There is widespread disagreement as to what the facts are concerning just when a collection of objects composes some further object; but there is widespread agreement that, whatever those facts are, they are necessary. I am unhappy to simply assume this, and in this paper I ask whether there is reason to think that the facts concerning composition hold necessarily. I consider various reasons to think so, but find fault with each of them. I examine the theory of composition as (...) identity, but argue that the version of this doctrine that entails universalism is implausible. I consider the claim that the a priority of such facts leads to their necessity, but give a defence of substantial contingent a priori truths. I ask whether the contingency of such facts would lead to unwelcome possibilities, but argue that the worrying looking possibilities can be blocked if it is desired. Next, I argue against the thought that the Lewis-Sider argument against restricted composition might give us reason to accept the necessity of universalism. Lastly, I respond to two objections from the 2006 BSPC. I conclude in favour of the contingency of the facts concerning when some things compose some thing. (shrink)

In his influential paper ‘‘Essence and Modality’’, Kit Fine argues that no account of essence framed in terms of metaphysical necessity is possible, and that it is rather metaphysical necessity which is to be understood in terms of essence. On his account, the concept of essence is primitive, and for a proposition to be metaphysically necessary is for it to be true in virtue of the nature of all things. Fine also proposes a reduction of conceptual and logical necessity in (...) the same vein: a conceptual necessity is a proposition true in virtue of the nature of all concepts, and a logical necessity a proposition true in virtue of the nature of all logical concepts. I argue that the plausibility of Fine's view crucially requires that certain apparent explanatory links between essentialist facts be admitted and accounted for, and I make a suggestion about how this can be done. I then argue against the reductions of conceptual and logical necessity proposed by Fine and suggest alternative reductions, which remain nevertheless Finean in spirit. (shrink)

I critically assess Stephen Yablo’s claim that cassinis are ovals is an a posteriori conceptual necessity. One does not know it simply by mastering the relevant concepts but by substantial empirical scrutiny. Yablo represents narrow content by would have turned out -conditionals. An epistemic reading of such conditionals does not bear Yablo’s claim. Two metaphysically laden readings are considered. In one reading, Yablo’s conditionals test under what circumstances concepts remain the same while their extensions diverge. As an alternative, I develop (...) a more literal metaphysical interpretation: Yablo’s conditionals draw on scenarios which are qualitatively identical to some original situation. None of these interpretations sustains Yablo’s core thesis. (shrink)

I investigate two asymmetrical approaches to knowledge of absolute possibility and of necessity--one which treats knowledge of possibility as more fundamental, the other according epistemological priority to necessity. Two necessary conditions for the success of an asymmetrical approach are proposed. I argue that a possibility-based approach seems unable to meet my second condition, but that on certain assumptions--including, pivotally, the assumption that logical and conceptual necessities, while absolute, do not exhaust the class of absolute necessities--a necessity-based approach may be able (...) to do so. (shrink)

Necessitarian accounts of the laws of nature have an apparent difficulty in accounting for counterlegal conditionals because, despite appearing to be substantive, on the necessitarian thesis they are vacuous. I argue that the necessitarian may explain the apparently substantive content of such conditionals by pointing out the presuppositions of counterlegal discourse. The typical presupposition is that a certain conceptual possibility has been realized; namely, that necessitarianism is false. (The idea of conceptual possibility is explicated in terms of recent work in (...) two-dimensional modal semantics.) If this sort of presupposition is made explicit in counterlegal utterances, we obtain a sentence such as: 'If it turns out that the laws of nature are contingent, then if the laws had been otherwise, then such and such would have been the case.' Sentences of this type are non-vacuous, and very often true. I argue that this goes a long way towards resolving the difficulty for necessitarianism. (shrink)

Theories of personal identity try to explain what the identity of a person necessarily consists in, but frequently leave open what kind of necessity is at issue. This paper is concerned with conceptual necessity. It proposes an analysis of the concept of personal identity in terms of a definite description. The analysis coheres with out judgments about clear cases and explains why cases of division seem indeterminate. The apparent indeterminacy results from attempting to apply a definite description to a situation (...) in which more than one object would satisfy the description. The definite description analysis also explains the strengths of the influential no-branching theory, while avoiding the problems with that view. The no-branching theory is in effect a second-order analysis, i.e., a combination of the definite description analysis of personal identity plus a Russellian analysis of the definite description. (shrink)

A complex theory concerning powers, natures, and causal necessity has emerged from the writings of P. H. Hare, E. H. Madden, and R. Harré. In the course of rebutting objections that other critics have raised to the power account of causation, I correct three of its genuine difficulties: its attempt to analyze power attributions in terms of conditional statements; its characterization of the relation between something's powers and its nature; and its doctrines concerning conceptual necessity. The resulting interpretation of causal (...) modalities is then subsumed under a more general power account of modality, related at a number of points to considerations concerning powers, and further illustrating their philosophical importance. (shrink)

