In this pathbreaking new work, Elizabeth Grosz proposes a theory of in place of the prevailing emphasis on in social, political and biological discourse. Drawing on evolutionary biology, she explores the effect of time on the organization of matter and the development of biological life. She argues that factoring in the relentless forward movement of time throws new light on the ever-growing complication of social life, and also on political struggle. Grosz juxtaposes the work of Darwin, Nietzsche and Bergson. Each theorises time as an active phenomenon with specific effects, with a profound impact on understandings of the body in relation to time. She shows how their concepts of life, evolution, and becoming are manifest in the work of Deleuze and Irigaray. Throughout , Grosz emphasizes the political and cultural imperative to fundamentally rethink time: the more clearly we understand our temporal location as beings straddling the past and the future without the security of a stable and abiding present, the more transformation becomes conceivable.