Ancient History & Civilisation

ANAXAGORAS OF CLAZOMENAE

As a prominent figure in intellectual circles in Athens in the middle of the fifth century, and a close friend of the great statesman Pericles, Anaxagoras attracted a great deal of rumour and suspicion. He became something of an archetypal wise man (calm in the face of the death of his son), and also an atheistic scientist figure (calm in the face of a solar eclipse)—and indeed there is some truth to this picture, since mechanical causes play a great part in his system, and he seems less inclined than some of his predecessors to describe even his cosmogonic mind as ‘god’. He may even have been put on trial for impiety, though, if so, the trial is likely to have been motivated by the political desire to hurt one of Pericles’ friends.

Anaxagoras’ book, written in ponderous and almost incantatory prose, followed a straightforward cosmogonical course, from the original state of affairs to the finished world. In F1 he sketches his picture of the original state: all the things that would later make up the finished world were mixed together in infinitely minute quantities—so small that nothing was distinct and the whole mixture was uniform (we shall return to the problem of air and aither in this fragment below). This original mixture seems to be envisaged as occupying the infinite region beyond the reaches of the spherical universe, and from this ‘vault’ air and aither were separated off in the beginning, as they still are now (F2). The infinitude of the original mixture is stressed in both F2 and F3: it is an inexhaustible source.

Next Anaxagoras immediately went on (F4 and F51) to state his two most startling theses—that all things, including humans, are aggregates of the stuffs that were present in the original mixture, so that all physical change is no more than the manifestation of what was previously latent; and that there is no reason not to think that more worlds than our own might have been separated out from the original mixture. Quite how he envisaged these parallel universes is not clear (and indeed the whole idea might be some kind of thought-experiment), but, however extraordinary it might seem, the most likely explanation is that Anaxagoras considered the possibility that the original mixture could generate not only large structures such as our world, but also extremely small ones. As F7stresses, there is equivalence between large structures and small structures, so why might there not be infinitely small universes? Also, if these infinitely small universes were contained within our familiar universe, this would explain the otherwise puzzling insistence in the doxographic tradition that Anaxagoras did not believe in a plurality of universes (T1; see also F6).2 But what is important to note is that Anaxagoras imagines all possible worlds to be identical in all respects except for size; in other words, he feels that the ingredients and factors and laws he will specify in his book guarantee only one kind of world. The seeds within the original mixture are seeds that can give rise only to certain kinds of things, just as in modern physics the nature of our universe is dictated by the set of laws that govern it, while a different set of laws would create a different universe.

Anaxagoras has stressed the uniformity of the original mixture, so it is odd to find him also asserting that there were ‘seeds’ present in it (F4), and then to read in F5 that these seeds are ‘dissimilar to one another’ and have shape, colour, and flavour. But some of the confusion is dispelled by attending to an important difference between F4 and F5: although one of the qualities the seeds have is said to be colour, it is also stressed that the original mixture does not have colour. In other words, talk of ‘seeds’ occurs at two stages of Anaxagoras’ cosmogony: in the finished things of the world there are seeds with determinate qualities, infinite in quantity but only ‘numerous’ in quality, but in the original mixture there are seeds with no qualities. If we are to preserve Anaxagoras’ emphatic talk of uniformity, we need to understand the seeds of the original mixture metaphorically. Although to us a ‘seed’ sounds like a discrete parcel of matter, it is more likely that Anaxagoras was merely trying to express, by a biological metaphor, the idea that the original mixture contained all things in potential. Though uniform and homogeneous, it contained the potential for aggregation in different proportions—which is just another way of saying that it contained in potential all the finished things of the universe, because anything and everything is no more than an aggregate of stuffs in a different proportion (F10). In this sense, the seeds are the true originative substances of the worlds.

