Racism is a universal affliction, but its representation as an oppressive and dogmatic ideology captured center stage only during the years between the World Wars. Prior to that time, social differentiation based upon real or assumed racial distinctions was thought to be part of the natural order. Hence, the principal retreat of racism conveyed the recognition that racial terminology is not value free, and that social organization based on a racial hierarchy is repugnant. To describe this change, I have reconstructed the scientific discourse on race among British and American anthropologists and biologists, whom I believe to have been pivotal in this shift. The actors in the story below were scientists of a very mixed bag, personally and professionally. Yet they all shared a belief that the centrality of race for cultural and political discourse depended largely on its scientific legitimacy. For various subjective motives – that is, sociological variables – they chose to address the topic of race, which was consequently transformed from a scientific fact into a political hot potato. Racism did not disappear but racial ideologies ceased to command respectability.

Despite the long–standing ambivalence about causality in the human sciences and although exclusionary explanatory claims have gradually diminished, the belief persists that affinities, long-term structural changes, and mentalité, provide the motives and rationale for historical changes. Admissions of contingency, indeterminism, and open-endedness often disguise a fundamental belief in causal relationships which cannot, however, be substantiated epistemologically.