This is a book about evolution – from a post-Darwinian perspective. It recounts the core ideas of one of the great French philosophers, Henri Bergson (1859-1941), and his rediscovery and legacy in the poststructuralist critical philosophies of the 1960s onwards. It explores the confluences of these approaches with the foundational ideas of complexity theory and complex adaptive systems in environmental biology. The failings in the development of systems theory, many of which complex systems theory overcomes, are retold; with Bergson, this book proposes, some of the rest may be overcome too. It asserts that Bergson's ideas can further our understanding of evolution, and of complex systems, and aid the work of scientists working in the field of ecological complexity.