Book Information: Occasions of Identity: The Metaphysics of Persistence, Change, and Sameness. By André Gallois. Clarendon Press. Oxford. 1998. Pp. xiii + 296. Hardback, £35.00.

André Gallois’s Occasions of Identity injects a refreshing new perspective into an old debate. Actually, what is new is the advocacy of the perspective: Gallois takes up a view that many consider a non-starter, and shows this reaction to be premature. The debate is over the right way to understand the traditional puzzles involving two things being in the same place at the same time; the perspective is that identity can hold temporarily. Suppose an amoeba, name it AMOEBA, (...) divides in two. One of the resultant amoebas, POND, lives in a pond; the other, SLIDE, is examined on a slide in a laboratory. Does AMOEBA survive this process, and if so, does it survive as POND or SLIDE? If we stipulate that POND and SLIDE are symmetrically related to AMOEBA then it seems arbitrary to identify AMOEBA with exactly one of POND and SLIDE. But we cannot identify AMOEBA with each, for then by the transitivity and symmetry of identity we would wrongly identify POND and SLIDE. We are left with the conclusion that AMOEBA is identical to neither. But this seems wrong too; surely fission does not result in death. So just what does happen to AMOEBA? How to respond to this and related cases has been much discussed.1 There are many proposals, each with distinctive strengths and weaknesses. To these Gallois adds his own, which runs as follows. After division, there are two amoebas, POND and SLIDE, each of which existed before division. But it does not follow that there were two amoebas before division. Though POND and SLIDE are numerically distinct after division, they were numerically identical before division. The identity relation can hold temporarily, or occasionally, as Gallois puts it. My sense is that this sort of claim is regarded by most metaphysicians as downright wacky. And yet there is something very natural about it. Why distinguish POND and SLIDE today because they will differ tomorrow? I suspect the “wackiness” reaction has two sources, one based on Leibniz’s Law.. (shrink)

[Stephen Yablo] The usual charge against Carnap's internal/external distinction is one of 'guilt by association with analytic/synthetic'. But it can be freed of this association, to become the distinction between statements made within make-believe games and those made outside them-or, rather, a special case of it with some claim to be called the metaphorical/literal distinction. Not even Quine considers figurative speech committal, so this turns the tables somewhat. To determine our ontological commitments, we have to ferret out all traces of (...) nonliterality in our assertions; if there is no sensible project of doing that, there is no sensible project of Quinean ontology. /// [Andre Gallois] I discuss Steve Yablo's defence of Carnap's distinction between internal and external questions. In the first section I set out what I take that distinction, as Carnap draws it, to be, and spell out a central motivation Carnap has for invoking it. In the second section I endorse, and augment, Yablo's response to Quine's arguments against Carnap. In the third section I say why Carnap's application of the distinction between internal and external questions runs into trouble. In the fourth section I spell out what I take to be Yablo's version of Carnap. In the last I say why that version is especially vulnerable to the objection raised in the second. (shrink)

Occasions of Identity is an exploration of timeless philosophical issues about persistence, change, time, and sameness. Andre Gallois offers a critical survey of various rival views about the nature of identity and change, and puts forward his own original theory. He supports the idea of occasional identities, arguing that it is coherent and helpful to suppose that things can be identical at one time but distinct at another. Gallois defends this view, demonstrating how it can solve puzzles about (...) persistence dating back to the Ancient Greeks, and investigates the metaphysical consequences of rejecting the necessity and eternity of identities. (shrink)

In this challenging study, André Gallois proposes and defends a thesis about the character of our knowledge of our own intentional states. Taking up issues at the centre of attention in contemporary analytic philosophy of mind and epistemology, he examines accounts of self-knowledge by such philosophers as Donald Davidson, Tyler Burge and Crispin Wright, and advances his own view that, without relying on observation, we are able justifiably to attribute to ourselves propositional attitudes, such as belief, that we consciously (...) hold. His study will be of wide interest to philosophers concerned with questions about self-knowledge. (shrink)

André Gallois’s Occasions of Identity is a detailed, well-written presentation and defense of one attempt to solve many of the recently much discussed puzzles in the metaphysics of material objects. It is engaging not only for Gallois’s ingenious attempt to defend his view that objects can be “occasionally identical”—identical at one time but not another —but for his discussion throughout of the puzzles and of alternative solutions. Gallois does a fine job of keeping the motivations for a (...) position, whether his own or others’, in view while working out details and responding to objections. Even where one disagrees, there is excellent food for thought and discussion here. (shrink)

Traditionally, this puzzle has been solved in various ways. Aristotle, for example, distinguished between “accidental” and “essential” changes. Accidental changes are ones that don't result in a change in an objects' identity after the change, such as when a house is painted, or one's hair turns gray, etc. Aristotle thought of these as changes in the accidental properties of a thing. Essential changes, by contrast, are those which don't preserve the identity of the object when it changes, such as when (...) a house burns to the ground and becomes ashes, or when someone dies. Armed with these distinctions, Aristotle would then say that, in the case of accidental changes, (1) and (2) are both false—a changing thing can really change one of its “accidental properties” and yet literally remain one and the same thing before and after the change. (shrink)

In my article "berkeley's master argument" I attempt to show that an argument berkeley uses in the 'dialogues' and 'principles' to support his contention that whatever is perceivable is perceived can be seen as an illuminating attempt to relate conceptualizing, Imaging and perceiving. In consequence it cannot be dismissed as resting on an elementary fallacy, But reflects on the conditions for the self ascription of experience.

