters 10 & 11

These chapters discuss how thinking things get going. Desire is necessary but not sufficient for deliberation about what to do. You’re on your own for the rest of these short chapters.


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