Truth-Value Gaps

Can God create an unliftable stone? Beall & Cotnoir propose that ‘God can create an unliftable stone’ is a truth-value gap (neither true nor false). However, this yields a revenge paradox on whether God can eschew gaps. Can God avoid gappy ascriptions of power? Either way, God’s power seems to have limits. In response, it may be said that ascribing God the power to avoid gaps is itself gappy—it concerns a power that God neither has nor lacks. Yet this ends (...) up being inconsistent, for it implies that God definitely lacks that power. Following Aquinas, perhaps Beall & Cotnoir could accept this lack and still uphold omnipotence, suggesting that the power to avoid gaps is impossible for God. Yet the Aquinian stratagem is enough to block the original paradox, which saps the motivation to proffer truth-value gaps in addition. I conclude that the gappy solution is either inadequate or insufficiently motivated. (shrink)

This article informally presents a solution to the paradoxes of truth and shows how the solution solves classical paradoxes (such as the original Liar) as well as the paradoxes that were invented as counterarguments for various proposed solutions (“the revenge of the Liar”). This solution complements the classical procedure of determining the truth values of sentences by its own failure and, when the procedure fails, through an appropriate semantic shift allows us to express the failure in a classical two-valued language. (...) Formally speaking, the solution is a language with one meaning of symbols and two valuations of the truth values of sentences. The primary valuation is a classical valuation that is partial in the presence of the truth predicate. It enables us to determine the classical truth value of a sentence or leads to the failure of that determination. The language with the primary valuation is precisely the largest intrinsic fixed point of the strong Kleene three-valued semantics (LIFPSK3). The semantic shift that allows us to express the failure of the primary valuation is precisely the classical closure of LIFPSK3: it extends LIFPSK3 to a classical language in parts where LIFPSK3 is undetermined. Thus, this article provides an argumentation, which has not been present in contemporary debates so far, for the choice of LIFPSK3 and its classical closure as the right model for the truth predicate. In the end, an erroneous critique of Kripke-Feferman axiomatic theory of truth, which is present in contemporary literature, is pointed out. (shrink)

This book argues that the standard (orthodox) doctrine of incarnation (of "God enfleshed") is best understood along glut-theoretic lines: the incarnate God is a contradictory being. Example: because God, the Christ figure is all-knowing; but because human, ignorant. And so on. Standard theological theory in the tradition recognizes the apparent contradiction in its core doctrines; Beall argues that the appearance should be accepted as veridical.

This book proposes a new solution to the problem of vagueness. There are several different ways of addressing this problem and no clear agreement on which one is correct. The author proposes that it should be understood as the problem of explaining vague predicates in a way that systematizes six intuitions about the phenomenon and satisfies three criteria of adequacy for an ideal theory of vagueness. The third criterion, which is called the “criterion of precisification”, is the most controversial one. (...) It is based on the intuition that a predicate is vague only if it is imprecise. The author considers some different definitions of linguistic imprecision, proposing that a predicate is imprecise if and only if there is no sharp boundary between objects to which its application yields some particular truth-value and objects to which its application does not yield that truth-value. The volume critically reviews the current theories of vagueness and proposes a new one, the Theory of Vagueness as Arbitrariness, which defines a vague predicate as an arbitrary predicate that must be precisified in order to contribute to a sentence that has truth-conditions. The main advantages of this theory over the current alternatives are that it satisfies all three criteria and systematizes the relevant intuitions. (shrink)

In this paper I introduce Horwich’s deflationary theory of truth, called ‘Minimalism’, and I present his proposal of how to cope with the Liar Paradox. The proposal proceeds by restricting the T-schema and, as a consequence of that, it needs a constructive specification of which instances of the T-schema are to be excluded from Minimalism. Horwich has presented, in an informal way, one construction that specifies the Minimalist theory. The main aim of the paper is to present and scrutinize some (...) formal versions of Horwich’s construction. (shrink)

One way in which we might approach the challenge posed by the Sorites Paradox is considering that Sorites-susceptible predicates have several candidate extensions, or several ways in which these expressions can be made precise. For example, a candidate extension for the predicate ‘is a baby’ is the set of humans of less than two years, but also the set of those less than two years and one second, and of those less than two years and two seconds. In this chapter (...) we present and discuss two theories for vague predicates based on this idea: supervaluationism and subvaluationism. The chapter is structured in three parts. The first presents the super- and subvaluationist theories: their similarities and differences in the semantics, the resulting logics with their most characteristic features. The second reviews the super- and subvaluationist solutions to the Sorites Paradox and provides discussion on several controversies surrounding these theories. The third part introduces proof procedures for s’valuationist logics. (shrink)

Restrictionism is a response to the Liar and other paradoxes concerning truth. Restrictionists—as I will call proponents of the strategy—respond to these paradoxes by giving up instances of the schema -/- <p> is true iff p. -/- My aim is to show that the current unpopularity of restrictionism is undeserved. I will argue that, whilst cautious versions of the strategy may face serious problems, a radical and previously overlooked version of restrictionism provides a strong and defensible response to the paradoxes.

