The paper defends the view that that a significant part of metaphysics should be understood as conceptual engineering, and explores its epistemological advantages and metaphysical implications. It discusses the challenge raised by moderate modal skepticism, which points out the lack of reliable methods for verifying modal statements through thought experiments. As I argue, a normative stance on metaphysical methodology, understanding it as engaging in conceptual engineering project, justifies the use of this method. By adopting an approach where (...) the method of cases offers reasons for adopting specific normative constraints on concept usage, the method becomes justifiable. Consequently, it can be employed to justify the revision of conceptual schemes and, in turn, validate certain modal claims about entities falling under the scrutinized concepts. The paper explores how this approach can methodologically enrich conceptual engineering-focused perspectives in metaphysics and examines its metaphysical consequences. In particular, it demonstrates that despite the mind-dependency of the method of cases results, it still leaves room for a metaphysically realistic viewpoint. (shrink)

This paper examines "moderate modal skepticism", a form of skepticism about metaphysical modality defended by Peter van Inwagen in order to blunt the force of certain modal arguments in the philosophy of religion. Van Inwagen’s argument for moderate modal skepticism assumes Yablo's (1993) influential world-based epistemology of possibility. We raise two problems for this epistemology of possibility, which undermine van Inwagen's argument. We then consider how one might motivate moderate modal skepticism by (...) relying on a different epistemology of possibility, which does not face these problems: Williamson’s (2007: ch. 5) counterfactual-based epistemology. Two ways of motivating moderate modal skepticism within that framework are found unpromising. Nevertheless, we also find a way of vindicating an epistemological thesis that, while weaker than moderate modal skepticism, is strong enough to support the methodological moral van Inwagen wishes to draw. (shrink)

My topic is moderate modal skepticism in the spirit of Peter van Inwagen. Here understood, this is a conservative version of modal empiricism that severely limits the extent to which an ordinary agent can reasonably believe “exotic” possibility claims. I offer a novel argument in support of this brand of skepticism: modal skepticism grounds an attractive (and novel) reply to Humean skepticism. Thus, I propose that modal skepticism be accepted on the (...) basis of its theoretical utility as a tool for dissolving philosophical paradox. (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)

This collection highlights the new trend away from rationalism and toward empiricism in the epistemology of modality. Accordingly, the book represents a wide range of positions on the empirical sources of modal knowledge. Readers will find an introduction that surveys the field and provides a brief overview of the work, which progresses from empirically-sensitive rationalist accounts to fully empiricist accounts of modal knowledge. Early chapters focus on challenges to rationalist theories, essence-based approaches to modal knowledge, and the (...) prospects for naturalizing modal epistemology. The middle chapters present positive accounts that reject rationalism, but which stop short of advocating exclusive appeal to empirical sources of modal knowledge. The final chapters mark a transition toward exclusive reliance on empirical sources of modal knowledge. They explore ways of making similarity-based, analogical, inductive, and abductive arguments for modal claims based on empirical information. Modal epistemology is coming into its own as a field, and this book has the potential to anchor a new research agenda. (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)

The thought experiment is a seemingly indispensable tool in the armchair philosopher’s toolbox. One wonders, for example, how philosophers could come to think that justified true belief isn’t knowledge, that reference isn’t determined by an expression’s associated description, or that moral responsibility doesn’t require the ability to do otherwise, without the use of thought experiments. But even if thought experiments play an integral role in philosophical methodology, their legitimacy is at least initially puzzling: one would think that significant knowledge of (...) the world requires extensive empirical investigation. But since thought experiments are done from the armchair, how can they tell us about the world? -/- A standard account of the nature and utility of thought experiments provides an answer to this question, and in a way that fits naturally with a standard picture of the nature of the facts philosophers investigate: Philosophers are about the business of investigating the essences of things and kinds. But a thing’s essential and accidental properties are modal properties. Thus, one can discern a thing’s essence by discovering its modal profile. But if so, then thought experiments are naturally suited as tools for the armchair philosopher. For thought experiments shed light on modal facts. Therefore, since philosophers investigate essences, facts about essence are modal facts, and the thought experiment is one of the few tools they have for discerning such facts, thought experiments play a legitimate and indispensable role in philosophical methodology. In my dissertation, I argue that the standard account of the nature and utility of thought experiments is inadequate, and sketch a more promising account. -/- First, I argue that our knowledge of possibility is restricted to the relatively humdrum. And if so, then since the standard account ties the utility of thought experiments to our knowledge of possibility, too many thought experiments will be ruled out as useless, which raises serious concerns about the significance, and perhaps even the legitimacy, of armchair philosophy. Thus, there is pressure for armchair philosophers to reject the standard account. -/- Second, I sketch an alternative picture of the nature of facts philosophers investigate – one that’s more fine-grained than the standard modal-profile picture. Relatedly, I sketch a correspondingly fine-grained semantics for claims about such facts. This alternative picture underwrites the legitimacy of a hitherto underappreciated sort of thought experiment, which I call the non-modal thought experiment. Such thought experiments shed light on facts about the world that are more fine-grained than what can be discerned by merely examining their modal profiles. I argue that non-modal thought experiments often succeed at just the points where the more familiar modal thought experiments fail, and thus that the two are naturally suited to complement one another in the philosopher’s practice. -/- Finally, I exploit the points mentioned above to sketch an account of the variety and utility of thought experiments that’s much more nuanced than that of the standard account. I then illustrate some of its virtues by indicating its ability to account for a wide range of epistemically forceful thought experiments – both humdrum and exotic –, and by demonstrating how it can be used to make progress in debates that have reached a stalemate due to conflicting modal intuitions. -/- . (shrink)

