Book excerpt: Developed in the twentieth century as an outgrowth of psychosomatic medicine, the biopsychosocial model is seen as an antidote to the constraints of the medical model of psychiatry. Nassir Ghaemi details the origins and evolution of the BPS model and explains how, where, and why it fails to live up to its promises. He analyzes the works of its founders, George Engel and Roy Grinker Sr., traces its rise in acceptance, and discusses its relation to the thought of William Osler and Karl Jaspers.