The Multi-Society Task Force (MSTF) on Persistent Vegetative State (PVS) recently released a landmark two-part consensus statement entitled "Medical Aspects of the Persistent Vegetative State," which, in 1994, was published in the New England Journal of Medicine.(1) This statement was approved by the governing bodies of several medical societies, including the American Academy of Neurology, American Neurological Association, American Association of Neurological Surgeons, and Child Neurology Society.
Those who contributed to the drafting of this important document included, among others, an impressive group of neurologists, pediatricians, and neurosurgeons, several of whom have been on the forefront of discussions in the contemporary medical ethics literature concerning the metaphysical and moral status of PVS patients.(2) In spite of their impressive medical credentials, though, and in spite of their many influential contributions to contemporary philosophical and neurological discussions concerning this condition, their present collective effort makes me quite uneasy. The primary source of this unease can be traced to the MSTF's conceptually misshapen defense of the thesis that all PVS patients are unconscious. The MSTF's defense of this thesis is defective in at least two ways. First, the MSTF fails convincingly to motivate the conceptual propriety of utilizing the particular characterization of (un)consciousness that it has, in fact, chosen to employ in this domain. I shall argue, in fact, that the MSTF commits itself to a conception of (un)consciousness that is conceptually incoherent. Second, I shall argue that even if the MSTF were to adopt a coherent and plausible conception of consciousness (and of cognition more generally construed), it has thus far given us no good reason to think that all PVS patients lack consciousness so construed. I further argue that a careful, rigorous analysis of (un)consciousness in the context of this discussion promises to yield those conceptual tools necessary for more precisely delineating the boundary between PVS and the locked-in state, as well as for properly situating akinetic mutism and other intermediate disorders of consciousness on the cognitive continuum that spans the chasm between those paradigmatic states which occupy the polar positions on this continuum.
The perceived dispensability of PVS patients, as portrayed in several recent essays in the medical ethics literature,(3) is typically predicated on the allegedly well-grounded conjecture that all PVS patients are cognitively quiescent. The widespread acceptance of this claim in conjunction with the (to my mind, mistaken) view that to be a live human being is, essentially, to be a member of a specific biological kind which instantiates certain specific, functionally intact, highly complex neuroarchitectural structures, has tempted several thinkers to deny that PVS patients are persons toward whom charity can be properly directed or, in more extreme cases, to deny that PVS patients are live human beings at all.(4) This process of dehumanization has profound, deeply troubling ethical implications-implications regarding which the MSTF is at best neutral and at worst complicit.
What Are the Medical Facts?
The MSTF views itself as simply summarizing "the medical facts about the persistent vegetative state," insisting that "it does not address associated ethical, legal, or other issues."(5) This disclaimer is misleading. In fact, many of the alleged "medical facts" that the MSTF claims to be summarizing really are pieces of quite complex, contentious, and conceptually subtle philosophy. One cannot help but be engaging in a philosophical activity when dealing reflectively with such matters as consciousness, evidence, purposiveness, awareness, irreversibility, and the self.
The MSTF begins its consensus statement by pointing out that "[t]he term `persistent vegetative state' was coined by [Bryan] Jennett and [Fred] Plum in 1972 to describe the condition of patients with severe brain damage in whom coma has progressed to a state of wakefulness without detectable awareness. …