Há pelo menos duas coisas que tornam o fenômeno da vagueza interessante. Primeiro, a vagueza está espalhada por toda a linguagem natural. Uma parte significativa das expressões de nossa linguagem são vagas e podemos encontrar a vagueza em expressões de diferentes categorias lógicas, como termos singulares, predicados e quantificadores. Por razões de simplicidade, contudo, ao longo deste artigo considero apenas o caso dos predicados vagos. Segundo, o fenômeno da vagueza está por trás de um difícil paradoxo, conhecido como Paradoxo Sorites. (...) Atualmente, há muitas tentativas de explicar esse fenômeno e resolver o Sorites, sendo uma delas a Teoria Trivalente da Vagueza. Essa teoria é interessante não apenas porque fornece uma explicação elegante da vagueza, acompanhada de uma solução engenhosa para o paradoxo em questão, mas também porque serve de base para a compreensão de outras teorias clássicas da vagueza. Tanto o Gradualismo como o Supervalorativismo, por exemplo, incorporam parte significativa de suas ideias centrais. A despeito disso, existem alguns sérios obstáculos para a Teoria Trivalente. Acredito que o principal deles é que ela falha em satisfazer pelo menos um dos três critérios de adequação para uma teoria ideal da vagueza: o critério da precisão. Meu objetivo é apresentar essa teoria e mostrar como essa dificuldade surge para ela. (shrink)

Scott Soames argues that consideration of the practice of legal judgement gives us good reason to favor the partial-definition/context-sensitive theory of vagueness against epistemicism. Despite the fact that the value of power-delegation through vagueness is evidenced in practice, Soames says, epistemicism cannot account for it theoretically, while the partial-definition/context-sensitive theory is capable of it. In this paper, I examine the two possible arguments against epistemicism that can be extracted from Soames’s account: (i) an argument based on unknown obligations, and (ii) (...) an argument based on power-delegation through vagueness. The first argument tries to convince us that, as based on epistemicism, the law has already decided the borderline cases, so that judges have obligatory decisions even in such cases: therefore epistemicism is inconsistent with the discretion of judges in borderline cases. I show that even if we sympathize with Soames’s intuitions concerning the legal practice, the argument he offers is not conclusive since it is either invalid, unsound, or paradoxical. The second argument holds that only the gaps which the partial-definition/context-sensitive theory predicts give judges the possibility of lawmaking in borderline cases. However, by categorizing the vague laws as imperfect laws, the judges can claim the right of lawmaking without any need to refer to gaps in the law. By neutralizing these arguments, I argue that epistemicism is able to explain the phenomena just as well as the partial-definition/context-sensitive theory. (shrink)

In matters of personal taste, faultless disagreement occurs between people who disagree over what is tasty, fun, etc., in those cases when each of these people seems equally far from the objective truth. Faultless disagreement is often taken as evidence that truth is relative. This article aims to help us avoid the truth-relativist conclusion. The article, however, does not argue directly against relativism; instead, the article defends non-relative truth constructively, aiming to explain faultless disagreement with the resources of semantic contextualism. (...) To this end the article describes and advocates a contextualist solution inspired by supervaluationist truth-value gap approaches. The solution presented here, however, does not require truth value gaps; it preserves both logical bivalence and non-relative truth, even while it acknowledges and explains the possibility of faultless disagreement. The solution is motivated by the correlation between assertions’ being true and their being useful. This correlation, furthermore, is used not only to tell which assertions are true, but also to determine which linguistic intuitions are reliable. (shrink)

This article deals with supervaluationism and the failure of truth-functionality. It draws some distinctions that may contribute to a better understanding of this semantic framework.

Category mistakes are sentences such as 'Green ideas sleep furiously' or 'Saturday is in bed'. They strike us as highly infelicitous but it is hard to explain precisely why this is so. Ofra Magidor explores four approaches to category mistakes in philosophy of language and linguistics, and develops and defends an original, presuppositional account.

