Full Idea
All things are not composed of opposites, because matter is not the opposite of anything.
Gist of Idea
Not everything is composed of opposites; what, for example, is the opposite of matter?
Source
Aristotle (Metaphysics [c.324 BCE], 1075a28)
Book Reference
Aristotle: 'Metaphysics', ed/tr. Lawson-Tancred,Hugh [Penguin 1998], p.386
A Reaction
A nice counterexample