 Deleuze was aware of the finitist revolution in the history of the differential calculus, despite Sokal and Bricmont’s 1999 intimations otherwise. He writes in Difference and Repetition, “it is a mistake to tie the value of the symbol dx to the existence of infinitesimals; but it is also a mistake to refuse it any ontological or gnoseological value in the name of a refusal of the latter. In fact, there is a treasure buried within the old so-called barbaric or pre-scientific interpretations of the differential calculus, which must be separated from its infinitesimal matrix. A great deal of heart and a great deal of truly philosophical naivety is needed in order to take the symbol dx seriously …” (170). It seems obvious here that Deleuze’s treatment of early forms of the differential calculus is not meant as an intervention into the history of mathematics, or an attempt at a philosophy of mathematics, but as an investigation seeking to form a properly philosophical concept of difference by means of extracting certain forms of thought from what he clearly labels as antiquated mathematical methods. (For positive views of Deleuze’s use of mathematics as provocations for the formation of his philosophical concepts, see the essays in Duffy 2006.)