Authors have a lot of leeway with regard to what they can make true in their story. In general, if the author says that p is true in the fiction we’re reading, we believe that p is true in that fiction. And if we’re playing along with the fictional game, we imagine that, along with everything else in the story, p is true. But there are exceptions to these general principles. Many authors, most notably Kendall Walton and Tamar Szabó Gendler, (...) have discussed apparent counterexamples when p is “morally deviant”. Many other statements that are conceptually impossible also seem to be counterexamples. In this paper I do four things. I survey the range of counterexamples, or at least putative counterexamples, to the principles. Then I look to explanations of the counterexamples. I argue, following Gendler, that the explanation cannot simply be that morally deviant claims are impossible. I argue that the distinctive attitudes we have towards moral propositions cannot explain the counterexamples, since some of the examples don’t involve moral concepts. And I put forward a proposed explanation that turns on the role of ‘higher-level concepts’, concepts that if they are satisfied are satisfied in virtue of more fundamental facts about the world, in fiction, and in imagination. (shrink)

In these few pages I shall try to demonstrate the emptiness of the most cumbersome piece of unexamined intellectual baggage at present being hauled about by English philosophers. I here cite one example to be going on with, at the end of the paper I shall give a handful more, and it would be easy to multiply the number by ten from the writings of reputable philosophers. The outstanding philosophical achievement of the ha1f-century which has just drawn to a close (...) [i.e. the period 1900-1950] has been an appreciation of the peculiar status of a priori judgments and of logically necessary or formally true propositions. . . . Though many problems remain unsolved, the main outline is now clear: formally true statements assert nothing about the world; instead, their function is to state principles according to which empirical propositions are deduced from other empirical propositions . . . (R. B. Braithwaite, ‘Moral Principles and Inductive Policies’, Proceedings of the British Academy 1950). What is wrong with this passage and with the myth of which it is an expression is its assumption that we have clear notions of what it is for a proposition to be logically necessary and of what it is for a proposition to assert something about the world, these notions being such that it is plausible to say that it has recently been discovered that every proposition having the first of these properties lacks the second. This assumption is wrong: there is no body of published theory giving a clear account of such notions, and despite fairly diligent searching I have so far failed to find, among the many philosophers who accept the myth, one who is able when challenged to supplement the literature on this vital point. Let me make it clear at once that I am not going to defend synthetic a priori truths - I am going to attack a popular mishandling of the truth that all necessary truths are analytic, and through this attack to draw right-wing conclusions from left-wing premisses.. (shrink)

In this paper I offer a straight solution to Hume's problem of induction by defusing the assumptions on which it is based. I argue that Hume's problem only arises if we accept (i) that there is no necessity but logical necessity, or (ii) that it is unreasonable to believe that there is any form of necessity in addition to logical necessity. I show that Hume's arguments in favour of (i) and (ii) are unsound. I then offer a suggestion as to (...) how the weakness of his arguments has escaped detection. Finally, having claimed that there remains a surmountable problem with inductive arguments, I end by characterising that problem and a possible approach to its solution. (shrink)

Which mathematical structures are possible, that is, instantiated by the concrete inhabitants of some possible world? Are there worlds with four-dimensional space? With infinite-dimensional space? Whence comes our knowledge of the possibility of structures? In this paper, I develop and defend a principle of plenitude according to which any mathematically natural generalization of possible structure is itself possible. I motivate the principle pragmatically by way of the role that logical possibility plays in our inquiry into the world.

In sections 1 through 5, I develop in detail what I call the standard theory of worlds and propositions, and I discuss a number of purported objections. The theory consists of five theses. The first two theses, presented in section 1, assert that the propositions form a Boolean algebra with respect to implication, and that the algebra is complete, respectively. In section 2, I introduce the notion of logical space: it is a field of sets that represents the propositional structure (...) and whose space consists of all and only the worlds. The next three theses, presented in sections 3, 4, and 5, respectively, guarantee the existence of logical space, and further constrain its structure. The third thesis asserts that the set of propositions true at any world is maximal consistent; the fourth thesis that any two worlds are separated by a proposition; the fifth thesis that only one proposition is false at every world. In sections 6 through 10, I turn to the problem of reduction. In sections 6 and 7, I show how the standard theory can be used to support either a reduction of worlds to propositions or a reduction of propositions to worlds. A number of proposition-based theories are developed in section 6, and compared with Adams's world-story theory. A world-based theory is developed in section?, and Stalnaker's account of the matter is discussed. Before passing judgment on the proposition based and world-based theories, I ask in sections 8 and 9 whether both worlds and propositions might be reduced to something else. In section 8, I consider reductions to linguistic entities; in section 9, reductions to unfounded sets. After rejecting the possibility of eliminating both worlds and propositions, I return in section 10 to the possibility of eliminating one in favor of the other. I conclude, somewhat tentatively, that neither worlds nor propositions should be reduced one to the other, that both worlds and propositions should be taken as basic to our ontology. (shrink)

Recently it has become almost the received wisdom in certain quarters that Kripke models are appropriate only for something like metaphysical modalities, and not for logical modalities. Here the line of thought leading to Kripke models, and reasons why they are no less appropriate for logical than for other modalities, are explained. It is also indicated where the fallacy in the argument leading to the contrary conclusion lies. The lessons learned are then applied to the question of the status of (...) the formula. (shrink)