It is axiomatic for Anaxagoras that, apart from mind, which is pure, everything contains a portion of everything else (F8–10); hence too he insists that even opposites are not entirely separate from each other (F5 and F6), and that just as there were seeds in the original mixture, so there are seeds in the finished things of this world.3 He found it as impossible as Parmenides had to imagine that anything could come into existence from something that did not already exist. Hence, in a cosmogonic context, the idea that the things of this world were preceded by seeds, and in the finished world the idea that the things of this world contain the seeds of everything else. But the seeds themselves, as well as their offspring, also consist of minute portions of everything else. Everything is present in every seed and in every item of the universe, but in different proportions. The difference in proportion explains the different qualities things have (F10, T5), while the fact that everything consists of the same ingredients explains how things can interact, and explains phenomena such as growth by nutrition and reproduction (T2, T3): our flesh can be nourished by eating bread because the bread already contains flesh in it (or the qualities that characterize flesh), and a child can come from a sperm because the sperm already contains the ingredients of the child’s body.4 A thing of finite size can contain an infinite number of ingredients, because of Anaxagoras’ principle of infinite smallness (F1, F7).

But can we further specify what these basic ingredients actually were in Anaxagoras’ system? Occasionally, in describing Anaxagoras’ ideas, the doxographic tradition makes use of the convenient Aristotelian term ‘homoeomeries’. For Aristotle, a homoeomerous substance was one which, as the name implies, is the same throughout: however far it is divided, it is the same substance. His prime examples are natural substances such as flesh and bone, wood and metal, and the four elements. There seems to be no reason not to accept this as an accurate paraphrase of Anaxagoras’ ideas, with the qualification added by T4 that Anaxagoras regarded the elements as compounds of his homoeomeries. The original mixture consisted of homoeomerous substances, fused into a uniform blend (with the ‘seeds’ of potential future growth), or compounded as air and aither; the finished products of this or any other world are made up of everything—all the seeds or homoeomerous substances—in different proportions.5 The proportion of the homoeomerous substances that make up flesh, say, remains constant throughout any bit of flesh. Of course, there are more than just homoeomeries in this world, but they can be broken down into homoeomeries; human beings are not homoeomerous in themselves, but their parts (flesh, bone, hair, etc.) are. Gold is homoeomerous, but an alloy is not; clay is, not cement; wheat, but not bread. But how can Anaxagoras simultaneously hold that some things are homoeomerous, and that ‘in everything there is a portion of everything’? Are these two ideas not contradictory, in the sense that a homoeomerous substance should consist only of parts that are identical in nature to the whole? No, they are not: even if, however far I divide a homoeomerous substance such as gold, I still get gold, that does not mean that what we call ‘gold’ does not contain minute portions of everything else, every other basic ingredient.

F7 and F8 closely connect the notion that everything contains a portion of everything with the idea of infinite smallness, and with the idea that the large and the small are numerically equal ‘since each thing is both large and small in relation to itself. F8 goes so far as to say, ‘Since there are numerically equal portions of the great and the small, it follows that everything is in everything.’ How does this follow? Perhaps Anaxagoras means that however many large (i.e. manifest) things there are, there are just as many small (i.e. unmanifest) things still latent in the mixture, and that this not only applies as a generalization relevant to the sum totality of all things, but is also true of any particular stuff. If there was not as much stuff latent in the mixture as there was manifest in the world, and if this was not true at any given time, then stuffs would begin to fail. From this it follows that everything is in everything.

Moreover, if it were not the case that in everything there was a portion of everything, we would be able to divide something down to its final component, which would be a particle of just one type of stuff, not a blend of all stuffs. This may be seen as an Anaxagorean response to Empedocles and Parmenides (except that it is not clear that his philosophical activity post-dated that of Empedocles): if a piece of copper, say, were not infinitely divisible, then it would be destroyed once it was divided down to its ultimate elements; but Parmenides had outlawed such destruction. Here, then, Anaxagoras sets his face against the idea of infinite divisibility, because it implies a particulate theory of matter, whereas on his theory there are no such particles.

The idea that there is no limit to smallness is also Anaxagoras’ solution to another potential difficulty, one generated from within his own system. He has posited an infinite number of stuffs, but it is also axiomatic for him that in everything there is a portion of everything. Everything contains infinite stuffs, then—but how is that possible without things being infinitely large? If every stuff in the mixture has finite size, then the object in question would be infinitely large. Anaxagoras’ solution is to deny that every stuff in the mixture has to have finite size. In fact this again disproves the idea (although it is a common interpretation of Anaxagorean physics) that when Anaxagoras says that everything is in everything, he means to imply a particulate theory of matter. If there were infinite particles in anything, it would be infinitely large. When Anaxagoras says that everything is in everything, he means to imply a smooth blend; ‘portions’ are not ‘pieces’. Everything is blended smoothly, but different things have different proportions of the homoeomeries in them.

