This paper aims to contribute to the analysis of the nature of mathematical modality and hyperintensionality, and to the applications of the latter to absolute decidability. Rather than countenancing the interpretational type of mathematical modality as a primitive, I argue that the interpretational type of mathematical modality is a species of epistemic modality. I argue, then, that the framework of two-dimensional semantics ought to be applied to the mathematical setting. The framework permits of a formally precise account of the priority (...) and relation between epistemic mathematical modality and metaphysical mathematical modality. The discrepancy between the modal systems governing the parameters in the two-dimensional intensional setting provides an explanation of the difference between the metaphysical possibility of absolute decidability and our knowledge thereof. I also advance a topic-sensitive epistemic two-dimensional truthmaker semantics, if hyperintensional approaches are to be preferred to possible worlds semantics. I examine the relation between two-dimensional hyperintensional states and epistemic set theory, providing two-dimensional hyperintensional formalizations of the modal logic of ZFC, large cardinal axioms, $\Omega$-logic, and the Epistemic Church-Turing Thesis. (shrink)

In this paper, we consider recent attempts to metaphysically explain agentive modality in terms of conditionals. We suggest that the best recent accounts face counterexamples, and more worryingly, they take some agentive modality for granted. In particular, the ability to perform basic actions features as a primitive in these theories. While it is perfectly acceptable for a semantics of agentive modal claims to take some modality for granted in getting the extension of action claims correct, a metaphysical explanation of agentive (...) modality cannot, at least not in the way that conditional approaches to agentive modality do. We argue that this problem was present even in the classical conditional analysis. By a pessimistic induction, we suggest that, probably, no conditional approach to agentive modality will succeed. (shrink)

It is a truth universally acknowledged that a claim of metaphysical modality, in possession of good alethic standing, must be in want of an essentialist foundation. Or at least so say the advocates of the reductive-essence-first view, according to which all modality is to be reductively defined in terms of essence. Here, I contest this bit of current wisdom. In particular, I offer two puzzles—one concerning the essences of non-compossible, complementary entities, and a second involving entities whose essences are modally (...) ‘loaded’—that together strongly call into question the possibility of reducing modality to essence. (shrink)

It is a truth universally acknowledged that a claim of metaphysical modality, in possession of good alethic standing, must be in want of an essentialist foundation. Or at least so say the advocates of thereductive-essence-firstview, according to which all modality is to be reductively defined in terms of essence. Here, I contest this bit of current wisdom. In particular, I offer two puzzles—one concerning the essences of non-compossible, complementary entities, and a second involving entities whose essences are modally ‘loaded’—that together (...) strongly call into question the possibility of reducing modality to essence. (shrink)

Over the last half century, possible worlds have bled into almost every area of philosophy. In the metaphysics of modality, for example, philosophers have used possible worlds almost exclusively to illuminate discourse about metaphysical necessity and possibility. But recently, some have grown dissatisfied with possible worlds. Why are horses necessarily mammals? Because the property of being a horse bears a special relationship to the property of being a mammal, they say. Not because every horse is a mammal in every possible (...) world. Some have recently begun to use properties to develop rivals to possible worlds semantics which may someday compare in formal power and capture the different systems of modal logic. In this paper, I do two things. I first offer a quick primer on possible worlds semantics. Then I discuss three rivals and the work they have left to do. (shrink)

A common compatibilist view says that we are free and morally responsible in virtue of the ability to respond aptly to reasons. Many hold a version of this view despite disagreement about whether free will requires the ability to do otherwise. The canonical version of this view is reductive. It reduces the pertinent ability to a set of modal properties that are more obviously compatible with determinism, like dispositions. I argue that this and any reductive view of abilities faces a (...) significant challenge: it cannot adequately explain the freedom-grounding element of this ability. The problem has the form of a dilemma. This leaves reasons-responsive compatibilists with two options: abandon theories of free will grounded in abilities or abandon reductive theories of abilities. (shrink)

Williamsonian modal epistemology is characterized by two commitments: realism about modality, and anti-exceptionalism about our modal knowledge. Williamson’s own counterfactual-based modal epistemology is the best known implementation of WME, but not the only option that is available. I sketch and defend an alternative implementation which takes our knowledge of metaphysical modality to arise, not from knowledge of counterfactuals, but from our knowledge of ordinary possibility statements of the form ‘x can F’. I defend this view against a criticism indicated in (...) Williamson’s own work, and argue that it is better connected to the semantics of modal language. (shrink)

Dispositionalists try to provide an account of modality—possibility, necessity, and the counterfactual conditional—in terms of dispositions. But there may be a tension between dispositionalist accounts of possibility on the one hand, and of counterfactuals on the other. Dispositionalists about possibility must hold that there are no impossible dispositions, i.e., dispositions with metaphysically impossible stimulus and/or manifestation conditions; dispositionalist accounts of counterfactuals, if they allow for non-vacuous counterpossibles, require that there are such impossible dispositions. I argue, first, that there are in (...) fact no impossible dispositions; and second, that the dispositionalist can nevertheless acknowledge the non-vacuity of some counterpossibles. The strategy in the second part is one of ‘divide and conquer’ that is not confined to the dispositionalist: it consists in arguing that counterpossibles, when non-vacuous, are read epistemically and are therefore outside the purview of a dispositional account. (shrink)

