Josh Dever

It is a fundamental feature of language that words refer to things. Much attention has been devoted to the nature of reference, both in philosophy and in linguistics. Puzzles of Reference is the first book to give a comprehensive accessible survey of the fascinating work on this topic from the 1970s to the present day. Written by two eminent philosophers of language, Puzzles of Reference offers an up-to-date introduction to reference in philosophy and linguistics, summarizing ideas such as Kripke's revolutionary theory and presenting the various challenges in a clear and accessible manner. As the text does not assume prior training in philosophy or linguistics, it is ideal for use as part of a philosophy of language course for philosophy students or for linguistics students. Puzzles of Reference belongs to the series Contemporary Introductions to Philosophy of Language, in which each book provides an introduction to an important area of the philosophy of language, suitable for students at any level.

In our book The Inessential Indexical we argue that the various theses of essential indexicality all fail. Indexicals are not essential, we conclude. One essentiality thesis we target in the third chapter is the claim that indexical attitudes are essential for action. Our strategy is to give examples of what we call impersonal action rationalizations , which explain actions without citing indexical attitudes. To defeat the claim that indexical attitudes are essential for action, it suffices that there could be even one successful impersonal action rationalization. In what follows we bolster our case against an essential connection between action and the de se (or indexicality), first by developing a range of new action models and secondly by responding to challenges from Dilip Ninan, Stephan Torre, and José Luis Bermúdez .

Can humans and artificial intelligences share concepts and communicate? Making AI Intelligible shows that philosophical work on the metaphysics of meaning can help answer these questions. Herman Cappelen and Josh Dever use the externalist tradition in philosophy to create models of how AIs and humans can understand each other. In doing so, they illustrate ways in which that philosophical tradition can be improved. The questions addressed in the book are not only theoretically interesting, but the answers have pressing practical implications. Many important decisions about human life are now influenced by AI. In giving that power to AI, we presuppose that AIs can track features of the world that we care about (for example, creditworthiness, recidivism, cancer, and combatants). If AIs can share our concepts, that will go some way towards justifying this reliance on AI. This ground-breaking study offers insight into how to take some first steps towards achieving Interpretable AI.

Context and Communication offers an introduction to a central theme in the study of language: the various ways in which what we say depends on the context of speech and thought. The period since 1970 has produced a vast literature on this topic, both by philosophers and by linguists. This book explores key data, questions, concepts, and theories of context sensitivity. It is written to be accessible to someone with no prior knowledge of the material or, indeed, any prior knowledge of philosophy, and is ideal for use as part of a philosophy of language course by students of philosophy or linguistics.

Linguistic intervention in rational decision making is standardly captured in terms of information change. But the standard view gives us no way to model interventions involving expressions that only have an attentional effects on conversational contexts. How are expressions with non‐informational content – like epistemic modals – used to intervene in rational decision making? We show how to model rational decision change without information change: replace a standard conception of value (on which the value of a set of worlds reduces to values of individual worlds in the set) with one on which the value of a set of worlds is determined by a selection function that picks out a generic member world. We discuss some upshots of this view for theorizing in philosophy and formal semantics.

In her very interesting ‘First-personal modes of presentation and the problem of empathy’, L. A. Paul argues that the phenomenon of empathy gives us reason to care about the first person point of view: that as theorists we can only understand, and as humans only evince, empathy by appealing to that point of view. We are skeptics about the importance of the first person point of view, although not about empathy. The goal of this paper is to see if we can account for empathy without the ideology of the first person. We conclude that we can.

The semantic puzzles posed by propositional attitude contexts have, since Frege, been understood primarily in terms of certain substitution puzzles. We will take as paradigmatic of such substitution puzzles cases in which two coreferential proper names cannot be intersubstituted salva veritate in the context of an attitude verb. Thus, for example, the following sentences differ in truth value: (1) Lois Lane believes Superman can fly. (2) Lois Lane believes Clark Kent can fly. despite the fact that "Superman" and "Clark Kent" pick out the same individual.1 Equivalently, the following sentence may be true: (3) Lois Lane believes that Superman can fly, but that Clark Kent cannot fly. despite the coreferentiality of the names. (It will at times be convenient to appeal to this conjunctive attitude report in order to fix a single context of utterance.) Substitution failures such as these create a puzzle when conjoined with the assumptions (a) that attitude reports report a binary relation between an individual and some object of that individual's attitude and (b) that that object of the attitude is determined by the content of the complement sentence in the attitude report. If all of the terms in two complement sentences (e.g., "Superman can fly" and "Clark Kent can fly") have the same semantic content, then, prima facie, they ought to generate the same object of believe and, a fortiori, materially equivalent attitude reports. Frege, famously, attempts to defuse the puzzle by positing a semantic value of sense in addition to that of reference, and thereby distinguishing the semantic contents of the two complement sentences.

