Tynan addresses Deleuze's assertion, that 'literature is an enterprise of health', and shows how a concern of health and illness was a characteristic of his philosophy as a whole, from his earliest works to his collaborations with Guattari, to his final, enigmatic statements on 'life'. He explains why alcoholism, anorexia, manic depression and schizophrenia are key concepts in Deleuze's literary theory, and shows how, with the turn to schizoanalysis, literature takes on a crucial political and ethical role in helping us to diagnose our present pathologies and articulate the possibilities of a health to come.