Part I: Presocratic Philosophy

Chapter VI

Atomism

In this chapter, we shall discuss a doctrine first advanced by Leucippus and carried on by Democritus, although the latter cannot technically be called a Presocratic, being roughly a contemporary of Socrates. There is good reason, as we shall see, for linking the two men, something that has been done since earliest times. Leucippus is said to have been a native of Elea, but also of Miletus; there seem to be better reasons for regarding him as a Milesian, although there is little strong evidence either way. As a matter of fact, we are not very well informed about Leucippus; even in ancient times there were those who doubted that he had existed at all. Democritus tells us in his The Little World Order that he was forty years younger than Anaxagoras, making it likely that he was born about 460/457 B.C. Now the assumption is that Leucippus first put forward the doctrine of atomism and that Democritus accepted and elaborated it. Freeman gives 430 B.C. as the floruit of Leucippus and 420 B.C. as that of Democritus. Leucippus was said to have written a book entitled The Great World Order and a book On Mind of which one sentence has come down to us: "Nothing happens at random, all happens out of reason or by necessity." The sentiment of this remark hardly accords with the implications of atomism, however, and it is conjectured that the remark is not really his, but that of a follower of Anaxagoras. Democritus, on the other hand, seems to have written a good deal, certainly much more than any of his predecessors. We are told that his works were later listed in groups of four, much as Plato's were, and that the total number of his writings was fifty-two. Among his physical works were The Little World Order, Cosmography, On the Planets. In later lists, his works were divided into Physical, Mathematical, Musical, Technical, and Ethical; it is from these latter works that most of the surviving fragments come. These included works on Pythagoras, on the philosophical nature, on courage and imperturbability, and on the next world. There were also works grouped under the heading, Causes. We are told that many of these works may have been written after the time of Democritus, but later collectors and listers tended to attribute them all to Democritus. Our ancient sources sometimes speak of Leucippus and Democritus separately but more often together; our presentation will not lay great stress on one man or the other. We shall regard the doctrine involved as one common to Leucippus, Democritus and their followers. Although the attribution of the theory may have to remain fuzzy, the theory itself is precise and fairly easy to set forth.

Aristotle leaves no doubt as to the motivation for the doctrine attributed to Leucippus and Democritus. He tells us of it after setting forth the Eleatic rejection of nature and of other reactions to it.

But Leucippus thought he had a theory which, being consistent with sense-perception, would not do away with coming-into-being or perishing or motion or the multiplicity of things. So much he conceded to appearances, while to those who uphold the one he granted that motion is impossible without void, that the void is not-being and that no part of being is not-being. For being, in the proper sense, is an absolute plenum. But such a plenum is not one, but there is an infinite number of them, and they are invisible owing to the smallness of their bulk. They move in the void (for the void exists), and by their coming together they effect coming-into-being by their separation perishing. (De gen.,1,8,325a23ff.)

Being in the strict sense does not come to be or perish, it simply is. But it is not one, but many, indeed, infinite in number. What truly are, are quite small particles, so small as to be invisible. If these are the things to which being properly applies, there is as well void, empty space, not-being, in which the particles move. Clusters of them form visible bodies and the things we mistakenly regard as beings in the proper sense; these things come to be and perish, to be sure, but not what is truly being, the small, invisible particles. As Aristotle remarks, this explanation saves the facts of sense perception but not at the expense of the Eleatic logic. We see that this reaction has much in common with those of Empedocles and Anaxagoras; where atomism differs is in its insistence that the void, too, must exist and that if by not-being we mean empty space, then not-being exists. Thus being and space, the plenum and the void, become the elements of explanalion.

Leucippus and his associate Democritus hold that the elements are the full and the void; they call them being and not-being respectively. Being is full and solid, not-being is void and rare. Since the void exists no less than body, it follows that not-being exists no less than being. The two together are the material causes of existing things. And just as those who make the underlying substance one, generate other things by its modifications, and postulate rarefactions and condensation as the origin of such modifications, in the same way these men too say that the differences in atoms are the causes of other things. They hold that these differences are three -- shape, arrangement and position. Being, they say, differs only in 'rhythm, touching turning,' of which 'rhythm' is shape, 'touching' is arrangement, and 'turning' is position; for A differs from N in shape, AN differs from NA in arrangement, and from H in position. (Metaphysics I,4,985b4)

