It is a venerable slogan due to David Hume, and inherited by the empiricist tradition, that the impossible cannot be believed, or even conceived. In Positivismus und Realismus, Moritz Schlick claimed that, while the merely practically impossible is still conceivable, the logically impossible, such as an explicit inconsistency, is simply unthinkable. -/- An opposite philosophical tradition, however, maintains that inconsistencies and logical impossibilities are thinkable, and sometimes believable, too. In the Science of Logic, Hegel already complained against “one of the (...) fundamental prejudices of logic as hitherto understood”, namely that “the contradictory cannot be imagined or thought” (Hegel 1931: 430). Our representational capabilities are not limited to the possible, for we appear to be able to imagine and describe also impossibilities — perhaps without being aware that they are impossible. -/- Such impossibilities and inconsistencies are what this entry is about... (shrink)

Platonism is the view that there exist such things as abstract objects — where an abstract object is an object that does not exist in space or time and which is therefore entirely non-physical and nonmental. Platonism in this sense is a contemporary view. It is obviously related to the views of Plato in important ways, but it is not entirely clear that Plato endorsed this view, as it is defined here. In order to remain neutral on this question, the (...) term ‘platonism’ is spelled with a lower-case ‘p’. (See entry on Plato.) The most important figure in the development of modern platonism is Gottlob Frege (1884, 1892, 1893-1903, 1919). The view has also been endorsed by many others, including Kurt Gödel (1964), Bertrand Russell (1912), and W.V.O. Quine (1948, 1951). (shrink)

John is currently thinking that the sun is bright. Consider his occurrent belief or judgement that the sun is bright. Its content is that the sun is bright. This is a truth- evaluable content (which shall be our main concern) because it is capable of being true or false. In virtue of what natural, scientifically accessible facts does John’s judgement have this content? To give the correct answer to that question, and to explain why John’s judgement and other contentful mental (...) states have the contents they do in virtue of such facts, would be to naturalize mental content. (shrink)

Approaches to truth and the Liar paradox seem invariably to face a dilemma: either appeal to some sort of hierarchy, or declare apparently perfectly coherent concepts incoherent. But since both options lead to severe expressive restrictions, neither seems satisfactory. The aim of this paper is a new approach, which avoids the dilemma and the resulting expressive restrictions. Previous approaches tend to appeal to some new sort of semantic value for the truth predicate to take. I argue that such approaches inevitably (...) lead to the dilemma in question. In contrast, the present proposal sticks with classical semantic values, but allows the compositional rules associated with these to admit of exceptions. I show how such an approach can be developed systematically. (shrink)

Most direct reference theorists about indexicals and proper names have adopted the thesis that singular propositions about physical objects are composed of physical objects and properties.1 There have been a number of recent proponents of such a view, including Scott Soames, Nathan Salmon, John Perry, Howard Wettstein, and David Kaplan.2 Since Kaplan is the individual who is best known for holding such a view, let's call a proposition that is composed of objects and properties a K-proposition. In this paper, I (...) will attempt to show that a direct reference view about the content of proper names and indexicals leads very naturally to the position that all singular propositions about physical objects are K-propositions.3 Then, I will attempt to show that this view of propositions is false. I will spend the bulk of the paper on this latter task. My goal in the paper, then, is to show that adopting the direct reference thesis comes at a cost problems the view has with problems such as opacity and the significance of some identity statements; it comes at even more of a cost). (shrink)

Paraphrase is ubiquitous in philosophy, especially in discussions about ontological commitment. But should it be? Paraphrases are seldom accompanied by evidence that would convince, say, a linguist that the paraphrase and the paraphrased sentence have the same meaning. Indeed, from the perspective of linguistics, many paraphrases would seem to be nothing but bad jokes. For this reason, many philosophers have become deeply suspicious about paraphrase. I ague in this paper that this worry is misguided--that successful paraphrases do not need to (...) preserve semantic content, and that the way that paraphrase has been used in Quinean meta-ontology, and philosophical inquiry more generally, corresponds, at least roughly, to the way it should be used. (shrink)

