Theories of Modality, Misc

This work presents a causal conception of metaphysical modality in which a state of affairs is metaphysically possible if and only if it can be caused by current entities. The conception is contrasted with what is called the “combinatorial” conception of modality, in which everything can co-exist with anything else. This work explains how the notion of ‘causality’ should be construed in the causal theory, what difference exists between modalities thus defined from nomological modality, how accessibility relations between possible worlds (...) should be interpreted, and what is the relation between the causal conception and the necessity of origin. (shrink)

Kant's claim that modality is a 'category' provides an approach to modality to be contrasted with Lewis's reductive analysis. Lewis's position is unsatisfactory, since it depends on an inherently modal conception of a world. This suggests that modality is 'primitive'; and the Kantian position is a prima facie plausible position of this kind, which is filled out by considering the relationship between modality and inference. This provides a context for comparing the Kantian position with Wright's non-cognitivist 'conventionalism'. Wright's position is (...) vulnerable to the type of argument used against ethical non-cognitivism, and the Kantian position is further confirmed by Blackburn's acknowledgment that modality is 'antinaturalistic to its core'. The position is further elaborated to show that it can accommodate the famous Kripkean categories of the empirically necessary and the contingent a priori, and finally defended against the criticisms used by Quine against Carnap. (shrink)

This book, written by one of the most distinguished of contemporary philosophers of mathematics, is a fully rewritten and updated successor to the author's earlier The Unprovability of Consistency. Its subject is the relation between provability and modal logic, a branch of logic invented by Aristotle but much disparaged by philosophers and virtually ignored by mathematicians. Here it receives its first scientific application since its invention. Modal logic is concerned with the notions of necessity and possibility. What George Boolos does (...) is to show how the concepts, techniques, and methods of modal logic shed brilliant light on the most important logical discovery of the twentieth century: the incompleteness theorems of Kurt Godel and the 'self-referential' sentences constructed in their proof. The book explores the effects of reinterpreting the notions of necessity and possibility to mean provability and consistency. (shrink)

While preparing my suitcase for Padua, I took care to put my favorite cds in a secured spot since they could have broken along the way. Which (non-mental) fact, if any, could possibly justify my action – i.e. what, if anything, makes it the case that my cds could have broken? The paper explores the nature of possibility. The three theories most widely endorsed thus far – fictionism, actualism, and modal realism – are introduced, with a particular attention to their (...) unpalatable ontological consequences. In order to avoid such consequences, a fourth theory is put forward. The goal of the theory is to explain the nature of possibility on the basis of actual (vs possible) entities while, at the same time, providing a non-circular interpretation of the meaning of our modal talk on the basis of such actual entities. Dispositions are meant to be the ontological ground of the theory. They play the role of possibilia – i.e. the entities on the basis of which we interpret modal assertions. A characterization of the sort of dispositions needed for grounding the theory is given. Finally follow some remarks on the effects of the theory upon the extension of the domain of possibilia. (shrink)

– The paper defends a naturalistic version of modal actualism according to which what is metaphysically possible is determined by dispositions found in the actual world. We argue that there is just one world—this one—and that all genuine possibilities are anchored by the dispositions exemplified in this world. This is the case regardless of whether or not those dispositions are manifested. As long as the possibility is one that would obtain were the relevant disposition manifested, it is a genuine possibility. (...) Furthermore, by starting from actual dispositional properties and branching out, we are able to include possibilities that are quite far removed from any state of affairs that happens to obtain, while still providing a natural and actual grounding of possibility. Stressing the importance of ontological considerations in any theory of possibility, it is argued that the account of possibility in terms of dispositional properties provides a more palatable ontology than those of its competitors. Coming at it from the other direction, the dispositional account of possibility also provides motivation for taking an ontology of dispositions more seriously. As well as the relevant dispositional notions required to lay out the view, the paper discusses the dispositional realism needed as the basis for the account of possibility. (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)