One skeptical strategy against A's claim to know that P is to hold that it is logically possible for someone to have the same "base" (a term needing explaining) for P as A does in spite of its not being true that P. Philosophical replies have focussed on showing that these are not genuine possibilities. Whether they are can be an interesting question of metaphysics, but it is argued in this paper that this metaphysical discussion is not the proper focus (...) for an assessment of skepticism. Even if there are the odd logical possibilities, they do not suffice to warrant skeptical doubts. Rather, there has to be good reason to think that there is a genuine chance of the alleged possibility obtaining. This requirement cannot be satisfied generically, and that is what is wrong with generic skepticism. (shrink)

This paper aims to explain how the Tractatus attempts to unify logic by deriving the truth-functionality of logical necessity from the thesis that a proposition shows its sense. I first interpret the Tractarian notion of showing as the displaying of what is intrinsic to an expression (or a symbol). Then I argue that, according to the Tractatus, the thesis that a proposition shows its sense implies the determinacy of sense, the possibility of the complete elimination of non-primitive symbols, the analyticity (...) thesis and the strong analyticity thesis. The picture theory emerges as what provides the only acceptable account of an elementary proposition, subject to the constraint that a proposition must show its sense. The picture theory and the analyticity thesis then entail the contingency thesis (that an elementary proposition is contingent) and the independence thesis (that elementary propositions are mutually logically independent) which, together with the strong analyticity thesis, imply that all logical propositions are tautologies. (shrink)

One of the most basic methods of philosophy is, and has always been, the consideration of counterfactual cases and imaginary scenarios. One purpose of doing so obviously is to test our theories against such counterfactual cases. Although this method is widespread, it is far from being commonly accepted. Especially during the last two decades it has been confronted with criticism ranging from complete dismissal to denying only its critical powers to a cautious defense of the use of thought experiments as (...) counterexamples. One of the strongest criticisms of the method of thought experimentation is "modal skepticism" as explicated and defended by Peter van Inwagen. Van Inwagen argues that the philosopher's notion of logical possibility is confused and that its epistemology is dubious. I argue that van Inwagen's skepticism is unwarranted. There is a sufficiently clear notion of logical possibility and a sufficiently straightforward way of getting to know what is logically possible. In the remainder of the paper I show how that connects with the methodology of thought experimentation in philosophy. (shrink)

HUME AND HIS FOLLOWERS HAVE TRIED UNSUCCESSFULLY TO ESTABLISH THE IMPOSSIBILITY OF MIRACLES BY APPEALING SOLELY TO THE DEFINITIONS OF MIRACLE AND NATURAL LAW. HUME’S ARGUMENT TRADES UPON THAT PART OF THE DEFINITION OF MIRACLE WHICH PERTAINS TO THE NUMERICAL INSIGNIFICANCE OF MIRACULOUS EVENTS. HE DID NOT REALIZE THAT THE LARGE NUMERICAL DIFFERENCE BETWEEN NON-REPEATABLE IRREGULAR EVENTS AND REPEATABLE REGULAR ONES LOGICALLY CANNOT BE USED AS A CRITERION BY WHICH TO DETERMINE THE EXISTENTIAL STATUS OF NUMERICALLY SMALL NON-REPEATABLE IRREGULAR EVENTS. (...) USING A SIMILAR STRATEGY, THE CONTEMPORARY HUMEAN APPEALS TO PART OF THE DEFINITION OF NATURAL LAW, TO THE IDEA OF ITS ESSENTIAL GENERALITY. WHETHER "ESSENTIALLY GENERAL" IS TAKEN TO MEAN AN INTRINSIC NATURAL NECESSITY OR A NECESSITY IMPUTED TO NATURE, IN NEITHER CASE CAN THE LOGICAL IMPOSSIBILITY OF MIRACLES BE ESTABLISHED. (shrink)

In his influential paper ‘‘Essence and Modality’’, Kit Fine argues that no account of essence framed in terms of metaphysical necessity is possible, and that it is rather metaphysical necessity which is to be understood in terms of essence. On his account, the concept of essence is primitive, and for a proposition to be metaphysically necessary is for it to be true in virtue of the nature of all things. Fine also proposes a reduction of conceptual and logical necessity in (...) the same vein: a conceptual necessity is a proposition true in virtue of the nature of all concepts, and a logical necessity a proposition true in virtue of the nature of all logical concepts. I argue that the plausibility of Fine's view crucially requires that certain apparent explanatory links between essentialist facts be admitted and accounted for, and I make a suggestion about how this can be done. I then argue against the reductions of conceptual and logical necessity proposed by Fine and suggest alternative reductions, which remain nevertheless Finean in spirit. (shrink)