Many philosophers have been attracted to a restricted version of the principle of indifference in the case of self‐locating belief. Roughly speaking, this principle states that, within any given possible world, one should be indifferent between different hypotheses concerning who one is within that possible world, so long as those hypotheses are compatible with one's evidence. My first goal is to defend a more precise version of this principle. After responding to several existing criticisms of such a principle, I argue (...) that existing formulations of the principle are crucially ambiguous, and I go on to defend a particular disambiguation of the principle. According to the disambiguation I defend, how we should apply this restricted principle of indifference sensitively depends on our background metaphysical beliefs. My second goal is to apply this disambiguated principle to classical skeptical problems in epistemology. In particular, I argue that Eternalism threatens to lead us to external world skepticism, and Modal Realism threatens to lead us to inductive skepticism. (shrink)

It has recently been argued that indeterminacy and indeterminism make most ordinary counterfactuals false. I argue that a plausible way to avoid such counterfactual skepticism is to postulate the existence of primitive modal facts that serve as truth-makers for counterfactual claims. Moreover, I defend a new theory of ‘might’ counterfactuals, and develop assertability and knowledge criteria to suit such unobservable ‘counterfacts’.

Radical skepticism relies on the hypothesis that one could be completely cut off from the external world. In this paper, I argue that this hypothesis can be rationally motivated by means of a conceivability argument. Subsequently, I submit that this conceivability argument does not furnish a good reason to believe that one could be completely cut off from the external world. To this end, I show that we cannot adequately conceive scenarios that verify the radical skeptical hypothesis. Attempts to (...) do so fall prey to one or another of three pitfalls: they end up incomplete, reveal a deep contradiction or recreate a non-skeptical hypothesis. I use these results to improve upon Pritchard’s recent attempt at undercutting radical skepticism. (shrink)

Modal intuitions are the primary source of modal knowledge but also of modal error. According to the theory of modal error in this paper, modal intuitions retain their evidential force in spite of their fallibility, and erroneous modal intuitions are in principle identifiable and eliminable by subjecting our intuitions to a priori dialectic. After an inventory of standard sources of modal error, two further sources are examined in detail. The first source - namely, (...) the failure to distinguish between metaphysical possibility and various kinds of epistemic possibility - turns out to be comparatively easy to untangle and poses little threat to intuition-driven philosophical investigation. The second source is the local misunderstanding of one's concepts . This pathology may be understood on analogy with a patient who is given a clean bill of health at his annual check-up, despite his having a cold at the time of the check-up: although the patient's health is locally disrupted, his overall health is sufficiently good to enable him to overcome the cold without external intervention. Even when our understanding of certain pivotal concepts has lapsed locally, our larger body of intuitions is sufficiently reliable to allow us, without intervention, to ferret out the modal errors resulting from this lapse of understanding by means of dialectic and/or a process of a priori reflection. This source of modal error, and our capacity to overcome it, has wide-ranging implications for philosophical method - including, in particular, its promise for disarming skepticism about the classical method of intuition-driven investigation itself. Indeed, it is shown that skeptical accounts of modal error are ultimately self-defeating. (shrink)

How should we understand the relationship between the contents of our color, causal, modal, and evaluative beliefs, on the one hand, and color, causal, modal, and evaluative properties, on the other? According to Barry Stroud (2011), because of the nature of the contents of those types of beliefs, we should also think that what he calls a “negative metaphysical verdict” on the latter is not one that we could consistently maintain. The metaphysical project aims to arrive at an (...) improved conception of ourselves and our relation the world, no matter if that conception is positive or negative. But if Stroud is right that we cannot consistently arrive at the view that all of our causal, modal, and evaluative beliefs are systematically false, we will see that we cannot consistently reach the negative verdict. But failure to reach the negative verdict doesn’t mean that we have reached the positive verdict. Stroud calls this philosophical failure “metaphysical dissatisfaction”. In this paper, I argue that we can appropriate a metaepistemological response to the problem of the external world which shares its core features with Stroud’s (2000, 2011) arguments, but which nevertheless leaves us with a distinctive kind of epistemological dissatisfaction. (shrink)

Modal epistemic conditions have played an important role in post-Gettier theories of knowledge. These conditions purportedly eliminate the pernicious kind of luck present in all Gettier-type cases and offer a rather convincing way of refuting skepticism. This motivates the view that conditions of this sort are necessary for knowledge. I argue against this. I claim that modal conditions, particularly sensitivity and safety, are not necessary for knowledge. I do this by noting that the problem cases for both (...) conditions point to a problem that cannot be fixed even by a revised similarity ranking or ordering of worlds. I offer as groundwork a set theoretical analysis of the profiles of the problem cases for safety and sensitivity. I then demonstrate that these conditions fail whenever necessary links constitutive of the epistemic situation actually obtain but are not modally preserved. (shrink)

This essay defends two theses regarding the explanation, or ground, of modality in the early modern period. First, for philosophers in the period, essences ground a range of important modal facts. Second, as the period progresses, we witness increased skepticism about certain modal facts, due to a growing skepticism about the scope or existence of essences. These theses are supported by examination of three case studies: Descartes’ treatment of substance and mode (which forms the core of (...) his ontology); Malebranche’s treatment of causation (which bears on his defense of occasionalism); and Locke’s treatment of necessary connections among properties (which is related to his accounts of individuals and kinds). It is shown that in each case, claims about necessity and possibility take center stage, and that in each case, the status of these claims hinges on the status of claims about essences. (shrink)