Mind has a unique role in Anaxagoras’ thought. Not only is it the only thing that is pure, without a portion of every other basic stuff, but it is the only thing that is not necessarily present in everything to some degree (F9, F10). Thus it is present in humans and horses and herbs, but not in stones and rivers. Moreover, it has a unique cosmogonic role to play, since it started the initial rotation which began to separate things out of the primordial mixture, which was originally at rest (F10).6 As a consequence of the heavy baggage mind carries in Anaxagoras’ philosophy, there is considerable ambiguity within the fragments between whether at any point he is talking about Mind with a capital M, almost equivalent to God, or mind—your mind and my mind. Obviously a mind may be regarded as a splinter of the Mind, but it is not clear whether a mind has all the attributes—e.g. omniscience—of Mind, or just the principle of movement.

The rotation (which is super-fast, F11) began in a small area and is still spreading outwards. It is probably to be thought of as a vortex, since it separates denser material from lighter material (F12). Although mind comes in for a great deal of praise for its work (F10), and is said to pervade everything (F13), it is not clear that it plays a part in the finished universe except in animate creatures. In a vortex, heavier material tends towards the centre, and at the same time Anaxagoras seems to have invoked another physical law—the attraction of like to like (T7). The action of these two laws sets up broad features of the universe as we know it (F16).

T5 and T6 are useful Aristotelian paraphrases of important features of Anaxagoras’ system, with good guesses as to his underlying thinking. In T4 Aristotle seems to suggest that air and aither, specified in F1 as somehow distinguishable within the original mixture, play an important cosmogonic role (see now F2 in this light). In fact, he implies that air and aither are the first principles of everything else, and so that the cosmogonic process goes, by stages, from the original mixture to the separation out of air and aither to the generation of the world as we know it. Assuming that Aristotle is correct in identifying Anaxagoras’ aither with fire, then in air and aither we have oppositely qualified substances: moist, dark, cloudy air, and light, bright, fiery aither. It cannot be a coincidence that these are precisely the sets of opposites that Anaxagoras specifies in F12 as vital within the cosmogonic process. It seems most likely, then, that ‘air’ and ‘aither’ are collective names for, respectively, seeds which are cold and moist, and seeds which are light, dry, and fiery (just as, in general, the only role the opposites seem to play in Anaxagoras’ thought is to specify the characteristics of seeds). In the original mixture, air and aither are not actually distinct, though since they represent the most primitive forms of matter, you could say that the original mixture contains limitless air and aither (F1), just as you can say that it contains seeds. Then in the early stages of the cosmogonic process these two masses were separated out, and then the action of the vortex and the attraction of like to like continued the creation of the world. The ‘air’ seeds are condensed into the things of this world (F16), while the ‘aither’ seeds form the outer heavens and the heavenly bodies. However, since ‘in everything there is a portion of everything’, there will be some aither inside the earth; although normally this has free passage to its natural upper region, under certain circumstances it can become trapped and cause earthquakes (T8). Because it is always the case that in everything there is a portion of everything, this and other natural processes will never fail. It is clear from F17 and F18, as well as T9–11, that Anaxagoras also found explanations for other familiar meteorological and astronomical phenomena. T12–15 remind us that he spread his scientific net wide, not only into botany and embryology, but also comparative anatomy and other areas; he even entered the fifth-century debate on why the Nile floods in summer (due to the melting of snow in the mountains of Ethiopia, he not unreasonably held). And, given his construction of the world out of seeds containing portions of everything within them, it is hardly surprising to find him disparaging the reliability of the senses as guides to the truth (F20; see also T3 and T5 in this context): we cannot see or taste the bitter ingredients of figs, fortunately. T16is a cursory report of Anaxagoras’ views on the various senses, in which it is noticeable how consistently he makes use of the principle of similars and dissimilars.