What deserves the name "being" are very small bodies, atoms, a word which means indivisibles, things which cannot be cut. Not only are these imperceptible, there is a countless number of them and they differ from one another in the ways indicated in the above passage, basically by size and shape. As irreducible elements of what we ordinarily call beings, the atoms cannot come from one another; each is given in its being and is not subject to change, to becoming or perishing. The void is where the atoms are not rather than where they are; each atom is full, compact, and endowed with motion whereby it can move through the void. Now, if visible, everyday bodies are compounded of atoms; the differences which strike us in such bodies are finally explicable in terms of the arrangement and shape of the component atoms. The usual opposites, hot-cold, wet-dry, etc., will be explained in this way. This reduction of the differences grasped by our senses to quantitative and local differences tends to commend the atomistic doctrine to contemporary thinkers, as if it were an anticipation of the physical theories with which we are familiar today. The atoms just happen to be the shape they individually are and they just happen to move around, so that the bodies we perceive and the world they compose seem reducible to chance.

The movement of the atoms may have been assigned to their weight, although we have conflicting testimony as to whether Democritus assigned weight to the atoms; some say that this was a later addendum of Epicurus. At any rate, that atoms had weight would seem to have been part of the theory of the Democritean school. It seems that weight was not invoked to explain particular kinds of motion -- motion in this direction as opposed to that -- but simply the random motion of the atoms in the void. In the case of the atoms, the weight would be in direct proportion to bulk or size, something not true of the bodies of our sense experience. A large mass of cotton will weigh less than a relatively small stone; this was attributed to the different portions of void in the two. A body with fewer interstices between its atoms would weigh more than another body of the same size comprising less atoms, and hence more empty space. This gives us an indication of why atoms and the void were said to be the elements of atomism. The shapes of the atoms were said to account for their clinging together when they collided, and the arrangements thus formed led to the further differences mentioned by Aristotle. If compounds result from collision, they can, of course, be destroyed in the same way, or larger compounds can be formed, the whole thing occurring by chance. The bodies which we would say come to be, then, are such that their becoming is consequent upon the local motion of atoms. Simplicius quotes the following from a lost work of Aristotle's, On Democritus.

As they move they collide and become entangled in such a way as to cling in close contact to one another, but not so as to form one substance of them in reality of any kind whatever; for it is very simple-minded to suppose that two or more could ever become one. The reason he gives for atoms staying together for a while is the intertwining and mutual hold of the primary bodies; for some of them are angular, some hooked, some concave, some convex, and indeed with countless other differences; so he thinks they cling to each other and stay together until such time as some stronger necessity comes from the surrounding and shakes and scatters them apart. (Kirk and Raven, n. 581, pp. 418-9)

This passage emphasizes that nothing which is simply one results from the entanglement of the atoms -- not a further atom, surely; but just as surely the atoms are not somehow subsumed in a being of a higher order. Atoms are the only real being there is; what might appear to us to be a being of a higher order is merely the result of the collision and sticking together of the atoms.

This account of the formation of the world (or worlds) is attributed to Leucippus by Diogenes Laertius. (IX, 31-32)

He declares the All to be unlimited, as already stated; but of the All part is full and part empty, and these he calls elements. Out of them arise the worlds unlimited in number and into them they are dissolved. This is how the worlds are formed. In a given section many atoms of all manner of shapes are carried from the unlimited into the vast empty space. These collect together and form a single vortex, in which they jostle against each other and, circling round in every possible way, separate off, by like atoms joining like. And, the atoms being so numerous that they can no longer revolve in equilibrium, the light ones pass into the empty space outside, as if they were being winnowed; the remainder keep together and, becoming entangled, go on their circuit together, and form a primarily spherical system. This parts off like a shell, enclosing within it atoms of all kinds; and, as these are whirled round by virtue of the resistance of the center, the enclosing shell becomes thinner, the adjacent atoms continually combining when they touch the vortex. In this way the earth is formed by portions brought to the center coalescing. And again, even the outer shell grows larger by the influx of atoms from outside, and, as it is carried round in the vortex, adds to itself whatever atoms it touches. And of these some portions are locked together and form a mass, at first damp and airy, but, when they have dried and revolve with the universal vortex, they afterwards take fire and form the substance of the stars.

The whirling vortex which is the first stage in the formation of a world is something we have already encountered in Anaxagoras, although then it had been begun by Nous. Here it just happens, given atoms and their motion; moreover, it can happen many times simultaneously, since there is no dearth of atoms and we need not think that all the atoms there are have gone into the composition of our world. The whirling motion causes like to be attracted to like. The similarity involved here would seem to be that of weight, though shape is not unimportant since the outer ring of fire-atoms were thought to be round and smooth, thus accounting for their mobility. Leucippus and Democritus were said to have maintained that each world is enclosed in a kind of skin, formed by the linking of hooked atoms, and through this more atoms were taken in after the initial stages of world-formation. Not all worlds are like our own; some have animals, some do not; some do not have sun or moon, or have ones of a much different size than ours. Presumably when a world stops growing -- by absorbing more atoms through its outer skin -- it begins to break up, its atoms returning to the common fund whence they can proceed to form another world at another time.