According to essentialism, metaphysical modality is founded in the essences of things, where the essence of a thing is roughly akin to its real definition. According to potentialism (also known as dispositionalism), metaphysical modality is founded in the potentialities of things, where a potentiality is roughly the generalized notion of a disposition. Essentialism and potentialism have much in common, but little has been written about their relation to each other. The aim of this paper is to understand better the relations (...) between essence and potentiality, on the one hand, and between essentialism and potentialism, on the other. It is argued, first, that essence and potentiality are not duals but interestingly linked by a weaker relation dubbed ‘semi-duality’; second, that given this weaker relation, essentialism and potentialism are not natural allies but rather natural competitors; and third, that the semi-duality of essence and potentiality allows the potentialist to respond to an important explanatory challenge by using essentialist resources without thereby committing to essentialism. (shrink)

According to a widely held principle—the poss-ability principle—an agent, S, is able to only if it is metaphysically possible for S to. I argue against the poss-ability principle by developing a novel class of counterexamples. I then argue that the consequences of rejecting the poss-ability principle are interesting and far-reaching.

In The Concept of Mind, Gilbert Ryle argued that a more sophisticated understanding of the dispositional nature of ‘intelligent capacities’ could bolster philosophical resistance to the tempting view that the human mind is possessed of metaphysically ‘occult’ powers and properties. This temptation is powerful in the context of accounting for the special qualities of responsible agency. Incompatibilists indulge the temptation; compatibilists resist it, using a variety of strategies. One recent strategy, reminiscent of Ryle’s, is to exploit a more sophisticated understanding (...) of dispositional properties to account for these qualities. But ‘new dispositionalists’ run up against a ‘hard problem’ that threatens the approach. This paper argues that the threat may be averted by embracing a yet more radical ‘Rylean’ view of the distinctive dispositional nature of ‘intelligent capacities’. (shrink)

This essay proposes a new theory of agentive modals: ability modals and their duals, compulsion modals. After criticizing existing approaches—the existential quantificational analysis, the universal quantificational analysis, and the conditional analysis—it presents a new account that builds on both the existential and conditional analyses. On this account, the act conditional analysis, a sentence like ‘John can swim across the river’ says that there is some practically available action that is such that if John tries to do it, he swims across (...) the river. The essay argues that the act conditional analysis avoids the problems faced by existing accounts of agentive modality and shows how the act conditional analysis can be extended to an account of generic agentive modal claims. The upshot is a new vantage point on the role of agentive modal ascriptions in practical discourse: ability ascriptions serve as a kind of hypothetical guarantee, and compulsion ascriptions as a kind of nonhypothetical guarantee. (shrink)

Can knowledge be defined? We expound an argument of John Cook Wilson's that it cannot. Cook Wilson's argument connects knowing with having the power to inquire. We suggest that if he is right about that connection, then knowledge is, indeed, indefinable.

Lucy O'Brien has argued that defenders of the object-dependence of singular thought should attend to mental agency. A recent trend in action theory, towards what John Maier calls ‘agentive modality’, suggests that we conceive agency in terms of the exercise of abilities, and this is how I propose to approach O'Brien's challenge. For Gareth Evans, an early defender of object-dependence, maintained that thinking is the exercise of a complex of abilities. The debate about object-dependence gives way to the question whether (...) we have what I call dedicated singular mental abilities. In arguing that we do, I defend the thesis of object-dependence. (shrink)

Ordinary disposition ascriptions appear to form a semantically heterogeneous class of clauses some of which can be straightforwardly analyzed as possibility claims, and some of which resist a simple quantificational treatment. For example, while “The block is breakable” is true if the block breaks at a relevant possible world, for “The block is fragile” to be true it doesn’t suffice that the block breaks at one of the worlds that matter to the evaluation of the ascription, since the block could (...) break accidentally and yet be sturdy. The contrast has been taken to indicate that sentences like “The block is fragile” don’t introduce mere existential quantification over sets of worlds, and should be represented as claims about sufficient ratios or proportions of worlds. However, recent work has suggested that by pairing the recalcitrant DAs with modified manifestation phrases, we can generalize the standard analysis of existential DAs to the problematic examples, and state a uniform characterization of DAs as claims of possibility. The paper discusses some counterexamples to the view that allegedly non-existential DAs are covert claims of fine-grained possibility, and sketches a hybrid account combining proportional quantification with fine-grained manifestations. (shrink)

