Orthodoxy has it that all counterpossibles are vacuously true. Yet there are strong arguments both for and against the use of non-vacuous counterpossibles in metaphysics. Even more compelling evidence may be expected from science. Arguably philosophy should defer to best scientific practice. If scientific practice comes with a commitment to non-vacuous counterpossibles, this may be the decisive reason to reject semantic orthodoxy and accept non-vacuity. I critically examine various examples of the purported scientific use of non-vacuous counterpossibles and argue that (...) they are not convincing. They neither establish that scientific practice comes with a commitment to the non-vacuity of counterpossibles, nor that incurring such a commitment would be useful in scientific practice. I illustrate a variety of counter-strategies on behalf of orthodoxy. (shrink)

This article discusses the role of a priori and a posteriori knowledge and methods in metaphysics and metametaphysics. Issues discussed include the viability of the distinction, the continuity of a priori and a posteriori methods, connections to modal epistemology, and the role of the distinction for science and naturalistic metaphysics.

The idea that justified modal belief can be accounted for in terms of empirically justified, non-modal belief is enjoying increasing popularity in the epistemology of modality. One alleged reason to prefer modal empiricism over more traditional, rationalist modal epistemologies is that empiricism avoids the problem with the integration challenge that arise for rationalism, assuming that we want to be realists about modal metaphysics. In this paper, I argue that given two very reasonable constraints on what it means to meet the (...) integration challenge for modality, empiricism is currently at best on a par with, but potentially worse off than, rationalist alternatives, with respect to the integration challenge. (shrink)

Are identity criteria grounding principles? A prima facie answer to this question is positive. Specifically, two-level identity criteria can be taken as principles related to issues of identity among objects of a given kind compared with objects of a more basic kind. Moreover, they are grounding metaphysical principles of some objects with regard to others. In the first part of the paper we criticise this prima facie natural reading of identity criteria. This result does not mean that identity criteria could (...) not be taken as grounding principles. In the second part, we propose some basic steps towards a conceptual reading of grounding. Such a way of understanding it goes along with an epistemic reading of identity criteria. (shrink)

Many philosophers since Hume have accepted that imagining/conceiving a scenario is our prime guide to knowing its possibility. Stephen Yablo provided a more systematic criterion: one is justified in judging that p is possible if one can imagine a world which one takes to verify p. I defend a version of Yablo’s criterion against van Inwagen’s moderate modal scepticism. Van Inwagen’s key argument is that we cannot satisfy Yablo’s criterion because we are not in a position to spell out far-fetched (...) possible scenarios in relevant detail. Van Inwagen’s argument can be applied to the use of conceivability for everyday possibility claims, leaving us with the spectre of pervasive modal scepticism. In order to answer the sceptical threat, I combine van Inwagen’s main example with general considerations about the nature of metaphysical modality to motivate a version of Yablo’s criterion and show that it does not lead to scepticism. One structural condition of p being metaphysically possible is that it coheres with a complete reality. This condition gives rise to Yablo’s criterion. However, for the criterion to be of any avail, we have to disregard details we are not in a position to specify. To account for our practice of doing so, I use Yablo’s distinction between imagining a world as determinate and imagining it determinately. I present a condition when we may simply disregard details as determinate. The condition results from integrating analogical reasoning into the conceivability test. (shrink)

According to Conceptualism, philosophy is an independent discipline that can be pursued from the armchair because philosophy seeks truths that can be discovered purely on the basis of our understanding of expressions and the concepts they express. In his recent book, The Philosophy of Philosophy, Timothy Williamson argues that while philosophy can indeed be pursued from the armchair, we should reject any form of Conceptualism. In this paper, we show that Williamson’s arguments against Conceptualism are not successful, and we sketch (...) a way to understand understanding that shows that there is a clear sense in which we can indeed come to know the answers to (many) philosophical questions purely on the basis of understanding. (shrink)

Are there ever good epistemic reasons to neglect base rates? Assuming an empiricist modal epistemology, I argue that we face an interesting tension between some very plausible epistemic norms: a norm requiring us to proportion our beliefs to the evidence may facilitate knowledge of the actual world, whilst inhibiting our acquisition of modal knowledge—knowledge of how things could be, but are not. The potential for this tension in our epistemic norms is a significant result in its own right. It can (...) also rationalize certain forms of demographic base-rate neglect. (shrink)

