In the early 1980s, publishing Neither Right nor Left, the Israeli historian Zeev Sternhell unleashed a virulent controversy, who attracted the most hostility from some historians of Sciences Po, supporters of the so-called “immunity thesis”. More than thirty years later, and as Sternhell published his memoirs, this article seeks to take a reflective look at the controversy. But the purpose of this article is not to resolve the debate. I will focus instead on the issues of the debate and its historiographical dimension. First, I will consider that “the immunity thesis” can not be detached from the context of the intellectual politics in France. Next, I will analyze the views of several historians that the generic fascism had little value as an analytical tool. Following Michel Dobry, French political scientist, they focused on the fundamental limits of “classificatory logic.” Finally, I suggest that Sternhell’s studies helped to clarify some categories of French and international debate on the topic of fascism and its origins. Sternhell gave an impressive reflection on the history of ideas, with his analysis of fascism both in a transnational context and a long-term perspective.