Semantic pathology is most widely recognized in the liar paradox, where an apparent inconsistency arises in ‘‘liar sentences’’ and their ilk. But the phenomenon of semantic pathology also manifests a sibling symptom—an apparent indeterminacy—which, while not largely discussed (save for the occasional nod to ‘‘truthteller sentences’’), is just as pervasive as, and exactly parallels, the symptom of inconsistency. Moreover, certain ‘‘dual symptom’’ cases, which we call naysayers, exhibit both inconsistency and indeterminacy and also manifest a higher-order indeterminacy between them. In (...) this paper, we explore and lay out the full, broader extent of semantic pathology. We then turn to the best-known attempts to diagnose and treat the phenomenon: consistentist approaches, proposed by Alfred Tarski and Saul Kripke, and an inconsistentist approach, originally presented by Graham Priest and dubbed ‘‘dialetheism’’. We explain the basic elements of each view and argue that each fails to provide an adequate way of dealing with the full extent of semantic pathology. We conclude that a new kind of approach is required and briefly sketch the pretense-based view that we favor. (shrink)

In this paper we investigate a semantics for first-order logic originally proposed by R. van Rooij to account for the idea that vague predicates are tolerant, that is, for the principle that if x is P, then y should be P whenever y is similar enough to x. The semantics, which makes use of indifference relations to model similarity, rests on the interaction of three notions of truth: the classical notion, and two dual notions simultaneously defined in terms of it, (...) which we call tolerant truth and strict truth. We characterize the space of consequence relations definable in terms of those and discuss the kind of solution this gives to the sorites paradox. We discuss some applications of the framework to the pragmatics and psycholinguistics of vague predicates, in particular regarding judgments about borderline cases. (shrink)

emantic pathologies of self-reference include the Liar (‘this sentence is false’), the Truth-Teller (‘this sentence is true’) and the Open Pair (‘the neighbouring sentence is false’ ‘the neighbouring sentence is false’). Although they seem like perfectly meaningful declarative sentences, truth value assignment to their uses seems either inconsistent (the Liar) or arbitrary (the Truth-Teller and the Open-Pair). These pathologies thus call for a resolution. I propose such a resolution in terms of relative-truth: the truth value of a pathological sentence use (...) varies with the context of its assessment. It always has a determinate truth value, but this truth value is relative to the context of its assessment. I start by considering a fairly esoteric pathology: the Truth-Teller, that is, sentences which assert nothing but their own truth. I make the case that truth value of a given truth-teller use must in general depend on the context of its assessment, and that one can indeed change its truth value at will. I then show how the notion of assessment-sensitive truth can help us provide solutions to other semantic paradoxes such as the Liar and the Open Pair and that those solutions are immune to revenge problems. I conclude by situating my proposal among the main approaches to the semantic paradoxes, and by drawing a very broad moral about pathological self-reference and intentionality. (shrink)

This is a concise, advanced introduction to current philosophical debates about truth. A blend of philosophical and technical material, the book is organized around, but not limited to, the tendency known as deflationism, according to which there is not much to say about the nature of truth. In clear language, Burgess and Burgess cover a wide range of issues, including the nature of truth, the status of truth-value gaps, the relationship between truth and meaning, relativism and pluralism about truth, and (...) semantic paradoxes from Alfred Tarski to Saul Kripke and beyond. Following a brief introduction that reviews the most influential traditional and contemporary theories of truth, short chapters cover Tarski, deflationism, indeterminacy, realism, antirealism, Kripke, and the possible insolubility of semantic paradoxes. The book provides a rich picture of contemporary philosophical theorizing about truth, one that will be essential reading for philosophy students as well as philosophers specializing in other areas. (shrink)

Hugh MacColl is commonly seen as a pioneer of modal and many-valued logic, given his introduction of modalities that go beyond plain truth and falsehood. But a closer examination shows that such a legacy is debatable and should take into account the way in which these modalities proceeded. We argue that, while MacColl devised a modal logic in the broad sense of the word, he did not give rise to a many-valued logic in the strict sense. Rather, his logic is (...) similar to a “non-Fregean logic”: an algebraic logic that partitions the semantic classes of truth and falsehood into subclasses but does not extend the range of truth-values. (shrink)

What is truth? Philosophers are interested in a range of issues involving the concept of truth beginning with what sorts of things can be true. This is a collection of eighteen new and original research papers on truth and other alethic phenomena by twenty of the most promising young scholars working on truth today.