Competing theories on the semantics of group pejorative terms (also known as‘slurs’)comprise both advocates and opponents to the Identity Thesis (IT), according to whichthese terms and their neutral counterparts do not differ in semantic value. In the oppo-nents’camp, Christopher Hom has offered an argument based on substitution of slurs andneutral counterparts that both supports his semanticist approach and cast doubts on all IT-based approaches to slurs. We aim to point to a dilemma triggered by this argument based on evidence showing (...) that substitution of some words (including but not restricted to slurs)for non-problematically co-referential pairs may fail to preserve truth-values in some linguistics contexts. (shrink)

In recent years, a number of new trends have seen light at the intersection of semantics and philosophy of language. They are meant to address puzzles raised by the context-sensitivity of a variety of natural language constructions, such as knowledge ascriptions, belief reports, epistemic modals, indicative conditionals, quantifier phrases, gradable adjectives, temporal constructions, vague predicates, moral predicates, predicates of personal taste. A diversity of labels have consequently emerged, such as 'contextualism', 'indexicalism', 'invariantism', 'literalism', 'minimalism', and 'relativism', variously qualified. The goal (...) of this essay is to pinpoint the issues that lie at the heart of the recent debates, clarify what is at stake, and provide a snapshot of the current theoretical landscape. (shrink)

In this paper, I shall explore a determiner in natural language which is ambivalent as to whether it should be classified as quantificational or objectdenoting: the determiner both. Both in many ways appears to be a paradigmatic quantifier; and yet, I shall argue, it can be interpreted as having an individual—an object—as semantic value. To show the significance of this, I shall discuss two ways of thinking about quantifiers. We often think about quantifiers via intuitions about kinds of thoughts. Certain (...) terms are naturally used to express singular thoughts, and appear to do so by contributing objects to the thoughts expressed. Other terms are naturally used to express general thoughts, and appear to do so by contributing higher-order properties to the thoughts expressed. Viewed this way, the main condition on whether a term is a quantifier or not is whether its semantic value is an object or a higher-order property. At least, these provide necessary conditions. Both can be interpreted as contributing objects to thoughts, and in many cases appears to express genuine singular thoughts. Thinking about quantifiers this way, both can appear object-denoting and non-quantificational. We also often think about quantifiers in terms of a range linguistic features, including semantic value, presupposition, scope, binding, syntactic distribution, and many others. Viewed this way, I shall argue, both can appear quantificational. In particular, it displays scope behavior that is one of the hallmarks of quantification. But, I shall show, it can do so even if given a semantics on which it denotes an object. Thus, both appears quantificational by some linguistic standards, and yet appears object-denoting by standards based on intuitions about the kinds.. (shrink)

Contemporary natural-language semantics began with the assumption that the meaning of a sentence could be modeled by a single truth condition, or by an entity with a truth-condition. But with the recent explosion of dynamic semantics and pragmatics and of work on non- truth-conditional dimensions of linguistic meaning, we are now in the midst of a shift away from a truth-condition-centric view and toward the idea that a sentence’s meaning must be spelled out in terms of its various roles in (...) conversation. This communicative turn in semantics raises historical questions: Why was truth-conditional semantics dominant in the first place, and why were the phenomena now driving the communicative turn initially ignored or misunderstood by truth-conditional semanticists? I offer a historical answer to both questions. The history of natural-language semantics—springing from the work of Donald Davidson and Richard Montague—began with a methodological toolkit that Frege, Tarski, Carnap, and others had created to better understand artificial languages. For them, the study of linguistic meaning was subservient to other explanatory goals in logic, philosophy, and the foundations of mathematics, and this subservience was reflected in the fact that they idealized away from all aspects of meaning that get in the way of a one-to-one correspondence between sentences and truth-conditions. The truth-conditional beginnings of natural- language semantics are best explained by the fact that, upon turning their attention to the empirical study of natural language, Davidson and Montague adopted the methodological toolkit assembled by Frege, Tarski, and Carnap and, along with it, their idealization away from non-truth-conditional semantic phenomena. But this pivot in explana- tory priorities toward natural language itself rendered the adoption of the truth-conditional idealization inappropriate. Lifting the truth-conditional idealization has forced semanticists to upend the conception of linguistic meaning that was originally embodied in their methodology. (shrink)