Anaxagoras’ reaction to Parmenides is noticeable right from the start of his book, with its emphatic denial of singularity. Parmenides had forbidden the generation of plurality out of singularity, so Anaxagoras generated plurality out of plurality. However, although like his pluralist peers, Empedocles and the atomists, he simply affirmed plurality, he did (again like his peers) address the problem of change, generation, and destruction within a Parmenidean framework (F19). His awareness of Parmenides’ poem is reflected in a number of Parmenidean phrases and echoes throughout the extant fragments, and in fact he adopts a particularly strong form of Eleaticism, maintaining not only that what-is cannot not be, but that since what-is cannot come from what-is-not it must already have existed.

F1 (DK 59B1; KRS 467) All things were together, with no limits set on either number or smallness; for there were in fact no limits set on smallness. And while everything was together the smallness of things meant that nothing was distinct. For air and aither prevailed over everything, since these two are limitless. (Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 155.26–9 Diels)

F2 (DK 59B2; KRS 488) For in fact air and aither are being separated off from the vault of the surrounding matter, which is limitless in amount. (Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 155.31–156.1 Diels)

F3 (DK 59B7) And the upshot is that it is impossible to know, in theory or in practice, the number of things that are being separated out. (Simplicius, Commentary on Aristotle’s ‘On the Heavens’, CAG VII, 608.26 Heiberg)

F4 (DK 59B4a; KRS 483, 498, 468) Since this is how things are, one is bound to think that in all things, which are compounds, there are many diverse stuffs—that is, that there are present in them the seeds of all things, possessed of all kinds of shapes, colours, and flavours. And one is bound also to think that human beings and every other kind of animate creature have been constructed. (Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 34.29–35.4 Diels)

F5 (DK 59B4b; KRS 498, 468) One is also bound to think that these human beings possess inhabited communities and manufactured objects, just as we do; that they have sun and moon and so on, just as we do; and that the earth yields all kinds of products for them, the most beneficial of which they gather into their homes and make use of. This is what I am saying about the separation—that separation would have taken place not only here with us, but also elsewhere. Before there was separation, while all things were together, not even any colour was distinct, because the mixture of all things made that impossible—the mixture of the moist and the dry, the warm and the cold, the bright and the dark,* with a great deal of earth among them, and an infinite number of seeds quite dissimilar to one another.* For in fact none of all the seeds is like any of the others. Since this is how things are, we are bound to think that all things were present in the totality. (pieced together from Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 35.4–9 and 34.21–6 Diels)

T1 (DK 59A63) Thales, Anaxagoras, Plato, Aristotle, and Zeno say that there is only one universe. (Aëtius 2.1.2 Diels)

F6 (DK 59B8; KRS 486) The items of the universe, which is one, are not separate from one another nor cut off from one another with an axe, neither the warm from the cold nor the cold from the warm. (Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 175.11–14 Diels)

T2 (DK 59B10; KRS 484) Anaxagoras, having come across an old theory that nothing comes from nothing, did away with creation and introduced dispersal instead. In his foolishness he claimed that everything was mixed with everything else and that everything grew as it was dispersed. He claimed that one and the same sperm contained hair, nails, veins, arteries, sinews, and bones, and that these were too minute to be perceived, but gradually grew as they were dispersed. For how, he says, could hair come from not-hair or flesh from not-flesh?* (Elias of Crete, Commentary on the Speeches of Gregory of Nazianzus 36.911 Migne)

T3 (DK 59A46; KRS 496) Anaxagoras of Clazomenae, the son of Hegesibulus, said that the first principles of things were the homoeomeries. For he found it completely impossible for anything to be generated out of non-being or to perish into non-being. So, for instance, he said that the plain, simple food we take in, such as bread and water, nourishes hair, veins, arteries, flesh, sinews, bones, and all the other parts of the body. Since this is so, he said, we have to admit that the food we eat contains all things, and that everything grows as a result of things that already exist. So in our food there must be parts that are productive of blood, sinews, bones, and so on. But these parts can be appreciated only by the rational mind, because there is no point in asking the senses to cope with everything, such as the fact that bread and water produce these things; no, in bread and water there are parts which only the rational mind can appreciate. Because these parts in our food are similar to the things that are generated by them, he called them ‘homoeomeries’ and declared that they are the first principles of things. He held that the homoeomeries were the matter, while the effective cause was mind, which organizes the universe. (Aëtius, Opinions 1.3.5 Diels)