We present the Jaina theory of sevenfold predication as a 7-valued logic, in which every logical value consists in a 3-tuple of opinions. A question-answer semantics is used in order to give an intuitive characterization of these logical values in terms of opinion polls. Two different interpretations are plausible for the latest sort of opinion, depending upon whether "non-assertability" refers to incompleteness or inconsistency. It is shown hat the incomplete version of JL_{G} is equivalent to Kleene's logic K3, whereas the (...) inconsistent version of JL_{M} is equivalent to Priest's Logic of Paradox LP. Finally, it is argued that the Indian logics depart from Western logics by conflating truth and justified belief: the different preconditions for belief ascription accounts for the difference between pluralist and skeptic logics. (shrink)

The current discussions of conceptual schemes and related topics are misguided; for they are based on a tacit assumption that the difference between two schemes consists in the different distributions in truth-values. I argue that what should concern us, in the discussions of conceptual schemes and related issues, is not truth-values of assertions, but rather the truth-value-status of the sentences used to make the assertions. This is because the genuine conceptual innovation between alternative theories or languages does not lie in (...) differences in determining truth-values of their sentences, but turns on whether these sentences have truth-values when considered within the context of a competing one. This new interpretation of the notion of conceptual schemes, which I refer to as presuppositional languages, is not only good in itself—for establishing the intelligibility and tenability of the notion—but quite beneficial in its effect on other related issues. (shrink)

Italian translation of "Conjunction and Contradiction" (2004), by Francesco Berto.

Vagueness is epistemic, according to some. Vagueness is ontological, according to others. This article deploys what I take to be a compromise position. Predicates are coined in specific contexts for specific purposes, but these limited practices do not automatically fix the extensions of predicates over the domain of all objects. The linguistic community using the predicate has rarely considered, much less decided, all questions that might arise about the predicate’s extension. To this extent, the ontological view is correct. But a (...) predicate that applies in some contexts can be reasonably extended to other contexts where it is initially vague. This process of development approximates the cognitive remedy for vagueness that the epistemic view prescribes. The process is piecemeal and inductive, akin to what von Wright described as the molding of concepts. Vagueness cannot be understood apart from the backdrop of classification, for vagueness is classification gone awry. Hence these pages explore the classification of particulars, both its clear successes and vague failures. How we classify unique particulars is the theme of Sections 2 and 3, which are primarily descriptive. Section 2 identifies a way of classifying particulars that pervades discourse of all sorts, and Section 3 illustrates its use in a field notorious for vagueness: ethics. Why a certain particular should (or should not) be classified in a certain way is a normative question, however, and it occupies Sections 4 and 5. Section 4 proposes a norm for strong arguments by analogy, and Section 5 illustrates how the norm might resolve vagueness in one kind of ethical dispute. This norm, which has a strong probabilistic component, is one way of affirming that probability is a guide to life. (shrink)

Vagueness, 'the quality or condition of being vague' (OED), has kept philosophers busy since ancient times. This article gives a concise account of vagueness.

The paper goes into the intricate logical relation between imperatives, precepts and norms. It shows that there need not be two senses of "ought", the one descriptive and the other prescriptive, since when the law-giver enacts a fresh statute he is hereby making a tru statement, whose truth is grounded on the statement itself.

The dissertation has two parts, each dealing with a problem, namely: 1) What is the most adequate account of fuzziness -the so-called phenomenon of vagueness?, and 2) what is the most plausible solution to the sorites, or heap paradox? I will try to show that fuzzy properties are those which are gradual, amenable to be possessed in a greater or smaller extent. Acknowledgement of degrees in the instantiation of a property allows for a gradual transition from one opposite to the (...) other, each intermediate stage constituting an overlap in certain proportion of both contraries. Hence, degrees in the possession of a property give rise to simple contradictions. The reason why I have chosen those two questions is that they provide the main philosophical motivation for a particular brand of an infinite valued and paraconsistent logic. I will claim that Classical logic (CL) is not adequate to handle fuzzy situations, and, being deficient, is in need of being expanded to make room for degrees of truth and weak contradictions. One can hardly deny the importance of the debate, since what is ultimately at stake is what the limits of truth, rationality, intelligibility and possibility are. The main disciplines within which the research moves are the philosophy of language, philosophy of logic, and ontology. (shrink)

The dissertation has two parts, each dealing with a problem, namely: 1) What is the most adequate account of fuzziness -the so-called phenomenon of vagueness?, and 2) what is the most plausible solution to the sorites, or heap paradox? I will try to show that fuzzy properties are those which are gradual, amenable to be possessed in a greater or smaller extent. Acknowledgement of degrees in the instantiation of a property allows for a gradual transition from one opposite to the (...) other, each intermediate stage constituting an overlap in certain proportion of both contraries. Hence, degrees in the possession of a property give rise to simple contradictions. The reason why I have chosen those two questions is that they provide the main philosophical motivation for a particular brand of an infinite valued and paraconsistent logic. I will claim that Classical logic (CL) is not adequate to handle fuzzy situations, and, being deficient, is in need of being expanded to make room for degrees of truth and weak contradictions. One can hardly deny the importance of the debate, since what is ultimately at stake is what the limits of truth, rationality, intelligibility and possibility are. The main disciplines within which the research moves are the philosophy of language, philosophy of logic, and ontology. (shrink)

