Demócrito

Democritus (mid 5th–4th century bc)

A co-founder with Leucippus of the theory of atomism, The Greek Philosopher Democritus developed it into a universal system, embracing physics, cosmology, epistemology, psychology and theology. He is also reported to have written on a wide range of topics, including mathematics, ethics, literary criticism and theory of language. His works are lost, except for a substantial number of quotations, mostly on ethics, whose authenticity is disputed. Our knowledge of his principal doctrines depends primarily on Aristotle’s critical discussions, and secondarily on reports by historians of philosophy whose work derives from that of Aristotle and his school.

The atomists attempted to reconcile the observable data of plurality, motion and change with Parmenides’ denial of the possibility of coming to be or ceasing to be. They postulated an infinite number of unchangeable primary substances, characterized by a minimum range of explanatory properties (shape, size, spatial ordering and orientation within a given arrangement). All observable bodies are aggregates of these basic substances, and what appears as generation and corruption is in fact the formation and dissolution of these aggregates. The basic substances are physically indivisible (whence the term atomon, literally ‘uncuttable’) not merely in fact but in principle; (1) because (as Democritus argued) if it were theoretically possible to divide a material thing ad infinitum, the division would reduce the thing to nothing; and (2) because physical division presupposes that the thing divided contains gaps. Atoms are in eternal motion in empty space, the motion caused by an infinite series of prior atomic ‘collisions’. (There is reason to believe, however, although the point is disputed, that atoms cannot collide, since they must always be separated by void, however small; hence impact is only apparent, and all action is at a distance.) The void is necessary for motion, but is characterized as ‘what-is-not’, thus violating the Eleatic principle that what-is-not cannot be.

Democritus seems to have been the first thinker to recognize the observer-dependence of the secondary qualities. He argued from the distinction between appearance and reality to the unreliability of the senses, but it is disputed whether he embraced scepticism, or maintained that theory could make good the deficiency of the senses. He maintained a materialistic account of the mind, explaining thought and perception by the physical impact of images emitted by external objects. This theory gave rise to a naturalistic theology; he held that the gods are a special kind of images, endowed with life and intelligence, intervening in human affairs. The ethical fragments (if genuine) show that he maintained a conservative social philosophy on the basis of a form of enlightened hedonism.

1 Life and works

Democritus lived from approximately the middle of the fifth century bc to well into the following century. Though he was a co-founder of atomism with Leucippus , the exact relation between the two is obscure; Aristotle and his school agree in treating Leucippus as the originator of the theory, but also in assigning its basic principles to both, while later sources treat the theory as the work of Democritus alone. He may have collaborated with Leucippus, and almost certainly developed the latter’s theory into a universal system.

Very little is known about Democritus’ life. He came from Abdera, on the north coast of the Aegean (also the native city of Protagoras). He describes himself as being young in the old age of Anaxagoras, that is, probably in the 430s bc, and was traditionally reported to have lived to a very great age. He is said to have visited Athens and to have had some slight acquaintance with Socrates. The list of his works preserved by the third-century ad biographer Diogenes Laertius is long and encyclopedic in scope, including a complete account of the physical universe, the Lesser World-System (so called to distinguish it from his predecessor Leucippus’ Great World-System ), and works on astronomy and other natural sciences, epistemology, ethics, mathematics and literature. None survives. Ancient sources preserve almost 300 purported quotations, the great majority on ethics, from two different, although overlapping, collections of ethical maxims, one by the fifth-century anthologist Stobaeus, the other from a collection, probably earlier than that of Stobaeus, traditionally known as ‘The Sayings of Democrates’. The authenticity of the ethical fragments is disputed. Sextus Empiricus preserves some important quotations on epistemology, and Plutarch, Galen and others preserve a few other miscellaneous quotations. For our knowledge of the physical doctrines we are reliant on the doxographical tradition stemming ultimately from Aristotle, who discusses atomism extensively (see doxography ).

