The faction fight in the Socialist Workers Party, its conclusion, and the recent formation of the Workers Party have been in my own case, the unavoidable occasion for the review of my own theoretical and political beliefs. This review has shown me that by no stretching of terminology can I regard myself, or permit others to regard me, as a Marxist.

As cited in: Marcel van der Linden (2007) Western Marxism and the Soviet Union: A Survey of Critical Theories and Debates Since 1917. p. 80 - Burnham's Letter of Resignation, 1940