Marion's book is an important contribution to the small but growing body of literature on Wittgenstein's philosophy of mathematics. Its value lies especially in the advance it makes over previous work in situating Wittgenstein's philosophy of mathematics not only in its philosophical, but also its mathematical context ... a welcome addition to the literature.

Mark A.Joseph

fine historical study ... Marion tells an interesting and convinving story. He carefully identifies both the continuities and the discontinuities in the evolution of Wittgenstein's ideas, and makes good sense of each ... Marion's book is certainly to be recommended both for its exegesis and, through its compelling presentation of these ideas, for its contribution to the philosophy of mathematics.

A W Moore, Studia Logica