I take up two questions raised by Luz Christopher Seiberth's meticulous reconstruction of Wilfrid Sellars's theory of intentionality. The first is whether we should regard Sellars as a transcendental phenomenalist in the most interesting sense of the term: as denying that even an ideally adequate conceptual structure would enable us to represent worldly objects as they are in themselves. I agree with Seiberth that the answer is probably yes, but I suggest that this is due not to Sellars's rejection of (...) the Myth of the Given or appeal to image-models (as Seiberth maintains), but to his view of modality as categorial but as absent from the world an sich. The second is whether, as Richard Rorty complained, Sellars's appeal to picturing lands his theory of intentionality in intractable skepticism. Pace Seiberth, I argue that the transcendental role of picturing does not mitigate this problem, and I suggest that Sellars's most fruitful resource for doing so is not his semantic externalism, but his purely pragmatic response to skepticism. (shrink)

Standard truthmaker theory has generally assumed a realist account of de re modality and essences. But there are reasons to be skeptical about such a view, and for considering antirealist alternatives. Can truthmaker theory survive in the face of such skepticism? I argue that it can, but that only certain antirealist perspectives on de re modality are acceptable for truthmaker theory. In particular, either a quasi-realist or conventionalist account of de re modality is needed to provide the best account (...) of essential and accidental features that can be put to work in truthmaker theory. An important consequence of this approach is that it offers an account of truthmaking that is consistent with a nominalist perspective on properties, and yet fully respects the ontological ambitions driving truthmaker theory. (shrink)

⦿ In my dissertation I introduce, motivate and take the first steps in the implementation of, the project of naturalising modal metaphysics: the transformation of the field into a chapter of the philosophy of science rather than speculative, autonomous metaphysics. -/- ⦿ In the introduction, I explain the concept of naturalisation that I apply throughout the dissertation, which I argue to be an improvement on Ladyman and Ross' proposal for naturalised metaphysics. I also object to Williamson's proposal that (...) class='Hi'>modal metaphysics --- or some view in the area --- is already a quasi-scientific discipline. -/- ⦿ Recently, some philosophers have argued that the notion of metaphysical modality is as ill defined as to be of little theoretical utility. In the second chapter I intend to contribute to such skepticism. First, I observe that each of the proposed marks of the concept, except for factivity, is highly controversial; thus, its logical structure is deeply obscure. With the failure of the "first principles" approach, I examine the paradigmatic intended applications of the concept, and argue that each makes it a device for a very specific and controversial project: a device, therefore, for which a naturalist will find no use for. I conclude that there is no well-defined or theoretically useful notion of objective necessity other than logical or physical necessity, and I suggest that naturalising modal metaphysics can provide more stable methodological foundations. -/- ⦿ In the third chapter I answer a possible objection against the in-principle viability of the project: that the concept of metaphysical modality cannot be understood through the philosophical analysis of any scientific theory, since metaphysical necessity "transcends'' natural necessity, and science only deals with the latter. I argue that the most important arguments for this transcendence thesis fail or face problems that, as of today, remain unsolved. -/- ⦿ Call the idea that science doesn't need modality, "demodalism''. Demodalism is a first step in a naturalistic argument for modal antirealism. In the fourth chapter I examine six versions of demodalism to explain why a family of formalisms, that I call "spaces of possibility'', are (i) used in a quasi-ubiquitous way in mathematised sciences (I provide examples from theoretical computer science to microeconomics), (ii) scientifically interpreted in modal terms, and (iii) used for at least six important tasks: (1) defining laws and theories; (2) defining important concepts from different sciences (I give several examples); (3) making essential classifications; (4) providing different types of explanations; (5) providing the connection between theory and statistics, and (6) understanding the transition between a theory and its successor (as is the case with quantisation). -/- ⦿ In fifth chapter I propose and defend a naturalised modal ontology. This is a realism about modal structure: my realism about constraints. The modal structure of a system are the relationships between its possible states and between its possible states and those of other systems. It is given by the plurality of restrictions to which said system is subject. A constraint is a factor that explains the impossibility of a class of states; I explain this concept further. First, I defend my point of view by rejecting some of its main rivals: constructive empiricism, Humean conventionalism, and wave function realism, as they fail to make sense of quantum chaos. This is because the field requires the notion of objective modal structure, and the mentioned views have trouble explaining the modal facts of quantum dynamics. Then, I argue that constraint realism supersedes these views in the context of Bohm's standard theory and mechanics, and underpins the study of quantum chaos. Finally, I consider and reject two possible problems for my point of view. -/- ⦿ A central concern of modal metaphysicians has been to understand the logical system that best characterises necessity. In the sixth chapter I intend to recover the logical project applied to my naturalistic modal metaphysics. Scientists and philosophers of science accept different degrees of physical necessity, ranging from purely mathematically necessary facts that restrict physical behaviour, to kinetic principles, to particular dynamical constraints. I argue that this motivates a multimodal approach to modal logic, and that the time dependence of dynamics motivates a logic of historical necessity. I propose multimodal propositional (classical) logics for Bohmian mechanics and the Everettian theory of many divergent worlds, and I close with a criticism of Williamson's approach to the logic of state spaces of dynamic systems. (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)

This paper introduces a novel strategy for responding to skeptical arguments based on the epistemic possibility of error or lack of certainty. I show that a nonclassical logic motivated by recent work on epistemic modals can be used to render such skeptical arguments invalid. That is, one can grant that knowledge is incompatible with the possibility of error and grant that error is possible, all while avoiding the skeptic’s conclusion that we lack knowledge.

