Full Idea
We must recognise three 'originative sources': first that which is potentially perceptible body, secondly the contrarities (e.g hot and cold), and thirdly Fire, Water, and the like. Only thirdly, however, for these bodies change into one another.
Gist of Idea
Basic is the potentially perceptible, then comes the contrary qualities, and finally the 'elements'
Source
Anaxagoras (fragments/reports [c.460 BCE]), quoted by Aristotle - The History of Animals 529a34
Book Reference
Aristotle: 'The Basic Works of Aristotle', ed/tr. McKeon,Richard [Modern Library Classics 2001], p.509
A Reaction
The 'potentially perceptible' seems to be matter. The surprise here is that the contraries are more basic than the elements, rather than being properties of them. Reality is modes of matter, it seems.
Related Idea
Idea 17994 The primary matter is the substratum for the contraries like hot and cold [Aristotle]