In 1959 two French neurologists, Pierre Mollaret and Maurice Goullon, coined the term coma dépassé to designate a state beyond coma. In this state, patients are not only permanently unconscious; they lack the endogenous drive to breathe, as well as brainstem reflexes, indicating that most of their brain has ceased to function. Although legally recognized in many countries as a criterion for death, brain death has not been universally accepted by bioethicists, by the medical community, or by the public. I this paper, I defend brain death as a biological concept. I challenge two assumptions in the brain death literature that have shaped the debate and have stood in the way of an argument for brain death as biological. First, I challenge the dualism established in the debate between the body and the brain. Second, I contest the emphasis on consciousness, which prevents the inclusion of psychological phenomena into a biological criterion of death. I propose that the term organism should apply both to the functioning of the body and the brain. I argue that the cessation of the organism as a whole should take into account three elements of integrated function. Those three elements are: 1) the loss of integrated bodily function; 2) the loss of psychophysical integration required for processing of external stimuli and those required for behavior; and, 3) the loss of integrated psychological function, such as memory, learning, attention, and so forth. The loss of those three elements of integrated function is death.