Note 43 — Chapter I · SPECULATIVE PHILOSOPHY IN GREECE, BEFORE AND IN THE TIME OF SOKRATES.

Aristot. Metaphys. A. 5, p. 986, a. 22. He goes on to say that Alkmæon, a semi-Pythagorean and a younger contemporary of Pythagoras himself, while agreeing in the general principle that “human affairs were generally in pairs,” (εἶναι δύο τὰ πολλὰ τῶν ἀνθρωπίνων), laid down pairs of fundamental contraries at random (τὰς ἐναντιότητας τὰς τυχούσας) — black and white, sweet and bitter, good and evil, great and little. All that you can extract from these philosophers is (continues Aristotle) the general axiom, that “contraries are the principia of existing things” — ὅτι τἀνάντια ἀρχαὶ τῶν ὄντων.

This axiom is to be noted as occupying a great place in the minds of the Greek philosophers.