Journal of Medicine and Philosophy 0360-5310/01/2605-457$16.002001, Vol. 26, No. 5, pp. 457±478#Swets & ZeitlingerThe Brain and Somatic Integration: Insights Intothe Standard Biological Rationale for Equating``Brain Death'' With DeathD. Alan ShewmonUniversity of California, Los Angeles, CaliforniaABSTRACTThe mainstream rationale for equating ``brain death'' (BD) with death is that the brain confersintegrative unity upon the body, transforming it from a mere collection of organs and tissues toan ``organism as a whole.'' In support of this conclusion, the impressive list of the brain'smyriad integrative functions is often cited. Upon closer examination, and after operationalde®nition of terms, however, one discovers that most integrative functions of the brain areactually not somatically integrating, and, conversely, most integrative functions of the body arenot brain-mediated. With respect to organism-level vitality, the brain's role is more modulatorythan constitutive, enhancing the quality and survival potential of a presupposedly livingorganism. Integrative unity of a complex organism is an inherently nonlocalizable, holisticfeature involving the mutual interaction among all the parts, not a top-down coordinationimposed by one part upon a passive multiplicity of other parts. Loss of somatic integrative unityis not a physiologically tenable rationale for equating BD with death of the organism as a whole.Key words: brain death, death, somatic integration, organism, unityI. INTRODUCTION``Brain death'' (BD)1is generally regarded as one of the few relatively settledissues of contemporary bioethics (Bernat, 1994, p. 115). Such consensus,however, remains at the level of statutory law and clinical praxis, while theconceptual basis for equating a dead brain with a dead human individualCorrespondence: D. Alan Shewmon, M.D., Professor of Pediatric Neurology, MDCC 22-474,UCLA Medical School, Box 951752, Los Angeles, CA 90095-1752, USA. E-mail:[email protected] as confused and controversial today as ever (Evers & Byrne, 1990;Halevy & Brody, 1993; Shewmon, 1992, 1997, 1998a, 1998b, 1999; Stapen-horst, 1996; Taylor, 1997; Tomlinson, 1990; Truog, 1997; Veatch, 1993;Youngner, 1994; Youngner et al., 1989).The concepts of death variously proposed as instantiated by BD fall intothree main categories:1. Essentially biological, predicated of the ``organism as a whole'' by virtueof loss of somatic integrative unity, and species-nonspeci®c (Bernat, 1984;Bernat, 1994; Bernat et al., 1981; Gert, 1995; Korein, 1978; Lamb, 1985;President's Commission, 1981; Swedish Committee, 1984; White et al.,1992),2. Essentially psychological, predicated of the human person (equated withmind) by virtue of irreversible loss of consciousness, and species-speci®c(Cranford & Smith, 1987; Lizza, 1993; Machado, 1995; Veatch, 1993;Zaner, 1988), and3. Essentially sociological, predicated of legal persons by virtue of cessationof societally conferred membership in the human community, and culture-speci®c(Beecher& Dorr, 1971;Dworkin,1973; Lachs, 1988; Pernick, 1988).The ®rst category can justi®ably be regarded as the ``standard,'' ``of®cial,'' or``orthodox'' rationale for BD. By contrast, the ``loss of personhood'' and ``lossof social membership'' rationales, despite eloquent argumentation by indivi-dual proponents, have not been formally endorsed by any large-scale medical,legal, philosophical, or religious group.This paper focuses exclusively on the ``orthodox,'' biological rationale ±speci®cally, the notion of ``somatic integrative unity'' or ``integrated function-ing of the organism as a whole'' and the empirical evidence for its purporteddependence on the coordinating activity of the brain. Despite its intuitiveappeal and the illustriousness of proponents, this explanation for why death ofthis particular organ should be equated with death of the entire organism hasachieved much less universal acceptance than that equation itself. Signi®cantly,the integrative-unity rationale was not introduced and promoted on a large scaleuntil as late as 1981 (with the President's Commission report and the seminalarticle of Bernat and colleagues (1981)), long after the neurological reformula-tion of death had already become ®rmly established in medical and legal praxis.Both before and after that signal year, the integrative-unity argument hasbeen rejected (at least implicitly) by not a few experts (Beecher & Dorr, 1971;Byrne et al., 1982/83; Evans & Lum, 1986; Wolstenholme & O'Connor, 1966;458D. ALAN SHEWMONYoungner & Bartlett, 1983). Moreover, despite several decades of pedagogicaleffort on the part of of®cial medicine, many health care professionals,including those involved in transplantation ± to say nothing of legislators,reporters and the lay public ± remain unconvinced, at least subliminally, thatBD is really death (Shewmon, 1992; Tomlinson, 1990; Youngner, 1994;Youngner et al., 1989). In recent years doubts concerning the validity andcoherence of BD orthodoxy have been raised by BD scholars with increasingfrequency and intensity (Byrne & Nilges, 1993; Danish Council, 1991; Evers& Byrne, 1990; Halevy & Brody, 1993; RodrõÂguez del Pozo, 1993; Shewmon,1997, 1998a, 1998b, 1999; Stapenhorst, 1996; Taylor, 1997; Truog, 1997;Veatch, 1993; Youngner, 1994).In this historical context, it is remarkable that both the American Academyof Neurology's recent practice parameter on BD (1995) and its companioncommentary (Wijdicks, 1995), which described in great detail how todiagnose that the brain is dead, devoted not a single word to explainingwhy this should mean that the patient is dead. Yet conceptual validity must beat least as important as diagnostic accuracy.Despite the vast number of published studies on BD, the empirical questionof whether or not a human body without brain function possesses integrativeunity has never been investigated with the methodological rigor typicallyapplied to similarly important but ethically more neutral scienti®c questions.(That is, beginning with careful operational de®nition of terms, followed byexamination of the physiological properties of actual BD bodies to seewhether they ful®ll those de®nitions.) This paper is intended as a step inthat direction.II. OPERATIONAL DEFINITION OF ``INTEGRATIVE UNITY''An adequate operational de®nition of ``integrative unity'' of an organism(synonymously, ``life of the organism as a whole''), in the spirit of theorthodox rationale, should