Epicureans believe that death cannot harm the one who dies because they hold the existence condition, which states that a subject is able to be harmed only while they exist. I show that on one reading of this condition death can, in fact, make the deceased worse off because it is satisfied by the deprivation account of death’s badness. I argue that the most plausible Epicurean view holds the antimodal existence condition, according to which no merely possible state of affairs (...) can be good or bad relative to the subject who dies. I go on to show how this condition, as well as any other condition that denies the deprivation account, results in skepticism about practical reason. Thus, the Epicurean faces a dilemma. Either our practical reasoning is hopelessly mistaken or death can make us worse off. Given that our practical reasoning seems at least mildly reliable, we should conclude that death can make us worse off. (shrink)

In this paper we intend to offer a first approach to the incorporation of certain formal tools in the elucidation of some issues discussed in epistemological contexts. The aim is not to offer an exhaustive resolution of these problems but merely to point out the usefulness of modal semantics when applied to different fields. Here we will show how a series of skeptical arguments eventually involve a modal (counterfactual) structure, which we will try to generalise into a useful (...) scheme. -/- . (shrink)

This dissertation is concerned with two of the largest questions that we can ask about the nature of physical reality: first, whether physical reality begin to exist and, second, what criteria would physical reality have to fulfill in order to have had a beginning? Philosophers of religion and theologians have previously addressed whether physical reality began to exist in the context of defending the Kal{\'a}m Cosmological Argument (KCA) for theism, that is, (P1) everything that begins to exist has a cause (...) for its beginning to exist, (P2) physical reality began to exist, and, therefore, (C) physical reality has a cause for its beginning to exist. While the KCA has traditionally been used to argue for God's existence, the KCA does not mention God, has been rejected by historically significant Christian theologians such as Thomas Aquinas, and raises perennial philosophical questions -- about the nature and history of physical reality, the nature of time, the nature of causation, and so on -- that should be of interest to all philosophers and, perhaps, all humans. While I am not a religious person, I am interested in the questions raised by the KCA. In this dissertation, I articulate three necessary conditions that physical reality would need to fulfill in order to have had a beginning and argue that, given the current state of philosophical and scientific inquiry, we cannot determine whether physical reality began to exist. -/- Friends of the KCA have sought to defend their view that physical reality began to exist in two distinct ways. As I discuss in chapter 2, the first way in which friends of the KCA have sought to defend their view that physical reality began to exist involves a family of a priori arguments meant to show that, as a matter of metaphysical necessity, the past must be finite. If the past is necessarily finite, then the past history of physical reality is necessarily finite. And if having a finite past suffices for having a beginning, then, since the past history of physical reality is necessarily finite, physical reality necessarily began to exist. I show that the arguments which have been offered thus far for the view that the past is necessarily finite do not succeed. Moreover, as I elaborate on in chapter 5, having a finite past does not suffice for having a beginning. -/- As I discuss in chapter 3, the second way in which friends of the KCA have sought to defend their view that physical reality began to exist involves a family of a posteriori arguments meant to show that we have empirical evidence that physical reality has a finite past history. For example, the big bang is sometimes claimed to have been the beginning of physical reality and, since we have excellent empirical evidence for the big bang, we have excellent empirical evidence for the beginning of physical reality. The big bang can be understood in two ways. On the one hand, the big bang can be understood as a theory about the history and development of the observable universe. Understood in that sense, then I agree that the big bang is supported by excellent empirical evidence and by a scientific consensus. On the other hand, some authors (particularly science popularizers, science journalists, and religious apologists) have wrongly interpreted big bang theory as a theory about the beginning of the whole of physical reality. As I argue, while a beginning of physical reality may be consistent with classical big bang theory, classical big bang theory does not provide good reason for thinking that physical reality began to exist. -/- In part II, I turn to discussing three necessary, but not necessarily sufficient, conditions for physical reality to have a beginning. Before discussing the three conditions, in chapter 4, I introduce three metaphysical accounts of the nature of time (A-theory, B-theory, and C-theory) as well as some formal machinery that will subsequently become useful in the dissertation. I introduce the first of the three conditions in chapter 5. According to the Modal Condition, physical reality began to exist only if, at the closest possible worlds without time, physical reality does not exist. I show that this condition helps us to make sense of various views in both theology and philosophy of physics. In chapter 6}, I introduce the second of my three conditions, the Direction Condition, according to which, roughly, physical reality began to exist only if all space-time points agree about the direction of time, so that all space-time points can agree that physical reality's putative beginning took place in their objective past. In chapter 7, I discuss the third condition, the Boundary Condition, according to which physical reality began to exist only if there is a past temporal boundary such that physical reality did not exist before the boundary. I show that there are two senses in which physical reality could be said to have had a past temporal boundary. Lastly, in chapter 8, I show that there is a relationship between my three conditions and classical big bang theory, even though the relationship is not the one usually identified in the literature. -/- In part III, I present four arguments for the view that, at the present stage of philosophical and scientific inquiry, we cannot know whether physical reality satisfies the three necessary conditions to have had a beginning and, consequently, we cannot know whether physical reality had a beginning. As I will prove in chapter 9, no set of observations that we currently have, when conjoined with General Relativity, entails that physical reality satisfies the Direction or Boundary Conditions. As I show in chapter 10, considerations in the philosophical foundations of statistical mechanics entail either that the Cosmos violates the Modal Condition or else that there is a transcendental condition on the possibility of our knowledge of the past that prevents our access to data we would need to gather to determine whether physical reality satisfies the Boundary Condition. In chapter 11, I show that there are a number of live cosmological models according to which physical reality does not satisfy the Boundary Condition. As long as we don't know whether any of those cosmological models are correct, we do not know whether physical reality satisfies the Boundary Condition. Lastly, I turn to confirmation theory and show that, at our present stage of inquiry, ampliative inferences for the conclusion that physical reality satisfies the Modal, Direction, and Boundary Conditions are not successful. (shrink)