T4 (DK 59A43; KRS 494) The views of Anaxagoras and Empedocles on the elements are opposed. While Empedocles says that fire and the others in the standard list are the elements of bodies and that everything is composed of them, Anaxagoras says, on the contrary, that the homoeomeries are the elements—e.g. flesh, bone, and so on—and that air and fire are blends of these and all the other seeds; for he says that air and fire are aggregates of all the invisible homoeomeries. That is why everything is generated out of air and fire (‘fire’ and ‘aither’ being the same in his terminology). (Aristotle, On the Heavens 302a28-b4 Allan)

F7 (DK 59B3; KRS 472) For there is no smallest part of the small, but there is always a smaller part (for it is impossible for division to make what-is not be); and by the same token there is always a larger part than what is large. And what is large is numerically equal to what is small, since each thing is both large and small in relation to itself. (Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 164.17–20 Diels)

F8 (DK 59B6; KRS 481) Since there are numerically equal portions of the great and the small, it follows that everything is in everything. It is impossible for there to be isolation, but everything has a portion of everything. Since there is no smallest part, it is impossible for there to be isolation, nor is it possible for anything to exist by itself; the original state of things still persists, and all things are together now as well. For there is a plurality of things present in everything, and in everything that is being separated off, however large or small it may be, there are equal portions. (Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 164.25–165.1 Diels)

F9 (DK 59B11; KRS 482) In everything there is a portion of everything except of mind, and there are some things in which mind is present too.* (Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 164.23–4 Diels)

F10 (DK 59B12; KRS 476) Everything else has a portion of everything, but mind is limitless* and independent; it is mixed with nothing, but is on its own and by itself. If it were not by itself, but were mixed with anything else, it would have a share of everything: all it would take is for it to be mixed with anything, since in everything there is a portion of everything, as I have already said. Moreover, the things mixed with it would stop it ruling anything in the way it does by being on its own and by itself. For it is the most refined and pure of all things, it forms every decision about everything, and there is nothing with more power than it. So, for instance, mind rules every animate creature, however large or small. Mind also controlled the whole rotation, in the sense that it was responsible for initiating the rotation.* At first it began to rotate out from a small area, but now it is rotating over a wider area, and it will rotate over a wider area still.* Mind decided about the combining, the separation, and the dispersal of all things. Mind ordered all the things that were to be (the things that formerly existed but do not now, the things that are now, and the things that will be in the future), including the present rotation in which the heavenly bodies, sun, moon, air, and aither are now rotating and being separated off (their separating off being a product of this rotation). And the dense is separated off from the rare, the warm from the cold, the bright from the dark, the dry from the moist. But there are numerous portions of a large number of things, and nothing except mind is completely separated off or dispersed from another thing. Wherever it is found, in larger or smaller amounts, mind is always identical, whereas nothing else has this kind of identity: each item is and was most distinctly those ingredients which predominate in its mixture. (pieced together from Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 164.24 and 156.13157.4 Diels)

T5 (DK 59A52; KRS 485) The differences between Empedocles and Anaxagoras are that according to Empedocles mixture and separation occur in cycles, while according to Anaxagoras the separation was a unique event, and that Anaxagoras separates out an infinite number of things—the homoeomerous substances and the opposites—while Empedocles separates out only the familiar elements. It seems likely that Anaxagoras posited an infinite number of things in this way because he assumed the truth of the view held by all the natural scientists that nothing comes into being from non-being. That is why they make statements like ‘Everything was originally mixed together’, and ‘This is the kind of thing that coming into being is—alteration’, though others talk in this context of combination and separation. They also thought that since the opposites come from each other, they must have been present in each other. They reasoned as follows: necessarily, everything which comes into being comes either from things with being or from things without being; but it is impossible for anything to come into being from non-being (all the natural scientists are unanimous on this point); therefore, the only remaining possible conclusion, they thought, was that anything which comes into being comes from things with being, which are already present in the source, but which are too small for us to detect with our senses. So the reason they say that everything is mixed in everything is because, in their view, everything comes from everything; and they explain the fact that although everything is a mixture consisting of an infinite number of ingredients, things still look different from one another and are called one thing rather than another, by saying that this depends on which ingredient is numerically predominant within the mixture. There is nothing, they say, which is wholly and purely pale or dark or sweet or flesh or bone; people assess the nature of an object according to whichever ingredient there is most of within that object. (Aristotle, Physics 187a23-b7 Ross)

