What is special about the philosophy of history when the history is about science? I shall focus on an impasse between two perspectives — one seeking an ideal of rationality to guide scientific practices, and one stressing the contingency of the practices. They disagree on what this contingency means for scientific norms. Their impasse underlies some fractious relations within History and Philosophy of Science. Since the late 1960s, this interdisciplinary field has been described, variously, as an “intimate relationship or marriage of convenience”, a “marriage for the sake of reason”, a “troubling interaction ”, a “precarious relationship”, or one at risk of “ epistemological derangement”. -/- My paper has three aims. First, I characterise two idealised perspectives in this impasse: the sublimers and subversives. Then I describe a curious dynamic in which each perspective accuses the other of, simultaneously, claiming too little and too much. Subliming is dismissed for being scholastic, and condemned for being imperialist. Subverting is disparaged for being merely sociological, then criticised for being irrational or relativist. Here I draw on and extend the analyses of science studies in Kitcher, Zammito and others. Second, I argue that sublimers and subversives often talk past each other. Their mutual dismissals and condemnations arise partly because each perspective misconstrues the other’s claims. Each fails to see that the other is interested in different problems and interprets concepts differently. Third, I suggest that my analysis clarifies some current disagreements and old debates about contingency in science. It may also apply to debates on the contingency of norms in non- scientific realms.