Consciousness is a mongrel concept: there are a number of very different "consciousnesses." Phenomenal consciousness is experience; the phenomenally conscious aspect of a state is what it is like to be in that state. The mark of access-consciousness, by contrast, is availability for use in reasoning and rationally guiding speech and action. These concepts are often partly or totally conflated, with bad results. This target article uses as an example a form of reasoning about a function of "consciousness" based on (...) the phenomenon of blindsight. Some information about stimuli in the blind field is represented in the brains of blindsight patients, as shown by their correct "guesses," but they cannot harness this information in the service of action, and this is said to show that a function of phenomenal consciousness is somehow to enable information represented in the brain to guide action. But stimuli in the blind field are BOTH access-unconscious and phenomenally unconscious. The fallacy is: an obvious function of the machinery of access-consciousness is illicitly transferred to phenomenal consciousness. (shrink)

The mainstream rationale for equating brain death (BD) with death is that the brain confers integrative unity upon the body, transforming it from a mere collection of organs and tissues to an organism as a whole. In support of this conclusion, the impressive list of the brains myriad integrative functions is often cited. Upon closer examination, and after operational definition of terms, however, one discovers that most integrative functions of the brain are actually not somatically integrating, and, conversely, most integrative (...) functions of the body are not brain-mediated. With respect to organism-level vitality, the brains role is more modulatory than constitutive, enhancing the quality and survival potential of a presupposedly living organism. Integrative unity of a complex organism is an inherently nonlocalizable, holistic feature involving the mutual interaction among all the parts, not a top-down coordination imposed by one part upon a passive multiplicity of other parts. Loss of somatic integrative unity is not a physiologically tenable rationale for equating BD with death of the organism as a whole. (shrink)

The concept of whole‐brain death is under attack again. Scholars are arguing that the concept of brain death per se—regardless of the focus on “higher,” “stem” or “whole”—is fundamentally flawed. These scholars have identified what they believe are serious discrepancies between the definition and criterion of brain death, and have pointed out that medical professionals and lay persons remain confused about its meaning. Yet whole‐brain death remains the standard for determining death in much of the Western world and its defenders (...) believe this concept best maps onto our everyday conception of death. (shrink)

“Brain death,” the determination of human death by showing the irreversible loss of all clinical functions of the brain, has become a worldwide practice. A biophilosophical account of brain death requires four sequential tasks: agreeing on the paradigm of death, a set of preconditions that frame the discussion; determining the definition of death by making explicit the consensual concept of death; determining the criterion of death that proves the definition has been fulfilled by being both necessary and sufficient for death; (...) and determining the tests of death for physicians to employ at the patient's bedside to demonstrate that the criterion of death has been fulfilled. The best definition of death is “the cessation of functioning of the organism as a whole.” The whole-brain criterion is the only criterion that is both necessary and sufficient for death. Brain death tests are used only in the unusual case in which a patient's ventilation is being supported. Brain death critics have identified weaknesses in its formulation. But despite its shortcomings, the whole-brain death formulation comprises a concept and public policy that make intuitive and practical sense and that has been well accepted by many societies. (shrink)

Most of the world now accepts the idea, first proposed four decades ago, that death means “brain death.” But the idea has always been open to criticism because it doesn't square with all of our intuitions about death. In fact, none of the possible definitions of death quite works. Death, perhaps surprisingly, eludes definition, and “brain death” can be accepted only as a refinement of what is in fact a fuzzy concept.

The whole brain-death criterion of death now enjoys a wide acceptance both within the medical profession and among the general public. That acceptance is in large part the product of the contention that brain death is the proper criterion for even a conservative definition of death – the irreversible loss of the integrated functioning of the organism as a whole. This claim – most recently made in the report of the Presidential Commission and in a comprehensive article by James Bernat (...) and others – is based upon a series of fallacious arguments. Chief among these is the argument that whole brain-death is the proper criterion for the conservative definition because the brain is the organ that integrates the rest of the organism. A central part of the paper shows that this argument rests upon a confusion between a function and the mechanism that performs it, and replies to the defenses that the Presidential Commission makes on this point. The concluding portion of the paper argues that this issue is not merely of academic interest, but has the potential for undermining the present consensus that supports the use of whole brain-death criteria. * Keywords: brain-death, definition of death, determination of death * I would like to thank Howard Brody and Bruce Miller for helpful suggestions and criticisms. CiteULike Connotea Del.icio.us What's this? (shrink)