The Atomist School
Leucippus and Democritus: atoms and the void as the ultimate constituents of reality; mechanical materialism and its denial of final causality.
Leucippus (fl. 440 BC) and Democritus of Abdera (c. 460–370 BC) developed the first comprehensive and systematic materialist philosophy. Reality consists of atoms — indivisible, indestructible, qualitatively identical, quantitatively and positionally different particles — moving in infinite empty space (the void). All sensible qualities (colour, warmth, taste) are purely subjective appearances; only atoms and the void are objectively real ('by convention sweet, by convention bitter; by reality atoms and void'). The soul consists of fine, spherical, mobile atoms and perishes when they disperse at death. There is no teleology, no divine providence, no mind: everything is the necessary product of mechanical collisions. This pure and rigorous materialism is the direct ancestor of Epicurean philosophy and — revived and mathematised in the 17th century — of the mechanical philosophy that shaped early modern science.
Article 5. The Atomist School
a) Leucippus ; b) Democritus; c) Others. The Atomist School represents a retrograde movement in philosophy. These philosophers made all things consist of a single kind of matter broken into tiny particles (atoms) and moved into diverse combinations by a necessary and unreasoned force. Thus the Atomists professed a doctrine of a cruder sort than the old Ionian hylozoism, which explained the universe as living and self-forming. The Atomists were out-and-out mechanists.
a) Leucippus. Leucippus is regarded by Aristotle and Theophrastus (both 4 century b. c.) as the founder of the Atomist School. Little or nothing is known of Leucippus, however, and some historians have questioned his existence. It is, nevertheless, fairly certain that he did exist, and that he was the predecessor and teacher of Democritus, the ablest exponent of atomism among the ancient Greeks.
b) Democr it us (Born about 470 b. c.)
Life: Democritus was born at Abdera, an Ionian colony in Thrace. He was well learned in the mathematical and physical sciences.
Works: An ancient catalogue attributes many writings to Democritus, and of these The Great Order is the most celebrated. Of this and other works some fragments survive. Aristotle (4 century b. c.) gives an account of the doctrines of the Atomists, assigning these to Democritus and Leucippus together.
Doctrine: The world-stuff is simply a collection of minute particles of matter, all of which have the same nature, but differ in size, shape, and weight. These particles or atoms do not adhere together contiguously, but are held apart by vacuoles or intervals of vacuum. Atoms and vacuoles compose all bodies. That the vacuoles exist is proved by the phenomena of bodily movement, rarefaction, condensation, expansion, and contraction. The variety in the world finds its explanation in the diverse unions of atoms which vary in weight, shape, and size. The atoms are eternal; they have been in motion from eternity and are perpetually shifting into new combinations. Sky and earth were formed by natural necessity, the lighter atoms moving upwards to form the firmament, and the heavier atoms sinking downwards to form the earth. Man’s soul is made of the more subtle atoms. These are spherical in shape, and permeate the body, penetrating everywhere, and causing it to live. The soul-atoms produce different effects in different bodily parts : in the head they produce thought; in the heart, love and anger; in the liver, senseappetite; etc. When the soul-atoms leave the body, death results. The respiratory duct is the only channel through which the soul-atoms can escape from the body, and as long as this is blocked by the passage of air—as it is in breathing—the soulatoms cannot depart. Therefore, a man lives as long as he can breathe. Brutes and plants, as well as man, have souls. Man’s knowledge is of two kinds, sensation and thought. Sensation is obscure and unreliable, but thought is trustworthy. Sensation is produced in man by the fact that objects in the world throw off images of themselves like shells or cast skins, and these enter the sense-organs through pores and so penetrate to the soul. But the shells or images of things do not correspond perfectly with their originals; sense-knowledge is therefore unreliable—a fact attested by the disagreement of men about the sense-qualities of things. Thought means the grasping of things as they are by the soul; it is the understanding of the very atoms and vacuoles which compose things. Thought is therefore reliable. The Atomists do not explain the manner in which thought is achieved. Man’s highest good is rest and tranquillity of soul. This good must be obtained during earthly life, since the soul loses its personality at death. To gain rest and tranquillity of soul man must cultivate pure thought, using the things of sense with the greatest moderation.
Remarks: The atomist doctrine maintains that nothing exists except bodily reality (materialism), and that the world is a great collection of atoms and vacuoles shaped into different things by force of natural necessity (mechanism). Sensation is declared obscure and untrustworthy, and thought, while asserted as valid, is not clearly or convincingly described : hence the atomist theory involves a latent skepticism.
c) Ot her At omist s. The following pupils of Democritus deserve mention in the History of Philosophy as exponents of the atomist doctrine:
1— Metrodorus of Chios;
2— Diogenes of Smyrna;
3— Anaxarchus, the companion of Alexander the Great.