This article surveys recent literature by Parsons, McGee, Shapiro and others on the significance of categoricity arguments in the philosophy of mathematics. After discussing whether categoricity arguments are sufficient to secure reference to mathematical structures up to isomorphism, we assess what exactly is achieved by recent ‘internal’ renditions of the famous categoricity arguments for arithmetic and set theory.

This article models legal interpretation through argumentation and provides a logical analysis of interpretive arguments, their conflicts, and the resulting indeterminacies. Interpretive arguments are modelled as defeasible inferences, which can be challenged and defeated by counterarguments and be reinstated through further arguments. It is shown what claims are possibly (defensibly) or necessarily (justifiably) supported by the arguments constructible from a given interpretive basis, i.e., a set of interpretive canons coupled with reasons for their application. It is finally established under what (...) conditions such arguments provide single outcomes or rather support alternative interpretive conclusions, thus leading to propositions of law whose truth‐value is undetermined. (shrink)

In constructing the three-valued logic, Jan Łukasiewicz was highly inspirited by the Aristotelian idea of logical contingency. Nevertheless, we can construct a four-valued logic for explicating the Stoic idea of logical determinacy. In this system, we have the following truth values: 0 (‘possibly false), 1 (‘necessarily false’), 2 (‘possibly true’), 3 (‘necessarily true’), where the designated truth value is represented by the two values: 2 and 3.

Martí argued that referential intuitions are not the right kind of empirical evidence for testing theories of reference. Machery, Olivola, and De Blanc replied with a survey aimed at providing evidence that referential intuitions are in sync with truth‐value judgments and argued that truth‐value judgments provide empirical data from linguistic usage. We present the results of a survey indicating that Machery, Olivola, and De Blanc's experiment fails to overcome Martí's objection: The truth‐value judgements tested (...) by Machery, Olivola, and De Blanc do not provide data relevant for testing theories of reference. (shrink)

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 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)

R-Dagger is the theory of relevant implication, Got from the calculus r (see belnap, Jsl, 32, 1-22), By adding machinery for propositional quantification. In r-Dagger define t as for some p, P, F as for all p, P. Then (t, F) is closed in r-Dagger under truth-Functions and relevant implication, Which, When confined to (t, F) acts just like material 'implication.' but r-Dagger admits of many propositions other than t, F. The article also contains polemics against extensionalism and nominalism. (...) (edited). (shrink)

In introductory logic courses the authors often limit their considerations to the truth-value operators. Then they write that conditionals and biconditionals of natural language ("if" and "if and only if") may be represented as material implications and equivalences ("⊃" and "≡"), respectively. Yet material implications are not suitable for conditionals. Lewis' strict implications are much better for this purpose. Similarly, strict equivalences are better for representing biconditionals (than material equivalences). In this paper we prove that the methods from (...) standard first courses in logic can be used for testing arguments with strict implications, strict equivalences and other operators which may represent connectives from natural language. (shrink)

Kuhn's alleged taxonomic interpretation of incommensurability is grounded on an ill defined notion of untranslatability and is hence radically incomplete. To supplement it, I reconstruct Kuhn's taxonomic interpretation on the basis of a logical-semantic theory of taxonomy, a semantic theory of truth-value, and a truth-value conditional theory of cross-language communication. According to the reconstruction, 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 the unmatchable taxonomic structures underlying them. So constructed, Kuhn's mature interpretation of incommensurability does not depend upon the notion of truth-preserving translatability, but rather depends on the notion of truth-value-status-preserving cross-language communication. The reconstruction makes Kuhn's notion of incommensurability a well grounded, tenable and integrated notion.Author Keywords: Incommensurability; Thomas Kuhn; Taxonomic structures; Lexicons; Truth-value; Untranslatability; Cross-language communication. (shrink)

