 A final assumption underlying the mainstream discussion of the definition of death is that human death is a morally crucial marker. Were it not, then accuracy in the definition of death would be of purely ontological, conceptual, or scientific interest. This attitude, of course, is not the prevailing one. Not only do we tend to regard many behaviors as appropriate only if an individual has died; the criminal law treats as momentous the question of whether one person has killed—that is, caused the death of—another person, even if such considerations as motive, deliberation, and special circumstances are also important.