Online research in philosophy

This paper presents an account of the understanding of statements involving metaphysical modality, together with dovetailing theories of their truth conditions and epistemology. The account makes modal truth an objective matter, whilst avoiding both Lewisian modal realism and mind-dependent or expressivist treatments of the truth conditions of modal sentences. The theory proceeds by formulating constraints a world-description must meet if it is to represent a genuine possibility. Modal truth is fixed by the totality of the constraints. To understand modal discourse is to have tacit knowledge of the body of information stated in these constraints. Modal knowledge is attained by evaluating modal statements in accordance with the constraints. The question of the general relations between modal truth and knowability is also addressed. The paper includes a discussion of which modal logic is supported by the presented theory of truth conditions for modal statements.

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

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.

David Chalmers supports his contention that there is a possible world populated by our zombie twins by arguing for the assumption that conceivability entails possibility. But, I argue, the modal epistemology he sets forth, ‘modal rationalism,’ ignores the problem of incompleteness and relies on an idealized notion of conceivability. As a consequence, this epistemology can’t justify our quotidian judgments of possibility, let alone those judgments that concern the mind/body connection. Working from the analogy that the imagination is to the possible as perception is to the actual, I set forth a competing epistemology, ‘modal empiricism.’ This epistemology survives the incompleteness objection and allows some of our everyday modal judgments to be justified. But this epistemology can’t justify the claim that Zombie World is possible, which leaves Chalmers’s property dualism without the support it needs.

Many important metaphysical arguments validly deduce an actuality from a possibility. For example: Because it is possible for me to exist in the absence of anything material, I am not my body. I argue that there is no reason to suppose that our capacity for modal judgment is equal to the task of determining whether the "possibility" premise of any of these arguments is true. I connect this thesis with Stephen Yablo's recent work on the epistemology of modal statements.

Modal rationalism includes the thesis that ideal primary positive conceivability entails primary possibility. Modal monism is the thesis that the space of logically possible worlds is coextensive with the space of metaphysically possible worlds. In this paper I explore the relation between the two theses. My aim is to show that the former thesis implies the latter thesis, and that problems with the latter make the former implausible as a complete picture of the epistemology of modality. My argument explores the relation between logical modality and metaphysical modality.

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.

In this paper we examine Lewis's attempts to provide an epistemology of modality and we argue that he fails to provide an account that properly weds his metaphysics with an epistemology that explains the knowledge of modality that both he and his critics grant. We argue that neither the appeals to acceptable paraphrases of ordinary modal discourse nor parallels with Platonistic theories of mathematics suffice. We conclude that no proper epistemology for modal realism has been provided and that one is needed.

I survey a number of views about how we can obtain knowledge of modal propositions, propositions about necessity and possibility. One major approach is that whether a proposition or state of affairs is conceivable tells us something about whether it is possible. I examine two quite different positions that fall under this rubric, those of Yablo and Chalmers. One problem for this approach is the existence of necessary a posteriori truths and I deal with some of the ways in which these authors respond to the problem, including the use of two-dimensional modal semantics. Conventionalism about modality offers a complementary approach to modal epistemology, prompting us to identify our knowledge of modal truths with our mastery of linguistic or conceptual conventions. Finally, I discuss an approach to modal epistemology deriving from David Lewis's work that seeks to identify structural features of the modal space over which necessity and possibility are defined.

This paper introduces a modal epistemology that centers on inference to the best explanation (i.e. abduction). In introducing this abduction-centered modal epistemology, the paper has two main goals. First, it seeks to provide reasons for pursuing an abduction-centered modal epistemology by showing that this epistemology aids a popular stance on the mind-body problem and allows an appealing approach to modality. Second, the paper seeks to show that an abduction-centered modal epistemology can work by showing that abduction can establish claims about necessity/possibility (i.e. modal claims)—where ‘necessity’ and ‘possibility’ denote metaphysical necessity and possibility, ways things may or may not have been given how they actually are.