There are many ways the world might be, for all I know. For all I know, it might be that there is life on Jupiter, and it might be that there is not. It might be that Australia will win the next Ashes series, and it might be that they will not. It might be that my great-grandfather was my great-grandmother's second cousin, and it might be that he was not. It might be that copper is a compound, and it (...) might be that it is not. (shrink)

This paper is an attempt to define a new modality with philosophical interest by combining the basic modal ingredients of possibility and knowledge. This combination is realized via product of modal frames so as to construct a knowability modality, which is a bidimensional constructor of arity one defined in a two-dimensional modal frame. A semantical interpretation for the operator is proposed, as well as an axiomatic system able to account for inferences related to this new modality. The resulting logic for (...) knowability LK is shown to be sound and complete with respect to its class of modal-epistemic product models. (shrink)

The notion of conceivability has traditionally been regarded as crucial to an account of modal knowledge. Despite its importance to modal epistemology, there is no received explication of conceivability. In recent discussions, some have attempted to explicate the notion in terms of epistemic possibility. There are, however, two notions of epistemic possibility, a more familiar one and a novel one. I argue that these two notions are independent of one another. Both are irrelevant to an account of modal knowledge on (...) the predominant view of modal reality. Only the novel notion is relevant and apt on the competing view of modal reality; but this latter view is problematic in light of compelling counterexamples. Insufficient care regarding the independent notions of epistemic possibility can lead to two problems: a gross problem of conflation and a more subtle problem of obscuring a crucial fact of modal epistemology. Either problem needlessly hampers efforts to develop an adequate account of modal knowledge. I conclude that the familiar notion of epistemic possibility (and the very term ‘epistemic possibility’) should be eschewed in the context of modal epistemology. (shrink)

We think we have lots of substantial knowledge about the future. But contemporary wisdom has it that indeterminism prevails in such a way that just about any proposition about the future has a non-zero objective chance of being false.2, 3 What should one do about this? One, pessimistic, reaction is scepticism about knowledge of the future. We think this should be something of a last resort, especially since this scepticism is likely to infect alleged knowledge of the present and past. (...) One anti-sceptical strategy is to pin our hopes on determinism, conceding that knowledge of the future is unavailable in an indeterministic world. This is not satisfying either: we would rather not be hostage to empirical fortune in the way that this strategy recommends. A final strategy, one that we shall explore in this paper, is one of reconciliation: knowledge of a proposition is compatible with a subject’s belief having a non-zero objective chance of error.4 Following Williamson, we are interested in tying knowledge to the presence or absence of error in close cases, and so we shall explore the connections between knowledge and objective chance within such a framework. We don’t want to get tangled up here in complications involved in attempting to formulate a necessary and sufficient condition for knowledge in terms of safety. Instead, we will assume the following rough and ready necessary condition: a subject knows P only if she could not easily have falsely believed P.5 Assuming that easiness is to be spelt.. (shrink)

Seven proposed accounts of epistemic possibility are criticized, and a new account is proposed, making use of the notion of having justification for dismissing a proposition. The new account explains intuitions about otherwise puzzling cases, upholds plausible general principles about epistemic possibility, and explains the practical import of epistemic modality judgements. It is suggested that judgements about epistemic possibility function to assess which propositions are worthy of further inquiry.

Gaining information can be modelled as a narrowing of epistemic space . Intuitively, becoming informed that such-and-such is the case rules out certain scenarios or would-be possibilities. Chalmers’s account of epistemic space treats it as a space of a priori possibility and so has trouble in dealing with the information which we intuitively feel can be gained from logical inference. I propose a more inclusive notion of epistemic space, based on Priest’s notion of open worlds yet which contains only those (...) epistemic scenarios which are not obviously impossible. Whether something is obvious is not always a determinate matter and so the resulting picture is of an epistemic space with fuzzy boundaries. (shrink)

A strong impossibility is a situation that is epistemically, but not metaphysically, possible. Opponents of strong impossibilities (including Chalmers, Jackson and Stalnaker) have argued that we have “overwhelming reason” to reject and “very little” or “no reason” to think that such impossibilities exist. This partial draft argues that there are strong impossibilities and (very briefly) discusses the manner in which the existence of strong impossibilities is related to some much-discussed arguments in the philosophy of conscious experience. (The full version of (...) the paper will ultimately include a reply to the most significant argument against strong impossibilities, and a (slightly) more involved discussion of the relevance of all of this to issues in the philosophy of conscious experience.). (shrink)

A problem inherited from Kripke is the reconciliation of commitments to various necessities with conflicting intuitions of contingency, intuitions that things "might have turned out otherwise." Kripke's reconciliation strategy is to say that while it is necessary that X is Y, and so impossible for X not to be Y, it is nevertheless epistemically possible for X not to be Y. But what are nonactual epistemic possibilities? Several answers are considered and it is concluded that scenarios adduced to explain away (...) the target intuitions are either themselves impossible, or not fully coherent, or not epistemic in the relevant sense. (shrink)

Mights plug gaps. If p lacks a truth-value, then ‘It might be that p’ should also lack truth-value. Yet epistemic hedges often turn an unassertible statement into an assertible one. The phenomenon is illustrated in detail for two kinds of statements that are frequently alleged to be counterexamples to the principle of bivalence: future contingents and statements that apply predicates to borderline cases. The paper concludes by exploring the prospects for generalizing this gap-plugging strategy.

What I am calling New Age Relativism is usually proposed as a thesis about the truth-conditions of utterances, where an utterance is an actual historic voicing or inscription of a sentence of a certain type. Roughly, it is the view that, for certain discourses, whether an utterance is true depends not just on the context of its making—when, where, to whom, by whom, in what language, and so on—and the “circumstances of evaluation”—the state of the world in relevant respects—but also (...) on an additional parameter: a context of assessment. Vary the latter and the truth-value of the utterance can vary, even though the context of its making and the associated state of the world remain fixed. (shrink)