Originally published in 1985, this book examines the concept of death against the background of dramatic changes in medical technology. The book argues that 'brain death' can be precisely defined and that a biological concept of death such as 'brain death' can be philosophically well-grounded. It examines traditional criteria for death and various formulations of the concept of death in both medical literature and philosophical texts. Definitions of 'brain death' - some of which have become statute law - are critically examined. The author also examines ethical and social policy questions which arise out of attempts to redefine the boundaries of life.