McFetridge (in Logical necessity and other essays . London: Blackwell, 1990 ) suggests that to treat a proposition as logically necessary—to believe a proposition logically necessary, and to manifest that belief—is a matter of preparedness to deploy that proposition as a premise in reasoning from any supposition. We consider whether a suggestion in that spirit can be generalized to cover all cases of absolute necessity, both logical and non-logical, and we conclude that it can. In Sect. 2, we explain the (...) significance that such an account of manifestation of belief in absolute necessity has for the prospects of a non-realist theory of modality. In Sect. 3, we offer a sympathetic articulation of the detail that underlies the McFetridge conception of belief in logical necessity. In Sects. 4 and 5, we show that the conception so articulated will not generalize to encompass all cases of belief in absolute necessity and proceed to offer a remedy. Our proposal is based upon a distinction between two kinds of suppositional act: A-supposing and C-supposing (Sect. 6). In Sect. 7, we then explain and defend our central thesis: (roughly) that (manifestation of) belief in absolute necessity is a matter of preparedness to deploy as a premise in reasoning under any C-supposition. Finally, we indicate that there is some promise in the parallel thesis that manifestation of the treatment of a proposition as a priori is a matter of preparedness to deploy as a premise in reasoning under any A-supposition (Sect. 8). (shrink)

The following questions are discussed here. Is induction a reasonable procedure in the context of a denial of physically necessary connections? What is physical necessity? If induction does presuppose physical necessity, what amount of it is presupposed? It is argued that with logic as the only restriction on what is to count as a possible world, it is unreasonable to claim that observed connections, whether universal or statistical, will continue to hold. The concept of physical necessity is no more problematic (...) than that of logical necessity, once it is recognized that the necessity of physical and logical necessity is the same. A variant of Keynes' principle of limited independent variety answers the question of the amount of physical necessity presupposed. (shrink)

Modal Platonism utilizes “weak” logical possibility, such that it is logically possible there are abstract entities, and logically possible there are none. Modal Platonism also utilizes a non-indexical actuality operator. Modal Platonism is the EASY WAY, neither reductionist nor eliminativist, but embracing the Platonistic language of abstract entities while eliminating ontological commitment to them.

Graham Oppy has argued that possible explanation entails explanation in order to object to Richard Gale and Alexander Pruss’s new cosmological argument that it does not improve upon familiar cosmological arguments. Gale and Pruss as well as Pruss individually have granted Oppy’s inference from possible explanation to explanation and argue that this inference provides a reason to believe that the strong principle of sufficient reason is true. In this article, I shall undermine Oppy’s objection to the new cosmological argument by (...) arguing that it is logically possible that some truths are merely possibly explained. (shrink)

I investigate two asymmetrical approaches to knowledge of absolute possibility and of necessity--one which treats knowledge of possibility as more fundamental, the other according epistemological priority to necessity. Two necessary conditions for the success of an asymmetrical approach are proposed. I argue that a possibility-based approach seems unable to meet my second condition, but that on certain assumptions--including, pivotally, the assumption that logical and conceptual necessities, while absolute, do not exhaust the class of absolute necessities--a necessity-based approach may be able (...) to do so. (shrink)

Must we believe in logical necessity? I examine an argument for an affirmative answer given by Ian McFetridge in his posthumously published paper 'Logical Necessity: Some Issues', and explain why it fails, as it stands, to establish his conclusion. I contend, however, that McFetridge's argument can be effectively buttressed by drawing upon another argument aimed at establishing that we ought to believe that some propositions are logically necessary, given by Crispin Wright in his paper 'Inventing Logical necessity'. My contention is (...) that Wright's argument, whilst it likewise fails, as it stands, to establish the necessity of necessity, established enough to close off what appears to me to be the only effective-looking sceptical response to McFetridge's original argument. My paper falls into four principal parts. In the first I expound McFetridge's argument and draw attention to the possibility of a certain type of sceptical counter to it. In the second, I begin a response to this sceptical move, taking it as far as I can without reliance upon argument of the kind given by Wright. Turning, then, to Wright's argument, I explain to what extent I think it is successful and seek to rebut some objections to the argument which, were they well-taken, would show that the argument cannot enjoy even the partial success I which to claim for it. Finally, I return to my main theme and try to show, with the assistance of what I take to be solidly established by Wright's argument, that the sceptical response collapses. (shrink)

The philosophy of modality investigates necessity and possibility, and related notions--are they objective features of mind-independent reality? If so, are they irreducible, or can modal facts be explained in other terms? This volume presents new work on modality by established leaders in the field and by up-and-coming philosophers. Between them, the papers address fundamental questions concerning realism and anti-realism about modality, the nature and basis of facts about what is possible and what is necessary, the nature of modal knowledge, modal (...) logic and its relations to necessary existence and to counterfactual reasoning. The general introduction locates the individual contributions in the wider context of the contemporary discussion of the metaphysics and epistemology of modality. (shrink)

The problem of the source of necessity is the problem of explaining what makes necessary truths necessarily true. Simon Blackburn has presented a dilemma intended to show that any reductive, realist account of the source of necessity is bound to fail. Although Blackburn's dilemma faces serious problems, reflection on the form of explanations of necessities reveals that a revised dilemma succeeds in defeating any reductive account of the source of necessity. The lesson is that necessity is metaphysically primitive and irreducible.

