Truth-Values

Belnap-Dunn logic, sometimes also known as First Degree Entailment, is a four-valued propositional logic that complements the classical truth values of True and False with two non-classical truth values Neither and Both. The latter two are to account for the possibility of the available information being incomplete or providing contradictory evidence. In this paper, we present a probabilistic extension of BD that permits agents to have probabilistic beliefs about the truth and falsity of a proposition. We provide a sound and (...) complete axiomatization for the framework defined and also identify policies for conditionalization and aggregation. Concretely, we introduce four-valued equivalents of Bayes’ and Jeffrey updating and also suggest mechanisms for aggregating information from different sources. (shrink)

In diesem Aufsatz argumentiere ich, dass die Standardauffassung von Propositionen und propositionalen Einstellungen inadäquat ist, ein Artefakt der gegenwärtig herrschenden theorielastigen Auffassung von Intentionalität, Sprache und Rationalität, und skizziere eine alternative Auffassung. Im folgenden Abschnitt belege ich erst einmal die These der Theorielastigkeit anhand einiger Beispiele vor allem aus der gegenwärtigen analytischen Philosophie. Der dritte Abschnitt erklärt, wie diese Theorielastigkeit im Standardverständnis von Propositionen und propositionalen Einstellungen verkörpert ist. Im vierten Abschnitt argumentiere ich, dass dieses Standardverständnis der Proposition zwei unvereinbare (...) Rollen zuweist. Sie kann nicht sowohl einen Sachverhalt repräsentieren, der Gegenstand praktischer genauso wie theoretischer Stellungnahmen sein kann, als auch wie eine theoretische Stellungnahme Wahrheitswertträger sein. In den folgenden Abschnitten versuche ich eine partielle Diagnose, wie es zu dieser Auffassung kommen kann: gewisse Formen der Neutralisierung von Stellungnahmen durch das bloße „in den Raum stellen“ (fünfter Abschnitt), durch fiktionale Kontexte (sechster Abschnitt) und den Kontext logischer Verknüpfungen (der so genannte „Frege-Punkt“; siebter Abschnitt) werden verwechselt mit der Neutralität zwischen dem Praktischen und Theoretischen, zwischen Wollen und Wahrheit, die die Standardauffassung erfordern würde. Der achte Abschnitt skizziert in groben Umrissen ein alternatives Bild. Demnach wird eine Repräsentation eines Sachverhalts erst durch die dazu kommende theoretische oder praktische Position zu einer Stellungnahme und damit zum Träger eines Erfüllungswerts. Die Bereiche des Praktischen und des Theoretischen sind parallel strukturiert und unterschieden sich im Wesentlichen nur durch die Verschiedenheit der Passrichtungen. Grundlegende rationale Operationen wie Deduktion, Abduktion und Induktion können auf praktischen Stellungnahmen genauso ausgeführt werden wie auf theoretischen. Im neunten Abschnitt verorte ich die tieferen Wurzeln der Theorielastigkeit in dem Verlangen, das Praktische an die dem Theoretischen eigene Form der Objektivität zu assimilieren. Dieses Verlangen muss aber fruchtlos bleiben, und die dem Praktischen eigene Form der Objektivität wird so verfehlt. Der letzte Abschnitt deutet an, wie sich Werturteile in dem skizzierten Rahmen deuten lassen. (shrink)

Truth Be Told explains how truth and falsity result from relations that sentences and their constituents have to the circumstances at which they are evaluated. It offers a precise analysis of truth and a diagnosis of the Liar paradox. Current semantic theory employs generalized quantifiers as the extensions of noun phrases. The book provides simpler extensions for noun phrases. These permit intuitive compositions of truth-values and a diagnosis of the Liar and Grelling paradoxes.

Misunderstanding occurs between speakers when they disagree about the meaning of words in use. In the case of truth-values, Frege took these to be referents of sentences which consist of classes of accepted (i.e. “true”) or rejected (i.e. “false”) sentences. From this usual depiction of truth and falsity, a general algebraic framework is proposed to systematize the use of truth-values from a dialogical point of view of logic. A special attention will be paid to two radically opposed pseudo-speakers: Heraclites and (...) Nagarjuna, according to whom truth-values respectively refer to everything or nothing. Finally, dialectical (pseudo-Hegelian) negation will be rendered as a very special function: an ontological object-forming operator, similar to the arithmetic successor-forming operator Sn+1(x) on integers and consistent within our generalized theory of truth-values as variable referents. (shrink)

This paper examines a puzzle about whether truth is a valuable property: Valuable properties, like beauty and moral goodness, come in degrees; but truth does not come in degrees. Hence, the argument concludes, truth is not valuable. This result is puzzling since it seems to conflict with a deep intuition that truth is valuable. It is suggested that a roughly Platonic theory, on which truth is distinguished into two different concepts, gives a satisfying answer to the puzzle. One of these (...) concepts can be had in degrees, which, it is suggested, may be determined by the true proposition's explanatory power. (shrink)