Infectious logics are systems that have a truth-value that is assigned to a compound formula whenever it is assigned to one of its components. This paper studies four-valued infectious logics as the basis of transparent theories of truth. This take is motivated as a way to treat different pathological sentences differently, namely, by allowing some of them to be truth-value gluts and some others to be truth-value gaps and as a way to treat (...) the semantic pathology suffered by at least some of these sentences as infectious. This leads us to consider four distinct four-valued logics: one where truth-value gaps are infectious, but gluts are not; one where truth-value gluts are infectious, but gaps are not; and two logics where both gluts and gaps are infectious, in some sense. Additionally, we focus on the proof theory of these systems, by offering a discussion of two related topics. On the one hand, we prove some limitations regarding the possibility of providing standard Gentzen sequent calculi for these systems, by dualizing and extending some recent results for infectious logics. On the other hand, we provide sound and complete four-sided sequent calculi, arguing that the most important technical and philosophical features taken into account to usually prefer standard calculi are, indeed, enjoyed by the four-sided systems. (shrink)

Thesis: Such things as beliefs, statements, assertions, remarks, hypotheses, and theories are those things that are true or false . (Example: we do say such things as "Her belief that her mother had phoned was false." Or, "His assertion that Alberta is smaller than British Columbia is true.").

Can mystics intuit something of what modern physicists calculate? And if so, how? The question of the relation between the classical mysticisms and modern science is approached in Part I in terms of the multiple forms and definitions of 'truth value'. Intuition/epiphany, pragmatism, coherence, and correspondence are considered as forms of truth that have also been proposed for unitive mystical experience. Since 'correspondence' or 'representation' has been the definition at the core of modern science, it in particular (...) is approached by combining Lakoff and Johnson on the roots of all abstract knowledge in physical metaphor and Gibson on the ecological array of perception as the template from which such metaphors must be drawn. A series of similarities between the maximally inclusive metaphors underlying unitive mystical experience and cosmological physics, as abstracted from an ecological array already resonant with multiple levels of physical reality, suggests a basis for the correspondence between these otherwise distinct cognitive domains. Part II extends this approach to widely posited cross cultural values of spiritual or mystical realization, in terms of gratitude, compassion, faith, and inner freedom. When fully embodied as forms of personal conduct, these are also ultimately derivable from the openness and flow patternings of the ecological array itself. The possibility that the more abstract spiritual values of the major world mysticisms exemplify not only revelatory and pragmatic forms of truth, but are also broadly correspondent with both the principles of immediate concrete perception and modern physics, may eventually allow a contemporary re- formulation of the microcosm-macrocosm unities basic to traditional cultures. (shrink)

We show that compactness is preserved by arbitrary direct products of lattices of truth values and that the Löwenheim-Skolem property is preserved by finite direct products of lattices of truth values.

This paper outlines a new pluralistic theory of normative reasons for belief, welfarist pluralism, which aims to explain how there can be basic alethic/epistemic reasons for belief and basic pragmatic/non-alethic reasons for belief that can combine to determine what one ought to believe. The paper shows how this non-derivative first-order pluralism arises from a purely welfarist account of the foundations of theoretical normativity, thereby combining foundational pragmatism with non-derivative pluralism about normative reasons for belief. In addition, this paper outlines how (...) welfarist pluralism provides a new and potentialy attractive account of the value of truth (or its indicators), namely that the value of truth (or its indicators) is its direct contribution to individuals' personal good or wellbeing. (shrink)

In this work we expand the foundational perspective of category theory on quantum event structures by showing the existence of an object of truth values in the category of quantum event algebras, characterized as subobject classifier. This object plays the corresponking role that the two-valued Boolean truth values object plays in a classical event structure. We construct the object of quantum truth values explicitly and argue that it constitutes the appropriate choice for the valuation of propositions describing (...) the behavior of quantum systems. (shrink)