I defend the view that linguistic meaning is a relation borne by an expression to a type of speech act, and that this relation holds in virtue of our overlapping communicative dispositions, and not in virtue of linguistic conventions. I argue that this theory gives the right account of the semantics–pragmatics interface and the best-available semantics for non-declarative clauses, and show that it allows for the construction of a rigorous compositional semantic theory with greater explanatory power than both truth-conditional and (...) dynamic semantics. (shrink)

This paper is a comparison of two structural theories of propositions: the theory proposed by Kazimierz Ajdukiewicz in the 1960s and the theory developed by Jeffrey King at the beginning of the 21st century. The first section of the paper is an overview of these theories. The second part is a detailed discussion of significant similarities shared by them. In this section, I also identify and analyze ways in which these theories differ and attempt to determine if these differences are (...) substantial or apparent. The last part is an attempt to determine if the discussed theories are capable of coping with the Benacerraf Problem. (shrink)

I suspect the answer to the question in the title of this paper is no. But the scope of my paper will be considerably more limited: I will be concerned with whether certain types of considerations that are commonly cited in favor of dynamic semantics do in fact push us towards a dynamic semantics. Ultimately, I will argue that the evidence points to a dynamics of discourse that is best treated pragmatically, rather than as part of the semantics.

In a series of publications, Robert Stalnaker and Hartry Field have undertaken a dispute about what is the correct way to explain intentionality naturalistically. Field wishes to assimilate mental intentionality to linguistic intentionality and to explain both kinds of intentionality using Tarskian truth theory plus the causal theory of reference. Stalnaker wishes to subsume mental intentionality under the notion of indication and to explain it on the model of measurement theory, leaving linguistic intentionality to be explained derivatively. I attempt to (...) adjudicate their dispute, paying particular attention to the question whether Tarskian truth theory has a role to play in explaining intentionality naturalistically. ;The first half of the dissertation examines Tarski's theory. I argue that Field and Stalnaker are incorrect when they agree that Tarski's reduction of the notion of truth is defective and I explain Tarski's 'structural' notion of truth. In the second half of the dissertation, I argue that Stalnaker's criticisms of Field mostly do not stand up to scrutiny, but that Field's theory is unsatisfactory nonetheless; I also argue that certain criticisms of Stalnaker do more damage than he thinks. I conclude that neither has solved 'the problem of intentionality', but that Stalnaker is right that truth theory as such will not have a role in the correct solution. (shrink)

The paper sketches an analysis of the notion of a self-fulfilling belief in terms of doxastic modal logic. We point out a connection between self-fulfilling beliefs and Moore’s paradox. Then we look at self-fulfilling beliefs in the context of neighborhood semantics. We argue that the analysis of several interesting self-fulfilling beliefs has to make essential use of propositional quantification.

