Chapter 4 focuses on the German tradition of conceptual history and its philosophical foundations. As it shows, both theories, the Cambridge school’s and the German conceptual history’s, must be placed within the frameworks of the break of the evolutionist-teleological views of history at the end of the nineteenth century. It paved the way to the emergence of a new idea of temporality articulated around the idea of the radical contingency of historical processes. In turn, it provided the basis for an opposition between “natural sciences” and “cultural sciences,” emphasizing the centrality of subjective intentionality in the latter. The philosophical expression of this conceptual turn was Neo-Kantian historicism, whose best representative is Wilhelm Dilthey and his project of a “critique of historical reason.” The premise for it is the assumption of the meaningful character of social actions, which entailed another way of breaking the opposition between “ideas” and “reality,” different from that of the Cambridge school.

This chapter offers a new interpretation of Raymond Aron’s doctoral thesis, Introduction à la philosophie de l’histoire (1938). Described by Aron as having established the basis of all his subsequent political thought, the Introduction contains a pluralist critique of Marx’s philosophy of history which doubles as a normative justification for political liberalism. Anticipating the ‘epistemology of doubt’ characteristic of later cold war liberalism, the book also served as the philosophical basis for Aron’s ethic of intellectual responsibility. Yet the extent to which the Introduction’s historical relativism undermines its ethical and normative arguments has been widely debated. Through an analysis of Aron’s previously under-explored interpretations of Dilthey and Heidegger, the chapter argues that scholarly disagreement on this issue reflects the Introduction’s ambiguous epistemological agnosticism. The chapter concludes with a discussion of the influence of the Introduction to the Philosophy of History on Jean-Paul Sartre's Critique of Dialectical Reason.