The domain of agential powers is marked by a contrast that does not arise in the case of dispositions of inanimate objects: the contrast between propensities or tendencies on the one hand, and capacities or abilities on the other. According to Ryle (1949), this contrast plays an important role in the ‘logical geography’ of the dispositional concepts used in the explanation and assessment of action. However, most subsequent philosophers use the terms of art ‘power’ or ‘disposition’ indiscriminately in formulating central (...) metaphysical claims about human agency, assuming that an adequate account of inanimate dispositions can safely be used for such purposes. As a result, the distinctive features of propensities and capacities drop out of view. This is bound to obscure distinctions of crucial importance to the understanding of human agency. In order to show this, I undertake to articulate some central differences between propensities and capacities. Propensities and capacities have a different relation to value, as well as a concomitant difference in their metaphysical structure. The argument points to an explanation of why the distinction between propensities and capacities does not arise in the case of non-agential powers. This explanation takes us back to questions about the nature of human agency. (shrink)

Determinism is frequently understood as implying the possibility of perfect prediction. This possibility then functions as an assumption in the Manipulation Argument for the incompatibility of free will and determinism. Yet this assumption is mistaken. As a result, arguments that rely on it fail to show that determinism would rule out human free will. We explain why determinism does not imply the possibility of perfect prediction in any world with laws of nature like ours, since it would be impossible for (...) an agent to predict with certainty any future event that is causally influenced by events outside her own backward light cone yet inside the backward light cone of the future event. This is the _light-cone limit_ and it undermines the Manipulation Argument or limits what this argument can tell us about the relevance of determinism to free will. We also respond to objections that the light-cone limit is irrelevant to the Manipulation Argument. (shrink)

Is knowledge-how, or “practical” knowledge, a species of knowledge-that, or “theoretical” knowledge? There is no comfortable position to take in the debate around this question. On the one hand, there are counterexamples against the anti-intellectualist thesis that practical knowledge is best analysed as an ability. They show that having an ability to ϕ is not necessary for knowing how to ϕ. On the other hand, the intellectualist analysis of practical knowledge as a subspecies of theoretical knowledge is threatened by its (...) own set of counterexamples, which convincingly establish that practical knowledge lacks many of the typical characteristics of theoretical knowledge. Most strikingly it does not even appear to require a belief. In this paper, I develop an account of practical knowledge that avoids these counterexamples. It also manages to preserve both the status of such knowledge as a cognitive achievement and its apparently close conceptual relation to abilities. I start with the counterexamples against the necessity of abilities for practical knowledge and show that they fail because they underestimate the cognitive demands of attempts. I then make use of the logic of dispositions to bridge the gap that counterexamples against the necessity of abilities for practical knowledge open. It is argued that, instead of the ability to ϕ, it is a specific disposition to have the ability to ϕ that constitutes practical knowledge about ϕ. The resulting theory is an anti-intellectualist position that preserves essential intellectualist motivations and thus should be satisfactory for proponents of both views. (shrink)

In many tragic plays, the protagonist is brought down by a disaster that is a consequence of the protagonist's own error, his or her hamartia, the tragic flaw. Tragic flaws are disconcerting to the audience because they are not known or fully recognized by the protagonist—at least not until it is too late. In this essay, I take tragic flaws to be unreliable belief-forming dispositions that are unrecognized by us in some sense. I describe some different types of flaws and (...) consider what we might do about them. Then I examine three types of policies for managing our tragic flaws: doxastic, dispositional, and methodological. (shrink)

According to dispositionalism, de re modality is grounded in the intrinsic natures of dispositional properties. Those properties are able to serve as the ground of de re modal truths, it is said, because they bear a special relation to counterfactual conditionals, one of truthmaking. However, because dispositionalism purports to ground de re modality only on the intrinsic natures of dispositional properties, it had better be the case that they do not play that truthmaking role merely in virtue of their being (...) embedded in some particular, extrinsic causal context. This paper examines a recent argument against dispositionalism that purports to show that the intrinsicality of that relation cannot be maintained, due to the ceteris paribus nature of the counterfactuals that dispositions make-true. When two prominent responses are examined, both are found wanting: at best, they require unjustified special pleading, and at worst, they amount to little more than ad hoc conceptual trickery. (shrink)

A compelling, and popular, thought is that ability entails control: S’s being able to φ entails that φ be, in some sense, in S’s control. But this intuition is inconsistent with a different prima facie compelling thought: that S’s succeeding in φ-ing entails that S is able to φ. In this paper, I introduce a new form of evidence to help adjudicate between these two theses: namely, probability judgments about ability ascriptions. I argue that these judgments provide evidence in favor (...) of the intuition that success entails ability, and against the intuition that ability requires control. Moreover, I argue that these judgments support one particular analysis which vindicates the success intuition, namely, the analysis of ability in terms of conditionals. (shrink)

We propose a new analysis of ability modals. After briefly criticizing extant approaches, we turn our attention to the venerable but vexed conditional analysis of ability ascriptions. We give an account that builds on the conditional analysis, but avoids its weaknesses by incorporating a layer of quantification over a contextually supplied set of actions.