Aristotle observes that substances have no contraries. Consider one possible role that the contrary of a substance might play, were it to exist. Just as objects serve as guarantors of the instantiation of properties, contraries of objects could serve as guarantors of the non‐instantiation of properties. By first considering a reframing of deontic logic that takes ‘being permitted’ rather than ‘being forbidden’ as the default state, I develop logical tools that allow the construction of extremal models in which everything is permitted and nothing is forbidden. Transferred to quantified logic, these same tools give us a conception of antiobjects which block property instantiation. The resulting picture of antiobjects is then used as a test case to examine questions about the role of symmetry considerations in philosophical methodology.

Variables is a project at the intersection of the philosophies of language and logic. Frege, in the Begriffsschrift, crystalized the modern notion of formal logic through the first fully successful characterization of the behaviour of quantifiers. In Variables, I suggest that the logical tradition we have inherited from Frege is importantly flawed, and that Frege's move from treating quantifiers as noun phrases bearing word-world connection to sentential operators in the guise of second-order predicates leaves us both philosophically and technically wanting.

Montague and Kaplan began a revolution in semantics, which promised to explain how a univocal expression could make distinct truth-conditional contributions in its various occurrences. The idea was to treat context as a parameter at which a sentence is semantically evaluated. But the revolution has stalled. One salient problem comes from recurring demonstratives: "He is tall and he is not tall". For the sentence to be true at a context, each occurrence of the demonstrative must make a different truth-conditional contribution. But this difference cannot be accounted for by standard parameter sensitivity. Semanticists, consoled by the thought that this ambiguity would ultimately be needed anyhow to explain anaphora, have been too content to posit massive ambiguities in demonstrative pronouns. This article aims to revived the parameter revolution by showing how to treat demonstrative pronouns as univocal while providing an account of anaphora that doesn't end up re-introducing the ambiguity.

Supervaluational accounts of vagueness have come under assault from Timothy Williamson for failing to provide either a sufficiently classical logic or a disquotational notion of truth, and from Crispin Wright and others for incorporating a notion of higher-order vagueness, via the determinacy operator, which leads to contradiction when combined with intuitively appealing ‘gap principles’. We argue that these criticisms of supervaluation theory depend on giving supertruth an unnecessarily central role in that theory as the sole notion of truth, rather than as one mode of truth. Allowing for the co-existence of supertruth and local truth, we define a notion of local entailment in supervaluation theory, and show that the resulting logic is fully classical and allows for the truth of the gap principles. Finally, we argue that both supertruth and local truth are disquotational, when disquotational principles are properly understood

Since Kaplan’s "Demonstratives", it has become a common-place to distinguish between the character and content of an expression, where the content of an expression is what it contributes to "what is said" by sentences containing that expression, and the character gives a rule for determining, in a context, the content of an expression. A tacit assumption of theories of character has been that character is autonomous from content – that semantic evaluation starts with character, adds context, and then derives content. One consequence of this autonomy thesis is that the rules for character can contain no variables bound by content-level operators elsewhere in the sentence. Tacit appeal to this consequence features essentially both in Jason Stanley’s recent argument that all contextual ambiguity must be linked to "elements in the actual syntactic structure of the sentence uttered" in his "Context and Logical Form" and in my arguments against character-based theories of complex demonstratives in my "Complex Demonstratives". However, I argue here that the autonomy thesis is unmotivated, and show that we can separate Kaplan’s notion of character into two independent components: an aspect of meaning which is context-sensitive, and an aspect of meaning that is exempted from scopal interactions with other operators. The resulting semantic framework allows constructions similar to Kaplan’s rejected notion of "monsters begat by elegance", but which are both more empirically adequate and more theoretically versatile. Having made the distinction between context-sensitivity and autonomy from scopal interaction, I show how it allows binding into the character of expressions and hence undermines the immediate success of both Stanley’s argument and my former argument against character-based theories of complex demonstratives, and discuss briefly the prospects for reinstating modified versions of those arguments. Finally, I show how that same distinction allows a defusing of Kripke’s modal argument against a descriptive theory of names. Once autonomy from semantic interaction is separated from context-sensitivity, the first of those two alone can be used to capture the modal rigidity of proper names..