Some intentional attitudes (beliefs, fears, desires, etc.) have a common focus in spite of there being no object at that focus. For example, two beliefs may be about the same witch even when there are no witches, different astronomers had beliefs directed at Vulcan, even though there is no such planet. This relation of having a common focus, whether or not there is an actual concrete object at that focus, is called intentional identity. In the first part of this thesis (...) I develop a new theory of intentional identity, the triangulation theory, and argue that it has significant advantages over the extant theories of intentional identity in the literature. Empty attitudes (attitudes that are not, prima facie, about anything that exists) will serve as useful cases for testing theories of intentional identity. -/- In the second part, I put the theory developed in the first part to work. I use triangulation theoretic tools to shed light on other debates about intentional attitudes. Some issues to which intentional identity are relevant are the debate about the content of intentional attitudes, the issue of whether or not we need to appeal to external constraints on the content of intentional attitudes, how we should understand the agreement and disagreement of attitudes, how we should construe communication and how we ought to solve Kripke’s puzzle about belief. The second part of this thesis also motivates a broadly internalist and individualistic approach to the con-tent of intentional attitudes; it turns out that if we take a closer look at the narrowly construed psychological states of agents we find materials that allow us to make sense of phenomena usually associated with externalist constraints on the content of attitudes (such as causal constraints and eligibility constraints) in a new way. (shrink)

A very simple contextualist treatment of a sentence containing an epistemic modal, e.g. a might be F, is that it is true iff for all the contextually salient community knows, a is F. It is widely agreed that the simple theory will not work in some cases, but the counterexamples produced so far seem amenable to a more complicated contextualist theory. We argue, however, that no contextualist theory can capture the evaluations speakers naturally make of sentences containing epistemic modals. If (...) we want to respect these evaluations, our best option is a relativist theory of epistemic modals. On a relativist theory, an utterance of a might be F can be true relative to one context of evaluation and false relative to another. We argue that such a theory does better than any rival approach at capturing all the behaviour of epistemic modals. (shrink)

In my 1991 paper, AAnti-Individualism and Privileged Access,@ I argued that externalism in the philosophy of mind is incompatible with the thesis that we have privileged , nonempirical access to the contents of our own thoughts.¹ One of the most interesting responses to my argument has been that of Martin Davies (1998, 2000, and Chapter _ above) and Crispin Wright (2000 and Chapter _ above), who describe several types of cases to show that warrant for a premise does not always (...) transmit to a known deductive consequence of that premise, and who contend that this fact under-mines my argument for incompatibilism. I will try to show here that the Davies/Wright point about transmission of warrant does not adversely affect my argument. (shrink)

A number of traditional roles that propositions are supposed to play are outlined. Philosophical theories of the nature of propositions are then surveyed, together with considerations for and against, with an eye on the question whether any single notion of a proposition is suited to play all or any of these roles. Approaches discussed include: (1) the structureless possible-worlds theory; (2) the structured Russellian theory; and (3) the structured Fregean theory. It is noted that it is often unclear whether these (...) are accounts of what propositions are, ontologically speaking, or whether they are accounts of how propositions are best represented in a formal semantic theory. (shrink)

The truthmaker theory rests on the thesis that the link between a true judgment and that in the world to which it corresponds is not a one-to-one but rather a one-to-many relation. An analogous thesis in relation to the link between a singular term and that in the world to which it refers is already widely accepted. This is the thesis to the effect that singular reference is marked by vagueness of a sort that is best understood in supervaluationist terms. (...) In what follows we show that the supervaluationist approach to singular reference, when wedded to the truthmaker idea, yields a framework of surprising power, which offers a uniform set of solutions to a range of problems regarding identity, reference and knowledge, problems which have hitherto been dealt with on an ad hoc basis. (shrink)