The philosophical problem of identity and the related problem of change go back to the ancient Greek philosophers and fascinated later figures including Leibniz, Locke, and Hume. Heraclitus argued that one could not swim in the same river twice because new waters were ever flowing in. When is a river not the same river? If one removes one plank at a time when is a ship no longer a ship? What is the basic nature of identity and persistence? In this (...) book, André Gallois introduces and assesses the philosophical puzzles posed by things persisting through time. Beginning with essential historical background to the problem he explores the following key topics and debates: mereology and identity, including arguments from 'Leibniz's Law' the constitution view of identity the 'relative identity' argument concerning identity temporary identity four-dimensionalism, counterpart and multiple counterpart theory supervenience the problem of temporary intrinsics the necessity of identity Indeterminate identity presentism criteria of identity conventionalism about identity. Including chapter summaries, annotated further reading and a glossary, this book is essential reading for anyone seeking a clear and informative introduction to and assessment of the metaphysics of identity. (shrink)

Ted Sider’s book makes a beautifully presented and compellingly argued case for four dimensionalism. Most of the arguments for four dimensionalism to be found in the literature seem to me to be uncompelling. Ted’s argument from vagueness, given in the last section of chapter 4, is a notable exception. After discussing that argument I will respond to his objections in section 5 chapter 5 to my own temporary identity view.

The philosophy problem of identity and the related problem of change go back to the ancient Greek philosophers and fascinated later figures including Leibniz, Locke and Hume. Heraclitus argued that one could not swim in the same river twice because new waters were ever flowing in. When is a river not the same river? If one removes one plank at a time when is a ship no longer a ship? What is the basic nature of identity and persistence? This book (...) introduces and asseses the philosophical puzzles posed by things persisting through time. Beginning with essential historical background to the problem it explores the following key topics and debates: mereology and identity, including 'Leibniz's Law' the constitution view of identity the 'relative identity' argument concerning identity temporary identity four-dimensionalism, counterpart and mulitiple counterpart theory supervenience the problem of temporary intrinsics the necessity of identity presentism ontological and epistemological criteria for persistence and the difference between them. Including chapter summaries, annotated further reading and a glossary this book is essential reading for anyone seeking a clear and informative introduction to and assessement of the metaphysics of identity. (shrink)

According to an externalist theory of content the content of an individual’s thoughts and the meaning of her words need not supervene on her intrinsic history. Two individuals may be intrinsically exactly alike yet entertain different thoughts, and attach different meanings to the words they use. ETC, which has been most notably defended by Saul Kripke, Hilary Putnam and Tyler Burge, has attained the status of current orthodoxy. Nevertheless, some maintain that combining ETC with the premisses that we have privileged (...) access to our intentional states yields a surprising conclusion. It yields the conclusion that we can have a priori knowledge of features of the external world that seem only accessible to empirical investigation. Call the argument from ETC and privileged access to this conclusion the main argument. Some take the main argument to be a reductio of ETC. Since we have privileged access to our intentional states, and lack the a priori knowledge attributed by the main argument, ETC is false. Some take the main argument to refute the premisses that we have privileged access to those intentional states falling within the scope of ETC. Others see the main argument as a refutation of external world scepticism. We will show that the main argument does not support any of these interesting conclusions. We will show that the main argument does not threaten to restrict privileged access, refute external world scepticism, or constitute a reductio of ETC. More exactly, we will show that the most defensible version of ETC, even when combined with the premiss that we have unrestricted privileged access to our intentional states, yields no a priori knowledge of the external world. (shrink)

I consider backtracking reasoning: that is, reasoning from backtracking counterfactuals such as if Hitler had won the war, he would have invaded Russia six weeks earlier. Backtracking counterfactuals often strike us as true. Despite that, reasoning from them just as often strikes us as illegitimate. A number of diagnoses have been offered of the illegitimacy of such backtracking reasoning which invoke the fixity of the past, or the direction of causation. I argue against such diagnoses, and in favor of one (...) that invokes a principle I call the fixity of reasons. Backtracking reasoning violates the fixity of reasons. But, the fixity of reasons is a principle that must be observed in order to engage in practical reasoning at all. (shrink)

