Physics

by Aristotle

Written circa 350 B.C.
Translated by R. P. Hardie and R. K. Gaye

Book III.4

The physicists, on the other hand, all of them, always regard the infinite as an
attribute of a substance which is different from it and belongs to the class of the
so-called elements-water or air or what is intermediate between them. Those who
make them limited in number never make them infinite in amount. But those who
make the elements infinite in number, as Anaxagoras and Democritus do, say that
the infinite is continuous by contact-compounded of the homogeneous parts
according to the one, of the seed-mass of the atomic shapes according to the other.
Democritus, for his part, asserts the contrary, namely that no element arises from
another element. Nevertheless for him the common body is a source of all things,
differing from part to part in size and in shape.

It is clear then from these considerations that the inquiry concerns the physicist.
Nor is it without reason that they all make it a principle or source. We cannot say
that the infinite has no effect, and the only effectiveness which we can ascribe to it
is that of a principle. Everything is either a source or derived from a source. But
there cannot be a source of the infinite or limitless, for that would be a limit of it.
Further, as it is a beginning, it is both uncreatable and indestructible. For there
must be a point at which what has come to be reaches completion, and also a
termination of all passing away. That is why, as we say, there is no principle of
this, but it is this which is held to be the principle of other things, and to encompass
all and to steer all, as those assert who do not recognize, alongside the infinite,
other causes, such as Mind or Friendship. Further they identify it with the Divine,
for it is 'deathless and imperishable' as Anaximander says, with the majority of the
physicists.