EXCERPT The preface and notice translated below read more like dares than invitations to study On Logic and the Theory of Science. Gaston Bachelard hints at the challenges to come in his description of Cavaillès’s sentences as ‘often enigmatic in their concision’. The work’s editors, Georges Canguilhem and Charles Ehresmann, were more frank when they presented the fruits of their original efforts in 1946. Apparently they considered authoring an intro-duction that might ‘shed some light on the background context of philosophical and mathematical culture which Cavaillès precisely wished to be taken for granted’. But they feared the result would be mere commentary. Instead, apart from filling in references, they presented the work without apparatus and with the conjecture that Cavaillès believed ‘those who did not make the effort to understand did not deserve to be enlightened’, a judgment all the more perplexing given that we are advised in the next paragraph that the problems raised in the pages to follow ‘cannot honestly receive any definitive solution’. Readers should know that translating Cavaillès’s essay has conferred no special advantage on this score. Our strategy has been less to resolve the enigmas of Cavail-lès’s writing than to preserve them in English. …