Total brain death is a valid criterion for pronouncing the death of human beings.

Total Brain Death: 

Valid Criterion of Death

by Patrick Lee and Germain Grisez 

Total brain death--the complete and irreversible cessation of functioning of all parts of the brain--has been widely accepted in ethics and law as a valid criterion for pronouncing the death of a human being. But in the last fifteen years, some philosophers and neurologists have advanced arguments that challenge this criterion. D. Alan Shewmon, a neurologist from UCLA, has advanced the strongest case so far. In our judgment, Shewmon has shown the unsoundness of the usual argument for the total brain death criterion, but we think--on different grounds than the standard rationale--that the criterion is a valid one for death.

The usual argument for the total brain death criterion has been that, once a human individual's brain has developed, it is the primary integrator of all the body's tissues and organs into a single organism. It seems to follow that, when all parts of the brain irreversibly cease to function, what remains is no longer a single organism, but an aggregate of tissues and organs.

However, Shewmon presents what appear to be counter-examples that disprove this criterion. Shewmon's evidence seems to show that some individuals have survived total brain death. In such cases, there are many functions that seem to belong to the individual as a whole. Among these are: homeostasis of a variety of mutually interacting chemicals and physiological parameters, detoxification and recycling of cellular wastes throughout the body, maintenance of body temperature (albeit at a lower than normal level), wound healing, and, of course, respiration and nutrition (though assisted). Shewmon describes an individual called "TK" who continued to manifest all those functions for more than twenty years, even as total brain death was confirmed by repeated clinical tests.

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