We think of logic as objective. We also think that we are reliable about logic. These views jointly generate a puzzle: How is it that we are reliable about logic? How is it that our logical beliefs match an objective domain of logical fact? This is an instance of a more general challenge to explain our reliability about a priori domains. In this paper, I argue that the nature of this challenge has not been properly understood. I explicate the challenge (...) both in general and for the particular case of logic. I also argue that two seemingly attractive responses – appealing to a faculty of rational insight or to the nature of concept possession – are incapable of answering the challenge. (shrink)

I lay out the framework for my theory of sensory imagination in “Imagining as a guide to possibility.” Sensory imagining involves mental imagery , and crucially, in describing the content of imagining, I distinguish between qualitative content and assigned content. Qualitative content derives from the mental image itself; for visual imaginings, it is what is “pictured.” For example, visually imagine the Philadelphia Eagles defeating the Pittsburgh Steelers to win their first Super Bowl. You picture the greenness of the field and (...) the football’s brown oblong shape. Some of what you imagine isn’t explicitly pictured, however. That it is Sunday, that it is the Super Bowl: these facts are assigned. (shrink)

Is the world internally connected by a web of necessary connections or is everything loose and independent? Followers of David Hume accept the latter by upholding Hume’s Dictum, according to which there are no necessary connections between distinct existences. Roughly put, anything can coexist with anything else, and anything can fail to coexist with anything else. Hume put it like this: “There is no object which implies the existence of any other if we consider these objects in themselves.” Since Hume’s (...) day, Hume’s Dictum has played a major role in philosophy, especially in contemporary metaphysics. In ruling out necessary connections, Hume’s Dictum implies that causal relations and the laws of nature are contingent. It makes other demands on our metaphysics of science as well; for example, it places restrictions on our metaphysics of counterfactuals, dispositions, and explanation. The principle has applications in other areas too. Hume’s Dictum places constraints on our theories of abstract objects and moral properties. For example, Hume’s Dictum rules out the view that moral properties are distinct from, but necessarily connected to, non-moral properties. While Hume’s Dictum is a prominent principle in metaphysics, few Humeans have defended the principle at length. It is assumed more often than it is argued for. As a result, Hume’s Dictum no longer enjoys the reputation it once did. It’s common to hear complaints about the lack of arguments in support of Hume’s Dictum. Moreover, philosophers are increasingly willing to defend views that are at odds with Hume’s Dictum. A striking example of this is the recent explosion of interest in views that take causal relations and the laws of nature to be necessary. Humeans can no longer afford to be complacent. An extended defense of Hume’s Dictum is called for, and that’s what this dissertation aims to offer. This dissertation has three parts. In the first part, I lay out some preliminaries and offer a precise formulation of Hume’s Dictum. In the second part, I develop three arguments in favor of Hume’s Dictum. In the final part, I defend Hume’s Dictum against objections. (shrink)

This book is about the idea that some true statements would have been true no matter how the world had turned out, while others could have been false. It develops and defends a version of the idea that we tell the difference between these two types of truths in part by reflecting on the meanings of words. It has often been thought that modal issues—issues about possibility and necessity—are related to issues about meaning. In this book, the author defends the (...) view that the analysis of meaning is not just a preliminary to answering modal questions in philosophy; it is not merely that before we can find out whether something is possible, we need to get clear on what we are talking about. Rather, clarity about meaning often brings with it answers to modal questions. In service of this view, the author analyzes the notion of necessity and develops ideas about linguistic meaning, applying them to several puzzles and problems in philosophy of language. Meaning and Metaphysical Necessity will be of interest to scholars and advanced students working in metaphysics, philosophy of language, and philosophical logic. [See my homepage for a sample chapter.]. (shrink)