T6 (DK 59A45) Anaxagoras said that every part is just as much a mixture as the whole universe is; he based this view on the observation that anything can come from anything. That is also probably why he said that all things were once mixed together. His reasoning was probably as follows: this flesh and this bone are like that, and so is anything else, so everything must be like that, and must have been like that at one and the same time, because not only is there a beginning of the separating process from which each individual arises, but there must also be a beginning for the universe as a whole. Why? Because anything which comes into being comes from that kind of body, and everything does in fact come into being (although not at the same time), and this process of coming to be must have a source. Moreover, this source must be a single principle, of the kind which Anaxagoras calls ‘mind’, and there is always a starting-point at which our minds stop thinking and set to work. And the upshot of all this is that everything must once have been mixed together and must have started changing at some point in time. (Aristotle, Physics 203a16–33 Ross)

F11 (DK 59B9; KRS 478) So these things are rotating in this way and are being separated off by force and speed (force being a product of speed). Their speed is unlike the speed of anything that now exists on earth, but is altogether many times as fast. (Simplicius,Commentary on Aristotle’s ‘Physics’, CAG IX, 35.14–18 Diels)

F12 (DK 59B15; KRS 489) The dense, the moist, the cold, and the dark came together here, where the earth is now, while the fine, the warm, the dry, and the bright departed into the further reaches of the aither. (Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 179.3–6 Diels)

F13 (DK 59B14; KRS 479) Mind controlled all that is, and mind is now where everything else is: it is in that which surrounds the plurality, in the aggregates that have been formed, and in the things that have been separated off. (Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 157.7–9 Diels)

F14 (DK 59B13; KRS 477) And when mind had initiated motion, separation began from everything that was in motion,* and all that mind set in motion was dispersed. And as things were moving and being dispersed, the rotation greatly accelerated the process of dispersal. (Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 300.31–301.1 Diels)

F15 (DK 59B5; KRS 473) One has to appreciate that this dispersal of these things did not either add to or subtract from the sum total of all things. It is impossible for there to be more things than all the things there are; no, all things are always equal in number. (Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 156.10–12 Diels)

F16 (DK 59B16; KRS 490) Earth is made out of these things* during the process of separation; for water is separated off from clouds and earth from water; stones are formed from earth by cold, and stones tend outwards more than water.* (pieced together from Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 179.8–10 and 155.21–3 Diels)

T7 (DK 59A41; KRS 492) Theophrastus says that Anaximander and Anaxagoras are very close on this issue; for Anaxagoras says that in the course of the dispersal of the boundless, like things are attracted to one another, and that what was gold in the original totality becomes gold, while what was earth becomes earth. (Theophrastus [fr. 228a Fortenbaugh et al.] in Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 27.11–14 Diels)

F17 (DK 59B18; KRS 500) The sun instils the moon with brightness. (Plutarch, On the Face on the Moon 929b3–4 Cherniss)

F18 (DK 59B19; KRS 501) What we call a ‘rainbow’ is light in the clouds, shining opposite the sun. (Scholiast on Homer, Iliad 17.547, Dindorf 6.233)

T8 (DK 59A89) On earthquakes, Anaxagoras says that aither causes earthquakes because it naturally tends upwards, but is trapped inside the nether regions and hollows of the earth. For the upper layer of the earth gets clogged up by rainfall, despite the fact that all earth is in fact naturally porous. (Aristotle, On Celestial Phenomena 365a19–23 Bekker)

