From starting his intellectual career as a surrealist, communist and co-founder of the Collège de Sociologie in 1937, Jules Monnerot (1911–95) ended it as a candidate for the Front National in 1989. In this article I offer an explanation for the unexpected trajectory of this thinker whose work is little known in the English-speaking world. Without overlooking the idea that the infamous College encouraged such tendencies, I argue that the notion of ‘secular religion’, as Monnerot developed it in his Sociology of Communism (1949), goes some way to explain his gradual radicalization from Cold Warrior to fascist, a path that otherwise seems unlikely for a French intellectual after World War II. In order to emphasize the unusualness of Monnerot's case, I contrast it with that of his erstwhile collaborator, Georges Bataille. I show that accusations of fascism often levelled against Bataille should be more accurately directed at Monnerot, indeed that the fascism inherent within the College of Sociology was brought out not by Bataille but by Monnerot. Monnerot's case is unsettling first because his definition of ‘secular religion’ contributed to his pro-fascist stance; and second, because it forces us to rethink what is meant by ‘philosophy after Auschwitz.’ This term usually brings to mind scholars such as T.W. Adorno, Emil Fackenheim or Emmanuel Levinas. Monnerot provides a rare example of a thinker whose fascism only developed after the Holocaust, a shocking response that demands the attention of all those interested in the relationship between religion and politics.