The essays included in this volume are based on papers delivered at the International Symposium on Varieties of Marxism, held at the Van Leer Jerusalem Foundation on June 16-19,1974, and dedicated to the memory of George Lichtheim. When the idea of such a symposium was first raised, the organizers planned to have George Lichtheim as one of the main speakers at the event. In our last and brief meeting in London, I suggested this to him and Lichtheim gave his consent to attend the symposium, though at that time no date was yet fixed. His tragic death a few months later left a gap not only in the program of the symposium but in Marxist studies generally; it was felt that per­ haps one way of paying tribute to his contribution to the study of a subject so near to his mind would be to name the symposium in his memory and devote an introductory paper to an attempt at an intel­ lectual portrait of George Lichtheim as an historian of ideas. The volume as published includes all papers delivered at the sym­ posium, with the excep,tion of the papers of J. L. Talmon (Jerusalem) on 'Marxism and Nationalism' and Gajo Petrovic (Zagreb) on 'Yugo­ slav Marxism'. Appended is also a short obituary written by me on Lichtheim for the journal Political Science published by the American Political Science Association.