Atomism was devised by Leucippus and his student Democritus. Democritus was born
about 460 B.C., which makes him about 40 years younger than Anaxagoras, and about 10
Atomism is the final, and most successful, attempt to rescue the reality of the physical world from the fatal
effects of Eleatic logic by means of a pluralistic theory. (Guthrie, vol. 2, p. 389)
Overview of atomism:
Imagine each atom, taken by itself, as a Parmenidean
. Each is
There is no differentiation between one part of an atom and another part. There is
no empty space within an atom
Thus, the atomists tried to agree with Parmenides about everything except the
of real beings.
Comparison with Anaxagoras and Empedocles: theirs was a
pluralism. The atomists offered a
Properties of atoms: each atom is uniform, homogeneous, colorless, tasteless, and
indivisible. (We will inquire in a moment into precisely the sense in which atoms are
, and (perhaps)
. And they can
. That is, atoms have
(what have come to be called)
qualities. As for such secondary qualities as
color, taste, etc., atoms do not have them
an atom cannot be yellow, or salty.
Democritus’s atomistic universe: atoms move about in the void (empty space), collide,
attach to others to form compounds. These compounds can have secondary qualities, but
such qualities can be reduced to the primary qualities of their component atoms. Cf.
He makes sweet that which is round and good-sized; astringent that which is large,
rough, polygonal, and not rounded; sharp tasting, as its name indicates, that which is
sharp in body, and angular, bent and not rounded; pungent that which is round and small
and angular and bent; salty that which is angular and good-sized and crooked and equal
sided; bitter that which is round and smooth, crooked and small sized; oily that which is
fine and round and small.
the (secondary) qualities of a compound are completely determined by and
reducible to the (primary) qualities of its component atoms
The coming together of atoms to form compounds
to be generation (new things
appear to come into existence) but it is explained away, as in Empedocles. For
are not real
, according to Democritus.
Nor are the apparent properties of those compounds of atoms real
. Such a compound
may appear to be white, or green, but this is not so. There is nothing that is
The only things that are real are the atoms, and the empty space they move about in. Cf.