We examine a prominent naturalistic line on the method of cases, exemplified by Timothy Williamson and Edouard Machery: MoC is given a fallibilist and non-exceptionalist treatment, accommodating moderate modal skepticism. But Gettier cases are in dispute: Williamson takes them to induce substantive philosophical knowledge; Machery claims that the ambitious use of MoC should be abandoned entirely. We defend an intermediate position. We offer an internal critique of Macherian pessimism about Gettier cases. Most crucially, we argue that Gettier cases (...) needn’t exhibit ‘disturbing characteristics’ that Machery posits to explain why philosophical cases induce dubious judgments. It follows, we show, that Machery’s central argument for the effective abandonment of MoC is undermined. Nevertheless, we engineer a restricted variant of the argument—in harmony with Williamsonian ideology–that survives our critique, potentially limiting philosophy’s scope for establishing especially ambitious modal theses, despite traditional MoC’s utility being partially preserved. (shrink)

Thought experiments that concoct bizarre possible world modalities are standard fare in debates on personal identity. Appealing to intuitions raised by such evocations is often taken to settle differences between conflicting theoretical views that, albeit, have practical implications for ethical controversies of personal identity in health care. Employing thought experiments that way is inadequate, I argue, since personhood is intrinsically linked to constraining facts about the actual world. I defend a moderate modal skepticism according to which intuiting across (...) conceptually incongruent worlds constitutes ‘invalid intuitioninferences’—i.e., carrying over intuitions gathered from facts about possible worlds that are at odds with facts about the actual world, for the purpose of making claims about real-life persons and their identity, leads to conceptual incongruences. Such a methodological fallout precludes accurate, informative judgments about personal identity in the actual world, calling into question the adequacy of thought experimental considerations for potential real world applications in medical ethics. (shrink)

Skeptical theism, broadly construed, is an attempt to leverage our limited cognitive powers, in some specified sense, against “evidential” and “explanatory” arguments from evil. Since there are different versions of these kinds of arguments, there are correspondingly different versions of skeptical theism. In this paper, I briefly explain three versions of these arguments from evil (two from William Rowe and one from Paul Draper) and the three versions of skeptical theism tailor-made to block them (from Stephen Wykstra, Michael Bergmann, and (...) Peter van Inwagen). (shrink)

kk states that knowing entails knowing that one knows, and K¬K states that not knowing entails knowing that one does not know. In light of the arguments against kk and K¬K⁠, one might consider modally qualified variants of those principles. According to weak kk, knowing entails the possibility of knowing that one knows. And according to weakK¬K⁠, not knowing entails the possibility of knowing that one does not know. This paper shows that weak kk and weakK¬K are much stronger than (...) they initially appear. Jointly, they entail kk and K¬K⁠. And they are susceptible to variants of the standard arguments against kk and K¬K⁠. This has interesting implications for the debate on positive introspection and for deeper issues concerning the structure and limits of knowability. (shrink)

This paper presents the theory of epistemic safety in relation to three problems: similarity, closure, and generality. Within the neo-Moorean framework of skepticism, the epistemic safety theory complements contextualist theories, where a difference is established between sceptical-thought and everyday contexts. In this way, it is claimed that conviction–i.e., when the bases upon which a belief is constructed remain unquestioned–is an intellectual virtue that makes trustworthy processes in near worlds possible. Finally, the aim of the paper is to highlight the (...) modal difference between beliefs that presuppose near worlds as their core and those that take nearby words as their core. (shrink)

Can we find propositions that cannot rationally be denied in any possible world without assuming the existence of that same proposition, and so involving ourselves in a contradiction? In other words, can we find transworld propositions needing no further foundation or justification? Basically, three differing positions can be imagined: firstly, a relativist position, according to which ultimately founded propositions are impossible; secondly, a meta-relativist position, according to which ultimately founded propositions are possible but unnecessary; and thirdly, an absolute position, according (...) to which such propositions are necessary. In this short essay I show that under the premise of modal logic S5 with constant domain there are ultimately founded propositions and that their existence is even necessary, and I will give some reasons for the superiority of S5 over other logics. (shrink)

Contrastivists view ought-sentences as expressing comparisons among alternatives. Deontic actualists believe that the value of each alternative in such a comparison is determined by what would actually happen if that alternative were to be the case. One of the arguments that motivates actualism is a challenge to the principle of agglomeration over conjunction—the principle according to which if you ought to run and you ought to jump, then you ought to run and jump. I argue that there is no way (...) of developing the actualist insight into a logic that invalidates the agglomeration principle without also invalidating other desirable patterns of inference. After doing this, I extend the analysis to other contrastive views that challenge agglomeration in the way that the actualist does. This motivates skepticism about the actualist’s way of challenging agglomeration. (shrink)