Following Hartry Field in distinguishing disquotational truth from a conception that grounds truth conditions in a community's usage, it is argued that the notions are materially inequivalent (since the latter allows truth-value gaps) and that both are needed. In addition to allowing blanket endorsements ("Everything the Pope says is true"), disquotational truth facilitates mathematical discovery, as when we establish the Gödel sentence by noting that the theorems are all disquotationally true and the disquotational truths are consistent. We require a more (...) substantial notion, however, if we intend to use truth values and truth conditions in explaining communication by language. (shrink)

The thesis deals with the concept of truth and the paradoxes of truth. Philosophical theories usually consider the concept of truth from a wider perspective. They are concerned with questions such as - Is there any connection between the truth and the world? And, if there is - What is the nature of the connection? Contrary to these theories, this analysis is of a logical nature. It deals with the internal semantic structure of language, the mutual semantic connection of sentences, (...) above all the connection of sentences that speak about the truth of other sentences and sentences whose truth they speak about. Truth paradoxes show that there is a problem in our basic understanding of the language meaning and they are a test for any proposed solution. It is important to make a distinction between the normative and analytical aspect of the solution. The former tries to ensure that paradoxes will not emerge. The latter tries to explain paradoxes. Of course, the practical aspect of the solution is also important. It tries to ensure a good framework for logical foundations of knowledge, for related problems in Artificial Intelligence and for the analysis of the natural language. Tarski’s analysis emphasized the T-scheme as the basic intuitive principle for the concept of truth, but it also showed its inconsistency with the classical logic. Tarski’s solution is to preserve the classical logic and to restrict the scheme: we can talk about the truth of sentences of a language only inside another essentially richer metalanguage. This solution is in harmony with the idea of reflexivity of thinking and it has become very fertile for mathematics and science in general. But it has normative nature | truth paradoxes are avoided in a way that in such frame we cannot even express paradoxical sentences. It is also too restrictive because, for the same reason we cannot express a situation in which there is a circular reference of some sentences to other sentences, no matter how common and harmless such a situation may be. Kripke showed that there is no natural restriction to the T-scheme and we have to accept it. But then we must also accept the riskiness of sentences | the possibility that under some circumstances a sentence does not have the classical truth value but it is undetermined. This leads to languages with three-valued semantics. Kripke did not give any definite model, but he gave a theoretical frame for investigations of various models | each fixed point in each three-valued semantics can be a model for the concept of truth. The solutions also have normative nature | we can express the paradoxical sentences, but we escape a contradiction by declaring them undetermined. Such a solution could become an analytical solution only if we provide the analysis that would show in a substantial way that it is the solution that models the concept of truth. Kripke took some steps in the direction of finding an analytical solution. He preferred the strong Kleene three-valued semantics for which he wrote it was "appropriate" but did not explain why it was appropriate. One reason for such a choice is probably that Kripke finds paradoxical sentences meaningful. This eliminates the weak Kleene three valued semantics which corresponds to the idea that paradoxical sentences are meaningless, and thus indeterminate. Another reason could be that the strong Kleene three valued semantics has the so-called investigative interpretation. According to this interpretation, this semantics corresponds to the classical determination of truth, whereby all sentences that do not have an already determined value are temporarily considered indeterminate. When we determine the truth value of these sentences, then we can also determine the truth value of the sentences that are composed of them. Kripke supplemented this investigative interpretation with an intuition about learning the concept of truth. That intuition deals with how we can teach someone who is a competent user of an initial language (without the predicate of truth T) to use sentences that contain the predicate T. That person knows which sentences of the initial language are true and which are not. We give her the rule to assign the T attribute to the former and deny that attribute to the latter. In that way, some new sentences that contain the predicate of truth, and which were indeterminate until then, become determinate. So the person gets a new set of true and false sentences with which he continues the procedure. This intuition leads directly to the smallest fixed point of strong Kleene semantics as an analytically acceptable model for the logical notion of truth. However, since this process is usually saturated only on some transfinite ordinal, this intuition, by climbing on ordinals, increasingly becomes a metaphor. This thesis is an attempt to give an analytical solution to truth paradoxes. It gives an analysis of why and how some sentences lack the classical truth value. The starting point is basic intuition according to which paradoxical sentences are meaningful (because we understand what they are talking about well, moreover we use it for determining their truth values), but they witness the failure of the classical procedure of determining their truth value in some "extreme" circumstances. Paradoxes emerge because the classical procedure of the truth value determination does not always give a classically supposed (and expected) answer. The analysis shows that such an assumption is an unjustified generalization from common situations to all situations. We can accept the classical procedure of the truth value determination and consequently the internal semantic structure of the language, but we must reject the universality of the exterior assumption of a successful ending of the procedure. The consciousness of this transforms paradoxes to normal situations inherent to the classical procedure. Some sentences, although meaningful, when we evaluate them according to the classical truth conditions, the classical conditions do not assign them a unique value. We can assign to them the third value, \undetermined", as a sign of definitive failure of the classical procedure. An analysis of the propagation of the failure in the structure of sentences gives exactly the strong Kleene three-valued semantics, not as an investigative procedure, as it occurs in Kripke, but as the classical truth determination procedure accompanied by the propagation of its own failure. An analysis of the circularities in the determination of the classical truth value gives the criterion of when the classical procedure succeeds and when it fails, when the sentences will have the classical truth value and when they will not. It turns out that the truth values of sentences thus obtained give exactly the largest intrinsic fixed point of the strong Kleene three-valued semantics. In that way, the argumentation is given for that choice among all fixed points of all monotone three-valued semantics for the model of the logical concept of truth. An immediate mathematical description of the fixed point is given, too. It has also been shown how this language can be semantically completed to the classical language which in many respects appears a natural completion of the process of thinking about the truth values of the sentences of a given language. Thus the final model is a language that has one interpretation and two systems of sentence truth evaluation, primary and final evaluation. The language through the symbol T speaks of its primary truth valuation, which is precisely the largest intrinsic fixed point of the strong Kleene three valued semantics. Its final truth valuation is the semantic completion of the first in such a way that all sentences that are not true in the primary valuation are false in the final valuation. (shrink)

