Online research in philosophy

Theories of personal identity try to explain what the identity of a person necessarily consists in, but frequently leave open what kind of necessity is at issue. This paper is concerned with conceptual necessity. It proposes an analysis of the concept of personal identity in terms of a definite description. The analysis coheres with out judgments about clear cases and explains why cases of division seem indeterminate. The apparent indeterminacy results from attempting to apply a definite description to a situation in which more than one object would satisfy the description. The definite description analysis also explains the strengths of the influential no-branching theory, while avoiding the problems with that view. The no-branching theory is in effect a second-order analysis, i.e., a combination of the definite description analysis of personal identity plus a Russellian analysis of the definite description.

Abstract In Reasons and Persons, Derek Parfit argues that personal identity is indeterminate and that identity is not what matters in personal survival. Parfit argues that traditional views of personal identity have counterintuitive consequences and that they violate a plausible requirement, suggested by Bernard Williams, that must be met by any acceptable criterion of identity. Parfit argues that, unlike traditional determinate views of personal identity, his view succeeds in accommodating intuitions and in meeting (an analogue to) Williams' requirement. I argue that Parfit's view has more counterintuitive consequences than do the traditional views of identity. Though the traditional views do seem to violate Williams' requirement, Parfit's view fares no better. In fact, it seems that any theory of personal survival that appeals to connections that may hold to a greater or lesser extent will fail to meet the relevant requirement. This is an important general point, since the requirement is a plausible one.

Olson (1997a) tries to refute the Psychological Approach to personal identity with his Fetus Argument, and Mackie (1999) aims to do the same with the Death Argument. With the help of a suggestion made by Baker (1999), the following discussion shows that these arguments fail. In the process of defending the Psychological Approach, it is made clear exactly what one is and is not committed to as a proponent of the theory.

What is the self? And how does it relate to the body? In the second edition of Personal Identity, Harold Noonan presents the major historical theories of personal identity, particularly those of Locke, Leibniz, Butler, Reid and Hume. Noonan goes on to give a careful analysis of what the problem of personal identity is, and its place in the context of more general puzzles about identity. He then moves on to consider the main issues and arguments which are the subject of current debate, including the work of Bernard Williams and Derek Parfit, and makes new and challenging interpretations of them. This new edition contains additional material assessing the biological approach which has become increasingly popular in recent years, and extends the treatment of indeterminate identity to take account of the epistemic view of vagueness. This book covers the problem of personal identity from its origin in Locke's work to the most recent debates in the philosophical literature, and will be invaluablereading for any student of the topic.

In this paper, I compare John Locke’s “memory theory” of personal identity and Memento (directed by Christopher Nolan). I argue that the plot of Memento is ambiguous, in that the main character (Leonard Shelby, played by Guy Pearce) seems to have two histories. As such, Memento is but a series of puzzle cases that intend to illustrate that, although our memories may not be chronologically related to one another, and may even be fused with the memories of other persons, those memories still constitute personal identity. Just as Derek Parfit argues, perhaps there is no personal identity as such, since only survival (in some degree) matters to us. In Memento, Leonard Shelby is not identity to his former self, but survives to some extent.

This thesis gives an overview of the topic of personal identity from a philosophical viewpoint, describing both numerical and qualitative aspects. Reductionist approaches to numerical identity, such as the neo-Lockean psychological continuity theory of Derek Parfit or the physical criterion theory of Bernard Williams, are subject to a discussion. Apart from some significant criticisms in detail, there is the more general problem that they appear to imply a kind of neo-dualism. As a consequence, the author suggests a holistic approach to numerical personal identity which is more in accord with our times, placing the body firmly at the center of focus. The section on qualitative identity aims to develop a more complex theory of psychological continuity and continuity per se than that generally found in the literature. The suggestion is made that the most viable way to bring together the various strands of personal identity, both numerical and qualitative, is a concept of narrativity. Narratives are both indicative of and constitutive of personal identity.

In this paper I shall argue that if the Parfitian psychological criterion or theory of personal identity is true, then a good case can be made out to show that the psychological theorist should accept the view I call “psychological sequentialism”. This is the view that a causal connection is not necessary for what matters in survival, as long as certain other conditions are met. I argue this by way of Parfit’s own principle that what matters in survival cannot depend upon a trivial fact.

In this paper, I attempt to map out the 'logical geography' of the territory in which issues of mental content and of personal identity meet. In particular, I investigate the possibility of combining a psychological criterion of personal identity with an externalist theory of content. I argue that this can be done, but only by accepting an assumption that has been widely accepted but barely argued for, namely that when someone switches linguistic communities, the contents of their thoughts do not change immediately, but only after the person becomes integrated within the new linguistic community. I also suggest that recent work on personal identity, notably by Derek Parfit, has tacitly assumed internalism regarding mental content. I do not intend to argue for either externalism or a psychological criterion. My aim is merely to explicate the issues involved in making them compatible.

This paper's ?I examines Derek Parfit's main, metaphysical, argument for reductionism about personal identity. ?II considers three possible ethical arguments for reductionism, and suggests a new approach to the question of what matters about personal identity which has to do with the notion of an ethical narrative.

The central claim of the Parfitian psychological approach to personal identity is that the fact about personal identity is underpinned by a non-branching psychological continuity relation. Hence, for the advocates of the Parfitian view, it is important to understand what it is for a relation to take or not take a branching form. Nonetheless, very few attempts have been made in the literature of personal identity to define the non-branching clause. This paper undertakes this task. Drawing upon a recent debate between Anthony Brueckner and Harold Noonan on the issue, I present three candidates for the non-branching clause.