For the past two decades, the medical profession and society have debated the definition of death. Some reasonable consensus has been reached on this issue, in theory and in practice. In the last few years, however, a far more important debate has been evolving — the definition of human personhood. Human personhood has been discussed extensively in the past with respect to the abortion question and other issues concerning the beginning of life. More recently, however, the definition of personhood has been raised with respect to termination of treatment decisions at the end of life and, in particular, on the appropriate care of patients in a persistent vegetative state.Our major premise is that consciousness is the most critical moral, legal, and constitutional standard, not for human life itself, but for human personhood. There is nothing highly original in our approach to this particular issue; others have advanced similar arguments in recent years.