A major source of latter-day skepticism about necessity is the work of David Hume. Hume is widely taken to have endorsed the Humean claim: there are no necessary connections between distinct existences. The Humean claim is defended on the grounds that necessary connections between wholly distinct things would be mysterious and inexplicable. Philosophers deploy this claim in the service of a wide variety of philosophical projects. But Saul Kripke has argued that it is false. According to Kripke, there are (...) necessary connections between distinct existences; in particular, there are necessary connections between material objects and their material origins. In this paper I argue that the primary motivation for the Humean claim, Hume's datum, also motivates the key premise in an argument for the necessity of origins. The very considerations that the Humean takes to show that necessary connections between wholly distinct things would be mysterious and inexplicable indicate that there must be some such necessary connections. Thus, in the absence of alternative support, there is no reason to believe the Humean claim. (shrink)

To reject skepticism and lay the foundation for the certainty of knowledge, Kant raised the question of how synthetic a priori proposition is possible. In his solution, the new content of knowledge comes from the syntheses of experience a posteriori, and the universal necessity of knowledge is guaranteed by it’s a priority. Under the influence of Kant, the concept of a priori and necessity has long been regarded as coextensive. But Saul Kripke believes that this will confuse different philosophical (...) fields: a priori is an epistemological concept, which involves the way or means of acquiring knowledge, and necessity is a metaphysical concept, which involves the possible ways or states of the world. The key point is that, on Kripke, there is no necessary connection between these two fields. He raised some famous examples of the necessary a posteriori. More remarkably, in his explanation of necessary a posteriori, although he did not clearly propose the distinction between epistemic possibility and metaphysical possibility, he had laid the foundation for this distinction. Furthermore, on Manuel Garcia-Carpintero and Josep Macia, when Kripke talks about necessary a posteriori by appealing to two relevant expressions, what he proposed can be taken as kind of ‘blueprint for 2-D accounts’. (Manuel Garcia-Carpintero and Josep Macia, 2006, p.2) There are different forms of two-dimensionalism in semantics. I will focus on David Chalmers’s epistemic version and Scott Soames’ criticism. With the framework of possible world semantics established by Kripke and others, David Chalmers’ epistemic two-dimensionalism deals with the relationship between epistemic and metaphysical modalities from a quite different perspective, and then gives an elegant definition to necessary a posteriori and other modal concepts. Scott Soames criticized two-dimensionalism based on Kripke's modal realism and essentialism, and developed Kripke's account of necessary a posteriori. But according to Chalmers, Soames also uses a two-dimensional system himself to analyze cases of the necessary a posteriori. In the first two part of this paper I will briefly introduce the epistemic two-dimensionalism and specify the similarities between Kripke-Soames and Chalmers when they interpret necessary a posteriori. In the third part I turn to their difference by the analysis of relationship between epistemic possibility and metaphysical possibility which is the key issue for illuminating necessary a posteriori. (shrink)

I explain why, from the perspective of knowledge-centric anti-luck epistemology, objective act consequentialist theories of ethics imply skepticism about the moral status of our prospective actions and also tend to be self-defeating, undermining the justification of consequentialist theories themselves. For according to knowledge-centric anti-luck epistemology there are modal anti-luck demands on both knowledge and justification, and it turns out that our beliefs about the moral status of our prospective actions are almost never able to satisfy these demands if (...) objective act consequentialism is true. This kind of applied moral skepticism introduces problematic limits on our ability to use objective act consequentialism’s explanatory power as evidence for its truth. This is, in part, a product of higher-order defeat as I explain in the final section. There is, however, a silver lining for objective act consequentialists. For there is at least one type of objective act consequentialism, prior existence consequentialism, that is poised to avoid at least some of the epistemic problems discussed in this paper. (shrink)

Grounding has become all the rage in recent philosophical work and metaphilosophical discussions. While I agree that the concept of ground marks something useful, I am skeptical about the metaphysical weight many imbue it with, and the picture of ‘worldly layering’ that grounding talk inspires. My skepticism centers around the fact that grounding involves necessitation, combined with reasons for thinking matters of necessity are matters of logical or conceptual (semantic, psychological) relations. I sketch an argument for deflationism about ground (...) based on this sort of deflationism about necessity and essence. I also note that in at least some cases, the considerations supporting modal deflationism directly support deflationism about whatever grounding relations may obtain in these cases. (shrink)

This paper contains replies to comments on the author's paper "A Priori Knowledge and the Scope of Philosophy." Several points in the argument of that paper are given further clarification: the notion of our standard justificatory procedure, the notion of a basic source of evidence, and the doctrine of modal reliabilism. The reliability of intuition is then defended against Lycan's skepticism and a response is given to Lycan's claim that the scope of a priori knowledge does not include (...) philosophically central topics such as the nature of consciousness. Next a counterfactual account of intuitions proposed by Sosa is criticized. Finally, in response to certain questions raised by Sosa, the explanation of the evidential status of intuition offered in the original paper receives further elaboration. (shrink)