Cosmological arguments attempt to prove the existence of God by appeal to the necessity of a first cause. Schematically, a cosmological argument will thus appear as: (1) All contingent beings have a cause of existence. (2) There can be no infinite causal chains. (3) Therefore, there must be some non-contingent First Cause. Cosmological arguments come in two species, depending on their justification of the second premiss. Non-temporal cosmological arguments, such as those of Aristotle and Aquinas, view causation as requiring explanatory or conceptual priority, and thus insist that there can be no infinite regresses in such priority. Temporal cosmological arguments, also called kalam cosmological arguments due to their historical roots in Islamic kalam philosophers such as Abu Yusuf Ya'qub b. Ishaq al-Kindi and Abu Ali al-Hussain ibn Sina, view causation as requiring temporal priority, and thus insist that there can be no infinite temporal regresses.1 The kalam cosmological argument thus requires some supporting argument showing the incoherence of an infinite temporal regress of causally related events. William Lane Craig, in "The Finitude of the Past and the Existence of God"2, attempts to provide such an argument: (4) An actual infinite cannot exist. (5) An infinite temporal regress of events is an actual infinite. (6) Therefore an infinite temporal regress of events cannot exist. (9) I will not be concerned here with the general status of cosmological arguments, kalam or otherwise, or with contesting Craig's assumption that an infinite past would (unlike an infinite future) constitute a problematic actual infinity. I am rather concerned with Craig's general working principle, embodied in (4) above, that actual infinities are impossible. Craig, of course, is not alone in denying the possibility of the actually infinite. Resistance to such infinities is at least as old as Aristotle (Physics 3.5.204b1 – 206a8), and, as Craig rightly points out, persists through much of modern (i.e., post-scholastic, pre-twentieth-century) philosophy..

Problems of Compositionality is a revised version of Zolt´an Szab´o’s 1995 doctoral dissertation. Of its five chapters, three have appeared (in heavily modified form) in print independently1, so I will concentrate most of my remarks on the second and third chapters, which remain unpublished outside the book. As it happens, I find these two chapters to be the most philosophically rewarding of the book. The principle of compositionality is a general constraint on the shape of a theory of meaning. Szab´o gives the following initial formulation of the principle: The meaning of a complex expression is determined by the meanings of its constituents and by its structure. (3) Recent discussion of compositionality branches in a number of different directions, including (at least) disputes over the precise formulation of the principle, investigations of the mathematical features of various such formulations, exploration of a plethora of apparent counterexamples to the compositionality of natural languages, scholarly work on the history of the principle (especially its role in Frege), and employment of the principle as a tool in other philosophical disputes. Szab´o’s path through this thicket begins, in the first chapter, with a defense of an idiosyncratic version of the compositionality principle against some more traditional alternatives, proceeds in the second and third chapters to the oft-neglected and philosophically crucial task of asking why the principle of compositionality ought to be one we seek to impose, and concludes in the fourth and fifth chapters by considering and rejecting two putative counterexamples (manifesting in the semantics of adjectives and of definite descriptions) to the principle. The principle of compositionality is most commonly given a functional implementation – a language L is compositional iff the meaning of a complex expression α of L is a function of the meanings of the parts of α and the syntactic structure of α. Equivalently, L is compositional iff synonyms can be intersubstituted salva significa- tio in complex expressions of L.2 Szab´o, however, rejects the functional/substitutional....

Modal fictionalists propose to defuse the unwanted ontological commitments of modal realism by treating modal realism as a fictional story, and modal assertions as assertions, prefixed by a fictionalist operator, that something is true in that story. However, consideration of conditionals with modal antecedents raises the problem ofembedding, which shows that the simple prefixing strategy cannotsucceed. A compositional version of the fictionalist strategy isdeveloped and critiqued, and some general semantic morals aredrawn from the failures of both strategies.

A “slingshot” proof suggested by Kurt Gödel (1944) has been recast by Stephen Neale (1995) as a deductive argument showing that no non-truthfunctional sentence connective can permit the combined use, within its scope, of two truth-functionally valid inference principles involving defi- nite descriptions. According to Neale, this result provides indirect support for Russell’s Theory of Descriptions and has broader philosophical repercussions because descriptions occur in non-truth-functional constructions used to motivate talk about (e.g.) necessity, time, probability, causation, obligation, facts, states of affairs, and propositions.

A total theory of linguistic understanding is often taken to require three subtheories: a syntactic theory, a semantic theory, and a pragmatic theory. The semantic theory occupies an intermediary role – it takes as input structures generated by the syntax, assigns to those structures meanings, and then passes those meanings on to the pragmatics, which characterizes the conversational 1 impact of those meanings. Semantic theories thus seek to explain phenomena such as truth conditions of and inferential relations among sentences/utterances, anaphoric relations among terms, and ambiguity and incoherence of expressions.