 The published work of Donald Williams (1899–1983) ranges across a broad spectrum in philosophy, but his importance as a philosopher rests in large measure on four major achievements. Firstly, in a period when the role of philosophy was being diminished and trivialized, he persisted with a traditional style of philosophizing.  Although it remained unfashionable throughout most of his active years, he held to the classic program of Western philosophy: to explain and defend our capacity to attain knowledge (so far as that reaches), in the light of that to present a well-reasoned account of the most general and fundamental features of Reality, and on that basis to propose a wise scheme for the good life. His unswerving allegiance to this project, keeping it alive in dark days, has had its reward. At least in Anglophone circles, these classic metaphysical, epistemic and ethical issues are once more firmly on the agenda.