A key to modern studies of 18th century Western philosophy, the Treatise considers numerous classic philosophical issues, including causation, existence, freedom and necessity and morality. This abridged edition has an introduction which explain's Hume's thought and places it in the context of its times.

Marya Schechtman takes issue with analytic philosophy's emphasis on the first sort of question to the exclusion of the second.

Derek Parfit’s argument against the platitude that identity is what matters in survival does not work given his intended reading of the platitude, namely, that what matters in survival to some future time is being identical with someone who is alive at that time. I develop Parfit’s argument so that it works against the platitude on this intended reading.

This book is a defense of modal realism; the thesis that our world is but one of a plurality of worlds, and that the individuals that inhabit our world are only a few out of all the inhabitants of all the worlds. Lewis argues that the philosophical utility of modal realism is a good reason for believing that it is true.

If a person, A, branches into B and C, then it is widely held that B and C are not identical to one another. Many think that this is because B and C have contradictory properties at the same time. In this paper, I show why this explanation cannot be right. I argue that contradictory properties at times are not necessary for non-identity between descendants, and that contradictory properties at times are not sufficient for non-identity. I also argue that the (...) standard explanation cannot be salvaged by a shift to personal time. Appeals to a lack of continuity, or to the absence of unity of consciousness likewise fail. Rather, B and C are non-identical simply because A branched into B and C. Why branching should be problematic for personal identity remains a deep puzzle though I offer some tentative suggestions. (shrink)

John Locke’s account of personal identity is usually thought to have been proved false by Thomas Reid’s simple ‘Gallant Officer’ argument. Locke is traditionally interpreted as holding that your having memories of a past person’s thoughts or actions is necessary and sufficient for your being identical to that person. This paper argues that the traditional memory interpretation of Locke’s account is mistaken and defends a memory continuity view according to which a sequence of overlapping memories is necessary and sufficient for (...) personal identity. On this view Locke is not vulnerable to the Gallant Officer argument. (shrink)

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. (shrink)

What does it mean to say that this person at this time is 'the same' as that person at an earlier time? If the brain is damaged or the memory lost, how far does a person's identity continue? In this book two eminent philosophers develop very different approaches to the problem.

Closest-continuer or best-candidate accounts of persistence seem deeply unsatisfactory, but it’s hard to say why. The standard criticism is that such accounts violate the ‘only a and b’ rule, but this criticism merely highlights a feature of the accounts without explaining why the feature is unacceptable. Another concern is that such accounts violate some principle about the supervenience of persistence facts upon local or intrinsic facts. But, again, we do not seem to have an independent justification for this supervenience claim. (...) Instead, I argue that closest continuer accounts are committed to unexplained correlations between distinct existences, and that this is their fundamental flaw. We can have independent justification for rejecting such correlations, but what the justification is depends upon much broader issues in ontology. There is no one-size-fits all objection to closest-continuer accounts of persistence. (shrink)

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)

Challenging, with several powerful arguments, some of our deepest beliefs about rationality, morality, and personal identity, Parfit claims that we have a false view about our own nature. It is often rational to act against our own best interersts, he argues, and most of us have moral views that are self-defeating. We often act wrongly, although we know there will be no one with serious grounds for complaint, and when we consider future generations it is very hard to avoid conclusions (...) that most of us will find very disturbing. (shrink)

The topic of personal identity has prompted some of the liveliest and most interesting debates in recent philosophy. In a fascinating new contribution to the discussion, Peter Unger presents a psychologically aimed, but physically based, account of our identity over time. While supporting the account, he explains why many influential contemporary philosophers have underrated the importance of physical continuity to our survival, casting a new light on the work of Lewis, Nagel, Nozick, Parfit, Perry, Shoemaker, and others. Deriving from his (...) discussion of our identity itself, Unger produces a novel but commonsensical theory of the relations between identity and some of our deepest concerns. In a conservative but flexible spirit, he explores the implications of his theory for questions of value and of the good life. (shrink)

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. (shrink)