Why has the spread of fake news taken grip on society so quickly? Why has there been a significant increase in violence among those who disagree on issues? Why is it that increasingly our society is shutting down speech they disagree with rather than engage in civil debate? This book explores each of these issues and traces their connection to the same root cause: the decay of truth in education. It presents a compelling case that documents how educational institutions (...) and political institutions alike have abandoned truth as a primary virtue. In doing so, our society has waded deeply into an environment loaded with deceit, distraction, and delusion. The targets of this critique range across political, religious, and social groups as this is a societal-level outcome of the educational malaise towards truth. The book underscores topics of practical interest and considers real opportunities for each individual to take to help restore truth as a virtue in education and in society. (shrink)

We develop a bottom-up approach to truth-value semantics for classical logic of partial terms based on equality and apply it to prove the conservativity of the addition of partial description and selection functions, independently of any strictness assumption.

The article is about one of the vital problem for analytic philosophy which is how to define truth value for sentences which include their own truth predicate. The aim of the article is to determine Saul Kripke’s approach to widen epistemological truth to create a systemic model of truth. Despite a lot of work on the subject, the theme of truth is no less relevant to modern philosophy. With the help of S. Kripke’s article (...) “Outline of the Theory of Truth” and R. L. Kirkham’s work “Theories of Truth: A Critical Introduction” the author tried to represent a non-classical approach which is now known as Saul Kripke’s truth value gaps theory. Considering his solving of the Liar Paradox, as well as the Strenghened Liar, it is obvious that there could be the circumstances (or facts) that make sentences have no truth value. In that case the solving of the paradox attracts Kleene’s non-classical three-valued logic which contains the third way and the solution falls into the gap between truth and falsity. Hence there are no relevant and full satisfactory ways to solve the Liar’s Paradox by the language-levels ap- proach. The task consists in an extension of the approach to natural languages and elimination of an ad hoc element as well. Besides that, the language-levels approach refers to the speaker that means that only the last one is allowed to define the hierarchy of the levels and truth value of sentence, but often he does not know what level he is speaking of. As Kripke stated, contingent facts can lead to a paradox which isn’t allowed for a logical point of view. However usage of mathematical apparatus allows the theory in question to be universalized and moreover paves the way to futher epistemological develop- ment of the problem in question. As Kripke’s theory is formalized and presented as a functional series, it gives access to a system model of truth whose elements would be epistemological theories (concepts) of truth. Such a model, for instance, confirms the validity of the deflationary concept of truth. Refs 7. (shrink)

The fact that a group of axioms use the word 'true' does not guarantee that that group of axioms yields a theory of truth. For Davidson the derivability of certain biconditionals from the axioms is what guarantees this. We argue that the test does not work. In particular, we argue that if the object language has truth-value gaps, the result of applying Davidson''s definition of a theory of truth is that no correct theory of truth (...) for the language is possible. (shrink)

This paper explores the ways in which truth is better than falsehood, and suggests that, among other things, it depends on the kinds of proposition to which these values are attached. Ordinary singular propositions like “It is raining” seem to fit best the bivalent “scheme” of classical logic, the general proposition “It is always raining” is more appropriately rated according to how often it rains, and a “practically vague” proposition like “The lecture will start at 1” is appropriately rated (...) according to its nearness to exactness. Implications for logic of this “rating system” are commented on. (shrink)

After summarizing approaches taken previously to the problem of the determination of truth-Value of statements constituting literary works (ryle, Russell, Quine, Strawson, Davidson, Et. Al.) the author argues for a treatment of the problem based upon the linguistic status of such statements as translocutions and their relation to the context in which they occur.