Kant's speculative theistic proof rests on a distinction between “logical” and “real” modality that he developed very early in the pre-critical period. The only way to explain facts about real possibility, according to Kant, is to appeal to the properties of a unique, necessary, and “most real” being. Here I reconstruct the proof in its historical context, focusing on the role played by the theory of modality both in motivating the argument (in the pre-critical period) and, ultimately, in undoing it (...) as a source of knowledge of God's existence (in the critical period). Along the way I examine Kant's version of the now-popular “actualist” thesis that facts about what is possible must be explained by facts about what is actual. I conclude by discussing why the critical Kant claims both that there are rational grounds for accepting the conclusion of his theistic proof, and that such acceptance can not count as knowledge. This is important, I argue, because the same considerations ultimately motivate his prohibition on knowledge of things-in-themselves generally. -/- . (shrink)

During a short-lived renaissance of medieval Nominalism lasting from approximately 1480 to 1530, many Renaissance Nominalist logicians devoted a great deal of attention to the task of developing an account of the truth and falsity of modal propositions. A modal proposition is any proposition containing one or more occurrences of the four modal terms: possible, necessary, impossible, and contingent. The Nominalist account follows the general procedure outlined in William of Ockham's Summa totius logicae, the goal of which is to translate (...) modal propositions into one or more non-modal propositions, each proposition the subject of a "metalinguistic" modal predicate. For example, the modal proposition 'George possibly is running' would be translated to: " thinspace'George is running' is possible." ;Renaissance Nominalists follow the practice of medieval logicians in distinguishing two types of modal propositions: the "composed" and the "divided". They differ from the medievals in how they define these. Composed modal propositions contain a "second intention" modal term; divided modal propositions contain "syncategorematic" modal terms. Second intention modes appear in either the subject or predicate positions in propositions, and refer to presently existing sentence tokens. Syncategorematic modes do not alone refer to anything, and extend or "ampliate" the reference of other terms in the proposition from presently existing actual entities to non-actual possible beings. ;Determining the truth value of a composed modal proposition was considered an easy task since the non-modal proposition into which the modal proposition is translated preserves the logical form of the original. However, the truth value of a divided modal propositions depends upon the modality belonging to the atomic propositions implied by it. ;A theory of modal truth is not complete unless it develops an account of the metaphysical nature of modality as the basis for ascribing truth values to modal propositions. The Nominalist logicians of the time offer only fragments of such a theory. Some suggested that modalities only exist in the mind; others believed that modalities are real, extramental relations holding between individuals. Such remarks were never fully reconciled with other modal notions found in these texts, particularly notions defined in terms of God's potencies. (shrink)

It is commonly assumed that all propositions have modal profiles and therefore bear their truth-values either contingently or necessarily. I argue against this commonly assumed view and in defence of amodalism, according to which certain true propositions are neither necessarily nor contingently true, but only true simpliciter. I consider three arguments against ‘possible-worlds theories’, which hold that modal concepts are to be analysed in terms of possible worlds. Although each of these arguments targets a different version of possible-worlds theory, these (...) versions jointly exhaust the entire range of possible-worlds theories. After showing that each argument is naturally addressed by adopting amodalism, I argue that all defenders of possible-worlds theory ought to accept amodalism. (shrink)

David Lewis' objection to a generic theory of modality which he calls ‘magical ersatzism’ is that its linchpin, a relation he calls ‘selection’, must be either an internal or an external relation, and that this is unintelligible either way. But the problem he points out with classifying selection as internal is really just an instance of the general problem of how we manage to grasp underdetermined predicates, is not peculiar to magical ersatzism, and is amenable to some familiar solutions. He (...) provides no compelling grounds for thinking that classifying selection as external is unintelligible, and his argument has a false presupposition. I conclude that magical ersatzism is still a viable option in the metaphysics of modality. (shrink)

