The epistemology of modality is gradually coming to play a central role in general discussions about modality. This paper is a contribution in this direction, in particular I draw a comparison between Lewis’s Modal realism and Timothy Williamson’s recent account of modality in terms of counterfactual thinking. In order to have criteria of evaluation, I also formulate four requirements which are supposed to be met by any theory of modality to be epistemologically adequate.

The epistemology of modality is gradually coming to play a central role in general discussions about modality. This paper is a contribution in this direction, in particular I draw a comparison between Lewis’s Modal realism and Timothy Williamson’s recent account of modality in terms of counterfactual thinking. In order to have criteria of evaluation, I also formulate four requirements which are supposed to be met by any theory of modality to be epistemologically adequate.

The question as to whether some objects are possible worlds that have an initial segment in common, i.e. so that their fusion is a temporal tree whose branches are possible worlds, arises both for those who hold that our universe has the structure of a temporal tree and for those who hold that what there is includes concrete universes of every possible variety. The notion of “possible world” employed in the question is seen to be the notion of an object (...) of a kind such that objects of that kind play a certain theoretical role. Lewis’s discussion of the question is thereby clarified but is nevertheless inadequate; his negative answer is correct but even from his combinatorialist viewpoint the rationale he provides for this answer is misguided. I explain why the combinatorialist advocate of concrete plenitude should hold that no object is a tree of possible worlds. Then I explain that for a different reason the nomic essentialist advocate of concrete plenitude should hold this much too. (shrink)

Here I explore the prospects for fictionalism about the mental, modeled after fictionalism about possible worlds. Mental fictionalism holds that the mental states posited by folk psychology do not exist, yet that some sentences of folk psychological discourse are true. This is accomplished by construing truths of folk psychology as “truths according to the mentalistic fiction.” After formulating the view, I identify five ways that the view appears self-refuting. Moreover, I argue that this cannot be fixed by semantic ascent or (...) by a kind of primitivism. Even so, I also show that the “self-refutation” charges are subtly question-begging. Nevertheless, the reply reveals that a mental fictionalist ought to be a kind of quietist. (shrink)

This paper discusses “inclusionism” in the context of David Lewis’s modal realism (and in the context of parasitic accounts of modality such as John Divers’s agnosticism about possible worlds). This is the doctrine that everything is a world. I argue that this doctrine would be beneficial to Divers-style agnosticism; that it suggests a reconfiguration of the concept of actuality in modal realism; and finally that it suffers from an as-yet unsolved difficulty, the problem of the unmarried husbands. This problem also (...) shows that Stephen Yablo’s analysis of “intrinsic” is inadequate. (shrink)

Many philosophers posit abstract entities – where something is abstract if it is acausal and lacks spatio-temporal location. Theories, types, characteristics, meanings, values and responsibilities are all good candidates for abstractness. Such things raise an epistemological puzzle: if they are abstract, then how can we have any epistemic access to how they are? If they are invisible, intangible and never make anything happen, then how can we ever discover anything about them? In this article, I critically examine epistemological objections to (...) belief in abstract objects offered by Paul Benacerraf, Colin Cheyne and Hartry Field. (shrink)

What is the function of modal judgment? Why do we make judgments of possibility and necessity? Or are such judgments, in fact, dispensable? This paper introduces and develops an answer to these questions based on Kant’s remarks in section 76 of the Critique of Judgment. Here, Kant appears to argue the following: that a capacity to make modal judgments using modal concepts is required for a capacity for objective representation, in light of our split cognitive architecture. This split cognitive architecture (...) leaves room for a mismatch between our concepts and intuitions and, Kant argues, that is why we need modal concepts and modal judgments. In this paper, I develop this account of the function of modal judgment and to explore the extent to which it may improve upon contemporary alternatives. I focus on one particularly important challenge for the account: to explain why a distinction between the actual and the possible, rather than merely a distinction between the actual and the non-actual, is required. In order to answer this question, I supplement the account with a particular way of thinking about objectivity. (shrink)

