This essay is an account of the “revisionism” movement of the 1970s and 1980s in Soviet history, analyzing its challenge to the totalitarian model in terms of Kuhnian paradigm shift. The focus is on revisionism of the Stalin period, an area that was particularly highly charged by the passions of the Cold War. These passions tended to obscure the fact that one of the main issues at stake was not ideological but purely disciplinary, namely a challenge by social historians to the dominance of political history. A similar challenge, this time against the dominance of social history on behalf of cultural history, was issued in the 1990s by “post-revisionists.” Although I was a participant in the battles of the 1970s, the essay is less a personal account than a case-based analysis of the way disciplinary orthodoxies in the social sciences and humanities are established and challenged, and why this happens when it does. In the case of Soviet history, I argue that new data and external events played a surprisingly small role, and generational change a large one.