My thesis centres on the question of whether imaginative states can give rise to knowledge - including whether, and the extent to which, imaginative states can justify beliefs. Across seven chapters, I answer that imaginative states can indeed give rise to knowledge. The first and final chapters introduce and summarise the thesis. In the second chapter, I ask both what different cases of imagining have in common and what sets them apart from other kinds of mental states. In the third (...) chapter, I set out two key challenges that any theory of knowledge by imagination should respond to. The voluntarism challenge asks how imagination can play an evidential role since its content can be voluntarily controlled. The reliability challenge asks whether imaginative states are reliable enough to produce knowledge. I explain what these challenges involve and why they are distinctive, and assess how existing theories of knowledge by imagination could respond to them. I then evaluate the effectiveness of each response. In Chapter 4, I focus on a particular theory of justification - Phenomenal Conservatism, which says that what we are justified in believing is what seems to us to be the case. On the face of it, such a theory appears to exclude imagination as a source of justification. However, I will show how an advocate of Phenomenal Conservatism can include justification by imagination in their model after all. Thereafter in Chapter 5, I ask whether imaginative states can give rise to a particular kind of knowledge: self-knowledge. I look at inward-looking, outward-looking and expressivist theories of self-knowledge. I close Chapter 5 by concluding that all three of these theories can explain how imaginative states can help us acquire self-knowledge. Then in Chapter 6, I turn to see how the Imagination Model of Dreams, which states that dreaming is a kind of imagining, faces a certain challenge if imagination can give rise to knowledge. However, I will show how the imagination model of dreams can be made compatible with justification by imagination, such that we do not have to choose between giving up on justification by imagination or giving in to the sceptic, thus also rescuing the safety of our everyday knowledge. (shrink)

The idea that justified modal belief can be accounted for in terms of empirically justified, non-modal belief is enjoying increasing popularity in the epistemology of modality. One alleged reason to prefer modal empiricism over more traditional, rationalist modal epistemologies is that empiricism avoids the problem with the integration challenge that arise for rationalism, assuming that we want to be realists about modal metaphysics. In this paper, I argue that given two very reasonable constraints on what it means to meet the (...) integration challenge for modality, empiricism is currently at best on a par with, but potentially worse off than, rationalist alternatives, with respect to the integration challenge. (shrink)

The dissertation is in the format of a collection of several academic texts, composed of a two-part presentation and three papers on the topic of conceivability and the epistemology of modality. The presentation is composed of, first, a general introduction to conceivability theses and objections and, second, a discussion of two cases. Following the presentation, Asger provides three papers. The first paper, Pretense and Conceivability: A reply to Roca-Royes, presents a problem and a dilemma for Roca-Royes’ Non-Standard Dilemma for conceivability-based (...) epistemologies of de re modality in which she concludes that conceivability cannot be the whole story of our de re modal knowledge. The second paper, Conceivability Externalized, proposes an externalist conceivability-based epistemology of possibility inspired by Stalnaker. The third paper, Inconceivability as a Guide to Impossibility, considers inconceivability as an epistemic guide to impossibility, aiming to explore and add support to the underexplored thesis that one can justify beliefs about the impossibility of P on the basis of the inconceivability of P. (shrink)

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)

Those who aim to give an account of modal knowledge face two challenges: the integration challenge of reconciling an account of what is involved in knowing modal truths with a plausible story about how we can come to know them, and the reliability challenge of giving a plausible account of how we could have evolved a reliable capacity to acquire modal knowledge. I argue that recent counterfactual and dispositional accounts of modal knowledge cannot solve these problems regarding specifically metaphysical modal (...) truths—leaving us with the threat of skepticism about large portions of metaphysics, and certain other areas of philosophy. I argue, however, that both of these problems look insuperable only if we assume that metaphysical modal discourse serves a describing or tracking function. If we adopt instead a normativist approach to metaphysical modal discourse, which sees the basic function of modal discourse as giving us perspicuous ways of conveying, reasoning with, and renegotiating semantic rules, the problems show up very differently. The modal normativist can give a plausible response to both of the classic problems of how we can come to know metaphysical modal truths. (shrink)

According to modalism, modality is primitive. In this paper, we examine the implications of this view for modal epistemology, and articulate a modalist account of modal knowledge. First, we discuss a theoretical utility argument used by David Lewis in support of his claim that there is a plurality of concrete worlds. We reject this argument, and show how to dispense with possible worlds altogether. We proceed to account for modal knowledge in modalist terms.