This thesis is concerned with the challenge truth-value gaps pose to the principle of bivalence. The central question addressed is: are truth-value gaps counterexamples to bivalence and is the supposition of counterexamples coherent? My aim is to examine putative cases of truth-value gaps against an argument by Timothy Williamson, which shows that the supposition of counterexamples to bivalence is contradictory. The upshot of his argument is that either problematic utterances say nothing, or they cannot be neither true nor false. I (...) start by identifying truth-bearers: an utterance, for instance, is a truth-bearer if it says that something is the case. Truth-bearers are evaluable items, with truth- and falsity-conditions statable in corresponding instances of schemas for truth and falsehood. A genuine case of a truth-value gap should be an utterance that is neither true nor false but says something to be the case. But it is inconsistent to accept the schemas for truth and falsehood and the existence of genuine cases of truth-value gaps. Secondly, I expound Williamson’s argument, which explores this inconsistency, and I identify two kinds of strategy to disarm his argument: those that preserve the schemas for truth and falsehood, and those that do not. Neither strategy is found to be persuasive. Thirdly, I argue that cases of reference failure causing truth-value gaps illustrate the upshot of Williamson’s argument. Fourthly, I examine Scott Soames’s account of liar sentences as counterexamples to bivalence. Soames adopts a strategy of the first kind to avoid contradictions. I argue that his solution allows some contradictions to be true, and that he fails to show that liar sentences are truth-bearers. Finally, I examine Charles Travis’s case for isostheneia: an equal balancing of reasons to evaluate a statement as true or as false, in which case a statement is neither. Travis avoids contradictions by adopting a strategy of the second kind. I argue that the schemas for truth and falsehood are immune to Travis’s objections, and that isostheneia fails to identify evaluable items. The cases examined confirm that utterances that are neither true nor false say nothing. My claim is thus that truth-value gaps are not counterexamples to bivalence. (shrink)

There are two ways of understanding the notion of a contradiction: as a conjunction of a statement and its negation, or as a pair of statements one of which is the negation of the other. Correspondingly, there are two ways of understanding the Law of Non-Contradiction (LNC), i.e., the law that says that no contradictions can be true. In this paper I offer some arguments to the effect that on the first (collective) reading LNC is non-negotiable, but on the second (...) (distributive) reading it is perfectly plausible to suppose that LNC may, in some rather special and perhaps undesirable circumstances, fail to hold. (shrink)

摘要：通常所接受对库恩有关不可通约性的分类学解释的理解建立在不可译性概念之上，因而是相当不完善的。为了弥补此不足，本文在分类之逻辑语义理论 (a logical-semantic theory of taxonomy)、真值语义理论 (a semantic theory of truth-value)，以及跨语言交流的真值条件理论 (a truth-value conditional theory of cross-language communication) 之基础上，对库恩有关不可通约性的分类学解释进行了重建。根据这种重建，如果两个科学语言具有不相匹配的分类结构，则当一科学语言的核心语句在其所属语境中具有真值、而在另一科学语言之语境中考虑缺乏真值时，这两 种科学语言乃不可通约。通过这种重建，库恩对于不可通约性的成熟解释并非基于保真 (truth-preserving) 可译性或不可译性的概念，而是基于保留真值状态 (truth-value-preserving) 的跨语言交流概念之上。这种重建使得库恩有关不可通约性的解释更具坚实的理论基础、也在概念上更加完整。.