Consider a specific type of fission where psychological continuity takes a branching form, and one of the offshoots comes into being later than the other offshoot. Let us say that the earlier offshoot comes into being in the left branch at t, and the later offshoot comes into being in the right branch at t+1. With regard to the question how many persons are involved in this case, three answers are worth considering: (i) The original subject persists up to t; (...) a distinct person comes into being immediately after t and continues to exist in the left branch; and the third person comes into being in the right branch at t+1. (ii) The original subject persists up to the moment immediately before t+1; a distinct person comes into being at t+1 and continues to exist in the left branch; and the third person comes into being in the right branch at t+1. (iii) The original subject continues to exist in the left branch; a distinct person comes into being in the right branch at t+1. For those who hold that personal identity consists in psychological continuity of some sort, the aforementioned three options exhaust the sensible ways of understanding how one persists in delayed fission. However, I argue that complications arise for each answer. Hence, delayed fission poses a challenge for the psychological approach to personal identity. (shrink)

An argument against the bias towards the near; how a defence of temporal neutrality is not a defence of S; an appeal to inconsistency; why we should reject S and accept CP.

Thomas Reid was a philosopher who founded the Scottish school of 'common sense'. Much of Reid's work is a critique of his contemporary, David Hume, whose empiricism he rejects. In this work, written after Reid's appointment to a professorship at the university of Glasgow, and published in 1785, he turns his attention to ideas about perception, memory, conception, abstraction, judgement, reasoning and taste. He examines the work of his predecessors and contemporaries, arguing that 'when we find philosophers maintaining that there (...) is no heat in the fire, nor colour in the rainbow … we may be apt to think the whole to be only a dream of fanciful men, who have entangled themselves in cobwebs spun out of their own brain'. Written by one of the Scottish Enlightenment's most important thinkers, this work brings to life the intellectual debates of the time. (shrink)

Can we understand what makes someone the same person without understanding what it is to be a person? Prereflectively we might not think so, but philosophers often accord these questions separate treatments, with personal-identity theorists claiming the first question and free-will theorists the second. Yet much of what is of interest to a person—the possibility of survival over time, compensation for past hardships, concern for future projects, or moral responsibility—is not obviously intelligible from the perspective of either question alone. Marya (...) Schechtman encourages us to adopt a more unified perspective. (shrink)

Any theory that analyses personal identity in terms of phenomenal continuity needs to deal with the ordinary interruptions of our consciousness that it is commonly thought that a person can survive. This is the bridge problem. The present paper offers a novel solution to the bridge problem based on the proposal that dreamless sleep need not interrupt phenomenal continuity. On this solution one can both hold that phenomenal continuity is necessary for personal identity and that persons can survive dreamless sleep.

Mentalistic (or Lockean) accounts of personal identity are normally formulated in terms of causal relations between psychological states such as beliefs, memories, and intentions. In this paper we develop an alternative (but still Lockean) account of personal identity, based on phenomenal relations between experiences. We begin by examining a notorious puzzle case due to Bernard Williams, and extract two lessons from it: first, that Williams's puzzle can be defused by distinguishing between the psychological and phenomenal approaches, second, that so far (...) as personal identity is concerned, it is phenomenal rather than psychological continuity that matters. We then consider different ways in which the phenomenal approach may be developed, and respond to a number of objections. That with which the consciousness of this present thinking thing can join itself, makes the same person, and is one self with it, and with nothing else; and so attributes to itself and owns all the actions of that thing, as its own, as far as that consciousness reaches, and no farther; as every one who reflects will perceive. Locke, Essay Concerning Human Understanding [II.xxvii.17]. (shrink)

Parfit's most controversial claim about personal identity is that personal identity does not matter in the way we uncritically think it does) I would like to analyze Parfit's reasons for making this claim. These reasons are complex, and they stand in some tension with one another. I would like to examine them carefully and to try to arrive at the strongest case that can be made for Parfit's controversial claim about what matters.

In this introduction to the special issue of Theoretical Medicine and Bioethics on the topic of personal identity and bioethics, I provide a background for the topic and then discuss the contributions in the special issue by Eric Olson, Marya Schechtman, Tim Campbell and Jeff McMahan, James Delaney and David Hershenov, and David DeGrazia.