I present an exemplary Humean modal epistemology. My version takes inspiration from but incurs no commitment to both Hume’s historical position and Lewis’s Humeanism. Modal epistemology should meet two challenges: the Integration challenge of integrating metaphysics and epistemology and the Reliability challenge of giving an account of how our epistemic capacities can be reliable in detecting modal truth. According to Lewis, modal reasoning starts from certain Humean principles: there is only the vast mosaic of spatiotemporally distributed local matters of fact. (...) The facts can be arbitarily recombined. These principles cannot be taken for granted. I suggest a bottom-up approach instead: Humean principles of recombining the mosaic of facts can be retrieved from the evolutionarily instilled and empirically informed use of imagination in exploring everyday circumstantial possibilities. This use of imagination conforms to a primitive conception of matter as freely recombinable. The modal beliefs that can be obtained from generalizing the more elementary exercise of imagination have to be corrected. Recombination is limited by sortal criteria of identity. Moreover, the overall picture of a recombinable spatiotemporal mosaic must be weighed against the results of science. (shrink)

RÉSUMÉDans l’esprit du scepticisme modal, Peter Hawke propose une épistémologie modale, la théorie de l’explication sûre (SET), qui adopte la forme de l’empirisme modal. Avec la SET, il essaie de défendre l’induction énumérative (EI) : on croit raisonnablement que tout X est F sur la base d’un échantillon suffisamment grand dans lequel tout X est F. Dans cet article, je soutiens que l’argmentation de Hawke échoue. De plus, je signale un problème avec la SET, lequel cause cet échec : la (...) SET est trop stricte pour expliquer certaines affirmations possibles que nous avons le droit de croire. (shrink)

Counterfactual reasoning has been used to account for many aspects of scientific reasoning. More recently, it has also been used to account for the scientific practice of modeling. Truth in a model is truth in a situation considered as counterfactual. When we reason with models, we reason with counterfactuals. Focusing on selected models like Bohr’s atom model or models of population dynamics, I present an account of how the imaginative development of a counterfactual supposition leads us from reality to interesting (...) model assumptions; how it guides our reasoning from these assumptions to interesting consequences for the model scenario via counterfactual entailment; and how it leads us back to conclusions on real target phenomena. (shrink)

Counterfactuals abound in science, especially when reasoning about and with models. This often requires entertaining counterfactual conditionals with nomologically or metaphysically impossible antecedents, namely, counternomics or counterpossibles. In this paper I defend the make-believe view of scientific counterfactuals, a naturalised fiction-based account of counterfactuals in science which provides a means to evaluate their meanings independently of the possibility of the states of affairs their antecedents describe, and under which they have non-trivial truth-values. Fiction is here understood as imagination (in contrast (...) with its most typical association with falsity), characterised as a propositional attitude of pretense or ‘make-believe’ (Walton 1990). The application of this theory to scientific counterfactuals makes their evaluation a game of make-believe: a counterfactual is (fictionally) true iff its antecedent and the rules of the game prescribe the imagining of its consequent (Kimpton-Nye 2020). The result is a practice-based account of counterfactuals and counterfactual reasoning in science which incorporates insights from theoretical and experimental analytic philosophy as well as cognitive science. This way, the make-believe view of scientific counterfactuals shows that the evaluation of scientific counterfactuals is none other than a question of scientific representation in disguise. (shrink)

We can safely infer that a proposition is possible if p is the case. But, I argue, this inference from the actual to the possible is merely explicative in nature, though we employ it at times as if it were ampliative. To make this inference ampliative, we need to include an inference to the best explanation. Specifically, we can draw a substantive conclusion as to whether p is possible from the fact that p is the case, if via our best (...) explanation we can explain how p could occur again in the complete and coherent set of propositions that describes the actual world. (shrink)