Dissertation, University of Oxford (
2016)
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Abstract
For hundreds of years, death had been defined by cardiopulmonary criteria. When heart and respiratory functions were permanently absent, doctors declared their patients dead. Three developments in intensive care medicine called into question these widely-accepted criteria, however: the advent of positive pressure ventilation and the promotion of cardiopulmonary resuscitation, both in the early 1950s, and the first successful heart transplantation in 1967. What had previously been diagnosed as the permanent absence of vital functions, suddenly became reversible. Not only could doctors replace a defective heart with a functioning transplant; patients could also be kept oxygenated in the total absence of spontaneous respiratory function. The traditional boundaries between life and death became blurred. Patients for whom there was not the remotest possibility of regaining consciousness following massive brain damage continued to consume valuable medical resources. Moreover, their organs could not be procured for transplantation. Were those patients still alive or could the ventilators be switched off? A criterion suited to indicate a patient’s death despite the provision of external life support was needed. In 1968 an ad hoc committee of the Harvard Medical School published the first comprehensive definition of what would soon become the new clinical standard: brain death. The brain bears a special relation to other organs; it directs bodily functions without carrying them out. When the brain is destroyed, it was argued, this control mechanism is irreversibly dysfunctional, so that the organism becomes unable to maintain its vital functions, loses its somatic unity and, consequently, ceases to exist. This neurological criterion has been controversial ever since its introduction. Whether brain death is indeed death is what I shall be investigating in this thesis. I will be asking three main questions: What are we? Is brain death the death of an organism? Is brain death the death of a psychological being? The question of personal identity and the question of the appropriate definition of death are intimately related. Only when we have determined what kind of entity we essentially are can we specify what conditions must apply for this entity to persist or to cease to exist. I shall argue that we are essentially psychological beings, which entails that our death is distinct from the death of our organisms. Hence, we need two different criteria – one for the death of each entity. I shall try to establish whether brainstem death and whole-brain death correspond to the irreversible cessation of organismic functioning. I will then determine by which criterion the death of a psychological being can be diagnosed.