We are reliable about logic in the sense that we by-and-large believe logical truths and disbelieve logical falsehoods. Given that logic is an objective subject matter, it is difficult to provide a satisfying explanation of our reliability. This generates a significant epistemological challenge, analogous to the well-known Benacerraf-Field problem for mathematical Platonism. One initially plausible way to answer the challenge is to appeal to evolution by natural selection. The central idea is that being able to correctly deductively reason conferred a (...) heritable survival advantage upon our ancestors. However, there are several arguments that purport to show that evolutionary accounts cannot even in principle explain how it is that we are reliable about logic. In this paper, I address these arguments. I show that there is no general reason to think that evolutionary accounts are incapable of explaining our reliability about logic. (shrink)

Timothy Williamson offers a reductive account of modal knowledge in terms of knowledge of counterfactual conditionals. The account is developed in a broader context of defending two more general theses regarding the subject matter and methodology of philosophy. My primary focus in this paper is Williamson’s account of modal knowledge. I argue (1) that his account of modal knowledge does not support his more general theses regarding the subject matter and methodology of philosophy; (2) that the two central claims of (...) his account of knowledge of counterfactuals are rooted in unsubstantiated empirical assumptions; and (3) that his argument in support of the conclusion that modal knowledge is a special case of counterfactual knowledge rests on three errors: conflating logical reduction and epistemological reduction, a misguided appeal to cognitive economy, and incorrectly locating what needs to be explained by an account of modal knowledge. (shrink)

A selective annotated bibliography of recent literature on a priori knowledge.

This dissertation concerns the foundations of epistemic modality. I examine the nature of epistemic modality, when the modal operator is interpreted as concerning both apriority and conceivability, as well as states of knowledge and belief. The dissertation demonstrates how phenomenal consciousness and gradational possible-worlds models in Bayesian perceptual psychology relate to epistemic modal space. The dissertation demonstrates, then, how epistemic modality relates to the computational theory of mind; metaphysical modality; deontic modality; logical modality; the types of mathematical modality; to the (...) epistemic status of undecidable propositions and abstraction principles in the philosophy of mathematics; to the apriori-aposteriori distinction; to the modal profile of rational propositional intuition; and to the types of intention, when the latter is interpreted as a modal mental state. Examining the nature of epistemic logic itself, I develop a novel approach to conditions of self-knowledge in the setting of the modal μ-calculus, as well as novel epistemicist solutions to Curry's, the liar, and the knowability paradoxes. Solutions to previously intransigent issues concerning the first-person concept; the distinction between fundamental and derivative truths; and the unity of intention and its role in decision theory, are developed along the way. (shrink)

Abstract Timothy Williamson has recently proposed to undermine modal skepticism by appealing to the reducibility of modal to counterfactual logic ( Reducibility ). Central to Williamson’s strategy is the claim that use of the same non-deductive mode of inference ( counterfactual development , or CD ) whereby we typically arrive at knowledge of counterfactuals suffices for arriving at knowledge of metaphysical necessity via Reducibility. Granting Reducibility, I ask whether the use of CD plays any essential role in a Reducibility-based reply (...) to two kinds of modal skepticism. I argue that its use is entirely dispensable, and that Reducibility makes available replies to modal skeptics which show certain propositions to be metaphysically necessary by deductive arguments from premises the modal skeptic accepts can be known. Content Type Journal Article Pages 1-19 DOI 10.1007/s11098-011-9784-4 Authors Juhani Yli-Vakkuri, Wolfson College, Oxford University, Oxford, OX2 6UD UK Journal Philosophical Studies Online ISSN 1573-0883 Print ISSN 0031-8116. (shrink)

Comparative syllogism is a type of scientific reasoning widely used, explicitly or implicitly, for inferences from observations to conclusions about effectiveness, but its philosophical significance has not been fully elaborated or appreciated. In its simplest form, the comparative syllogism derives a conclusion about the effectiveness of a factor (e.g. a treatment or an exposure) on a certain property via an experiment design using a test (experimental) group and a comparison (control) group. Our objective is to show that the comparative syllogism (...) can be understood as encoding a simulation view of counterfactuals, in that counterfactual situations are conceptual constructs that can be correctly simulated by homogeneous comparison groups. In this simulation view, the empirical data from the comparison groups play an evidential role in the evaluation of counterfactuals and in obtaining counterfactual knowledge. We further indicate how successful experimental designs can help us to obtain correct simulations, and thus to bring us to scientifically-empirically based counterfactual knowledge. (shrink)

