Most philosophers writing about personal identity in recent years claim that what it takes for us to persist through time is a matter of psychology. In this groundbreaking new book, Eric Olson argues that such approaches face daunting problems, and he defends in their place a radically non-psychological account of personal identity. He defines human beings as biological organisms, and claims that no psychological relation is either sufficient or necessary for an organism to persist. Olson rejects several famous thought-experiments dealing (...) with personal identity. He argues, instead, that one could survive the destruction of all of one's psychological contents and capabilities as long as the human organism remains alive--as long as its vital functions, such as breathing, circulation, and metabolism, continue. (shrink)

According to Peter van Inwagen, visible inanimate objects do not, strictly speaking, exist. In defending this controversial thesis, he offers fresh insights on such topics as personal identity, commonsense belief, existence over time, the phenomenon of vagueness, and the relation between metaphysics and ordinary language.

Biological theory demands a clear organism concept, but at present biologists cannot agree on one. They know that counting particular units, and not counting others, allows them to generate explanatory and predictive descriptions of evolutionary processes. Yet they lack a unified theory telling them which units to count. In this paper, I offer a novel account of biological individuality, which reconciles conflicting definitions of ‘organism’ by interpreting them as describing alternative realisers of a common functional role, and then defines individual (...) organisms as essentially possessing some mechanisms that play this role. (shrink)

Conjoined twinning is said to show that the number of human people—the number of us—can differ from the number of human organisms, and hence that we are not organisms. The paper shows that these arguments either assume the point at issue, rely on dubious and undefended assumptions, or add nothing to more familiar arguments for the same conclusion.

We defend the view that we are not identical to organisms against the objection that it implies that there are two subjects of every conscious state one experiences: oneself and one’s organism. We then criticize animalism —the view that each of us is identical to a human organism—by showing that it has unacceptable implications for a range of actual and hypothetical cases of conjoined twinning : dicephalus, craniopagus parasiticus, and cephalopagus.

So-called Locke's thesis is the view that no two things of the same kind may coincide, that is, may be completely in the same place at the same time. A number of counter-examples to this view have been proposed. In this paper, some new and arguably more convincing counter-examples to Locke's thesis are presented. In these counter-examples, a particular entity (a string, a rope, a net, or similar) is interwoven to obtain what appears to be a distinct, thicker entity of (...) the same kind. It is argued that anyone who subscribes to certain standard metaphysical arguments, which are generally taken for granted in the debate about Locke's thesis, is virtually compelled to accept the counter-examples. (shrink)

It is not easy to be a materialist and yet believe that there is a way for human beings to survive death. Peter van Inwagen identifies the central obstacle the materialist faces: Namely, the need to posit appropriate “immanent-causal” connections between my body as it is at death and some living body elsewhere or elsewhen. I offer a proposal, consistent with van Inwagen’s own materialist metaphysics, for making materialism compatible with the possibility of survival.

The question “What is an organism?”, formerly considered as essential in biology, has now been increasingly replaced by a larger question, “What is a biological individual?”. On the grounds that i) individuation is theory-dependent, and ii) physiology does not offer a theory, biologists and philosophers of biology have claimed that it is the theory of evolution by natural selection which tells us what counts as a biological individual. Here I show that one physiological field, immunology, offers a theory, which makes (...) possible a biological individuation based on physiological grounds. I give a new answer to the question of the individuation of an organism by linking together the evolutionary and the immunological approaches to biological individuation. (shrink)

A property, F, is maximal iff, roughly, large parts of an F are not themselves Fs.' Maximality makes trouble for a recent analysis of intrinsicality by Rae Langton and David Lewis.

