What is needed for something new to appear? According to Gilles Deleuze, one of the most brilliant contemporary philosophers, this question of "novelty" is the major problem posed by Bergson"s work. In this companion book to Bergson"s Matter and Memory, Deleuze demonstrates both the development and the range of three fundamental Bergsonian concepts: duration, memory, and the élan vital. Bergsonism is also important to an understanding of Deleuze"s own work, influenced as it is by Bergson. Gilles Deleuze is Professor of Philosophy at the University of Paris VIII, Vincennes/Saint Denis. Among his most recent books in translation are Nietzsche and Philosophy, Cinema: Image Movement and, with Felix Guattari, Anti-Oedipus, Kafka, and One Thousand Plateaus. Hugh Tomlinson is the translator of Deleuze"s Nietzsche and Philosophy and Kant"s Critical Philosophy. Barbara Habberjam is a translator living in England.