Why is mutual understanding between two substantially different comprehensive language communities often problematic and even unattainable? To answer this question, the author first introduces a notion of presuppositional languages. Based on the semantic structure of a presuppositional language, the author identifies a significant condition necessary for effective understanding of a language: the interpreter is able to effectively understand a language only if he/she is able to recognize and comprehend its metaphysical presuppositions. The essential role of the knowledge of metaphysical presuppositions (...) in understanding is further strengthened by developing a truth-value conditional theory of understanding. It is concluded that if the interpreter approaches an incompatible alien language from the standpoint of the interpreter's own language by projecting the metaphysical presuppositions of his/her own language upon the alien language, then the mutual understanding between the two language communities is doomed to failure. (shrink)

斯特劳逊 （Strawson）的语义预设概念在语义学和语言哲学研究上颇有建树。尽管如此，语义预设概念一直遭受来自各方面的批判。概要说来，对语义预设概念之批判主要来自两个方面：其一，试图抽去语义预设概念的逻辑基础 ，即非真值概念 (the notion of truthvaluelessness)，从而达到间接地拒斥语义预设概念之目的。其二，直接批判语义预设概念本身。他们或者论证此概念在理论上不自恰或微不足道，或者断定即使此概念本身在理论上自恰，但实为一空 洞无物之概念。因为我们根本找任何一个语义预设的具体例证。所以，语义预设概念不具任何真正的哲学意义。它只是一个当代神话，理应拒斥。 -/- 玻尔(S. Ber)和莱肯(W. Lycan)对语义预设概念的批判集中代表了以上两个方面。据我所知，迄今不曾有人对他们的批判予以全面和公正的反驳，以致于许多人人云亦云，使得他们的论点至今颇有影响。给予玻尔和莱恩的批判以全面反驳乃本文初 衷。于此相关，我以为很有必要澄清对语义预设概念的诸多误解，从而确立一个理论上自恰，实际上可行，和确有实质性内容的语义预设概念。基于以上考虑，我对语义预设概念批判之反驳包括正 反两个方面。在第二节，我试图建立一个自恰，完备，非庸俗的语义预设概念。基于这一概念，第三节对玻尔和莱恩反对语义预设的两个核心批判予以全面反驳。第四节着重辩护非真值概念。本文的最后结论是：各种批判并未损 伤斯特劳逊的语义预设概念的精髓。语 义预设概念非但不是一个当代神话，而且具有重大哲学意义。 .

This paper is an attempt to clarify the notion of semantic presupposition and to refute Böer and Lycan's critique of that notion. The author presents a feasible and coherent formal definition of semantic presupposition after examining several popular definitions of the notion. In terms of this definition, two central arguments against semantic presupposition presented by Böer and Lycan are analyzed and responded to with care. It is concluded that the notion of semantic presupposition is not empty but rather is philosophically (...) interesting and fruitful. (shrink)

Since its first appearance in 1966, the notion of a supervaluation has been regarded by many as a powerful tool for dealing with semantic gaps. Only recently, however, applications to semantic gluts have also been considered. In previous work I proposed a general framework exploiting the intrinsic gap/glut duality. Here I also examine an alternative account where gaps and gluts are treated on a par: although they reflect opposite situations, the semantic upshot is the same in both cases--the value of (...) some expressions is not uniquely defined. Other strategies for generalizing supervaluations are considered and some comparative facts are discussed. (shrink)

This paper is an attempt to clarify the notion of semantic presupposition and to refute Böer and Lycan's critique of that notion. The author presents a feasible and coherent formal definition of semantic presupposition after examining several popular definitions of the notion. In terms of this definition, two central arguments against semantic presupposition presented by Böer and Lycan are analyzed and responded to with care. It is concluded that the notion of semantic presupposition is not empty but rather is philosophically (...) interesting and fruitful. (shrink)

