ly assume origination and destruction, for nothing
originates and nothing is destroyed. All is only mixed and unmixed out
of pre-existent things, and it were more correct to call the one
process composition and the other process decomposition."

The Atomists had assumed the ultimate constituents of things to be
atoms composed of the same kind of matter. Empedocles had believed in
four ultimate and underived kinds of matter. With neither of these
does Anaxagoras agree. For him, all the different kinds of {96} matter
are equally ultimate and underived, that is to say, such things as
gold, bone, hair, earth, water, wood, etc., are ultimate kinds of
matter, which do not arise from anything else, and do not pass over
into one another. He also disagrees with the conception of the
Atomists that if matter is divided far enough, ultimate and
indivisible particles will be reached. According to Anaxagoras matter
is infinitely divisible. In the beginning all these kinds of matter
were mixed together in a chaotic mass. The mass stretches infinitely
throughout space. The different kinds of matter wholly intermingle and
interpenetrate each other. The process of world-formation is brought
about by the unmixing of the conglomeration of all kinds of matter,
and the bringing together of like matter with like. Thus the gold
particles separating out of the mass come together, and form gold; the
wood particles come together and form wood, and so on. But as matter
is infinitely divisible and the original mixing of the elements was
complete, they were, so to speak, mixed to an infinite extent.
Therefore the process of unmixing would take infinite time, is now
going on, and will always go on. Even in the purest element there is
still a certain admixture of particles of other kinds of matter. There
is no such thing as pure gold. Gold is merely matter in which the gold
particles predominate.

As with Empedocles and the Atomists, a moving force is required to
explain the world-process of unmixing. What, in the philosophy of
Anaxagoras, is this force? Now up to the present point the philosophy
of Anaxagoras does not rise above the previous philosophies of
Empedocles and the Atomists. On the contrary, in clearness {97} and
logical consistency, it falls considerably below the teaching of the
latter. But it is just here, on the question of the moving force, that
Anaxagoras becomes for the first time wholly original, and introduces
a principle peculi