Does it make sense to employ modern logical tools for ancient philosophy? This well-known debate2 has been re-launched by the indologist Piotr Balcerowicz, questioning those who want to look at the Eastern school of Jainism with Western glasses. While plainly acknowledging the legitimacy of Balcerowicz's mistrust, the present paper wants to propose a formal reconstruction of one of the well-known parts of the Jaina philosophy, namely: the saptabhangi, i.e. the theory of sevenfold predication. Before arguing for this formalist approach to (...) philosophy, let us return to the reasons to be reluctant at it. (shrink)

Down through the ages, logic has adopted many strange and awkward technical terms: assertoric, prove, proof, model, constant, variable, particular, major, minor, and so on. But truth-value is a not a typical example. Every proposition, even if false, no matter how worthless, has a truth-value:even “one plus two equals four” and “one is not one”. In fact, every two false propositions have the same truth-value—no matter how different they might be, even if one is self-contradictory and one is consistent. It (...) is not such a big surprise that every true proposition, no matter how worthless, has a truth-value. Every proposition, whether valuable or worthless, has a truth-value.But it is a little strange that every two true propositions, no matter how different they might be, have the same truth-value. The Pythagorean Theorem has the same truth-value as the proposition that one is one. It is a stretch to think of truth-values as values in any of the normal senses of the word ‘value’. (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. -/- Hugh MacColl est présenté d’ordinaire comme un pionnier des logiques modales et multivalentes, suite à son introduction de modalités qui vont au-delà de la simple vérité et fausseté. Mais un examen plus attentif montre que cet héritage est discutable et devrait tenir compte de la façon dont ces modalités procédaient. Bien que MacColl ait conçu une logique modale au sens large du terme, nous montrerons qu’il n’a pas produit une logique multivalente au sens strict. Sa logique serait comparable plutôt à une « logique non-fregéenne », c’est-à-dire une logique algébrique qui effectue une partition au sein de la classe des vérités et faussetés mais n’étend pas pour autant le domaine des valeurs de vérité. (shrink)

1. Semantische Vagheit 2. Bivalenz und Wahrheitsgrade 3. Zutreffen und Wahrsein 4. Mehrwertigkeit und andere Holzwege 5. Wahrheit und Genauigkeit: Einige Beispiele 6. Die Platon-Herberger-Kontroverse 7. Der Parameter der Auflösung 8. Auflösungsgrade statt Wahrheitsgrade 9. Ein der Annahme von Wahrheitsgraden komplementärer Fehler 10. Wahrheitsrelativismus, Kontextualismus, Supervaluationismus 11. Noch einmal: Wahrheit und Vagheit -/- .

1. Einleitung 2. Herausforderungen für das Nichtgraduierbarkeits- und das Bivalenzprinzip 3. Freges Einwand gegen graduale Wahrheit 4. Warum semantische Vagheit keine Wahrheitsgrade erfordert 5. Grenzen ziehen, wo noch keine gezogen sind.

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.

Timothy Williamson famously offered an argument from these Tarskian principles in favor of bivalence. I show, dwelling on (Andjelkovic & Williamson, 2000), that the argument depends on a contentious formulation of the Tarskian principles about truth (and falsity), which the supervaluationist can reject without jeopardizing the Tarskian insight. In the mentioned paper, Adjelkovic and Williamson argue that, even if the appropriate formulation seems to make room for failure of bivalence in borderline cases, this appearance is illusory, once one grants an (...) independent further principle involving biconditionals. I finally argue that the formulation of this is, however, contentious in a similar manner. (shrink)

I present an account of truth values for classical logic, intuitionistic logic, and the modal logic S5, in which truth values are not a fundamental category from which the logic is defined, but rather, an idealisation of more fundamental logical features in the proof theory for each system. The result is not a new set of semantic structures, but a new understanding of how the existing semantic structures may be understood in terms of a more fundamental notion of logical consequence.

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)

Here are considered the conditions under which the method of diagrams is liable to include non-classical logics, among which the spatial representation of non-bivalent negation. This will be done with two intended purposes, namely: a review of the main concepts involved in the definition of logical negation; an explanation of the epistemological obstacles against the introduction of non-classical negations within diagrammatic logic.