T9 (DK 59A42; KRS 502) Anaxagoras said that the earth is flat, and stays suspended because of its size, because there is no void, and because it is carried like a vessel by the air, which is extremely strong … The sun, moon, and all the heavenly bodies are fiery stones which have been taken up by the rotation of the aither.* Beneath the heavenly bodies are certain bodies, invisible to us, that are carried around along with the sun and moon.* We do not feel the heat of the heavenly bodies because of their distance from the earth; moreover, they are not as hot as the sun because the region they occupy is colder. The moon is lower than the sun and nearer to us. The sun is larger than the Peloponnese. The moon does not have its own light, but gains it from the sun. The stars in their revolution go under the earth. Eclipses of the moon occur when the earth gets in the way, but sometimes when the bodies beneath the moon get in the way; solar eclipses occur when the new moon gets in the way. (Hippolytus, Refutation of All Heresies 1.8.3–9.2 Marcovich)

T10 (DK 59A81) Anaxagoras and Democritus say that comets are a conjunction of planets, when they come close enough to appear to touch one another.* (Aristotle, On Celestial Phenomena 342b27–9 Bekker)

T11 (DK 59A80) Anaxagoras and Democritus say that the Milky Way is the light of certain of the heavenly bodies. They say that the sun, as it travels under the earth, does not look upon some of the heavenly bodies. The light of those which are in the line of sight of the sun is invisible, because it is impeded by the sun’s rays, and the Milky Way is the light proper to those which are screened by the earth in such a way that they are not in the line of sight of the sun.* (Aristotle, On Celestial Phenomena 345a25–9 Bekker)

T12 (DK 59A117) Anaxagoras and Empedocles say that plants are moved by desire, and they also assert that they feel sensations and experience sadness and pleasure. Anaxagoras’ inference that plants are animals and feel happiness and sadness was based on the way they bend their leaves.* … Anaxagoras also held that plants breathe. (Ps.-Aristotle, On Plants 815a15–19, 816b26 Apelt)

T13 (DK 59A1) Animals were generated out of what is moist, warm, and earthy, and then subsequently from one another. (Diogenes Laertius, Lives of Eminent Philosophers 2.9.10–12 Long)

T14 (DK 59A117; KRS 506) Anaxagoras says that the air contains seeds of all things and that when these are carried down along with water they generate plants. (Theophrastus, Enquiry into Plants 3.1.4.3–5 Hort)

T15 (DK 59A110) Anaxagoras and many others say that food comes to the foetus through the navel. (Censorinus, On Birthdays 6.3.2–4 Jahn)

F19 (DK 59B17; KRS 469) Greek usage of the words ‘generation’ and ‘destruction’ is incorrect. Nothing is generated or destroyed; things are combined from already existing things and dispersed. It would therefore be correct to use ‘combination’ for ‘generation’ and ‘dispersal’ for ‘destruction’. (Simplicius, Commentary on Aristotle’s ‘Physics’, CAG IX, 163.20–4 Diels)

F20 (DK 59B21; KRS 509) The weakness [of the senses] means that we are incapable of discerning the truth. (Sextus Empiricus, Against the Professors 7.90.3–4 Bury)

T16 (DK 59A92; KRS 511) Anaxagoras says that perception occurs thanks to opposites, because similars are unaffected by one another. He undertakes to account for each sense separately. So we see, he says, thanks to the reflection in the pupil, but there is no reflection in pupils of the same colour, only in those of a different colour. In the majority of cases the pupil is differently coloured by day, but in some people it is differently coloured by night, and that is why they see well then; in general, however, night is more likely to be the same colour as the eyes. *

The same goes for the way touch and taste discern their objects. For anything with the same degree of warmth or cold does not warm or cool us when it comes near us, and also we certainly do not recognize sweet or sour tastes by means of those same qualities. No, we discern something cold by something warm, something drinkable by something brackish, something sweet by something sour—in other words, depending on our deficiency in each quality. For everything, he says, is already in us. The same goes for smell and hearing … (Theophrastus, On the Senses 27–8 Stratton)

D. Bargrave-Weaver, ‘The Cosmogony of Anaxagoras’, Phronesis, 4 (1959), 77–91.

F. M. Cornford, ‘Anaxagoras’ Theory of Matter’, in [26], ii. 275–322 (first pub. Classical Quarterly, 24 (1930)).

D. J. Furley, ‘Anaxagoras in Response to Parmenides’, in [32], 61–85.

M. Furth, ‘A “Philosophical Hero”? Anaxagoras and the Eleatics’, Oxford Studies in Ancient Philosophy, 9 (1991), 95–129; repr. in R.W. Sharples (ed.), Modern Thinkers and Ancient Thinkers (London: UCL Press, 1993), 27–65.

