Alan Sidelle

In section 96 of Reasons and Persons, Derek Parfit offers his now familiar tripartite distinction among candidates for ‘what matters’: (1) Relation R with its normal cause; (2) R with any reliable cause; (3) R with any cause. He defends option (3). This paper tries to show that there is important ambiguity in this distinction and in Parfit's defence of his position. There is something strange about Parfit's way of dividing up the territory: I argue that those who have followed him in viewing the choice among (1)–(3) as the (or an) important question in thinking about ‘what matters’ are mistaken, and that they bypass what seems to be a more important, even crucial, set of options and considerations. I am less concerned with what he does say than with what he ought to say, given his intuitions and arguments, and the general framework within which he is working. And I am particularly concerned to show that whether or not I am correct about what he is doing with his tripartite distinction, it is a distinction with which we should not be particularly concerned in the analysis either of what matters or of psychological continuity

The Aristotelian doctrine of hylomorphism has seen a recent resurgence of popularity, due to the work of a number of well-known and impressive philosophers. One of the recently motivating virtues claimed for the doctrine is its ability to solve the grounding problem for philosophers who believe in coinciding entities. In this brief article, I will argue that when fully spelled out, hylomorphism does not, in fact, contribute a distinctive solution to this problem. It is not that it offers no solution at all, but that it is not really a different solution from other familiar, seemingly non-hylomorphic, solutions on offer

Most contemporary internalists are fallibilists, denying that there need be anything about which we are infallible for us to have knowledge or justified beliefs. At the same time, internalists standardly appeal to ‘internal twins’ in arguing against externalism and motivating internalism---a Cartesian demon can ruin the ‘external’ relations we have to the world, but one is equally well justified in one’s beliefs whether or not one is subject to such deception. Even if one doesn’t motivate one’s internalism by appeal to internal twins, any internalist must agree that internal twins are equally well justified in their beliefs. I argue that the internal twins argument for, or commitment of internalism, commits one to the claim that the conditions in virtue of which one is justified must be ones about which a believer is infallible. The basic argument is that for anything about which one can be mistaken, one has an internal twin who is mistaken, but is equally well justified---and so, not in virtue of that about which one can be mistaken. If the argument can be resisted, this should tell us something useful about how to properly understand both internalism in general, and the idea of internal twins in particular

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.

Some relations - like supervenience and composition - can appear very much like identity. Sometimes, the relata differ only in modal, or modally-involved features. Yet, in some cases, we judge the pairs to be identical (water/H2O; Hesperus/Phosphorus), while in others, many judge one of the weaker relations to hold (c-fiber firing/pain; statues/lumps). Given the seemingly same actual properties these pairs have, what can justify us in sometimes believing identity is the relation, and sometimes something weaker? I argue that it can only be knowledge of differences of individuative criteria that we know a priori because they are built into the meanings of the words/concepts involved. Possible metaphysical conclusions are considered.

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