The modal antirealist, as presented here, aims to secure at least some of the benefits associated with talking in genuine modal realist terms while avoiding commitment to a plurality of Lewisian (or ersatz) worlds. The antirealist stance of agnosticism about other worlds combines acceptance of Lewis's account of what world-talk means with refusal to assert, or believe in, the existence of other worlds. Agnosticism about other worlds does not entail a comprehensive agnosticism about modality, but where such agnosticism about modality (...) is enforced, the aim of the agnostic programme is to show that it is not detrimental to our modal practices. The agnostic programme consists in an attempt to demonstrate the rational dispensability of that disputed class of modal beliefs which the agnostic eschews, but which are held by the realist and the folk. Here I attempt to motivate, describe, and illustrate such an agnostic antirealist programme in modal philosophy. (shrink)

The essays that constitute this dissertation explore three strategies for understanding the role of modality in philosophical accounts of propensities, randomness, and causation. In Chapter 1, I discuss how the following essays are to be considered as illuminating the prospects for these strategies, which I call reductive essentialism, subjectivism and pragmatism. The discussion is framed within a survey of approaches to modality more broadly construed. ;In Chapter 2, I argue that any broadly dispositional analysis of probability as a physical property (...) will either fail to give an adequate explication of probability, or else will fail to provide an explication that can be gainfully employed elsewhere . The diversity and number of arguments suggests that there is little prospect of any successful analysis along these lines. ;The concept of randomness has been unjustly neglected in recent philosophical literature, and when philosophers have thought about it, they have usually acquiesced in views about the concept that are fundamentally flawed. In Chapter 3 I try to redress this. After indicating the ways in which the existing accounts are flawed, I propose that randomness is to be understood as a special case of the epistemic concept of the unpredictability of a process. This proposal arguably captures the intuitive desiderata for the concept of randomness; at least it should suggest that the commonly accepted accounts cannot be the whole story and more philosophical attention needs to be paid. ;Russell famously argued that causation should be dispensed with. He gave two explicit arguments for this conclusion, which can be defused if we loosen the ties between causation and determinism. In Chapter 4, I define a concept of causation which meets Russell's conditions but does not reduce to triviality. Unfortunately, a further serious problem is implicit beneath the details of Russell's arguments, which I call the causal exclusion problem. Meeting this problem involves deploying a pragmatic account of the nature and function of modal concepts. Russell's scruples about causation can be accommodated, even as we partially legitimise the pervasiveness of causal explanations in folk and scientific practice. (shrink)

We argue that genuine modal realism can be extended, rather than modified, so as to allow for the possibility of nothing concrete, a possibility we term ‘metaphysical nihilism’. The issue should be important to the genuine modal realist because, not only is metaphysical nihilism itself intuitively plausible, but also it is supported by an argument with pre-theoretically credible premises, namely, the subtraction argument. Given the soundness of the subtraction argument, we show that there are two ways that the genuine modal (...) realist can accommodate metaphysical nihilism: (i) by allowing for worlds containing only spatiotemporal points and (ii) by allowing for a world containing nothing but the null individual. On methodological grounds, we argue that the genuine modal realist should reject the former way but embrace the latter way. (shrink)

Are there, in addition to the various actual objects that make up the world, various possible objects? Are there merely possible people, for example, or merely possible electrons, or even merely possible kinds? We certainly talk as if there were such things. Given a particular sperm and egg, I may wonder whether that particular child which would result from their union would have blue eyes. But if the sperm and egg are never in fact brought together, then there is no (...) actual object that my thought is about. Or again, in the semantics for modal logic we presuppose an ontology of possibilia twice over. For first, we countenance various possible worlds, in addition to the actual world; and second, each of these worlds is taken to be endowed with its own domain of objects. These will be the actual objects of the world in question, but they need not be actual simpliciter, i.e., actual objects of our world. What are we to make of such discourse? There are four options: (i) the discourse is taken to be unintelligible; (ii) it is taken to be intelligible but nonfactual, i.e. as not in the business of stating facts; (iii) it is taken to be factual but reducible to discourse involving no reference to possibilia; (iv) it is taken to be both factual and irreducible. These options range from a full-blooded form of actualism at one extreme to a full-blooded form of possibilism at the other. The two intermediate positions are possibilist in that they accept the intelligibility of possibilist discourse but actualist in that they attempt to dispense with its prima facie commitment to possibilia. All four positions have found advocates in the literature. Quine, in his less irenic moments, favours option (i); Forbes advocates option (ii), at least for certain parts of possibilist discourse; many philosophers, including Adams and myself, opt for (iii); while Lewis and Stalnaker have endorsed versions of (iv), that differ in how full-blooded they take the possible objects to be.. (shrink)