As a number of philosophers have observed, our knowledge of what is passing through our own minds appears to be quite different to our knowledge of other things. I do not, it seems, need to accumulate evidence in order to know what psychological states I am in. 1 Without relying on evidence I am able to effortlessly attribute to myself beliefs, desires, intentions, hopes, fears, and a host of other psychological states. The distinctive knowledge we have of our own psychological (...) states is sometimes labeled privileged access. If ’privileged access’ means knowledge that is not evidentially based we certainly seem to have privileged access to some psychological states including those exhibiting intentionality.2 Nevertheless, some have questioned whether we do enjoy privileged access to our intentional states. One reason for doing so derives from the findings of psychologists. The time honored thesis that we have privileged access to our own psychological states is threatened by such findings (see especially Nesbitt and Wilson, 1977). Moreover, there is threat to privileged access from a different direction. It comes from a philosophical thesis commonly referred to as externalism. Externalism is the view that the content of an intentional state such as a belief is fixed by the environment external to the believer. Some externalists deny that externalism conflicts with privileged access. Donald Davidson and Tyler Bürge in particular have developed what might be called a minimalist account of privileged access which, they would claim, reconciles privileged access with externalism. An interesting feature of their account is that it suggests a defense of privileged access in the light of the psychological findings mentioned above. However, that is a topic for another paper. Here I will confine myself to assessing the Davidson Burge account of privileged access, and its implications for the relationship between privileged access and externalism. (shrink)

My concern is with a version of scepticism which, following a number of philosophers, I will entitle global scepticism. According to global scepticism no one is to any degree justified in holding any belief. Global scepticism is a live option, and has at least one compelling argument in its favour1 Nevertheless, one's first reaction to global scepticism is likely to be that it is self-refuting. The issue I will be discussing here is whether global scepticism is self-refuting. In the first (...) section I consider arguments to the conclusion that global scepticism is self-refuting, and argue that the global sceptic need take only one of them seriously. In the next I examine a global sceptic's reply to the argument in question, and a response to that reply available to the anti-sceptic. What emerges is an apparent impasse. The global sceptic has a response to each reply that the anti-sceptic makes in support of the anti-sceptic's original argument. However, it seems that the anti-sceptic is able to effectively reply to each of the global sceptic's responses. In the last section I develop an argument to show that global scepticism is self-refuting which breaks the deadlock between the global sceptic and anti-sceptic. (shrink)

André Gallois (1998) attempts to defend the occasional identity thesis (OIT), the thesis that objects which are distinct at one time may nonetheless be identical at another time, in the face of two influential lines of argument against it. One argument involves Kripke’s (1971) notion of rigid designation and the other, Leibniz’s law (affirming the indiscernibility of identicals). It is reasonable for advocates of (OIT) to question the picture of rigid designation and the version of Leibniz’s law that these (...) arguments employ, but, the problem is, some form of rigidity is required for one to affirm the occasional identity of objects, and some (restricted) version of Leibniz’s law must be conceded if identity really is involved. Gallois accordingly recommends an account of rigidity and a version of Leibniz’s law to this end.1 We find Gallois’ proposals entirely inadequate to their task. We aim in this paper is to explicate and defend an alternative approach for occasional identity theorists. We do not seek to defend (OIT) per se; our aim, rather, is simply to show that the arguments from rigid designation and Leibniz’s law are inconclusive. Let’s begin with an outline of these arguments. (shrink)

André Gallois argues that individuals that undergo fission are on some occasions identical, but on others distinct. Occasional identity however, is metaphysically costly. I argue that we can get all the benefits of occasional identity without the metaphysical costs. On the proposed account, the names of ordinary material objects refer indeterminately to stages that belong to reference classes determined by the context of utterance or temporal adverbs. In addition, temporal markers indicating the perspective from which we count objects and (...) assign properties to them determine how many count and what is true of them. So, as Gallois holds, the truth value of claims about what is true at a time may change over time and, where fission or fusion occur, does change. The current account, however, secures this result without commitment to occasional identity: reference, predication and counting are “occasional”; identity is not. (shrink)

André Gallois’s book is a sustained defence of first-person authority in epistemology and the philosophy of mind. His work is set against the externalist tide of current epistemology in which many philosophers are sceptical about first-person authority with respect to their beliefs. This implies that other individuals are in a better position to determine what our beliefs are than we ourselves can be, which highlights the authority of third person accounts of justification. Gallois’s work is a direct attack (...) on such views since he argues that it is only from within the first-person perspective that an individual can determine whether s is justified in believing x. Without relying on observation, an individual can justifiably self-attribute consciously held beliefs. Thus, first-person authority is essential for developing an adequate theory of knowledge since the justification of belief is impossible unless the first-person perspective is prior and privileged. (shrink)