This paper explores some consequences of Lewis’s (Australas J Philos 74(4):549–567, 1996) understanding of how knowledge is compartmentalized. It argues, first, that he underestimates how badly it impacts his view. When knowledge is compartmentalized, it lacks at least one of two essential features of Lewis’s account: (a) Elusiveness—familiar skeptical possibilities, when relevant, are incompatible with everyday knowledge. (b) Knowledge is a modality—when a thinker knows that p, there is no relevant possibility where p is false. Lewis proposes compartmentalized knowledge to (...) keep treating knowledge as a modality while mitigating one of its unrealistic epistemological implications: In normal modal epistemic logic (and standard possible world semantics), a thinker always counts as knowing the strongest proposition that follows from the set of all the individual propositions that this thinker knows. Lewis’s compartmentalization proposal is that thinkers merely know the conjunctions of propositions that are known in each of, but not across, their compartments. The irony is that in avoiding overblown knowledge the view now allows for thinkers to attend to skeptical error possibilities and yet knowledge is present. The account avoids inflation of knowledge in one sense only to acquire another type of knowledge the view denies subjects can have. This problem motivates an inspection of knowledge accounts whose intra-compartment closure principles are weaker than those that are valid in normal modal-logic. The conclusion is that some formulations of closure can avoid the challenge Lewis’s view faces. Nevertheless, even these closure principles pose a barrier—perhaps an implausible barrier—for knowledge of ignorance. Even when the reasoning supporting the lack of knowledge is sound, a subject cannot always know she doesn’t know. Interestingly, this obstacle is one that knowledge of knowledge doesn’t seem to face. (shrink)

This book is primarily about checking and only derivatively about knowing. Checking is a very common concept for describing a subject’s epistemic goals and actions. Surprisingly, there has been no philosophical attention paid to the notion of checking. In Part I, I develop a sensitivity account of checking. To be more explicit, I analyze the internalist and externalist components of the epistemic action of checking which include the intentions of the checking subject and the necessary externalist features of the method (...) used. Crucially, successfully checking whether p is true requires using a method that is sensitive with respect to p, i.e. a method that would not indicate that p, if p were false. In Part II, I use the distinction between knowing and checking to explain central puzzles about knowledge, particularly puzzles centering on knowledge closure, puzzles concerning bootstrapping and the skeptical puzzle. Moreover, the book clarifies a dispute about modal epistemology, concerning the application of the sensitivity principle. By arguing that sensitivity is necessary for checking but not knowing, I explain where our persisting intuitions about sensitivity have their place in epistemology. (shrink)

Thomas Polger has argued in favor of the mind-brain type-identity theory, the view that mental states or processes are type-identical to states of the central nervous system. Acknowledging that the type-materialist must respond to Kripke's modal anti-materialist argument, Polger insists that Kripke's argument rests on dubious assumptions concerning the identity conditions of brain states. In brief, Polger claims that one knows that x and y are non-identical when one knows the identity conditions for both x and y. Replace x (...) and y with 'brain states' and 'sensations' and it follows that one can know that brain states and sensations are non-identical only if one knows the identity conditions for brain states. But, according to Polger, we do not know the identity conditions for brain states. Hence, we should not be so confident that brains states and sensations are non-identical after all. But Polger's account is terribly flawed. Ironically, if Polger's skepticism is warranted, then Polger himself has no good reasons to be a type-materialist. But more importantly, Polger's skepticism regarding the identity conditions of brain states is deeply defective. We do, I submit, understand the identity conditions of brain states. In the end, I submit, Kripke is safe from Polger. (shrink)

Abstract -/- Before Descartes, middle age philosophers like Thomas Aquinas (1225-1274), Duns Scotus (1266-1308), and Francisco Suarez (1548-1617) used to discuss the distinction between essence and existence in three ways (of course, Ibn-Sina was the first who made this distinction to rehabilitate Aristotelian philosophy in the Islamic heritage). Descartes was aware of that, but discussed it according to the relation between mind and body. Yet, he told us many times that he was used to separate essence from existence in metaphysical (...) issues. The objective of this paper is first to rephrase his untold opinion about the relation between essence and existence on the basis of his conception of the problem of distinction according to mind and body, and second, to disclose that Descartes's conception of existence is twofold. At the end, it is claimed that his twofold notion of existence and his inability to overcome it, is the principal factor in his failure to explicate everything according to first principles, and so in his failure to defeat skepticism. (shrink)

Sensitivity has sometimes been thought to be a highly epistemologically significant property, serving as a proxy for a kind of responsiveness to the facts that ensure that the truth of our beliefs isn’t just a lucky coincidence. But it's an imperfect proxy: there are various well-known cases in which sensitivity-based anti-luck conditions return the wrong verdicts. And as a result of these failures, contemporary theorists often dismiss such conditions out of hand. I show here, though, that a sensitivity-based understanding of (...) epistemic luck can be developed that respects what was attractive about sensitivity-based approaches in the first place but that's immune to these failures. (shrink)

Counterfactual scepticism holds that most ordinary counterfactuals are false. The main argument for this view appeals to a ‘chance undermines would’ principle: if ψ would have some chance of not obtaining had ϕ obtained, then ϕ □→ ψ is false. This principle seems to follow from two fairly weak principles, namely, that ‘chance ensures could’ and that ϕ □→ ψ and ϕ ⋄→ ¬ ψ clash. Despite their initial plausibility, I show that these principles are independently problematic: given some modest (...) closure principles, they entail absurdities. Moreover, on the most promising strategy for saving these principles, they do not, in the relevant sense, entail the chance-undermines-would principle. Instead, they entail a principle that only supports counterfactual indeterminism, the view that most ordinary counterfactuals are chancy, that is, not settled true. I demonstrate this by developing an indeterminist semantics that vindicates the clash and chance-ensures-could principles but not the chance-undermines-would principle. This view, I argue, offers a better account of our credal and linguistic judgements than counterfactual scepticism. (shrink)

