The reason why, unlike the West, Boris Hessen's achievements were virtually forgotten in the USSR even after his rehabilitation (1956), was that in the Soviet context his ideas concerning Isaac Newton lost the polemical sting they possessed when first formulated, which was directed against the old and "bourgeois" tradition of pure history of ideas (Mayer, Chivers). For the early Soviet context, Hessen's externalism was commonplace and ranged with a number of similar programs for studying the determination of knowledge