The symposium »Does the Concept of ›Truth‹ Have Value in the Pursuit of Cross-Cultural Philosophy?« hones on a methodological question which has deep implications on doing philosophy cross-culturally. Drawing on early Confucian writers, the anchor, Henry Rosemont, Jr., attempts to explain why he is skeptical of pat, affirmative answers to this question. His co-symposiasts James Maffie, John Maraldo, and Sonam Thakchoe follow his trail in working out multi-faceted views on truth from Mexican, Japanese Confucian, and Tibetan Buddhist (...) perspectives respectively. As these positions substantiate, the aforementioned non-Anglo-European traditions seem to draw on an integrated view of thinking, feeling, and living a human life. For their practitioners, truth is less of a correspondence with a given external reality. In fact, it enables human beings to strike the right path in living good, social lives. (shrink)

This paper examines the concept of ‘areti’ as encountered in the Aristotelian ethical system in order to establish its relationship to the modern concept of virtue as well as to that of moral truth, that is, to identify its truth-value. I intend to show that the Aristotelian ‘areti’ as a developed state of character and as an advanced stage of ethical understanding entails moral truth. ‘Areti’ as a good-in-itself possesses an intrinsic value which reflects moral (...) truth, and as a means for the accomplishment of ‘eudaimonia’ (ultimate happiness) it possesses an instrumental value. I also wish to argue that this position calls for a realist as well as an objectivist (or nonrelativist) approach in Aristotle. To that effect, I examine the elements of ‘areti’ that relate it to truth, and then I use reference to some of theAristotelian virtues, such as ‘andreia’ (courage), ‘philia’ (friendship), ‘dikaiosyne’ (justice), and ‘megalopsychia’ (magnanimity), in order to examine the way moral truth functions. This examination will also try to show that Aristotle’s aretaic approach does not suffer from the ills of virtue ethics theories. (shrink)

An approach to the treatment of inference in the presence of uncertain truth values is described, based on representing uncertainties by sets of ordinary (certain) truth values. Both the algebraic and the logical aspects are studied for a variety of lattices used as truth value spaces in the domain of many-valued logic.

This paper sheds light on the relationship between the logic of generalized truth values and the logic of bilattices. It suggests a definite solution to the problem of axiomatizing the truth and falsity consequence relations, \ and \ , considered in a language without implication and determined via the truth and falsity orderings on the trilattice SIXTEEN 3 . The solution is based on the fact that a certain algebra isomorphic to SIXTEEN 3 generates the variety of (...) commutative and distributive bilattices with conflation. (shrink)

Presupposition, vagueness, and oddness can lead to some sentences failing to have a clear truth value. The homogeneity property of plural predication with definite descriptions may also create truth-value gaps: The books are written in Dutch is true if all relevant books are in Dutch, false if none of them are, and neither true nor false if, say, half of the books are written in Dutch. We study the projection property of homogeneity by deploying methods of (...) general interest to identify truth-value gaps. Method A consists in collecting both truth judgments and, independently, falsity judgments. The second method, employed in experiment series B and C, is based on one-shot ternary judgments: completely true vs. completely false vs. neither. After a calibration of these methods, we use them to demonstrate that homogeneity projects out of negation, the scope of universal sentences and the scope of non-monotonic quantifiers such as exactly two, to some extent. We assess our results in light of different theoretical approaches to homogeneity—approaches based on presuppositions, scalar implicatures, and something like supervaluations, respectively. We identify free parameters in these theories and assess various variants of them based on our results. Our experimental paradigms may be of broader significance insofar as they can be applied to other phenomena which result in the failure of a sentence to have a definite truth value. (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. (shrink)

This paper explores the ways in which truth is better than falsehood, and suggests that, among other things, it depends on the kinds of proposition to which these values are attached. Ordinary singular propositions like “It is raining” seem to fit best the bivalent “scheme” of classical logic, the general proposition “It is always raining” is more appropriately rated according to how often it rains, and a “practically vague” proposition like “The lecture will start at 1” is appropriately rated (...) according to its nearness to exactness. Implications for logic of this “rating system” are commented on. (shrink)

