In this paper, I set out to consider the extent to which Horkheimer and Adorno's account of the transition from Kant's philosophy to key features of the novels of the Marquis de Sade in the Second Excursus of their Dialectic of Enlightenment can be viewed as a fragment of the ‘history of philosophy’ and to explain this account in a way that allows us to ask whether it succeeds in establishing a necessary connection between Kant's philosophy and Sade's novels. In (...) connection with, a particular problem emerges. This problem concerns the role played by a non-instrumental form of reason in Horkheimer and Adorno's attempt to establish an essential connection between Kant's theoretical philosophy and Sade's novels, in which the practical implications of the theoretical employment of reason allegedly become explicit. It will be shown that, despite appearances to the contrary, an employment of reason of the relevant type is not identified by Kant in the Critique of Pure Reason. (shrink)