The purpose of this study is to propose new similarity measures namely rough variational coefficient similarity measure under the rough neutrosophic environment. The weighted rough variational coefficient similarity measure has been also defined. The weighted rough variational coefficient similarity measures between the rough ideal alternative and each alternative are xxxxx calculated to find the best alternative. The ranking order of all the alternatives can be determined by using the numerical values of similarity measures. Finally, an illustrative example has been provided (...) to show the effectiveness and validity of the proposed approach. Comparisons of decision results of existing rough similarity measures have been provided. (shrink)

This paper is devoted to present Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method for multi-attribute group decision making under rough neutrosophic environment. The concept of rough neutrosophic set is a powerful mathematical tool to deal with uncertainty, indeterminacy and inconsistency. In this paper, a new approach for multi-attribute group decision making problems is proposed by extending the TOPSIS method under rough neutrosophic environment. Rough neutrosophic set is characterized by the upper and lower approximation operators and the (...) pair of neutrosophic sets that are characterized by truth-membership degree, indeterminacy membership degree, and falsity membership degree. In the decision situation, ratings of alternatives with respect to each attribute are characterized by rough neutrosophic sets that reflect the decision makers’ opinion. Rough neutrosophic weighted averaging operator has been used to aggregate the individual decision maker’s opinion into group opinion for rating the importance of attributes and alternatives. Finally, a numerical example has been provided to demonstrate the applicability and effectiveness of the proposed approach. (shrink)

Though ancient Pyrrhonian skepticism is apparently based on disagreement, this aspect of skepticism has been widely neglected in contemporary discussion on skepticism. The paper provides a rational reconstruction of the skeptical argument from disagreement that can be found in the books of Sextus Empiricus. It is argued that this argument forms a genuine skeptical paradox that has no fully satisfactory resolution. All attempts to resolve it make knowledge or justified belief either intuitively too easy or impossible.

Boris Kment takes a new approach to the study of modality that emphasises the origin of modal notions in everyday thought. He argues that the concepts of necessity and possibility originate in counterfactual reasoning, which allows us to investigate explanatory connections. Contrary to accepted views, explanation is more fundamental than modality.

Epistemic modal operators give rise to something very like, but also very unlike, Moore's paradox. I set out the puzzling phenomena, explain why a standard relational semantics for these operators cannot handle them, and recommend an alternative semantics. A pragmatics appropriate to the semantics is developed and interactions between the semantics, the pragmatics, and the definition of consequence are investigated. The semantics is then extended to probability operators. Some problems and prospects for probabilistic representations of content and context are (...) explored. (shrink)

According to Amie Thomasson’s modal normativism, the function of modal discourse is to convey semantic rules. But what is a "semantic rule"? I raise three worries according to which there is no conception of a semantic rule that can serve the needs of a modal normativist. The first worry focuses on de re and a posteriori necessities. The second worry concerns Thomasson's inferential specification of the meaning of modal terms. The third worry asks about the normative (...) status of semantic rules. (shrink)

This paper outlines a new type of skepticism that is both compatible with fallibilism and supported by work in psychology. In particular, I will argue that we often cannot properly trust our ability to rationally evaluate reasons, arguments, and evidence (a fundamental knowledge-seeking faculty). We humans are just too cognitively impaired to achieve even fallible knowledge, at least for many beliefs.

Discrimination is a central epistemic capacity but typically, theories of discrimination only use discrimination as a vehicle for analyzing knowledge. This paper aims at developing a self-contained theory of discrimination. Internalist theories of discrimination fail since there is no compelling correlation between discriminatory capacities and experiences. Moreover, statistical reliabilist theories are also flawed. Only a modal theory of discrimination is promising. Versions of sensitivity and adherence that take particular alternatives into account provide necessary and sufficient conditions on discrimination. Safety (...) in contrast is not sufficient for discrimination as there are cases of safety that are clearly instances of discrimination failure. The developed account of discrimination between objects will be extended to discrimination between kinds and between types. (shrink)

This paper explains and defends the idea that metaphysical necessity is the strongest kind of objective necessity. Plausible closure conditions on the family of objective modalities are shown to entail that the logic of metaphysical necessity is S5. Evidence is provided that some objective modalities are studied in the natural sciences. In particular, the modal assumptions implicit in physical applications of dynamical systems theory are made explicit by using such systems to define models of a modal temporal logic. (...) Those assumptions arguably include some necessitist principles. -/- Too often, philosophers have discussed ‘metaphysical’ modality — possibility, contingency, necessity — in isolation. Yet metaphysical modality is just a special case of a broad range of modalities, which we may call ‘objective’ by contrast with epistemic and doxastic modalities, and indeed deontic and teleological ones (compare the distinction between objective probabilities and epistemic or subjective probabilities). Thus metaphysical possibility, physical possibility and immediate practical possibility are all types of objective possibility. We should study the metaphysics and epistemology of metaphysical modality as part of a broader study of the metaphysics and epistemology of the objective modalities, on pain of radical misunderstanding. Since objective modalities are in general open to, and receive, natural scientific investigation, we should not treat the metaphysics and epistemology of metaphysical modality in isolation from the metaphysics and epistemology of the natural sciences. -/- In what follows, Section 1 gives a preliminary sketch of metaphysical modality and its place in the general category of objective modality. Section 2 reviews some familiar forms of scepticism about metaphysical modality in that light. Later sections explore a few of the many ways in which natural science deals with questions of objective modality, including questions of quantified modal logic. (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)