According to the accepted translation-failure interpretation, the problem of incommensurability involves the nature of the meaning-referential relation between scientific languages. The incommensurability thesis is that some competing scientific languages are mutually untranslatable due to the radical variance of meaning or/and reference of the terms they employ. I argue that this interpretation faces many difficulties and cannot give us a tenable, coherent, and integrated notion of incommensurability. It has to be rejected. ;On the basis of two case studies, I find that (...) the confrontations between many classical incommensurable languages are not confrontations between two untranslatable languages with different distribution of truth values, but rather the confrontations between incompatible fundamental presuppositions at the ontological level. We can always identify a truth-value gap between two incommensurable languages. Such a truth-value gap indicates a communication breakdown between the two language communities on the one hand, and is caused by the incompatible fundamental presuppositions underlying them on the other. ;I thereby identify the truth-value functional relationship between sentences, instead of the meaning-referential relationship between terms, as the dominant semantic relation between two incommensurable languages. According to my presuppositional interpretation of incommensurability, the real secret of incommensurability lies in the ontological setup of two competing presuppositional languages. When two presuppositional languages with incompatible factual commitments encounter with each other, the confrontation leads to a truth-value gap, and consequently a communication breakdown between them. Formally put, two scientific languages are incommensurable when core sentences of one language, which have truth values when considered within its own context, lack truth values when considered within the context of the other due to an ontological gap between them. ;The presuppositional interpretation makes many significant contributions to the discussion of the issue of incommensurability and the related metaphysical and epistemological issues: It confirms the existence of the phenomenon of incommensurability and makes it metaphysically and epistemologically significant. It establishes the tenability and integrity of the notion of incommensurability. It avoids many alleged unattractive epistemological and metaphysical consequences of the translation-failure interpretation. (shrink)

Meinong justifies the need of his Gegenstandstheorie by presenting it as a generalization of (existing) metaphysics, in that the former deals with both existent and non-existent objects, whereas the latter used to deal with existent objects only. But this justification is disingenuous, since the notion of a non-existent object is virtually a contradiction in terms for the traditional paradigm. What Meinong is really proposing is a conceptual revolution of a Kantian variety, and we need to get clearer about the full (...) import of this revolution. This is what the present paper attempts to do. (shrink)

For a very long time truth-value gaps were under a cloud of suspicion because they were considered logically unmanageable. So Frege declared that:“as regards concepts we have a requirement of sharp delimitation; if this were not satisfied it would be impossible to set forth logical laws about them”.Three-valued logic promised to dispel the cloud but in the eyes of many it had promised more than it could deliver. So in response to Reichenbach's plea for a three-valued quantum logic Russell replied:“This (...) is one of a number of questions as to which I am prevented from accepting a certain view by difficulties in carrying it out, but am prepared to alter my opinion if technical skill supplies an answer to my difficulties”.‘By now technical skill has supplied many alternative systems of three-valued logic, but few answers and numerous additional difficulties.’. (shrink)

In the fourth chapter, I show how the semantics developed in the third chapter can be applied to the seemingly unrelated problem of discourse concerning fictional objects. Using the theory of nonexistent objects developed by Parsons as a point of departure, I show how this theory can be both simplified and enriched by the use of a truth-value gap semantics. ;In the third chapter, I develop a truth-value gap semantics for a fragment of English which includes both sortally correct and (...) sortally incorrect sentences using the formal devices of partial functions, supervaluations, and sorted quantification which evaluates simple sortally incorrect sentences as being neither true nor false, retains the classical truths of logic, and avoids the problems had by Thomason's system concerning quantification. ;In the first chapter, I argue that the deviance of these sentences cannot be based on purely syntactic characteristics ) or merely by appeal to Grician maxims of conversation, and that any account of such sentences must be given in the semantic component of a grammar for a language. ;In the second chapter, a number of alternative semantic accounts of such sentences are investigated, including the bivalent system proposed by Bergmann , the four-valued system developed by Martin , and the truth-value gap semantics advocated by Thomason . After showing that all of these systems fail to adequately treat quantification, I argue that, while the differences in the approaches can be traced to disagreements so fundemental that no one of them can be chosen on the grounds of adequately accounting for the data, the type of approach taken by Thomason is preferable to the others on the theoretical grounds of simplicity and generality. ;The bulk of this work is an attempt to deal with sentences such as "The theory of relativity is shiny," which are called category mistakes by philosophers and sortally incorrect sentences by linguists. (shrink)

To eliminate incompleteness, undecidability and inconsistency from formal systems we only need to convert the formal proofs to theorem consequences of symbolic logic to conform to the sound deductive inference model. -/- Within the sound deductive inference model there is a (connected sequence of valid deductions from true premises to a true conclusion) thus unlike the formal proofs of symbolic logic provability cannot diverge from truth.

Tarski "proved" that there cannot possibly be any correct formalization of the notion of truth entirely on the basis of an insufficiently expressive formal system that was incapable of recognizing and rejecting semantically incorrect expressions of language. -/- The only thing required to eliminate incompleteness, undecidability and inconsistency from formal systems is transforming the formal proofs of symbolic logic to use the sound deductive inference model.