 

2 Physical doctrines

According to Aristotle, the atomists attempted to reconcile the observable data of plurality, motion and change with the Eleatic denial of the possibility of coming to be or ceasing to be. Accordingly they postulated unchangeable primary substances, and explained apparent generation and corruption as the formation and dissolution of aggregates of those substances. Since the theory had to account for an assumed infinity of phenomena, it assumed an infinite number of primary substances, while postulating the minimum range of explanatory properties, specifically shape, size, spatial ordering and orientation within a given arrangement. All observable bodies are aggregates of basic substances, which must therefore be too small to be perceived. These corpuscles are physically indivisible (atomon, literally ‘uncuttable’), not merely in fact but in principle; Aristotle reports an (unsound) atomistic argument, which has some affinities with one of Zeno of Elea’s arguments against plurality, that if (as Anaxagoras maintained) it were theoretically possible to divide a material thing ad infinitum, the division must reduce the thing to nothing (see Zeno of Elea §4; Anaxagoras §2). This Zenonian argument was supported by another for the same conclusion; atoms are theoretically indivisible because they contain no void. On this view, bodies split along their interstices; hence, where there are no interstices, as in an atom, no splitting is possible. (The same principle accounts for the immunity of the atoms to other kinds of change, such as reshaping, compression and expansion; all require displacement of matter within an atom, which is impossible without any gaps to receive the displaced matter.) It is tempting to connect the assumption that bodies split only along their interstices with the Principle of Sufficient Reason, which the atomists appealed to as a fundamental principle of explanation (arguing, for example, that the number of atomic shapes must be infinite, because there is no more reason for an atom to have one shape than another (Simplicius, On Aristotle’s Physics 28.9–10), and that there must be infinitely many worlds because there is no more reason for one to have been formed here than elsewhere. Given the total uniformity of an atom, they may have thought that there could be no reason why it should split at any point, or in any direction, rather than any other. Hence, by the Principle of Sufficient Reason, it could not split at all.

Atoms are in a state of eternal motion in empty space; the motion is not the product of design, but is determined by an infinite series of prior atomic collisions (whence two of Aristotle’s principle criticisms of Democritus: that he eliminated final causation and that he made all atomic motion ‘unnatural’, that is to say, imposed by external force). Empty space was postulated as required for motion, but was characterized as ‘what-is-not’, thus violating the Eleatic principle that what-is-not cannot be. We have no evidence of how the atomists met the accusation of outright self-contradiction. As well as explaining the possibility of motion, the void was postulated to account for the observed plurality of things, since the atomists followed Parmenides (fr. 8.22–5) in maintaining that there could not be many things if there were no void to separate them (see Parmenides §6). The theoretical role of the void in accounting for the separation of atoms from one another has an interesting implication, recorded by Philoponus (On Aristotle’s On Physics 494.19–25, On Aristotle’s On Generation and Corruption 158.26–159.7). Since atoms are separated from one another by the void, they can never strictly speaking come into contact with one another. For if they did, even momentarily, there would be nothing separating them from one another. But then they would be as inseparable from one another as the inseparable parts of a single atom, whose indivisibility is attributed to the lack of void within it (see above); indeed, the two former atoms would now be parts of a single larger atom. But, the atomists held, it is impossible that two things should become one. Holding atomic fusion to be theoretically impossible, and taking it that any case of contact between atoms would be a case of fusion (since only the intervening void prevents fusion), they perhaps drew the conclusion that contact itself is theoretically impossible. Hence what appears to be impact is in fact action at an extremely short distance; rather than actually banging into one another, atoms have to be conceived as repelling one another by some sort of force transmitted through the void. Again, although no source directly attests this, the interlocking of atoms which is the fundamental principle of the formation of aggregates is not strictly speaking interlocking, since the principle of no contact between atoms forbids interlocking as much as impact. Just as impact has to be reconstrued as something like magnetic repulsion, so interlocking has to be reconstrued as quasi-magnetic attraction. If this suggestion is correct (and it is fair to point out that no ancient source other than Philoponus supports it), it is a striking fact that, whereas the post-Renaissance corpuscular philosophy which developed from Greek atomism tended to take the impossibility of action at a distance as an axiom, the original form of the theory contained the a priori thesis that all action is action at a distance, and consequently that impact, as far from giving us our most fundamental conception of physical interaction, is itself a mere appearance which disappears from the world when the description of reality is pursued with full rigour (see Blasius of Parma §4; Bruno, G. §5 ).

