On Generation and corruption   

the same in name and nature; while Democritus and Leucippus say that

there are indivisible bodies, infinite both in number and in the

varieties of their shapes, of which everything else is composed-the

compounds differing one from another according to the shapes,

'positions', and 'groupings' of their constituents.)

For the views of the school of Anaxagoras seem diametrically opposed

to those of the followers of Empedocles. Empedocles says that Fire,

Water, Air, and Earth are four elements, and are thus 'simple'

rather than flesh, bone, and bodies which, like these, are

'homoeomeries'. But the followers of Anaxagoras regard the

'homoeomeries' as 'simple' and elements, whilst they affirm that

Earth, Fire, Water, and Air are composite; for each of these is

(according to them) a 'common seminary' of all the 'homoeomeries'.

Those, then, who construct all things out of a single element,

must maintain that coming-tobe and passing-away are 'alteration'.

For they must affirm that the underlying something always remains

identical and one; and change of such a substratum is what we call

'altering' Those, on the other hand, who make the ultimate kinds of

things more than one, must maintain that 'alteration' is distinct from

coming-to-be: for coming-to-be and passingaway result from the

consilience and the dissolution of the many kinds. That is why

Empedocles too uses language to this effect, when he says 'There is no

coming-to-be of anything, but only a mingling and a divorce of what

has been mingled'. Thus it is clear (i) that to describe

coming-to-be and passing-away in these terms is in accordance with

their fundamental assumption, and (ii) that they do in fact so

describe them: nevertheless, they too must recognize 'alteration' as a

fact distinct from coming to-be, though it is impossible for them to

do so consistently with what they say.

That we are right in this criticism is easy to perceive. For

'alteration' is a fact of observation. While the substance of the

thing remains unchanged, we see it 'altering' just as we see in it the