“Brain death,” the determination of human death by showing the irreversible loss of all clinical functions of the brain, has become a worldwide practice. A biophilosophical account of brain death requires four sequential tasks: agreeing on the paradigm of death, a set of preconditions that frame the discussion; determining the definition of death by making explicit the consensual concept of death; determining the criterion of death that proves the definition has been fulfilled by being both necessary and sufficient for death; (...) and determining the tests of death for physicians to employ at the patient's bedside to demonstrate that the criterion of death has been fulfilled. The best definition of death is “the cessation of functioning of the organism as a whole.” The whole-brain criterion is the only criterion that is both necessary and sufficient for death. Brain death tests are used only in the unusual case in which a patient's ventilation is being supported. Brain death critics have identified weaknesses in its formulation. But despite its shortcomings, the whole-brain death formulation comprises a concept and public policy that make intuitive and practical sense and that has been well accepted by many societies. (shrink)