The present volume contains the correspondence, or the bulk of what is known to have survived of it, between Wittgenstein and the chief of his Cambridge friends, by which we mean those who can fairly be regarded as his equals or even mentors rather than his disciples – Bertrand Russell, G. E. Moore, J. M. Keynes, and later Frank Ramsey and (represented by a single but important letter) Piero Sraffa.

It conveys a picture of an important side of Wittgenstein’s development. He appears here in turn shy and affectionate, fierce and censorious, happy to collaborate and sure of his own judgments. Four quarrels and four reconciliations are documented. His struggles to publish the Tractatus can be followed, his retreat from the world, his being wooed back to philosophy by Keynes and Ramsey, later plans of his too to leave philosophy, all in the end reversed. A constant theme, despite ambivalence, is the pull of the Cambridge that these friends represented.