ABSTRACT: In its strongest unqualified form, the principle of wholistic reference is that in any given discourse, each proposition refers to the whole universe of that discourse, regardless of how limited the referents of its non-logical or content terms. According to this principle every proposition of number theory, even an equation such as "5 + 7 = 12", refers not only to the individual numbers that it happens to mention but to the whole universe of numbers. This principle, its history, (...) and its relevance to some of Oswaldo Chateaubriand's work are discussed in my 2004 paper "The Principle of Wholistic Reference" in Essays on Chateaubriand's "Logical Forms". In Chateaubriand's réplica (reply), which is printed with my paper, he raised several important additional issues including the three I focus on in this tréplica (reply to his reply): truth-values, universes of discourse, and formal ontology. This paper is self-contained: it is not necessary to have read the above-mentioned works. The principle of wholistic reference (PWR) was first put forth by George Boole in 1847 when he espoused a monistic fixed-universe viewpoint similar to the one Frege and Russell espoused throughout their careers. Later, Boole elaborated PWR in 1854 from the pluralistic multiple-universes perspective. (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。.

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)

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)

I begin with one way of making a distinction between something that can be called Realism, and its alternatives. It is a semantic distinction--about whether sentences of the relevant part of language have truth conditions, where truth is correctness of representation. This kind of truth is not warranted assertibility, and is not guaranteed by acceptance or agreement. The issue to be addressed comes from the combination of two things. The first is the naturalness of the view that sentences have truth (...) conditions, the naturalness of the corresponding interpretation of science, and the apparent inadequacies of the alternatives. The second is that there are problems for that view, as shown by arguments that correctness for use of language can't go beyond correctness according to the norms of a linguistic community--and this kind of correctness is warranted assertibility, not truth. ;I address one attempt to show that sentences can have truth conditions. That attempt invokes an aspect of the "Causal Theory of Reference". I argue that the part of the Causal Theory of Reference that might have been a solution to the problems I've raised is wrong. ;In the final part of the dissertation, I give a solution to the problem raised. I contrast two standpoints from which the situation of language use can be described. One is the standpoint of someone external to a linguistic practice, who is engaged in the task of giving an account of meaning for that language. The other standpoint is that of someone in a position to use the language. ;I argue that in the position of someone who is able to use the language, there is a kind of correctness for language use that applies, which is not guaranteed by acceptance, agreement, nor by satisfaction of operational standards. Because this kind of correctness possesses these properties, I suggest that this kind of correctness is truth as correctness of representation. (shrink)

The major assumption in my thesis is that truth is objective. This I characterize as the invariance of a claim's truth-value among people. The objectivity thesis is grounded in the correspondence 'theory' of truth, which in regard to the physical world is essentially the idea that truth is dependent upon the existence of mind-independent objects. Obviously ontological realism must incorporate this position. Various philosophers, including Putnam and Rorty, have suggested the idea of objects logically independent of experience leads to scepticism (...) about the world. In Chapter One I seek to defend realism from this charge, and indicate that the realist can coherently claim knowledge of the physical world may be acquired by means of sensory experience. ;Chapter Two concerns whether there is any truth or falsity. Ramsey and Strawson offer variant 'no-truth' theories, which maintain phrases like 'is true' do not denote. Both arguments fail, although for different reasons. We have no reason to deny that 'is true' denotes a property. ;In Chapter Three I consider the issue of the truth-value bearer. In order that the objectivity thesis have significance, it must be possible for different people to grasp, assert, believe, etc. the same thing. That nothing can be true for one yet false for another simply because no two individuals can grasp or believe the same thing is a trivial, philosophically worthless position. I defend the view, held by Church, that statements of assertion and belief are incapable of adequate nominalistic analysis. Not only are sentence-tokens inadequate, but so are 'abstract' sentence-types. Propositions will have to number among the truth-value bearers as the objects of assertion and belief. ;In the final chapter, I consider certain pertinent issues regarding propositions, particularly Quine's objection that propositions lack adequate identity criteria. Here my basic position is that rigid adherence to Quine's demand results in there being no adequate individuation criteria for most things--including sentence types, which are his own candidates for truth-value bearers. (shrink)

Truth exists in the form of true propositions. Therefore identification of the nature of truth means identification of the conditions in which a proposition is true. A proposition is true if its content is not dependent upon the knower, and it constitutes a reflection of objective reality. Such a proposition yields knowledge. We shall call it a cognitive proposition.

One of the most interesting and fruitful applications of logics, classical or other, has been in supplying formal frameworks for the semantics of natural language. In this paper, I discuss the following puzzle: there seem to be arguments that are logically valid - more precisely, that are instances of the rule of universal instantiation, and yet, the utterance of the premise is intuitively true while the conclusion is false. I will discuss two strategies, developed in response to different sorts of (...) problems, that seem immediately applicable to this puzzle. While the so-called contextualist strategy blocks the puzzle at the level of syntax, the index-shifting strategy actually embraces the apparently paradoxical claim that there are logically valid arguments with premises whose utterances are true and a conclusion whose utterance is false, but insists that different points of evaluation come into play in determining the truth values of the utterances involved in the alleged counter-instances to rules of logic. (shrink)