 

 

3 Epistemology and psychology

Democritus seems to have been the first philosopher to recognize the observer- dependence of the secondary qualities. Perception of the secondary qualities reveals merely how things seem to us (and these qualities are said to be merely nomōi, or ‘convention’), as opposed to how they really (eteēi) are – aggregates of unobservable corpuscles. The perception of any secondary quality is a response, not to the properties of an individual atom, but to a physical stimulus constituted by a continuous bombardment of a series of arrays of atoms. Thus visual perception, including the perception of colour, is a response to the impact on the visual organs of a continuous succession of films of atoms (eidōla) flowing from the surface of the perceived object. For an object to be red, for example, is thus for it to emit films of atoms of such a nature that, when those films collide with an appropriately situated perceiver, the object will look red to that perceiver.

It is therefore a necessary consequence of the atomists’ account of the secondary qualities not merely that secondary qualities are among the causally significant properties of the atoms, but, more strongly, that atoms have no secondary qualities. Colour, sound, taste and smell are qualities of aggregates, not of single atoms. To ascribe one of these qualities to a subject is to describe that subject as so structured as to prompt a certain sensory response in a certain kind of perceiver; and the structure in question as described in terms of the intrinsic properties (shape and size) and relational properties (arrangement and orientation) of its constituent atoms. The persuasiveness or otherwise of the account of the secondary qualities cannot be separated from that of the whole theory of perception of which it is part, and that in turn cannot be separated from the theory of human nature, and ultimately of the natural world as a whole. As presented by the atomists, the theory is entirely speculative, since it posits as explanatory entities microscopic structures of whose existence and nature there could be no experimental confirmation. Modern developments in sciences such as neurophysiology have revised our conceptions of the structures underlying perceptual phenomena to such an extent that modern accounts would have been unrecognizable to Leucippus or Democritus; but the basic intuitions of ancient atomism – that appearances are to be explained at the level of the internal structure of the perceiver and of the perceived object, and that the ideal of science is to incorporate the description of those structures within the scope of a unified and quantitatively precise theory of the nature of matter in general – have stood the test of time.

According to some sources, Democritus used the contrast between unobservable atomic structures and the appearances which they present to us to demonstrate the unreliability of the senses. He then faced the problem of the justification of his theory, which was founded on data provided by the senses; in a famous fragment quoted by Galen the senses say to the mind, ‘Wretched mind, you get your evidence from us, and yet do you overthrow us? The overthrow is a fall for you’ (fr. 125). It is disputed whether Democritus drew a sceptical conclusion, or whether his position was rather that, since there can be no ground for preferring one piece of sensory information to another, the task of theory is to provide an account of how all appearances are appropriate representations of an underlying unobservable reality (that is, all appearances are true, a thesis which Aristotle attributes to him, and which was later explicitly maintained by the Epicureans; see Epicureanism (§6) ).

Democritus’ uncompromising materialism extended to his psychology. Although there is some conflict in the sources, the best evidence is that he drew no distinction between the rational soul or mind and the non-rational soul or life principle, giving a single account of both as a physical structure of spherical atoms permeating the entire body. This theory of the identity of soul and mind extended beyond identity of physical structure to identity of function; Democritus explained thought, the activity of the rational soul, by the same process as that by which he explained perception, one of the activities of the sensitive or non-rational soul. Both are produced by the impact on the soul of extremely fine, fast-moving films of atoms (eidōla), constantly emitted in continuous streams by the surfaces of everything around us. This theory combines a causal account of both perception and thought with a crude pictorial view of thought. The paradigm case of perception is vision; seeing something and thinking of something alike consist in picturing the thing seen or thought of, and picturing consists in having a series of actual physical pictures of the thing impinge on one’s soul. While this assimilation of thought and experience has some affinities with classical Empiricism , it differs in one crucial respect; whereas the basic doctrine of empiricism is that thought derives from experience, for Democritus thought is a form of experience, or, more precisely, the categories of thought and experience are insufficiently differentiated to allow one to be characterized as more fundamental than the other. Among other difficulties, this theory faces the problem of accounting for the distinction, central to Democritus’ epistemology, between perception of the observable properties of atomic aggregates and thought of the unobservable structure of those aggregates. We have no knowledge of how, if at all, Democritus attempted to deal with this problem.