The Standard View of personal identity says that someone who exists now can exist at another time only if there is continuity of her mental contents or capacities. But no person is psychologically continuous with a fetus, for a fetus, at least early in its career, has no mental features at all. So the Standard View entails that no person was ever a fetus--contrary to the popular assumption that an unthinking fetus is a potential person. It is also mysterious what (...) does ordinarily happen to a human fetus, if it does not come to be a person. Although an extremely complex variant of the Standard View may allow one to persist without psychological continuity before one becomes a person but not afterwards, a far simpler solution is to accept a radically non-psychological account of our identity. (shrink)

Both advocates and opponents of the animalist view that we are fundamentally biological organisms have typically assumed that animalism is incompatible with intuitive verdicts about cerebrum isolation and transplantation. It is argued here that this assumption is a mistake. Animalism, developed in a natural way, in fact strongly supports these intuitive verdicts. The availability of this attractive resolution of a central puzzle in the personal identity debate has been obscured by a range of factors, including the prevalence in contemporary metaphysics (...) of a certain conception of the nature of organisms. I end by explaining how the animalist can use intuitive verdicts, usually thought to present a difficulty for the view, as positive evidence for claims about the persistence conditions of the relevant kind of organism. (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)

In The Human Animal I argued that we are animals, and that those animals do not persist by virtue of any sort of psychological continuity. Rather, personal identity in this sense consists in having the same biological life. And I said that a human life requires a functioning brainstem. Rina Tzinman takes this and other remarks to imply that personal identity consists in the continued functioning of the brainstem, which looks clearly false. I say it doesn’t follow. But Alan Shewmon (...) appears to have refuted my claim about the brainstem. (shrink)

What kind of thing are we? Paul Snowdon's answer is that we are animals, of a sort. This view--'animalism'--may seem obvious but on the whole philosophers have rejected it. Snowdon argues that animalism is a defensible way of thinking about ourselves. Its rejection rests on the tendency when doing philosophy to mistake fantasy for reality.

What are you and I essentially? When do you and I come into and go out of existence? A common response is that we are essentially organisms, that is, we come into existence as organisms and go out of existence when we cease to be organisms. Jeff McMahan has put forward two arguments against the Organism View: the case of dicephalus and a special case of hemispheric commissurotomy. In this paper, I defend the Organism View against these two cases. Because (...) it is possible to devise more McMahanian-type cases, I also provide a more general solution to these kinds of cases. (shrink)

Darwin’s classic ‘Origin of Species’ (Darwin 1859) described forces of selection acting upon individuals, but there remains a great deal of controversy about what exactly the status and definition of a biological individual is. Recently some authors have argued that the individual is dispensable – that an inability to pin it down is not problematic because little rests on it anyway. The aim of this paper is to show that there is a real problem of biological individuality, and an urgent (...) need to arbitrate over the current plethora of solutions to it. (shrink)

We address three fundamental questions: What does it mean for an entity to be living? What is the role of inter-organismic collaboration in evolution? What is a biological individual? Our central argument is that life arises when lineage-forming entities collaborate in metabolism. By conceiving of metabolism as a collaborative process performed by functional wholes, which are associations of a variety of lineage-forming entities, we avoid the standard tension between reproduction and metabolism in discussions of life – a tension particularly evident (...) in discussions of whether viruses are alive. Our perspective assumes no sharp distinction between life and non-life, and does not equate life exclusively with cellular or organismal status. We reach this conclusion through an analysis of the capabilities of a spectrum of biological entities, in which we include the pivotal case of viruses as well as prions, plasmids, organelles, intracellular and extracellular symbionts, unicellular and multicellular life-forms. The usual criterion for classifying many of the entities of our continuum as non-living is autonomy. This emphasis on autonomy is problematic, however, because even paradigmatic biological individuals, such as large animals, are dependent on symbiotic associations with many other organisms. These composite individuals constitute the metabolic wholes on which selection acts. Finally, our account treats cooperation and competition not as polar opposites but as points on a continuum of collaboration. We suggest that competitive relations are a transitional state, with multi-lineage metabolic wholes eventually outcompeting selfish competitors, and that this process sometimes leads to the emergence of new types or levels of wholes. Our view of life as a continuum of variably structured collaborative systems leaves open the possibility that a variety of forms of organized matter – from chemical systems to ecosystems – might be usefully understood as living entities. (shrink)