What is needed for something new to appear? According to Gilles Deleuze, one of the most brilliant of contemporary philosophers, this question of “novelty” is the major problem posed by Bergson’s work. In , Deleuze demonstrates both the development and the range of three fundamental Bergsonian concepts: duration, memory, and the élan vital. A perfect companion book to Bergson’s , is also of particular interest to students of Deleuze’s own work, influenced as it is by Bergson. Given his texts on Nietzsche, Kafka, and cinema, this book by Deleuze is essential to his English-reading audience. The paperback contains a new afterword prepared by the author especially for this English-language edition.