On Generation and corruption   

changes of magnitude called 'growth' and 'diminution'. Nevertheless,

the statements of those who posit more 'original reals' than one

make 'alteration' impossible. For 'alteration, as we assert, takes

place in respect to certain qualities: and these qualities (I mean,

e.g. hot-cold, white-black, dry-moist, soft-hard, and so forth) are,

all of them, differences characterizing the 'elements'. The actual

words of Empedocles may be quoted in illustration-



The sun everywhere bright to see, and hot,

The rain everywhere dark and cold;



and he distinctively characterizes his remaining elements in a similar

manner. Since, therefore, it is not possible for Fire to become Water,

or Water to become Earth, neither will it be possible for anything

white to become black, or anything soft to become hard; and the same

argument applies to all the other qualities. Yet this is what

'alteration' essentially is.

It follows, as an obvious corollary, that a single matter must

always be assumed as underlying the contrary 'poles' of any change

whether change of place, or growth and diminution, or 'alteration';

further, that the being of this matter and the being of 'alteration'

stand and fall together. For if the change is 'alteration', then the

substratum is a single element; i.e. all things which admit of

change into one another have a single matter. And, conversely, if

the substratum of the changing things is one, there is 'alteration'.

Empedocles, indeed, seems to contradict his own statements as well

as the observed facts. For he denies that any one of his elements

comes-to-be out of any other, insisting on the contrary that they

are the things out of which everything else comes-to-be; and yet

(having brought the entirety of existing things, except Strife,

together into one) he maintains, simultaneously with this denial, that

each thing once more comes-to-be out of the One. Hence it was