That the atomists meant that the world came about by chance seems clear enough. Surely it is not enough to suggest, as Freeman does, that motion, collision and formation of conglomerates is something which follows on the very nature of the elements. "The second stage was the collision of atoms, and consequent coagulation; this, the original formation of each cosmos, seems to be assigned to chance; but it was a 'chance' arising out of the essential nature of things." (p. 303) Precisely, and it is the world that comes about by chance, since the essential nature of things does not determine that their random movements, collisions and coagulations should result in just this order of things.

The first members of living species, including the human, were generated from mud or slime; simply appearing by chance. Procreation somehow becomes natural and Democritus compared the sexual act to epilepsy -- an atomic collision which is itself a kind of disease. Many biological opinions are attributed to Democritus, in the realm of embryology, generation, etc. He did not think death instantaneous, since nails and hair continue to grow; the corpse is still alive and perceptive, though heading toward complete dissolution. Democritus' views on sense perception are of interest here, although Aristotle wrote, "Democritus and the majority of natural philosophers who discuss perception are guilty of a great absurdity; for they represent all perception as being by touch." (De Sensu, 442a29)

Aristotle's criticism is of a position that seems inevitable for atomism. We recall that the atoms, the only things that really are, are imperceptible because of the smallness of their size. Now, if what really is cannot be grasped by the senses, the objects of perception must be appearances, in the sense of not being wholly real. If perception is of what is not wholly real, this does not mean that it is false; what we must grasp is that the wholes we perceive are compounds of atoms, but this is something we grasp by understanding. To know about the atomic structure of macrocosmic things is knowledge and to speak of perceptible things in terms of atoms is to speak the truth. The atomistic explanation of color, tastes, hot and cold entails reducing them to atoms and their movements; thus, though we retain these words out of custom, we will not say that they really are.

Sweet exists by convention, bitter by convention, color by convention; atoms and Void (alone) exist in reality . . . We know nothing accurately in reality, but (only) as it changes according to the bodily condition, and the constitution of those things that flow upon (the body) and impinge upon it. (Fr. 9; Freeman)

If this should lead us to look with condescension on the senses, one fragment gives their reply. "Miserable Mind, you get your evidence from us, and do you try to overthrow us? The overthrow will be your downfall." (Fr. 125) Thus, perception is not dismissed as totally unreal; if we did not perceive the things we do, we could never go on to the knowledge that they are composed of atoms and the void. Our perceptions consist of an impingement of things on our senses, much as Empedocles had explained them.

They attributed sight to certain images, of the same shape as the object, which were continually streaming off from the objects of sight and impinging on the eye. This was the view of the school of Leucippus and Democritus . . . . (Alexander)

The same explanation apparently served for thought, since the soul is itself composed of atoms. "Democritus says that the spherical is the most mobile of shapes; and such is mind and fire." (De Anima, 1,2,405 all) These atoms are subtle, easily moved, and, if quite corporeal, at the extreme of fineness and thinness. Sensation and thought seem to involve the movement of the atoms of percipient and thinker in response to the impingement from without. The soul is spread throughout the body, although what we call mind is a concentration of atoms in the bosom. Breathing has as its result the keeping of the soul atoms in the body; death is the escape of the soul atoms -- an escape which is gradual, not instantaneous.

Democritus does not so much account for the divine as for man's belief in the gods. Fear and awe of natural phenomena, such as under, storms, eclipses, and gratitude for unlooked for goods, tend underpin belief in the gods; but Democritus will allow for no inrporeal reality. He seems to accept the reality of visions, both those in dreams and when awake, and attaches divinity to these, ugh they are not immortal. From the point of view of his natural and psychological opinions, there is no role for the gods to play. That is why it would appear that Democritus is simply trying to account for belief of his fellows. Visions are produced by atoms present in the air; this being so, animals are as much struck by what men call the divine as are men themselves. In his ethical remarks, however, Democritus sometimes relies on this belief in gods.