Contingency is the presence of non-actualized possibility in the world. Fatalism is a view of reality on which there is no contingency. Since it is contingency that permits agency, there has traditionally been much interest in contingency. This interest has long been embarrassed by the contention that simple and plausible assumptions about the world lead to fatalism. I begin with an Aristotelian argument as presented by Richard Taylor. Appreciation of this argument has been stultified by a question pertaining to the (...) source of necessity and possibility and a closely related one regarding the nature of metaphysics itself. Answering these questions reveals the crucial issue here, to wit, necessity and possibility in a temporal world. This issue is investigated through an important later criticism of Taylor by David Foster Wallace. Wallace’s critique is significant because it brings to the fore the pivotal notion for understanding contingency in a temporal world, that of synchronic possibility, the idea that incompatible states of affairs are possible at a single moment. This notion provides the basis of distinguishing two systematic accounts of truth, modality and time: two metaphysics of contingency. On one account, Taylor’s Aristotelian argument is straightforwardly valid and compelling; on the other, it is fallacious. In closing, I present reasons why the former account, supporting the Aristotelian views of time and truth, is correct and make some comments to ameliorate this conclusion. (shrink)

Sydney Shoemaker’s causal theory of properties is an important starting place for some contemporary metaphysical perspectives concerning the nature of properties. In this paper, I discuss the causal and intrinsic criteria that Shoemaker stipulates for the identity of genuine properties and relations, and address George Molnar’s criticism that holding both criteria presents an unbridgeable hypothesis in the causal theory of properties. The causal criterion requires that properties and relations contribute to the causal powers of objects if they are to be (...) deemed genuine rather than ‘mere-Cambridge’. The intrinsic criterion requires that all genuine properties and relations be intrinsic. Molnar’s S-property argument says that these criteria conflict if one considers extrinsic spatiotemporal properties and relations to contribute causally. In this paper, I argue that a solution to the contradiction that Molnar identifies involves a denial of discreteness between objects, leading to a power holist perspective and a resulting deflationary account of intrinsicality. (shrink)

In this paper we discuss Brandom's definition of necessity, which is part of the incompatibility sematnics he develops in his fifth John Locke Lecture. By comparing incompatibility semantics to standard Kripkean possible worlds semantics for modality, we motivate an alternative definition of necessity in Brandom's own terms. Our investigation of this alternative necessity will show that - contra to Brandom's own results - incompatibility semantics does not necessarily lead to the notion of necessity of the modal logic S5.

This book addresses the importance of space and time, of existence unperceived, of publicity and action, and of natural laws.

The branching time analysis grounds the possibilities entailed by temporal indeterminism in a branching temporal structure. I construct a spatial analog of the branching time analysis – the branching space analysis – according to which the possibilities entailed by spatial indeterminism are grounded in branching spatial structure. The construction proceeds in such a way as to show the analogies between the branching space and branching time analyses. I argue that the two views are a package. In particular: the theoretical virtues (...) of the one are theoretical virtues of the other and so if one ought to be accepted, then the other should also be accepted. And: if one ought to be denied, then the other ought to be denied as well. Thus, the branching space analysis functions either as a counterexample to the reductive strategy embodied in the branching time analysis or as a reasonable extension of it – as a lesson learned from it. (shrink)

