Full Idea
Not one of the ancient philosophers had the courage for a theory of the 'unfree will' (i.e. for a theory that denies morality).
Gist of Idea
None of the ancients had the courage to deny morality by denying free will
Source
Friedrich Nietzsche (The Will to Power (notebooks) [1888], §428)
Book Reference
Nietzsche,Friedrich: 'The Will to Power', ed/tr. Kaufmann,W /Hollingdate,R [Vintage 1968], p.232
A Reaction
The ancients were struck by fate, and by the elusiveness of truth, and Heraclitus said that "character is fate". But Nietzsche seems basically correct.