Understanding Brain Death
Until 30 years ago it was breathing and heartbeat which were taken to signify the continued life of a human being, and it was the permanent cessation of these activities which were taken to constitute human death. However various medical advances throughout the 1950s and 1960s altered the perceived significance of these signs. Recovery from cardiac arrest became more common; mechanical ventilation assisted those not able to breathe spontaneously. Then on December 3rd 1967, the first successful heart transplant was carried out on a human being. The heart seemed not to be irreplaceable after all. Further, if machines could substitute for the function of the heart or the lungs then these organs could not themselves constitute human life. Only the brain seemed irreplaceable in this way; so criteria for death shifted from referring to heart and lungs to referring to the brain. (The author gratefully acknowledges the encouragement of Prof. Elisabeth Anscombe and Dr. D.W. Evans and the comments of David Braine and Helen Watt on earlier drafts of this article. Also especially helpful was P. McCullagh Brain Dead, Brain Absent, Brain Donors (1993), John Wiley and Sons Ltd., both for clarity concerning the issues involved and for many empirical details.)
In 1968 an ad hoc committee of Harvard Medical School proposed a new definition of death, related not to heart or lung activity but to brain activity1. In 1970 the State of Kansas enacted legislation giving legal status to the notion of "brain-death" by which was meant, death pronounced on the basis of loss of brain function2. This legislation was criticised by Capron and Kass in 1972 who proposed an alternative statute3. In 1981 a U.S. President's commission produced a proposal for a Uniform Determination of Death Act4. Subsequently, each state enacted legislation based on the Capron-Kass proposal, the President's commission or some version of their own.