If a possible-worlds semantic theory for modal logics is pure, then the assertion of the theory, taken at face-value, can bring no commitment to the existence of a plurality of possible worlds (genuine or ersatz). But if we consider an applied theory (an application of the pure theory) in which the elements of the models are required to be possible worlds, then assertion of such a theory, taken at face-value, does appear to bring commitment to the existence of a plurality (...) of possible worlds. Or at least that is so if the applied theory is adequate. For an applied possible-worlds semantic theory that is constrained to contain only one-world models is bound to deliver results on validity, soundness and completeness that are apt to seem disastrous. I attempt to steer a course between commitment to the existence of a plurality of possible worlds and commitment to such a disastrous applied possible-worlds semantics by noting, and developing, the position of one who asserts such a theory at face-value but who remains agnostic about the existence of other (non-actualized) possible worlds. Thus, a novel interpretation of applied possible-worlds semantics is offered on which we may lay claim to whatever benefits such a theory offers while avoiding realism about (other) possible worlds. Thereby, the contention that applied possible-worlds semantics gives us reason to be realists about possible worlds is (further) undermined. (shrink)

In this paper, I explore Rosen’s ‘transcendental’ objection to constructive empiricism—the argument that in order to be a constructive empiricist, one must be ontologically committed to just the sort of abstract, mathematical objects constructive empiricism seems committed to denying. In particular, I assess Bueno’s ‘partial structures’ response to Rosen, and argue that such a strategy cannot succeed, on the grounds that it cannot provide an adequate metalogic for our scientific discourse. I conclude by arguing that this result provides some interesting (...) consequences in general for anti-realist programmes in the philosophy of science.Keywords: Constructive empiricism; Mathematical fictionalism; Partial structures; Modality. (shrink)

James Ladyman ([2000]) argues that constructive empiricism is untenable because it cannot adequately account for modal statements about observability. In this paper, I attempt to resist Ladyman's conclusion, arguing that the constructive empiricist can grant his modal discourse objective, theory-independent truth-conditions, yet without compromising his empiricism.

I discuss a modification of Lewisian modal realism called 'inclusionism'. Inclusionism is the thesis that some worlds contain other worlds as proper parts. Inclusionism has some attractive consequences for theories of modality. Josh Parsons, however, has raised a problem for inclusionism: the problem of unmarried husbands. In this paper I reply to this problem. My strategy is twofold: first I claim, pace Parsons, that it is not clear why the inclusionist cannot avail herself of an obvious solution to the problem; (...) and second, I argue that even if there is no available solution, the same problem also afflicts Lewis' original theory. Therefore, even if the problem remains unsolved, we have not been given any reason to think that an inclusionist version of Lewisian realism is worse than the original. (shrink)

The broad aim of this thesis is to explore fruitful connections between ideology theory and the philosophy of possible worlds. Ideologies are full of modal concepts, such as possibility, potential, necessity, essence, contingency and accident. Typically, PWs are articulated for the analysis and illumination of modal concepts. That naturally suggests a method for theorising ideological modality, utilising PW theory. The specific conclusions of the thesis proffer a number of original contributions to knowledge: 1) PWs should only be used for explication (...) and not as evidence or criteria of assessment in ideology theory. The estimation of utopian possibilities, human essences and freedoms must be determined by extrinsic criteria. PWs can serve only as a window or means of expression but not as a set of evaluative premises. 2) For this purpose, a modified version of Lewisian genuine realism, with its device of counterpart theory, is the best approach; the alternative theories risk constricting possibilities or smuggling in assumptions that ought to be objects of analysis in ideology theory. This is instructive, since ideology theorists are prone to pick and choose favoured aspects of modal philosophy without further argument. 3) Conclusions and suggest the adoption of GR or fictionalist GR. Overall, the actualist options are less adequate. Fictionalism, by contrast, is a worthwhile contender, but it too presents comparative weaknesses which reinforce GR’s standing as a potent challenger to the modal metaphysician. Therefore, this thesis presents additional reasons to think GR true. The conclusions are not knockdown, and I draw out incentives and consequences for adopting alternative stances. The various chapters also provide specific details for comprehending and debating ideological modals. (shrink)