An impossible world is a world which necessarily does not exist. Besides the paradigm of necessity, wich is logical necesslty, we must consider physical necessity and ethical necessity, both of wich can beexpressed in terms of logical necessity, in the way suggested by Montague. Accordingly, an impossible world can be logically impossible, physically impossible or ethically impossible, but in every case the impossibility can be reduced to logical impossibility, and in consequence an impossible world is irrational and cannot be understood (...) by us. An illustration is taken from the incongruities of Kafka’s story in Di Verwandlung. (shrink)

Information is often modelled as a set of relevant possibilities, treated as logically possible worlds. However, this has the unintuitive consequence that the logical consequences of an agent's information cannot be informative for that agent. There are many scenarios in which such consequences are clearly informative for the agent in question. Attempts to weaken the logic underlying each possible world are misguided. Instead, I provide a genuinely psychological notion of epistemic possibility and show how it can be captured in a (...) formal model, which I call a fan. I then show how to use fans to build formal models of being informed, as well as knowledge, belief and information update. (shrink)

This paper analyzes the logical truths as (very roughly) those truths that would still have been true under a certain range of counterfactual perturbations.What’s nice is that the relevant range is characterized without relying (overtly, at least) upon the notion of logical truth. This approach suggests a conception of necessity that explains what the different varieties of necessity (logical, physical, etc.) have in common, in virtue of which they are all varieties of necessity. However, this approach places the counterfactual conditionals (...) in an unfamiliar foundational role. (shrink)

An attempt is made to show that Wittgenstein's later philosophy of logic is not the kind of conventionalism which is often ascribed to him. On the contrary, Wittgenstein gives expression to a “mixed” theory which is not only interesting but tends to resolve the perplexities usually associated with the question of the a priori character of logical truth. I try to show that Wittgenstein is better understood not as denying that there are such things as “logical rules” nor as denying (...) that the results of applying such rules are “logically necessary,” but as trying to understand what it is to appeal to a logical rule and what it means to say that the results of applying such a rule are “necessary.” He is not so much overthrowing standard accounts of logical necessity as discovering the limits of the concept. (shrink)

In his book The Concept of Miracle and his paper ‘For the Possibility of Miracles’ Swinburne claims that there are no logical difficulties in supposing that there could be strong historical evidence for the occurrence of miracles. This claim is based on three assertions; two of which I demonstrate are only true contingently. In this paper I identify several logical difficulties regarding the possibility of attaining historical evidence for the occurrence of miracles. On the strength of these logical difficulties I (...) hope to demonstrate that there is sufficient reason to doubt Swinburne’s central claim. (shrink)

A prevailing view in contemporary philosophy of mind is that zombies are logically possible. I argue, via a thought experiment, that if this prevailing view is correct, then I could be transformed into a zombie. If I could be transformed into a zombie, then surprisingly, I am not certain that I am conscious. Regrettably, this is not just an idiosyncratic fact about my psychology; I think you are in the same position. This means that we must revise or replace some (...) important positions in the philosophy of mind. We could embrace radical skepticism about our own consciousness, or maintain the complete and total infallibility of our beliefs about our own phenomenal experiences. I argue that we should actually reject the logical possibility of zombies. (shrink)

Quentin Smith has argued that it is logically impossible for there to be a divine cause of the universe. His argument is based on a Humean analysis of causation (confined to event causation, specifically excluding any consideration of agency) and a principle drawn from that analysis that he takes to be a logical requirement for every possibly valid theory of causation. He also thinks that all divine volitions are efficacious of logical necessity. We argue that all of these claims are (...) faulty, and that theists can resist Smith’s arguments without merely begging the question in favor of a divine cause. (shrink)

This paper responds to criticism of the Kripkean account of logical truth in first-order modal logic. The criticism, largely ignored in the literature, claims that when the box and diamond are interpreted as the logical modality operators, the Kripkean account is extensionally incorrect because it fails to reflect the fact that all sentences stating truths about what is logically possible are themselves logically necessary. I defend the Kripkean account by arguing that some true sentences about logical possibility are not logically (...) necessary. (shrink)

I set up a dilemma, concerning metaphysical modality de re, for the essentialist opponent of a ‘two senses’ view of necessity. I focus specifically on Frank Jackson's two-dimensional account in his From Metaphysics to Ethics (Oxford: Oxford University Press, 1998). I set out the background to Jackson's conception of conceptual analysis and his rejection of a two senses view. I proceed to outline two purportedly objective (as opposed to epistemic) differences between metaphysical and logical necessity. I conclude that since one (...) of these differences must hold and since each requires the adoption of a two senses view of necessity, essentialism is not consistent with the rejection of a two senses view. (shrink)

Some philosophers, for example Quine, doubt the possibility of jointly using modalities and quantification. Simple model-theoretic considerations, however, lead to a reconciliation of quantifiers with such modal concepts as logical, physical, and ethical necessity, and suggest a general class of modalities of which these are instances. A simple axiom system, analogous to the Lewis systems S1 —S5, is considered in connection with this class of modalities. The system proves to be complete, and its class of theorems decidable.

