Category: Persons

Democritus (and Plato)

The last, most important and boldest Presocratic philosopher, Democritus introduced the atomist theory and is considered to be Plato’s great theoretical opponent.

Biographical data

Hailing from Abdera in Thrace, like Protagoras who was slightly older, Democritus travelled a lot, but avoided Athens. He was born around 460 BCE and lived to old age. Hence he is younger than Socrates and the Sophists and, chronologically viewed, he should not be included in the Presocratic philosophers. If he is listed among them, it is because his philosophical system is in every way the culmination of Presocratic thought.

Democritus wrote extensively, as much as very few ancient authors, and it is a great misfortune that his works are not extant. What has been brought down to us includes some titles (Megas and Mikros Diakosmos [Major and Minor World System]) and many fragments, most of which however are on ethics and not physics. It has been said that the total size of his works was comparable to Plato’s, his great theoretical rival. The predominance of Platonic philosophy during the fourth century BCE and the spread of Platonic schools must be the reasons why Democritean thought was brushed aside.

The Atomist Theory

The atomist theory, for which Democritus is renowned, is attributed by ancient writers jointly to him and Leucippus. However, for the latter we have no information of any importance, other than his seniority to Democritus.

Democritus begins with Parmenides. They share many points: they are suspicious of the reliability of the senses, they give precedence to the intellectual path, they are certain of the immutability of what truly is. Against Parmenides’ single Being Democritus introduces the atoms and the void. One should conceive of these atoms as the smallest units of matter -- “atomon” in Greek signifies what is indivisible, what cannot be divided into smaller parts. Their minuscule size renders them invisible, inaccessible to the senses; hence, since the atoms and the void are beyond the reach of the senses, it is fair to assume that Democritus’ certainty about them must have been grounded on some intellectual inference:

by convention there is sweet and bitter, by convention there is hot and cold, by convention there is colour: in truth there are atoms and the void [Democritus, fragment 9] The atoms are infinite in number and they differ in shape and size. What makes up the visible masses, the various visible objects we see and feel, is the clustering of many atoms. Democritus holds that the birth of a thing is in reality a joining together of pre-existing elements: a combination of many atoms and, thus, death is the disintegration of a cluster of atoms. It is likely that Democritus came to think of the atoms as infinite in number, in shape and in size, in order to account for the infinity of visible objects in the world. Compounds of atoms make up inanimate objects, living organisms and man himself. The characteristic feature of certain bodies is attributed to the shape of atoms:e.g. fire and the soul are made up of spherical atoms (Aristotle, De anima 405a11). Human perception and intellect are also explained based on the movement and combination of atoms.

One could, therefore, think that Democritus’ thinking was inclined to reducing qualitative differences of visible bodies to quantitative differences (number, shape and size) of atoms, much like modern physics came to do much later. The problem of Democritus’ atomist doctrine, however, was that it did not determine the quantitative traits of the atoms and, thus, could offer in fact no precise accounts for particular visible phenomena.

Eternal change

Nonetheless, Democritus was not aiming to offer a precise quantitative science, but a general model for explaining physical/natural reality. This goal was achieved; and with surprising completeness. The general principle of the atomists, that the atoms and the void is all there is, is held to with absolute consistency in every field of phenomena. Apparently different phenomena, such as the coming-to-be of everyday objects or the movements of terrestrial and heavenly bodies or human physiology, are explained in the same way.

The world comes to be when many atoms of various shapes gather and produce a whirl, which separates the fine bodies while bringing together the heavier bodies and uniting them at the centre in a first spherical structure, the earth (Diogenes Laertius, IX.31). Moreover, given that there are infinite atoms and that the void is also infinite, there is no reason for us to consider the coming to be of our world as a unique phenomenon. The atomists, therefore, are the first thinkers to have clearly put forward the idea that there are infinite worlds (Hippolytus, Refutation, I.13.2). In the atomists’ system there are three eternally existing elements: the atoms, the void and change [kinesis]. Leucippus and Democritus took for granted that the atoms were from the very start in motion and it appears that they did not feel the need to justify the existence of this change. When Democritus proposed, in rejection of the cosmic forces introduced by Empedocles and Anaxagoras (Love and Strife, Nous), that change is eternal, he was aware that in this way he was removing all anthropomorphic elements from the natural world. The atomists’ universe is bare and faceless. Human psychology and human ethics have no relation to the mechanisms that determine the world.

Necessity and Chance

The dispute with Plato. The mechanisms of nature function without being regulated by any higher power. Does this mean then that everything in nature happen without order and by chance? Judging by Plato and Aristotle, many who came after Democritus have interpreted the atomist theory in this way. In the Laws Plato launches a harsh attack against Democritus (without mentioning his name at all, however) and the “wicked and disrespectful young wise men”, who claim that the greatest and finest things have come to be without the intervention of some intellect or god (889c), and are works of nature and chance (889a). These philosophers are mistaken in underestimating the role of the soul, to which they attribute a material substance, but also of the intelligent purposefulness governing the universe. The controversy with Democritus may be the motive for the late Plato to write the Timaeus, in which he attempts to construct a teleological cosmology in full contrast to the mechanistical Democritean universe. Neither in the Timaeus do we find any direct reference to Democritus, not even when Plato adopts a peculiar system of mathematical atomism, in which the atoms of Democritus are replaced by elementary triangles.

The atomists, nonetheless, never spoke of chance as ruling the universe. Their own key-word is “necessity”. nothing happens in vain, but all things happen for a reason and by necessity. Leucippus, fragment 1 Necessity is not to be identified with Chance -- in a way, it is actually its opposite. The atomists wish to underscore the necessity governing all physical change. Movements and collisions of atoms, the deeper workings that precede physical change, necessarily determine its upshot. Democritus’ world has no Demiurge, obeys no plan and fulfils no purpose; but it is not a realm of Chance. The necessity involved in every particular step, every change and every phenomenon is enough to bring coherence in the world. In the atomist theory we discern the natural completion of the long trajectory of thought that begun in Miletus two hundred years before.

Author: Vassilis Kalfas
  • Furley, D.J. Two Studies in the Greek Atomists,. Princeton, 1967.
  • Luria, S, Democritea. Λενινγκραντ, 1970.
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