In this analysis of one major philosopher by another, Gilles Deleuze identifies three pivotal concepts - duration, memory, and élan vital - that are found throughout Bergson's writings and shows the relevance of Bergson's work to contemporary philosophical debates. He interprets and integrates these themes into a single philosophical program, arguing that Bergson's philosophical intentions are methodological. They are more than a polemic against the limitations of science and common sense, particularly in Bergson's elaboration of the explanatory powers of the notion of duration - thinking in terms of time rather than space.