Tenseless theories of time entail that earlierthan, later than and simultaneous with (i.e.,McTaggart's `B-series') are the only temporalproperties exemplified by events. Such theories oftencome under attack for being unable to satisfactorilyaccount for tensed language. In this essay I arguethat tenseless theories of time are capable of twofeats that critics, such as Quentin Smith, argue arebeyond their grasp: (1) They can coherently explainthe impossibility of translating all tensed sentencesby tenseless counterparts; (2) They can account forcertain obviously valid entailment relations betweentensed sentence (...) types. In analyzing tensed entailmentrelations tenselessly, I favor a date analysis oftensed language over a token-reflexive theory. Theupshot is that tenseless theories of time are notundermined by the linguistic facts. (shrink)

It is argued that miracles are best understood as natural events with supernatural causes and that such causal interaction is logically possible. Such miracles may, or may not, involve violations of natural laws. If violations of laws are possible, Humean supervenience views of laws are best avoided. Where miracles violate laws, it shows that what is naturally impossible may be actual and what is naturally necessary may not be actual. Whether or not miracles actually occur, this demonstrates that the nomic (...) modalities differ from the logical. The theory contrasts favourably with competitors and allows, contrary to an interpretation of Aquinas, that Creation would have been a miracle. (shrink)

In this paper I argue that Kierkegaard's theory of change is motivated by a robust notion of contingency. His view of contingency is sharply juxtaposed with a strong notion of absolute necessity. I show that how he understands these notions explains certain of his claims about causation. I end by suggesting a compatibilist interpretation of Kierkegaard's philosophy.

Against Russell’s skeptical conjecture, that the world and its entire population came into existence five minutes ago, it is argued that any one of the following is logically incompatible with the conjunction of the other two: ostensible memories of certain events, records of such events, and the non-occurrence of these same events. This conclusion is reached through a critical examination of (1) the arguments advanced by Norman Malcolm in trying to show that Russell’s “hypothesis” does not express a logical possibility, (...) and (2) the counterarguments by which James W. Cornman tries to show that it does. (shrink)

Critical (necessary or sufficient) features in categorisation have a long history, but the empirical evidence makes their existence questionable. Nevertheless, there are some cases that suggest critical feature effects. The purpose of the present work is to offer some insight into why classification decisions might misleadingly appear as if they involve critical features. Utilising Tversky's (1977) contrast model of similarity, we suggest that when an object has a sparser representation, changing any of its features is more likely to lead to (...) a change in identity than it would in objects that have richer representations. Experiment 1 provides a basic test of this suggestion with artificial stimuli, whereby objects with a rich or a sparse representation were transformed by changing one of their features. As expected, we observed more identity judgements in the former case. Experiment 2 further confirms our hypothesis, with realistic stimuli, by assuming that superordinate categories have sparser representations than subordinate ones. These results offer some insight into the way feature changes may or may not lead to identity changes in classification decisions. (shrink)

A recombinationist like the earlier Armstrong (1989) claims that logically possible worlds are recombinations of items found in the actual world, with some items reduplicated if need be and others deleted. An immediate consequence of this is that if an alien property is a property that could only be defined in terms of fundamental properties that are actually uninstantiated, then it is logically impossible that an alien property be instantiated as no recombination of the items in the actual world can (...) yield a world with an entity having such a property. Recombinationism immediately implies that S5 is false. To see this, suppose for simplicity, as I will throughout this paper, that electric charge is a fundamental property--otherwise, a different example would have to be used. Then, let w be a possible world lacking any charged objects. At w, then, it is true that it is logically impossible that there be a charged particle since no recombination of the entities in w yields a charged particle. Therefore, contrary to S5, what is possible at w differs from what is possible at the actual world, since charged particles are actual and hence logically possible at the actual world. While this argument may make one sceptical of recombinationism, the recombinationist will say that it is not surprising that if we follow out the Aristotelian intuition that possibility is to be grounded in actually existing entities, then what is possible will depend on what is actual. Henceforth I will no longer assume S5, and so logical possibilities will have to be relativized to worlds if recombinationism is true: it is logically possible at the actual world for charged particles to exist, but at a world at which there are no charged particles it is logically impossible for charged particles to exist... (shrink)

Millikan and Her Critics offers a unique critical discussion of Ruth Millikan's highly regarded, influential, and systematic contributions to philosophy of mind and language, philosophy of biology, epistemology, and metaphysics. These newly written contributions present discussion from some of the most important philosophers in the field today and include replies from Millikan herself.