Possible worlds, concrete or abstract as you like, are irrelevant to the truthmakers for modality—or so I shall argue in this paper. First, I present the neo-Humean picture of modality, and explain why those who accept it deny a common sense view of modality. Second, I present what I take to be the most pressing objection to the neo-Humean account, one that, I argue, applies equally well to any theory that grounds modality in possible worlds. Third, I present an alternative, (...) properties-based theory of modality and explore several specific ways to flesh the general proposal out, including my favored version, the powers theory. And, fourth, I offer a powers semantics for counterfactuals that each version of the properties-based theory of modality can accept, mutatis mutandis. Together with a definition of possibility and necessity in terms of counterfactuals, the powers semantics of counterfactuals generates a semantics for modality that appeals to causal powers and not possible worlds. (shrink)

Possibility offers a new analysis of the metaphysical concepts of possibility and necessity, one that does not rely on any sort of "possible worlds." The analysis proceeds from an account of the notion of a physical object and from the positing of properties and relations. It is motivated by considerations about how we actually speak of and think of objects. Michael Jubien discusses several closely related topics, including different purported varieties of possible worlds, the doctrine of "essentialism," natural kind terms (...) and alleged examples of necessity a posteriori. The book also offers a new theory of the functioning of proper names, both actual and fictional, and the discussion of natural kind terms and necessity a posteriori depends in part on this theory. (shrink)

In the presentation I will analyse Kant’s conception of modalities and consider its relevance to his critical metaphysics. With his Tables of Judgements and of Categories Kant makes an important division between two kinds of modality, of which the former is only logical and the latter transcendental, i.e., objective. Only judgements that are necessary in both ways are properly metaphysical. This distinction is important for Kant’s distinction between Transcendental Analytic and Transcendental Dialectic, i.e., between acceptable and unacceptable metaphysics. I submit (...) that not only is Kant’s theory of modality useful for properly understanding his arguments in the Dialectic, but that only by distinguishing between the two types of modality can one can make sense of his theory that the ideas of reason are simultaneously inevitable and erroneous. This modal analysis thus offers a new and important point of view to Kant’s metaphysics and its critique. (shrink)

God’s relationship to modalities poses a serious problem for the theist. If God determines modalities, then it seems that he can do anything. If, on the other hand, modalities determine God’s actions, then it seems that he is not genuinely free. Conceptualism offers a solution to this problem by maintaining that modalities are determined by what is conceivable for the intellects of the universe that God has chosen to create. Prior to the creation of intellects, there are no modalities restricting (...) God’s choice. Consequently, God is genuinely free. What is more, prior to creation there are no modalities, thus it is not the case that anything is possible. However, there are several problems with conceptualism. In particular, because the necessary features of the modal concepts themselves are independent of the shape of any intellect, no form of conceptualism will succeed as a solution to the problem of modalities. (shrink)

This paper replies to Nanay’s response to my recent paper. My suggestions are the following. First, “should” or “ought” does not need to be deontic. Second, etiological theories of function, like provability logic, do not need to attribute modal force to their explanans. Third, the explanans of the homological account of trait type individuation does not appeal to a trait’s etiological function, that is, what a trait should or ought to do. Finally, my reference to Cummins’s notion of function was (...) intended to note that the homological account is permitted to use this non-etiological notion of function. (shrink)

Naturalistic teleological accounts of mental content rely on an etiological theory of function. Nanay has raised a new objection to an etiological theory, and proposed an alternative theory of function that attributes modal force to claims about function. The aim of this paper is both to defend and to cast a new light on an etiological theory of function. I argue against Nanay’s “trait type individuation objection,” suggesting that an etiological theory also attributes modal force to claims about function. An (...) etiological theory of function can be thought to analyze claims about function with modal force, not relying on any theory of counterfactuals. (shrink)