Alan Sidelle

One obvious solution to the puzzles of apparently coincident objects is a sort of reductionism - the tree really just is the wood, the statue is just the clay, and nothing really ceases to exist in the purported non-identity showing cases. This paper starts with that approach and its underlying motivation, and argues that if one follows those motivations - specifically, the rejection of coincidence, and the belief that 'genuine' object-destroying changes must differ non-arbitrarily from accidental changes, that one can plausibly be pushed to an extreme nihilism, that denies the existence of any objects at all.

The phenomenon of rigid designation - in particular, de jure rigidity - is typically treated metaphysically. The picture is: reference is gained in a way that puts no constraints on what an object in other worlds, or counterfactual situations must be like, in order to be the referent of that term, other than 'being this thing'. This allows 'pure metaphysical' investigation into, and discovery of 'the nature' of the referent. It is argued that this presupposes a 'privileged' ontology, of a sort that is far from obvious. An alternative picture of rigidity is sketched, terms have associated criteria of identity and criteria of application for counterfactual situations. A term is rigid when these coincide. Aside from being a better account of rigidity, it also undermines the picture of rigid terms allowing us to 'metaphysically' investigate the nature of the referent: matters of identity and essence for the referent are settled by these semantic constraints (though it can be done in a way that allows are a posteriori necessities).

A not-unpopular position in the metaphysics of material objects (Ted Sider's, for instance) combines realism about what objects there are and the conditions of objecthood with conventionalism about de re modality. I argue that this is not a coherent combination of views: one must go fully conventionalist, or fully realist. The central argument displays the difficulty for the modal conventionalist/object realist in specifying the object that satisfies de re modal predicates. I argue that if this is a mind-independent object, contradictions arise when we consider the possibility or actuality of non-equivalent conventions both applying to 'the same object'.

Many philosophers believe that identity through time cannot depend on features extrinsic to the relata and relations between them. This goes with the view that one must deny identity in cases for which there is a ‘duplication case’-a case just like the first, but for an additional, ‘external’ element which provides an equal or better ‘candidate’ for identity with one of the relata. Such friends of intrinsicness cannot remedy the failure of continuity of function/form to be one-one by non-branching or closest competitor clauses. The obvious intrinsic approach-perhaps taken for granted-appeals to considerations of quantity of matter, requiring over 50% shared matter between identicals . But this rules out plausible cases of halving and doubling for which there are not duplication cases. After bringing out this problem, I ask what makes duplication cases possible, and use this to formulate an intrinsic condition which allows identity whenever there is continuity of function, but no threat to intrinsic ness via duplication cases

Philosophy and science employ abstract hypothetical scenarios- thought experiments - to illustrate, defend, and dispute theoretical claims. Since thought experiments furnish no new empirical observations, the method prompts two epistemological questions: whether anything may be learnt from the merely hypothetical, and, if so, how. Various sceptical arguments against the use of thought experiments in philosophy are discussed and criticized. The thesis that thought experiments in science provide a priori knowledge through non-sensory grasping of abstract entities is discussed and rejected. The thesis that thought experimentation consists in manipulations of mental models is examined and found to be of limited epistemological relevance. It is argued that thought experiments are associated with characteristic arguments in a manner similar to ordinary experiments. It is further argued that thought experiments function in the same way as experiments in general: by providing premises for their associated arguments. Like other experiments, a thought experiment is successful when the premises it provides are true. This holds both for philosophical and scientific thought experiments. An argument schema is proposed and shown to be a formal analogue to that associated with ordinary experiments; similar in being subject to epistemological holism; but differing in being modal: in employing statements about possibility and necessity. The evaluation of thought experiments thus depends on how modal statements may be justified. Intuition and conceivability are discussed as sources of modal justification and found problematic. Instead it is suggested that evaluation proceed by accommodation of the statements describing the experiment's hypothetical scenario. The method of accommodation is developed and applied to five influential thought experiments in philosophy: the brain in a vat; Putnam's Twin Earth; Burge's arthritis example; Searle's Chinese Room; and Newcomb's problem. Its application shows some of these to be failed, others to be successful only relative to controversial philosophical doctrines

This paper defends the traditional view that the laws of nature are contingent, or, if some of them are necessary, this is due to analytic principles for the individuation of the law-governed properties. Fundamentally, I argue that the supposed explanatory purposes served by taking the laws to be necessary --showing how laws support counterfactuals, how properties are individuated, or how we have knowledge of properties--are in fact undermined by the continued possibility of the imagined scenarios--this time, described neutrally--which seemed to disprove the claim to necessity in the first place. I speculate that this will be true for any proposed necessary a posteriori truths, and is a basis for rejecting their supposed metaphysical significance.