Hume's arguments for the contention that causal necessity precludes logical necessity depend on the questionable principle that a cause must precede its effect. Hobbes' definition of entire cause, although it fails to account for causal priority, is not refuted by Hume. The objections of Myles Brand and Marshall Swain (Philosophical Studies, 1976) to my counterexample against Hume (Philosophical Studies, 1975) are ineffective. Their other objections to my criticisms of their argument against defining causation in terms of necessary and sufficient conditions (...) (Synthese, 1970) are also mostly ineffective. (shrink)

Myles Brand and Marshall Swain advocate the principle that if A is the set of conditions individually necessary and jointly sufficient for the occurrence of B, then if C is a set of conditions individually necessary for the occurrence of B, every member of C is a member of A. I agree with John Barker and Risto Hilpinen who each argue that this principle is not true for causal necessity and sufficiency, but I disagree with their claim that it is (...) true for logical necessity and sufficiency. The original appeal of the principle may be due to confusing two kinds of totality: to say that when every member of set A obtains, then every condition necessary for E obtains is not to say that every condition necessary for E is a member of A. All the authors mentioned believe that causal necessity precludes logical necessity. I deny this on the basis of an example from kinematics. Hume has not refuted definitions of causation in terms of logically necessary and sufficient conditions, nor have Brand and Swain. (shrink)

In this paper I challenge the core of David Chalmers' argument against materialism-the claim that "there is a logically possible world physically identical to ours, in which the positive facts about consciousness do not hold." First, I analyze the move from conceivability to logical possibility. Following George Seddon, I consider the case of a floating iron bar and argue that even this seemingly conceivable event has implicit logical contradictions in its description. I then show that the distinctions Chalmers employs between (...) primary and secondary intensions, and a priori and a posteriori entailment, break down upon close examination-with iron bars and with consciousness it is impossible to know where primary intensions end and secondary intensions begin. I extend this analysis of logical possibility to the famous zombie thought experiment and conclude not that a zombie world is logically impossible, but rather that, at present, the question is open. Finally, I show how a similar line of argument may be used to undermine the "Mary the color scientist" thought experiment as well. (shrink)

This paper defends (especially in response to Brian Leftow’s recent attack) logical nominalism, the thesis that logically necessary truth belongs primarily to sentences and depends solely on the conventions of human language. A sentence is logically necessary (that is, a priori metaphysically necessary) iff its negation entails a contradiction. A sentence is a posteriori metaphysically necessary iff it reduces to a logical necessity when we substitute for rigid designators of objects or properties canonical descriptions of the essential properties of those (...) objects or properties. The truth-conditions of necessary sentences are not to be found in any transcendent reality, such as God’s thoughts. "There is a God" is neither a priori nor a posteriori metaphysically necessary; God is necessary in the sense that His existence is not causally contingent on anything else. (shrink)

I believe that Craig's arguments for the possibility of (DT) are important for two reasons: first, because the line he takes, though unsuccessful in my opinion, is the most plausible (or least implausible) line available; and second, because he sets forth with startling clarity some of the propositions that someone who takes this line must be willing to accept. But in the end, I shall argue, he not only fails to establish that (DT) is possible; he also fails in the (...) lesser task of trying to undermine my own argument that (DT) is impossible. Although Craig nowhere gives formal shape it, his argument for the possibility of (DT) seems to run something like this: He first insists that certain propositions other than (DT) are possible in the broadly logical sense, and he then tries to deduce the possibility of (DT) from these other possibilities; that is, he casts about for some proposition p - perhaps a conjunction of several propositions - that will enable him to argue as follows: (1) p entails (DT). (2) p is possible in the broadly logical sense. (3) Therefore, (DT) is also possible in the broadly logical sense. And, of course, the challenge he faces in defending such an argument is this: If, for some p, he.. (shrink)

This study investigated individual differences in the belief bias effect, which is the tendency to accept conclusions because they are believable rather than because they are logically valid. It was observed that the extent of an individual's belief bias effect was unrelated to a number of measures of reasoning competence. Instead, as predicted by mental models theory, it was related to a person's ability to generate alternative representations of premises: the more alternatives a person generated, the less likely they were (...) to show a belief bias effect. In contrast to belief effects, which were predicted by the number of alternatives generated, scores on logical reasoning tasks were predicted by an individual's understanding of the concept of logical necessity. These two mediating variables, ability to generate alternatives and understanding of logical necessity, were themselves predicted by similar variables, such as cognitive motivation and abstract reasoning ability. Our findings strongly support the mental models interpretation of the belief bias effect, and suggest that individual differences in this effect are associated with a specific ability to generate alternatives, rather than with a general logical competence. (shrink)

Prior research shows that reasoners' confidence is poorly calibrated (Shynkaruk & Thompson, 2006). The goal of the current experiment was to increase calibration in syllogistic reasoning by training reasoners on (a) the concept of logical necessity and (b) the idea that more than one representation of the premises may be possible. Training improved accuracy and was also effective in remedying some systematic misunderstandings about the task: those in the training condition were better at estimating their overall performance than those who (...) were untrained. However, training was less successful in helping reasoners to discriminate which items are most likely to cause them difficulties. In addition we explored other variables that may affect confidence and accuracy, such as the number of models required to represent the problem and whether or not the presented conclusion was necessitated by the premises, possible given the premises, or impossible given the premises. These variables had systematically different relationships to confidence and accuracy. Thus, we propose that confidence in reasoning judgements is analogous to confidence in memory retrievals, in that they are inferentially derived from cues that are not diagnostic in terms of accuracy. (shrink)