Modal epistemology has been dominated by a focus on establishing an account either of how we have modal knowledge or how we have justified beliefs about modality. One component of this focus has been that necessity and possibility are basic access points for modal reasoning. For example, knowing that P is necessary plays a role in deducing that P is essential, and knowing that both P and ¬P are possible plays a role in knowing that P is accidental. Chalmers (2002) (...) and Williamson (2007) provide two good examples of contrasting views in modal epistemology that focus on providing an account of modal knowledge where necessity and possibility are basic access points for modal knowledge, and Yablo (1993) provides a good account of how we have justified beliefs about modality. In contrast to this tradition I argue for and outline a modal epistemology based on objectual understanding and essence, rather than knowledge or justification and necessity and possibility. The account employs a non-modal conception of essence and takes objectual understanding of essence, rather than knowledge of essence to be basic in modal reasoning. I begin by articulating Kvanvig’s (2003) account of objectual understanding, on which objectual understanding of Φ is not equivalent to propositional knowledge of Φ. I then argue that an epistemology of essence that uses property variation-in-imagination is better construed as a model that delivers objectual understanding of essence rather than knowledge of essence. I argue that this is so, since the latter and not the former runs into a version of the Meno paradox. I show how this account can be applied to two issues in modal epistemology: the Benacerraf problem for modality, and the architecture of modal knowledge. (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)

This article surveys recent developments in the epistemology of modality.

It is widely assumed that sense perception cannot deliver knowledge of nonactual (metaphysical) possibilities. We are not supposed to be able to know that a proposition p is necessary or that p is possible (if p is false) by sense perception. This paper aims to establish that the role of sense perception is not so limited. It argues that we can know lots of modal facts by perception. While the most straightforward examples concern possibility and contingency, others concern necessity and (...) impossibility. The possibility of a perceptual route to some modal knowledge is not as radical as it may at first sound. On the contrary, acknowledging it has benefits. (shrink)

The paper argues against Peacocke's moderate rationalism in modality. In the first part, I show, by identifying an argumentative gap in its epistemology, that Peacocke's account has not met the Integration Challenge. I then argue that we should modify the account's metaphysics of modal concepts in order to avoid implausible consequences with regards to their possession conditions. This modification generates no extra explanatory gap. Yet, once the minimal modification that avoids those implausible consequences is made, the resulting account cannot support (...) Peacocke's moderate rationalism. (shrink)

I discuss several problems for Williamson’s counterfactual-theory of modal knowledge and argue that they have a common source, in that the theory neglects to elucidate the proper constraints on modal reasoning. Williamson puts forward an empirical hypothesis that rests on the role of counterfactual reasoning for modal knowledge. But he overlooks central questions of normative modal epistemology. In order for counterfactual reasoning to yield correct beliefs about modality, it needs to be suitably constrained. I argue that what is needed is, (...) specifically, information concerning the nature or essence of things. By integrating this information, essentialist deduction arguably provides a better account of our knowledge of modality. Furthermore, I argue that essences have distinctive causal and explanatory powers—indeed, essences are superexplanatory for how things are. Compared to Williamson’s counterfactual-theory, superexplanatory essentialism clarifies what the proper constraints on modal reasoning are, and why they have such a special status. (shrink)