Words have meaning. Sentences also have meaning, but their meaning is different in kind from any collection of the meanings of the words they contain. I discuss two puzzles related to this difference. The first is how the meanings of the parts of a sentence combine to give rise to a unified sentential meaning, as opposed to a mere collection of disparate meanings (UP1). The second is why the formal ontology of linguistic meaning changes when grammatical structure is built up (...) (UP2). For example, the meaning of a sentence is a proposition evaluable for truth and falsity. In contrast, a collection of the meanings of its parts does not constitute a proposition and is not evaluable for truth. These two puzzles are closely related, since change in formal ontology is the clearest sign of the unity of meaning. The most popular strategy for answering them is taking the meanings of the parts as abstractions from primitive sentence meanings. However, I argue that, given plausible psychological constraints, sentence meanings cannot be taken as explanatory primitives. Drawing on recent work in Generative Grammar and its philosophy, I suggest that the key to both unity questions is to distinguish strictly between lexical and grammatical meaning. The latter is irreducible and determines how lexical content is used in referential acts. I argue that these referential properties determine a formal ontology, which explains why and how formal ontology changes when grammatical structure is built up (UP2). As for UP1, I suggest that, strictly speaking, lexical meanings never combine. Instead, whenever grammar specifies a formal ontology for the lexical meanings entering a grammatical derivation, further lexical (or phrasal) meanings can only specify aspects of this recursive grammatical process. In this way, contemporary grammatical theory can be used to address old philosophical problems. (shrink)

This thesis comprises three main chapters—each comprising one relatively standalone paper. The unifying theme is fragmentalism about truth, which is the view that the predicate “true” either expresses distinct concepts or expresses distinct properties. -/- In Chapter 1, I provide a formal development of alethic pluralism. Pluralism is the view that there are distinct truth properties associated with distinct domains of subject matter, where a truth property satisfies certain truth-characterizing principles. On behalf of pluralists, I propose an account of logic (...) and semantics that shows how they can answer central conceptual and logical challenges for their view. -/- In Chapter 2, I motivate and develop a modal account of propositions on the basis of an iterative conception of propositions, where the modality is logico-mathematical. The modal account of propositions takes the conception to motivate an inherently potential hierarchy of propositions. I show that the account helps provide satisfying solutions to the intensional paradoxes of Russell-Myhill, Kaplan, and Prior. -/- In Chapter 3, I propose that “true” is polysemous. I suggest that “true” is initially polysemous between correspondence truth and disquotational truth, and further polysemous between the meanings corresponding to the subconcepts of the concept truth generated by the indefinite extensibility of that concept. I show that the proposal provides satisfying solutions to the semantic paradoxes. (shrink)

The main chapters of this thesis develop and defend a version of two-dimensional semantics that provides an account of Kripkean a posteriori necessity.

This dissertation addresses a variety of foundational issues pertaining to the notion of algorithm employed in mathematics and computer science. In these settings, an algorithm is taken to be an effective mathematical procedure for solving a previously stated mathematical problem. Procedures of this sort comprise the notional subject matter of the subfield of computer science known as algorithmic analysis. In this context, algorithms are referred to via proper names of which computational properties are directly predicated )). Moreover, many formal results (...) are traditionally stated by explicitly quantifying over algorithms. These observations motivate the view that algorithms are themselves abstract mathematical objects -- a view I refer to as algorithmic realism. The status of this view is clearly related to that of Church's Thesis -- i.e. the claim that a function is computable by an algorithm just in case it is partial recursive. But whereas Church's Thesis is widely accepted on the basis of several well-known mathematical analyses of algorithmic computability, there is presently no consensus on how we can uniformly identify individual algorithms with mathematical objects. In the first chapter of this work, I attempt to illustrate the theoretical significance of algorithmic realism. I suggest that this view is not only of foundational significance to computer science, but also worth highlighting due to the role algorithms play in the fixation of mathematical knowledge and their relationship to intensional entities such as propositions and properties. Chapter Two presents a formal framework for reducing computational discourse to mathematical discourse modeled on contemporary discussion of mathematical nominalism. Chapter Three is centered on a case study intended to illustrate the technical exigencies involved with defending algorithmic realism. Chapter Four explores various ways in which algorithms might be identified with models of computation. And finally, Chapter Five argues that no such identification can uniformly satisfy all statements of algorithmic identity and non-identity affirmed by computational practice. I suggest that the technical crux of algorithmic realism lies in the necessity of reducing recursive specifications of algorithms to iterative models of computation in a manner which preserves algorithmic identity. (shrink)