Harold Noonan

In Part IV of Book I of Hume’s Treatise Hume frequently appeals to an identity-ascribing mechanism of the imagination. A psychological mechanism of which it is a special case, to ‘compleat the union’, is also prominent. These mechanisms belong to the imagination narrowly conceived according to a distinction in section ix of Part III. The role and significance of these mechanisms in the development of Hume’s scepticism is explored. Appreciation of their significance is also argued to cast light on Hume’s refusal to locate necessity in objects and to suggest a plausible explanation of his second thoughts about personal identity

What am I? And what is my relationship to the thing I call ‘my body’? Thus each of us can pose for himself the philosophical problems of the nature of the self and the relationship between a person and his body. One answer to the question about the relationship between a person and the thing he calls ‘his body’ is that they are two things composed of the same matter at the same time (like a clay statue and the piece of clay which presently constitutes it). This is the ‘constitution view’. In this paper we give a novel overview of the literature on personal identity, the constitution view, and surrounding topics.

Can identity itself be vague? Can there be vague objects? Does a positive answer to either question entail a positive answer to the other? In this paper we answer these questions as follows: No, No, and Yes. First, we discuss Evans’s famous 1978 argument and argue that the main lesson that it imparts is that identity itself cannot be vague. We defend the argument from objections and endorse this conclusion. We acknowledge, however, that the argument does not by itself establish either that there cannot be vague objects or that there cannot be identity statements that are indeterminate for ontic reasons. And we further acknowledge that it does not by itself establish that there cannot be identity statements that are indeterminate in virtue of the existence of vague objects. We then go on to argue that, despite this, one who believes in vague objects cannot endorse Evans’s argument. To establish this we offer supplementary arguments that show that if vague objects exist then identity is vague, and that if identity is vague then vague objects exist. Finally we draw attention to an argument parallel to that of Evans’s, but safer, which can be employed against the putative ontic indeterminacy in identity of vague objects which can be differentiated by identity-free properties.

In Chapter 12 of his book Material Beings (Van Inwagen, Peter. 1990. Material Beings. Ithaca: Cornell University Press) van Inwagen argues that there are no artefacts, or very few, certainly fewer than most people believe. Artisans very rarely create, at least in the sense of causing things to come into existence. The argument in Chapter 12 is a very powerful one. I do not think that it establishes van Inwagen’s conclusion, but it does, I think, given its (plausible) premise, establish that if there are not far fewer material things in the world than we ordinarily believe, then there are far more. In this sense it establishes, as Russell once said, ‘the truth about physical objects must be strange’. Furthermore, I argue at the end, we cannot avoid this conclusion even if we reject van Inwagen’s premise. Thus the defender of our common sense ontology is caught on the horns of a dilemma. So our commonsense ontology is indefensible.

This chapter considers Geach's claims solely as pertaining to the philosophy of language and philosophical logic, though much of the interest of the concept of relative identity concerns its applicability to other areas: the metaphysical controversy about personal identity and the debate in philosophical theology on the doctrine of the Trinity. It describes Geach's views under six headings: the non‐existence of absolute identity; the sortal relativity of identity; the derelativization thesis; the counting thesis; the thesis of the irreducibility of restricted quantification; and the 'name for an A'/'name of an A' distinction. The sortal relativity thesis depends for its significance on the distinction between sortal terms and non‐sortal terms. An important component of Geach's position is his thesis that for any sortal term 'A' there is a distinction between restricted quantification over As and unrestricted quantification over things that are As.

Much of the debate about identity in recent decades has been about personal identity, and specifically about personal identity over time, but identity generally, and the identity of things of other kinds, have also attracted attention. Various interrelated problems have been at the centre of discussion, but it is fair to say that recent work has focussed particularly on the following areas: the notion of a criterion of identity; the correct analysis of identity over time, and, in particular, the disagreement between advocates of perdurance and advocates of endurance as analyses of identity over time; the notion of identity across possible worlds and the question of its relevance to the correct analysis of de re modal discourse; the notion of contingent identity; the question of whether the identity relation is, or is similar to, the composition relation; and the notion of vague identity. A radical position, advocated by Peter Geach, is that these debates, as usually conducted, are void for lack of a subject matter: the notion of absolute identity they presuppose has no application; there is only relative identity. Another increasingly popular view is the one advocated by Lewis: although the debates make sense they cannot genuinely be debates about identity, since there are no philosophical problems about identity. Identity is an utterly unproblematic notion. What there are, are genuine problems which can be stated using the language of identity. But since these can be restated without the language of identity they are not problems about identity. (For example, it is a puzzle, an aspect of the so-called “problem of personal identity”, whether the same person can have different bodies at different times. But this is just the puzzle whether a person can have different bodies at different times. So since it can be stated without the language of personal “identity”, it is not a problem about identity, but about personhood.) This article provides an overview of the topics indicated above, some assessment of the debates and suggestions for further reading.

According to genuine modal realism, some things (including numbers and properties) lack distinct counterparts in different worlds. So how can they possess any of their properties contingently? Egan (2004) argues that to explain such accidental property possession, the genuine modal realist must depart from Lewis and identify properties with functions, rather than with sets of possibilia. We disagree. The genuine modal realist already has the resources to handle Egan's proposed counterexamples. As we show, she does not need to amend her analysis of possibility statements, or her theory of what properties are

In Naming and Necessity Kripke introduces the concept of a rigid designator and argues that proper names are rigid designators. He argues that in this way they are different from typical definite descriptions (though he allows that some definite descriptions, e.g., ‘the actual winner of the lottery’, ‘the square of 3’, are rigid designators). His opponents have either argued that names can be regarded as abbreviations of rigid descriptions (e.g., ‘actualized’ ones) or have tried to deny that names are rigid designators. I shall argue that no unambiguous descriptions are non-rigid. All unambiguous descriptions are rigid. The appearance of non-rigidity in descriptions is simply an illusion, a manifestation of ambiguity. I shall then go on to show that an explanation of the difficulty which has been found in extending the rigid/non-rigid distinction from singular terms to predicates follows.

Jacob Ross argues that the fission cases discussed in the personal identity literature cannot be accommodated without rejecting basic intuitions of everyday ethical thinking. He notes that many philosophers have responded to the challenge of fission ‘by rejecting the metaphysical assumptions on which it rests’. In particular, that many have denied that in fission one ceases to exist. He contends that these denials do not meet the challenge to commonsense ethical thinking. I reject these claims. One of the metaphysical views he considers is the multiple occupancy view of Lewis and Robinson, according to which in fission there are all along two numerically distinct, initially collocated, persons. I claim that Ross has not shown that this view has counterintuitive ethical implications.