 

 

4 Theology

Another disputed question is whether Democritus’ materialistic account of the universe left any room for the divine. According to most of the ancient sources he believed that there are gods, which are living, intelligent, material beings (of a peculiar sort), playing a significant role in human affairs. They are atomic compounds, and like all such compounds they come to be and perish. They did not create the physical world (of which they are part), nor, although they are intelligent, do they organize or control it. They are as firmly part of the natural order as any other living beings. Specifically, Democritus believed the gods to be living eidōla, probably of gigantic size, possessing intelligence, moral character and interest in human affairs. While some sources suggest that these eidōla emanate from actual divine beings, the majority of sources agree that they are themselves the only divine beings which Democritus recognized. Some modern scholars (for example, Barnes 1982 ) interpret this as amounting to atheism, taking Democritus to have held that the gods are nothing more than the contents of human fantasy. But for Democritus eidōla are not intrinsically psychological; they are not contents of subjective states, but part of the objective world, causing psychological states through their impact on physical minds. In this case his theory must explain their source and their properties, notably their being alive. Since the gods were of human form, it is plausible to suggest that their source is actual human beings, possibly giants living in the remote past. They are themselves alive in that, flowing from beings permeated with soul-atoms, they contain soul-atoms themselves. Consistently with this naturalistic theology Democritus gave a naturalistic account of the origin of religion, identifying two types of phenomena as having given rise to religious belief: first, the occurrence of eidōla themselves, presumably in dreams and ecstatic states; and second, celestial phenomena such as thunder, lightning and eclipses.

Democritus’ theology thus contrives to incorporate some of the most characteristic features of the gods of traditional belief, notably their anthropomorphism, power, longevity (although not, crucially, immortality), personal interaction with humans and interest (for good or ill) in human affairs, within the framework of a naturalistic and materialistic theory. It is thus, despite the bold originality of its account of the divine nature, notably more conservative than some of its predecessors (especially the non-anthropomorphic monotheism normally attributed to Xenophanes) and than that of its Epicurean successor, whose main concern is to exclude the gods from all concern with human affairs (see Xenophanes §3; Epicureanism §§8–9 ).

 

 

5 Ethics and politics

The evidence for Democritus’ ethical views differs radically from that for the areas discussed above, since while the ethical doxography is meagre, our sources (see §1) preserve a large body of purported quotations on ethical topics. While the bulk of this material is probably Democritean in origin, the existing quotations represent a long process of excerpting and paraphrase, making it difficult to determine how close any particular saying is to Democritus’ own words. Various features of style and content suggest that Stobaeus’ collection of maxims contains a greater proportion of authentically Democritean material than does the collection which passes under the name of ‘Democrates’.

Subject to the limitations imposed by the nature of this material, we can draw some tentative conclusions about Democritus’ ethical views. He was engaged with the wide-ranging contemporary debates on individual and social ethics of which we have evidence from Plato and other sources. On what Socrates presents as the fundamental question in ethics, ‘How should one live?’ (Plato, Gorgias 500c, Republic 352d), Democritus is the earliest thinker reported as having explicitly posited a supreme good or goal, which he called ‘cheerfulness’ or ‘wellbeing’, and which he appears to have identified with the untroubled enjoyment of life. It is reasonable to suppose that he shared the presumption of the primacy of self-interest which is common both to the Platonic Socrates (§6) and to his immoralist opponents, Callicles and Thrasymachus. Having identified the ultimate human interest with ‘cheerfulness’, the evidence of the testimonia and the fragments is that he thought that it was to be achieved by moderation, including moderation in the pursuit of pleasures, by discrimination of useful from harmful pleasures and by conformity to conventional morality. The upshot is a recommendation to a life of moderate, enlightened hedonism, which has some affinities with the life recommended by Socrates (whether in his own person or as representing ordinary enlightened views is disputed) in Plato’s Protagoras ), and, more obviously, with the Epicurean ideal of which it was the forerunner.

