Remarks on the Foundations of Mathematics, revised edition
"Wittgenstein's work remains, undeniably, now, that off one of those few philosophers who will be read by all future generations. It is by far the richest twentieth-century source of philosophical ideas, which it will take us more decades yet properly to apprehend and to absorb; despite the difficulty with which his work presents the reader, there is nothing that is likely to be more rewarding. The philosophy of mathematics was one of his earliest and most persistent preoccupations.... The present edition... is a selection from seven distinct pieces of writing by Wittgenstein, with none of which he was content. For all that, it demands the most thorough attention from anyone interested in his philosophy, because the subject occupied so important a place in his thought."