The essays published in this volume were originally delivered as lectures by Professor Cranston in 1968 on the C.B.C. public affairs program "Ideas", under the title Marxism and Existentialism.

A previous volume on Sartre which Cranston published in 1963 under the title: Jean-Paul Sartre, dealt mainly with Sartre's literary output. While the present volume does not ignore his creative works, it is mainly biographical, philosophical, and political in emphasis