balls. This was certainly the view of Epicurus, who in most respects based his theories on those
of Democritus, while trying, rather unintelligently, to take account of Aristotle's criticisms. But
there is considerable reason to think that weight was not an original property of the atoms of
Leucippus and Democritus. It seems more probable that, on their view, atoms were originally
moving at random, as in the modern kinetic theory of gases. Democritus said there was neither
up nor down in the infinite void, and compared the movement of atoms in the soul to that of
motes in a sunbeam when there is no wind. This is a much more intelligent view than that of
Epicurus, and I think we may assume it to have been that of Leucippus and Democritus. *
As a result of collisions, collections of atoms came to form vortices. The rest proceeded much
as in Anaxagoras, but it was an advance to explain the vortices mechanically rather than as due
to the action of mind.
It was common in antiquity to reproach the atomists with attributing everything to chance. They
were, on the contrary, strict determinists, who believed that everything happens in accordance
with natural laws. Democritus explicitly denied that anything can happen by chance. â€
Leucippus, though his existence is questioned, is known to have said one thing: "Naught
happens for nothing, but everything from a ground and of necessity." It is true that he gave no
reason why the world should originally have been as it was; this, perhaps, might have been
attributed to chance. But when once the world existed, its further development was unalterably
fixed by mechanical principles. Aristotle and others reproached him and Democritus for not
accounting for the original motion of the atoms, but in this the atomists were more scientific
than their critics. Causation must start from something, and wherever it starts no cause can be
assigned for the initial datum. The world may be attributed to a Creator, but even then the
Creator Himself is unaccounted for. The theory of the atomists, in fact, was more nearly that of
modern science than any other theory propounded in antiquity.
The atomists, unlike Socrates, Plato, and Aristotle, sought to ex-
* This interpretation is adopted by Burnet, and also, at least as regards Leucippus, by Bailey
(op. cit. p. 83).â
€
See Bailey, op. cit., p. 121, on the determinism of Democritus.