Recently both whole brain death (WBD) and higher brain death (HBD) have come under attack. These attacks, we argue, are successful, leaving supporters of both views without a firm foundation. This state of affairs has been described as “the death of brain death.” Returning to a cardiopulmonary definition presents problems we also find unacceptable. Instead, we attempt to revive brain death by offering a novel and more coherent standard of death based on the permanent cessation of mental processing. This approach (...) works, we claim, by being functionalist instead of being based in biology, consciousness, or personhood. We begin by explaining why an objective biological determination of death fails. We continue by similarly rejecting current arguments offered in support of HBD, which rely on consciousness and/or personhood. In the final section, we explain and defend our functionalist view of death. Our definition centers on mental processing, both conscious and preconscious or unconscious. This view provides the philosophical basis of a functional definition that most accurately reflects the original spirit of brain death when first proposed in the Harvard criteria of 1968. (shrink)