The fourteen papers in this collection offer a variety of original contributions to the epistemology of modality. In seeking to explain how we might account for our knowledge of possibility and necessity, they raise some novel questions, develop some unfamiliar theoretical perspectives, and make some intriguing proposals. Collectively, they advance our understanding of the field. In Part I of this Introduction, I give some general background about the contemporary literature in the area, by sketching a timeline of the main tendencies (...) of the past twenty-five years or so, up to the present debates. Next, I focus on four features that largely characterize the latest literature, and the papers in the present collection in particular: (i) an endorsement of the importance of essentialism; (ii) a shift to a “metaphysics-first” approach to modal epistemology; (iii) a focus on metaphysical modality as opposed to other kinds of modality; and (iv) a preference for non-uniform modal epistemology. In Part II, I present the individual papers in the volume. These are organized around the following four chapters, based on their topic: (A) Skepticism & Deflationism; (B) Essentialism; (C) Non-Essentialist Accounts; (D) Applications. -/- LIST OF CONTRIBUTORS: Francesco Berto; Stephen Biggs & Jessica Wilson; Justin Clark-Doane; Philip Goff; Bob Hale; Frank Jackson; Mark Jago; Boris Kment; Antonella Mallozzi; Graham Priest; Gabriel Rabin; Amie Thomasson; Anand Vaidya & Michael Wallner; Jennifer Wang. -/- The volume is dedicated to the memory of Bob Hale. -/- . (shrink)

It is standard practice in philosophical inquiry to test a general thesis (of the form 'F iff G' or 'F only if G') by attempting to construct a counterexample to it. If we can imagine or conceive of1an F that isn't a G, then we have evidence that there could be an F that isn't a G — and thus evidence against the thesis in question; if not, then the thesis is (at least temporarily) secure. Or so it is standardly (...) claimed.But there is increasing skepticism about how seriously to take what we can imagine or conceive as evidence for (or against) a priori philosophical theses, given the many historical examples of now-questionable theses that once seemed impossible to doubt — and also the recent experimental research .. (shrink)

A counterpossible is a counterfactual with an impossible antecedent. Counterpossibles present a puzzle for standard theories of counterfactuals, which predict that all counterpossibles are semantically vacuous. Moreover, counterpossibles play an important role in many debates within metaphysics and epistemology, including debates over grounding, causation, modality, mathematics, science, and even God. In this article, we will explore various positions on counterpossibles as well as their potential philosophical consequences.

During the last quarter of a century, a number of philosophers have become attracted to the idea that necessity can be analyzed in terms of a hyperintensional notion of essence. One challenge for proponents of this view is to give a plausible explanation of our modal knowledge. The goal of this paper is to develop a strategy for meeting this challenge. My approach rests on an account of modality that I developed in previous work, and which analyzes modal properties in (...) terms of the notion of a metaphysical law. I discuss what information about the metaphysical laws is required for modal knowledge. Moreover, I describe two ways in which we might be able to acquire this information. The first way employs inference to the best explanation. The metaphysical laws, including the essential truths, play a crucial role in causal and grounding explanations and we can gain knowledge of these laws by abductive inferences from facts of which we have perceptual or a priori knowledge. The second way of gaining information about the metaphysical laws rests on knowledge that is partly constitutive of competence with the concepts that are needed to express the relevant information. Finally, I consider how knowledge of the metaphysical laws can be used to establish modal claims, paying special attention to the much-discussed connection between conceiving and possibility. (shrink)

What sorts of things are the intuitions generated via thought experiment? Timothy Williamson has responded to naturalistic skeptics by arguing that thought-experiment intuitions are judgments of ordinary counterfactuals. On this view, the intuition is naturalistically innocuous, but it has a contingent content and could be known at best a posteriori. We suggest an alternative to Williamson's account, according to which we apprehend thought-experiment intuitions through our grasp on truth in fiction. On our view, intuitions like the Gettier intuition are necessarily (...) true and knowable a priori. Our view, like Williamson's, avoids naturalistic skepticism. (shrink)

What method should we use to determine the nature of perceptual experience? My focus here is the Kantian thought that transcendental arguments can be used to determine the nature of perceptual experience. I set out a dilemma for the use of transcendental arguments in the philosophy of perception, one which turns on a comparison ofthe transcendental method with the first-personal method of early analytic philosophy, and with the empirical methods of much contemporary philosophy of mind. The transcendental method can avoid (...) this dilemma only if it commits to our possessing a capacity for imaginative reflection, one which is capable of identifying certain formal properties of experience.This result indicates some of the commitments which must be made if transcendental arguments are to be used in the philosophy of perception, and it has implications for those views that take the philosophy of perception to be autonomous of the empirical science of perception. (shrink)

