Ludwig Wittgenstein's On Certainty was finished just before his death in 1951 and is a running commentary on three of G.E. Moore's greatest epistemological papers. In the early 1930s, Moore had written a lengthy commentary on Wittgenstein, anticipating some of the issues Wittgenstein would discuss in On Certainty.

In this book, Avrum Stroll examines the philosophical relationship between these two great philosophers and their overlapping but nevertheless differing views. Both defended the existence of certainty and thus opposed any form of skepticism. However, their defenses and conceptions of certainty diverged widely, as did their understanding of the nature of skepticism and how best to combat it.

Moore and Wittgenstein on Certainty contains a careful and critical analysis of the two philosophers' differing approaches to a set of fundamental epistemological problems. Stroll extends their account to current issues in cognitive science and philosophy of mind.