An interesting feature of the fragments is the frequent stress on individual conscience. Some fragments stress the pleasures of a good conscience and the torments of a bad one (frs 174, 215) while others recommend that one should be motivated by one’s internal sense of shame rather than by concern for the opinion of others (frs 244, 264, ‘Sayings of Democrates’ 84). This theme may well reflect the interest, discernible in contemporary debates, in what later came to be known as the question of the sanctions of morality. A recurrent theme in criticisms of conventional morality was that, since the enforcement of morality rests on conventions, someone who can escape conventional sanctions, for example by doing wrong in secret, has no reason to comply with moral demands. Proponents of such a belief include Antiphon (fr. 44), Critias (fr. 25) (see Physis and nomos) and Plato, in Glaucon’s tale of Gyges’ ring in the Republic (359b–360d). A defender of conventional morality who, like Democritus and Plato, accepts the primacy of self-interest therefore faces the challenge of showing, in one way or another, that self-interest is best promoted by the observance of conventional moral precepts.

The appeal to divine sanctions, cynically described in Critias’ fragment 25, represents one way of doing this, and there are some traces of the same response in Democritus. While his theory of the atomic, and hence mortal, nature of the soul admits no possibility of postmortem rewards and punishments, the theory allows for divine rewards and punishments in this life. Fragment 175 suggests a complication: the gods bestow benefits on humans, but humans bring harm on themselves through their own folly. Is the thought that the gods do not inflict punishment arbitrarily, but that humans bring it on themselves? Or is it rather that the form which divine punishments take is that of natural calamities, which humans fail to avoid through their own folly? The latter alternative would make the pangs of conscience one of the forms of divine punishment, while the former would see it as a further sanction. Either way (and the question is surely unanswerable), we have some evidence that Democritus was the earliest thinker to make the appeal to ‘internal sanctions’ central to his attempt to derive morality from self-interest, thus opening up a path followed by others including Bishop Butler (§§2–4) and John Stuart Mill (§11) .

The attempt, however pursued, to ground morality in self-interest involves the rejection of the antithesis between law or convention (nomos) and nature (physis) which underlies much criticism of morality in the fifth and fourth centuries bc (see Physis and nomos ). For Antiphon, Callicles, Thrasymachus and Glaucon, nature prompts one to seek one’s own interest while law and convention seek, more or less successfully, to inhibit one from doing so. But if one’s long-term interest is the attainment of a pleasant life, and if the natural consequences of wrong-doing, including ill health, insecurity and the pangs of conscience, give one an unpleasant life, while the natural consequences of right-doing give one a contrastingly pleasant life, then nature and convention point in the same direction, not in opposite directions as the critics of morality allege. (We have no evidence whether Democritus had considered the objections that conscience is a product of convention, and that exhorting people to develop their conscience assumes that it must be.) Although the texts contain no express mention of the nomos/physis contrast itself, several of them refer to law in such a way as to suggest rejection of the antithesis. Fragment 248 asserts that the aim of law is to benefit people, thus contradicting Glaucon’s claim (Plato, Republic II 359c) that law constrains people contrary to their natural bent. Fragment 248 is supplemented and explained by fragment 245: laws interfere with people living as they please in order only to stop them from harming one another, to which they are prompted by envy. So law frees people from the aggression of others, thus benefiting them by giving them the opportunity to follow the promptings of nature towards their own advantage. The strongest expression of the integration of nomos and physis is found in fragment 252: the city’s being well run is the greatest good, and if it is preserved everything is preserved, while if it is destroyed everything is destroyed. That is to say, a stable community is necessary for the attainment of that wellbeing which is nature’s goal for us. This quotation encapsulates the central point in the defence of nomos (emphasized in Protagoras’ myth at (Plato, Protagoras 322a–323a) that law and civilization are not contrary to nature, but required for human nature to flourish, a point also central to the Epicurean account of the development of civilization.