I compare two prominent approaches to knowledge of metaphysical modality, the more traditional approach via conceiving viz. imagining a scenario and a more recent approach via counterfactual reasoning. In particular, Timothy Williamson has claimed that the proper context for a modal exercise of imagination is a counterfactual supposition. I critically assess this claim, arguing that a purely conceivability/imaginability-based approach has a key advantage compared to a counterfactual-based one. It can take on board Williamson’s insights about the structure of modal imagination (...) while avoiding aspects of counterfactual reasoning which are orthogonal to figuring out metaphysical modality. In assessing whether A is possible, we creatively devise test scenarios, psychologically and metaphysically apt A-scenarios, which manifest the relevant metaphysical requirements and test them for their compatibility with A. In this exercise, imagination is subject to implicit constraints as Williamson has it, but it is not bound to drawing consequences from minimally altering actuality such as to make room for A. (shrink)

Imagination seems to play an epistemic role in philosophical and scientific thought experiments, mindreading, and ordinary practical deliberations insofar as it generates new knowledge of contingent facts about the world. However, it also seems that imagination is limited to creative generation of ideas. Sometimes we imagine fanciful ideas that depart freely from reality. The conjunction of these claims is what I call the puzzle of knowledge through imagination. This chapter aims to resolve this puzzle. I argue that imagination has an (...) epistemic role to play, but it is limited to the context of discovery. Imagination generates ideas, but other cognitive capacities must be employed to evaluate these ideas in order for them to count as knowledge. Consideration of the Simulation Theory's so-called "threat of collapse” provides further evidence that imagination does not, on its own, yield new knowledge of contingent facts, and it suggests a way to supplement imagination in order to get such knowledge. (shrink)

In our thought, we employ rules of inference and belief-forming methods more generally. For instance, we (plausibly) employ deductive rules such as Modus Ponens, ampliative rules such as Inference to the Best Explanation, and perceptual methods that tell us to believe what perceptually appears to be the case. What explains our entitlement to employ these rules and methods? This chapter considers the motivations for broadly internalist answers to this question. It considers three such motivations—one based on simple cases, one based (...) on a general conception of epistemic responsibility, and one based on skeptical scenarios. The chapter argues that none of these motivations is successful. The first two motivations lead to forms of internalism—Extreme Method Internalism and Defense Internalism—that are too strong to be tenable. The third motivation motivates Mental Internalism (Mentalism), which does not fit with plausible accounts of entitlement. (shrink)

The paper compares the suitability of two different epistemologies of counterfactuals—(EC) and (W)—to elucidate modal knowledge. I argue that, while both of them explain the data on our knowledge of counterfactuals, only (W)—Williamson’s epistemology—is compatible with all counterpossibles being true. This is something on which Williamson’s counterfactual-based account of modal knowledge relies. A first problem is, therefore, that, in the absence of further, disambiguating data, Williamson’s choice of (W) is objectionably biased. A second, deeper problem is that (W) cannot satisfactorily (...) elucidate modal knowledge. Third, from a naturalistic perspective, the nature of this second problem favours (EC) against (W). (shrink)

Among the tools the epistemologist brings to the table ought to be, I suggest, a firm understanding of the imagination--one that is informed by philosophy of mind, cognitive psychology, and neuroscience. In my dissertation, I highlight several ways in which such an understanding of the imagination can yield insight into traditional questions in epistemology. My dissertation falls into three parts. In Part I, I argue that dreaming should be understood in imaginative terms, and that this has important implications for questions (...) about dream skepticism. In Part II, I argue that an understanding of the imagination is important for understanding important parts of philosophical methodology--particularly those involving thought experiments. I mean in Part II to be vindicating a great deal of traditional methodology. In Part III, I explore what I take to be a number of deep connections between knowledge and counterfactuals. I defend a form of contextualism in each domain, and argue that inference among imaginings, with its important structural similarities to inference in belief, plays a central role in the epistemology of counterfactuals. (shrink)