D. W. Graham, ‘The Postulates of Anaxagoras’, Apeiron, 27 (1994), 77–121.

B. Inwood, ‘Anaxagoras and Infinite Divisibility’, Illinois Classical Studies, 11(1986), 17–33.

C. H. Kahn, ‘The Historical Position of Anaxagoras’, in [24], 203–10.

O. Kember, ‘Anaxagoras’ Theory of Sex Differentiation and Heredity’, Phronesis, 18 (1973), 1–14.

G. B. Kerferd, ‘Anaxagoras and the Concept of Matter Before Aristotle’, in [30], 489–503 (first pub. Bulletin of the John Rylands Library, 52 (1969)).

D. Konstan, ‘Anaxagoras on Bigger and Smaller’, in M. Capasso et al. (eds.), Studi di filosofia preplatonica (Naples: Bibliopolis, 1985), 137–57.

A. Laks, ‘Mind’s Crisis: On Anaxagoras’ Nous’, Southern Journal of Philosophy, 31 (1993), suppl. vol., 19–38.

J. H. Lesher, ‘Mind’s Knowledge and Powers of Control in Anaxagoras DK B12’, Phronesis, 40 (1995), 125–42.

W. E. Mann, ‘Anaxagoras and the Homoiomerē’, Phronesis, 25 (1980), 228–49.

J. Mansfeld, ‘The Chronology of Anaxagoras’ Athenian Period and the Date of his Trial’, in [29], 264–306 (first pub. Mnemosyne, 32 (1979) and 33 (1980)).

A. L. Peck, ‘Anaxagoras and the Parts’, Classical Quarterly, 20 (1926), 57–62.

—— ‘Anaxagoras: Predication as a Problem in Physics’, Classical Quarterly, 25 (1931), 27–37, 112–20.

M. Reesor, ‘The Meaning of Anaxagoras’, Classical Philology, 55 (1960), 1–8.

—— ‘The Problem of Anaxagoras’, in [21], 81–7 (first pub. Classical Philology 58 (1963)).

C. D. C. Reeve, ‘Anaxagorean Panspermism’, Ancient Philosophy, 1 (1980/1), 89–108.

M. Schofield, An Essay on Anaxagoras (Cambridge: Cambridge University Press, 1980).

—— ‘Anaxagoras’ Other World Revisited’, in K. Algra et al. (eds.), Polyhistor: Studies in the History and Historiography of Ancient Philosophy (Leiden: Brill, 1996), 3–20.

D. Sider, The Fragments of Anaxagoras (Meisenheim am Glam: Hain, 1981).

M. C. Stokes, ‘On Anaxagoras’, Archiv für Geschichte der Philosophie, 47 (1965), 1–19, 217–50.

C. Strang, ‘The Physical Theory of Anaxagoras’, in [30], 361–80 (first pub. Archiv für Geschichte der Philosophie, 45 (1963)).

S.-T. Teodorsson, Anaxagoras’ Theory of Matter (Göteberg: Acta Universitatis Gothoburgensis, 1982).

S. S. Tigner, ‘Stars, Unseen Bodies and the Extent of the Earth in Anaxagoras’ Cosmogony: Three Problems and their Simultaneous Solution’, in G. Bowersock et al. (eds.), Arktouros: Hellenic Studies Presented to Bernard M. W. Knox (Berlin: de Gruyter, 1979), 330–5.

G. Vlastos, ‘The Physical Theory of Anaxagoras’, in [26], ii. 323–53, and in [30], 459–88, and in [33], 303–27 (first pub. Philosophical Review, 59 (1950)).

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