In “Innocuous Infallibility,” Earl Conee argues that the infallibility to which I argue Internalism is committed, in “An Argument that Internalism Requires Infallibility,” is harmless and trivial. I maintain that this overlooks the fact that Internalism makes use of an intuitive notion of ‘epistemic twinhood’ to drive its position, rather than one antecedently defined with a filled‐out notion of ‘relevant epistemic circumstances’. Conee is correct that any theory requires, and trivially gets, some sort of infallibility‐but it is not trivial that there is a coherent and univocal notion of the sort of relevant circumstances‐and so, twinhood and infallibility‐behind the Internalist strategy and motivation.

One common objection to Conventionalism about modality is that since it is contingent what our conventions are, the modal facts themselves will thereby be contingent. A standard reply is that Conventionalists can accept this, if they reject the S4 axiom, that what is possibly possible is possible. I first argue that this reply is inadequate, but then continue to argue that it is not needed, because the Conventionalist need not concede that the contingency of our conventions has any bearing on the modal status of necessary truths. It is explained why this does not compromise the Conventionalist claim that necessity – and particularly, essence – is due to conventions

ABSTRACT: Rudolf Carnap’s “Empiricism, Semantics and Ontology” (ESO) has received a good deal of sympathetic interest over the years from philosophers who are not particularly sympathetic to verificationism, or suspicious of metaphysics in general. Recent work has favorably cited ESO in connection with doubts about the genuine content of debates in the metaphysics of material objects. But, when we look at how Carnap introduces his central notion of a ‘framework’, and the questions he wants to use it to deflate, there seem to be significant differences in his approach and aim from that of contemporary deflationists about the metaphysics of material objects. This paper first looks at some of these differences, and suggests a way of seeing them as arising more from differences in focus and interest than fundamental approach. However, a further question is whether philosophers who may entirely disagree with Carnap about abstract entities, or the substantiveness of the debate between Realists and Idealists – possibly all of his negative conclusions in ESO - can really be seen as heirs to his approach and argument therein. We look first at his discussion of the Realism/Idealism debate, to sort out different aspects of his analysis, and determine to what extent one can disagree with it while not thinking this undermines other analyses using the same general strategy. In the course of this, we are able to distinguish the basic Carnapian analysis of metaphysical disputes, from the question of whether, if the analysis is correct, this actually subverts the disputes. I suggest that, if we put verificationism aside, ESO really provides us with an approach and a type of skeptical challenge more than an argument, and it is open to contemporary philosophers to think that this skeptical challenge can (or can’t) be met, or can be supplemented by further argument, on a case by case basis.

Plausible recent arguments for the existence of necessary truths a posteriori have led many philosophers to believe, at least implicitly, that conventionalism about necessity is false, and that necessity is in fact a real-world quantity. Necessary truths, on this view, are no more independent upon our linguistic conventions than any other truths; assertions of necessity and essential predications are, like any other claims, true or false as they correspond or not to a wholly independent reality. I believe that this view is not supported by the finding of necessary truths a posteriori, and further, that we have excellent reason to reject this realism about necessity, and to accept instead a conventionalist account. My dissertation attempts to argue for this view, and to present and defend such a conventionalist account. ;In Chapter One, I present a conventionalist explanation of necessary truths a posteriori, and thus argue that the existence of such truths does not establish realism about necessity. My account makes use of general conventions which I call 'general principles of individuation.' If these principles are products of our conventions, then we can both allow for and explain how there can be such 'empirical' necessary truths within a conventionalist framework. ;Chapter Two argues that conventionalism about necessity and essences has traditionally been grounded in metaphysical worries about necessity, not upon now outdated epistemological and semantic views, as is often claimed by the opponents of conventionalism. ;In Chapter Three, I present my central arguments for conventionalism and against realism about necessity. I argue that only conventionalism can explain how we have the knowledge that we do of what is necessary, and further, that it is not even clear that we can make sense of necessity as an independent feature of the world. Chapter Four responds to worries stemming from the fact that my account requires that there be systematically important analytic truths. ;Finally, in Chapter Five, I attempt to apply my findings to the theory of reference. I argue that if conventionalism about necessity and essences is true, then empiricist semantics must be basically correct, and that causal theories of reference must thus be either compatible with empiricist semantics, or false

Many philosophers believe that identity through time cannot depend on features extrinsic to the relata and relations between them. This goes with the view that one must deny identity in cases for which there is a `duplication case'-a case just like the first, but for an additional, `external' element which provides an equal or better `candidate' for identity with one of the relata. Such friends of intrinsicness cannot remedy the failure of continuity of function/form to be one-one by non-branching or closest competitor clauses. The obvious intrinsic approach-perhaps taken for granted-appeals to considerations of quantity of matter, requiring over 50% shared matter between identicals. But this rules out plausible cases of halving and doubling for which there are not duplication cases. After bringing out this problem, I ask what makes duplication cases possible, and use this to formulate an intrinsic condition which allows identity whenever there is continuity of function, but no threat to intrinsicness via duplication cases.