We have already mentioned that the bulk of the fragments of Democritus that have come down to us is from his ethical writings. The Democritean ethics is ordered to the acquisition of happiness. "Happiness does not dwell in flocks or in gold. The soul is the dwelling place of the (good and evil) genius." (Fr. 171, Freeman) The ethical views of Democritus seem to bear little relation to his atomism; there is no mention of atoms in the ethical fragments which have come down to us. We have seen that, for Democritus, the soul pervades the body, that it is, so to say, a body within a body, since the soul atoms are corporeal; mind however is centered in the breast. This division in the soul, between what we may call its rational and irrational parts, finds its analogue in the distinction of soul from body. "It is right that men should value the soul rather than the body; for the perfection of soul corrects the inferiority of the body, but physical strength without intelligence does nothing to improve the mind." (Fr. 187, Freeman) Pleasure is to be surmounted, or at least pleasure in mortal things, since pleasure is a criterion.

The criterion of the advantageous and the disadvantageous is enjoyment and lack of enjoyment. (Fr. 188, Freeman) The best way for a man to lead his life is to have been as cheerful as possible and to have suffered as little as possible. This could happen if one did not seek one's pleasures in mortal things. (Fr. 189, Freeman)

What is called for, then, is a discrimination between pleasures, for the works of justice bring cheerfulness.

The cheerful man, who is impelled towards works that are just and lawful, rejoices by day and by night, and is strong and free from care. But the man who neglects justice, and does not do what he ought, finds all such things disagreeable when he remembers any of them, and he is afraid and torments himself. (Fr.174, Freeman)

A man should be concerned with society and with public affairs.

One must give the highest importance to affairs of the State, that it may be well run; one must not pursue quarrels contrary to right, nor acquire a power contrary to the common good. The well-run State is the greatest protection, and contains all in itself; when this is safe, all is safe; when this is destroyed, all is destroyed. (Fr. 252, Freeman)

Justice is what should be done; injustice its opposite. (Fr. 256) This is not very enlightening, of course; nor is concern with the common good urged for altruistic reasons.

To good men, it is not advantageous that they should neglect their own affairs for other things; for their private affairs suffer. But if a man neglects public affairs, he is ill spoken of, even if he steals nothing and does no wrong. And if he is negligent and does wrong, he is liable not only to be ill-spoken of but also to suffer bodily harm. To make mistakes is inevitable, but men find it hard to forgive. (Fr. 253; Freeman)

Nevertheless, it is not the censure of others we should fear, but rather our own.

One must not respect the opinion of other men more than one's own; nor must one be more ready to do wrong if no one will know than if all will know. One must respect one's own opinion most, and this must stand as the law of one's soul, preventing one from doing anything improper. (Fr. 264, Freeman)

Democritus has a lively sense of the role chance plays in human affairs. "Courage is the beginning of action, but Fortune is the arbiter of the goal." (Fr. 269, Freeman) But only fools are shaped by the gifts of chance (Fr. 197), and more men become good through effort than by nature. (Fr. 242) An important aspect of Democritus' ethical pronouncements is his injunction that we should limit our desires, strive for the possible. (Fr. 285, 286) The key to true pleasure is moderation. (Fr. 211)

Cheerfulness is created for men through moderation of enjoyment and harmoniousness of life. Things that are in excess or lacking are apt to change and cause great disturbance in the soul. Souls which are stirred by great divergences are neither stable nor cheerful. Therefore one must keep one's mind on what is attainable, and be content with what one has, paying little heed to things envied and admired, and not dwelling on them in one's mind. Rather must you consider the lives of those in distress, reflecting on their intense sufferings, in order that your own possessions and condition may seem great and enviable, and you may, by ceasing to desire more, cease to suffer in your soul. For he who admires those who have, and who are called happy by other mortals, and who dwells on them in his mind every hour, is constantly impelled to undertake something new and to run the risk, through his desire, of doing something irretrievable among those things which the laws prohibit. Hence one must not seek the latter, but must be content with the former, comparing one's own life with that of those in worse cases, and must consider oneself fortunate, reflecting on their sufferings, in being so much better off than they. If you keep to this way of thinking, you will live more serenely, and will expel those not-negligible curses in life, envy, jealousy and spite. (Fr. 191, Freeman)

While in no way in conflict with his natural doctrine, the ethical pronouncements of Democritus are relatively independent of atomism and seem a continuation of the Greek concern with moderation, responsibility and justice. The similarity between several of the moral dicta of Democritus and those of Heraclitus is often pointed out. If there is a more or less distinctive note, it is that the popular religion is one of fear and that moral maturity can enable one to surmount such fears. "People are fools who hate life and yet wish to live through fear of Hades." (Fr. 199, Freeman) The fact is that death is the end, and tales of an afterlife are the products of imagination.