Modal rationalism includes the thesis that ideal primary positive conceivability entails primary possibility. Modal monism is the thesis that the space of logically possible worlds is coextensive with the space of metaphysically possible worlds. In this paper I explore the relation between the two theses. My aim is to show that the former thesis implies the latter thesis, and that problems with the latter make the former implausible as a complete picture of the epistemology of modality. My argument explores the (...) relation between logical modality and metaphysical modality. (shrink)

I look at a recent argument offered in defense of a doctrine which I will call generalized scientific essentialism. This is the doctrine according to which, not only are some facts about substance composition metaphysically necessary, but, in addition, some facts about substance behavior are metaphysically necessary. More specifically, so goes the argument, not only is water necessarily composed of H2O and salt is necessarily composed of NaCl, but, in addition, salt necessarily dissolves in water. If this argument is sound, (...) and if the statement that necessarily salt dissolves in water is a statement of a law of nature, then one conclusion of the argument is that there is at least one metaphysically necessary law of nature. My paper examines the extent to which this kind of argument could be generalized to provide a case for a full-blown scientific essentialism: the doctrine according to which all of the laws of nature are necessary. Or, in terms of dispositions, it is the doctrine according to which natural kinds have all of their powers, capacities and propensities as a matter of necessity. (shrink)

In the last 30 years much philosophical discussion has been generated by Kripke’s proof of the necessity of origin for material objects presented in footnote 56 of ‘Naming and Necessity’. I consider the two most popular reconstructions of Kripke’s argument: one appealing to the necessary sufficiency of origin, and the other employing a strong independence principle allegedly derived from the necessary local nature of prevention. I argue that, to achieve a general result, both reconstructions presuppose an implicit Humean atomistic thesis (...) of recombination, according to which any two (non-overlapping) possible objects can simultaneously coexist in one and the same world. Yet recombination ill accords with the other assumptions of the proofs. I also argue that the locality of prevention does not entail strong independence. (shrink)

In the history of philosophy, especially its recent history, a number of definitions of necessity have been ventured. Most people, however, find these definitions either circular or subject to counterexamples. I will show that, given a broadly Fregean conception of properties, necessity does indeed have a noncircular counterexample-free definition.

This paper introduces a modal epistemology that centers on inference to the best explanation (i.e. abduction). In introducing this abduction-centered modal epistemology, the paper has two main goals. First, it seeks to provide reasons for pursuing an abduction-centered modal epistemology by showing that this epistemology aids a popular stance on the mind-body problem and allows an appealing approach to modality. Second, the paper seeks to show that an abduction-centered modal epistemology can work by showing that abduction can establish claims about (...) necessity/possibility (i.e. modal claims)—where ‘necessity’ and ‘possibility’ denote metaphysical necessity and possibility, ways things may or may not have been given how they actually are. (shrink)

Simon Blackburn posed a dilemma for any realist attempt to identify the source of necessity. Either the facts appealed to to ground modal truth are themselves necessary, or they are contingent. If necessary, we begin the process towards regress; but if contingent, we undermine the necessity whose source we wanted to explain. Bob Hale attempts to blunt both horns of this dilemma. In this paper I examine their respective positions and attempt to clear up some confusions on either side. I (...) come to defend Hale’s conclusion that both horns of the dilemma can be resisted. I end by defending my own account of the source of necessity, and showing why it does not fall victim to Blackburn’s problem. (shrink)

I begin by contrasting three approaches one can take to the distinction between the essential and accidental properties: an ontological, a deflationary, and a mind-dependent approach. I then go on to apply that distinction to the necessary a posteriori, and defend the deflationist view. Finally I apply the distinction to modal truth in general and argue that the deflationist position lets us avoid an otherwise pressing problem for the actualist: the problem of accounting for the source of modal truth.

In this paper I argue that there are some sentences whose truth makes no demands on the world, being trivially true in that their truth-conditions are trivially met. I argue that this does not amount to their truth-conditions being met necessarily: we need a non-modal understanding of the notion of the demands the truth of a sentence makes, lest we be blinded to certain conceptual possibilities. I defend the claim that the truths of pure mathematics and set theory are trivially (...) true, and hence accepting their truth brings no ontological commitment; I further defend the claim that the truths of applied mathematics and set theory do not demand the existence of numbers or sets. While the notion of a demand must not be reduced to anything modal, I nonetheless argue that sentences that are trivially true must also be necessary, lest we violate a very weak version of the principle that truth depends on the world. I further argue that all necessary truths are trivially true, lest we admit unexplained necessities. I end by showing one important consequence of this: I argue that if there are truthmakers for intrinsic predications, they must be states of affairs rather than tropes. (shrink)

Some truths are necessary, others could have been false. Why? What is the source of the distinction between the necessary and the contingent? What's so special about the necessary truths that account for their necessity? In this article, we look at some of the most promising accounts of the grounds of necessity: David Lewis' reduction of necessity to truth at all possible worlds; Kit Fine's reduction of necessity to essence; and accounts of necessity that take the distinction between the necessary (...) and the contingent to be a matter of convention. (shrink)