Some men, not knowing about the dissolution of mortal nature, but acting on the knowledge of the suffering in life, afflict the period of life with anxieties and fears, inventing false tales about the period after the end of life. (Fr. 297, Freeman)

Democritean ethics promises no great solutions. Contentment, moderation, restraint -- these are the keys. When things go badly, consider that there are others worse off, but do not take pleasure in their misfortune. "Those to whom their neighbors' misfortunes give pleasure do not understand that the blows of fate are common to all; and also they lack cause for personal joy." (Fr. 293, Freeman)

With atomism, the reaction to Parmenides' way of truth, which nonetheless accepts its logic, has gone about as far as it can go. Being can neither come to be, nor can it cease to be. Empedocles and Anaxagoras agree but see no reason why a multiplicity of beings is impossible; many beings which do not come to be, do not perish. The atomists add the void or not-being, speak of an infinity of like ultimate beings which differ only in shape and size. What all these reactions have in common is the view that the things we customarily call beings are really not such, largely because they undeniably come to be and pass away. This calls for a new look at the validity of sense perception, and while none of these reactions rejects sense perception out of hand, there is the sharpening of a distinction between appearance and reality. Anaxagoras stands out from the others because of his attempt to assign a role to Nous or Mind, an entity he manages to describe in such a way that he more nearly achieves success in delineating the incorporeal. Empedocles had introduced, over and above the four elements, Love and Strife, but they seem clearly corporeal principles. Atomism has no room at all for anything other than atoms and empty space; whatever regularities and apparent laws we may think to discover in our world, the world has come about by chance. Once more, these are three reactions to the austere Parmenidean pronouncement that being does not become; no direct questioning of the pronouncement is involved in these reactions, but rather all three are ways of accomodating the world we preceive to the Parmenidean laws. Only in the next period of ancient philosophy, the Golden Age of Greek philosophy, do we encounter frontal assaults on the way of truth.

A. Diogenes of Apollonia

Diogenes of Apollonia is said to have flourished in the second half of the fifth century, that is, about 440-430 B.C. He is consequently considered to be one of the last of the natural philosophers; his doctrine is often called an eclectic one and his fragments indicate his indebtedness to his predecessors. We know from Simplicius (see Kirk and Raven, n. 600, p. 428) that Diogenes wrote several works, but at the time of Simplicius only one was extant, On Nature. Here, as so often before, it is on Simplicius that we principally depend for our knowledge of the doctrine.

"In beginning any discourse, it seems to me that one should make one's starting point something indisputable, and one's expression simple and dignified." (Fr. 1; Burnet) In obvious conformity with this methodological remark, Diogenes writes:

My view is, to sum it all up, that all things are differentiations of the same thing, and are the same thing. And this is obvious; for, if the things which are now in this world -- earth and water and fire and air, and other things which we see existing in this world -- if any one of these things, I say, were different from any other, different, that is, by having a substance peculiar to itself; and if it were not the same thing that is often changed and differentiated, then things could not in any way mix with one another, nor could they do one another good or harm. Neither could a plant grow out of the earth, nor any animal nor anything else come into being unless things were composed in such a way as to be the same. But all these things arise from the same thing; they are differentiated and take different forms at different times, and return again to the same thing. (Fr. 2; Burnet)

Diogenes is often linked with Anaximines because, like the earlier philosopher, Diogenes makes the common nature, air. Air is life and intelligence, which men and animals draw in by breathing; deprived of air, they necessarily die. (Fr. 4) Air is divine and pervades the universe; indeed, it has the attributes Anaxagoras assigned to Nous.

And my view is, that that which has intelligence is what men call air, and that all things have their course steered by it, and that it has power over all things. For this very thing I hold to be a god, and to reach everywhere, and to dispose everything, and to be in everything; and there is not anything which does not partake in it. Yet no single thing partakes in it just in the same way as another; but there are many modes both of air and of intelligence. (Fr. 5; Burnet)

It is by transformations described in terms of rarefaction and condensation that many things are produced from the divine air. The order among things so produced can only be ascribed to intelligence; this is the best of all possible worlds. (Fr. 3)

The cosmology of Diogenes is one of the last positive efforts of pre-Socratic natural philosophy and it manages to combine elenents from all preceding attempts, from the earliest Ionian to the doctrines consequent upon Parmenides' way of truth. While Diogenes loes little to advance natural philosophy, his fragments indicate to us the tradition in terms of which the individual talent sought to develop. It is that tradition which not even Parmenides had been able to disrupt, which is called radically into question by the Sophists.