In Philosophical Logic, the Liar Paradox has been used to motivate the introduction of both truth value gaps and truth value gluts. Moreover, in the light of “revenge Liar” arguments, also higher-order combinations of generalized truth values have been suggested to account for so-called hyper-contradictions. In the present paper, Graham Priest's treatment of generalized truth values is scrutinized and compared with another strategy of generalizing the set of classical truth values and defining an (...) entailment relation on the resulting sets of higher-order values. This method is based on the concept of a multilattice. If the method is applied to the set of truth values of Belnap's “useful four-valued logic”, one obtains a trilattice, and, more generally, structures here called Belnap-trilattices. As in Priest's case, it is shown that the generalized truth values motivated by hyper-contradictions have no effect on the logic. Whereas Priest's construction in terms of designated truth values always results in his Logic of Paradox, the present construction in terms of truth and falsity orderings always results in First Degree Entailment. However, it is observed that applying the multilattice-approach to Priest's initial set of truth values leads to an interesting algebraic structure of a “bi-and-a-half” lattice which determines seven-valued logics different from Priest's Logic of Paradox. (shrink)

This book explains the Problem of Truth’s Value and offers a virtue-theoretic solution to it. The Problem of Truth’s Value arises because it is hard to reconcile good theories of truth’s nature with good theories of why we should value truth. Some theories build value into the very nature of truth, but they tend to obscure the connection between what is true and how things are in the world. Other theories treat (...) truth as a purely descriptive feature of claims. They struggle to explain how such a feature could make something good or right to believe. To solve the problem, this book proposes a “Strong Virtue Theory” of truth’s value. On that theory, truth is worth caring about, but not because of any pre-existing value that inheres in states of true belief. Instead, truth is worth caring about because caring about truth is a moral virtue; it is part of being a morally good person. The book offers an account of Truthfulness as a moral virtue, independent of any value that inheres in states of true belief. It also criticizes several alternative ways of explaining truth’s value. Those alternatives include the idea that truth is inherently normative, the idea that truth makes beliefs intrinsically or instrumentally valuable, and the idea that truth confers a special sort of “epistemic value” on beliefs. (shrink)

Since the famous debate between Russell (Mind 14: 479–493, 1905, Mind 66: 385–389, 1957) and Strawson (Mind 59: 320–344, 1950; Introduction to logical theory, 1952; Theoria, 30: 96–118, 1964) linguistic intuitions about truth values have been considered notoriously unreliable as a guide to the semantics of definite descriptions. As a result, most existing semantic analyses of definites leave a large number of intuitions unexplained. In this paper, I explore the nature of the relationship between truth value intuitions (...) and non-referring definites. Inspired by comments in Strawson (Introduction to logical theory, 1964), I argue that given certain systematic considerations, one can provide a structured explanation of conflicting intuitions. I show that the intuitions of falsity, which proponents of a Russellian analysis often appeal to, result from evaluating sentences in relation to specific questions in context. This is shown by developing a method for predicting when sentences containing non-referring definites elicit intuitions of falsity. My proposed analysis draws importantly on Roberts (in: Yoon & Kathol (eds.) OSU working papers in Linguistics: vol. 49: Papers in Semantics 1998; in: Horn & Ward (eds.) Handbook of pragmatics, 2004) and recent research in the semantics and pragmatics of focus. (shrink)

An account of the logic of bivalent languages with truth-value gaps is given. This account is keyed to the use of tables introduced by S. C. Kleene. The account has two guiding ideas. First, that the bivalence property insures that the language satisfies classical logic. Second, that the general concepts of a valid sentence and an inconsistent sentence are, respectively, as sentences which are not false in any model and sentences which are not true in any model. What (...) recommends this approach is (1) its relative simplicity, and (2) the fact that it leaves the fundamental features of classical logic intact. (shrink)

Colin Howson has recently argued that accuracy arguments for probabilism fail because they assume a privileged ‘coding’ in which TRUE is assigned the value 1 and FALSE is assigned the value 0. I explain why this is wrong by first showing that Howson’s objections are based on a misconception about the way in which degrees of confidence are measured, and then reformulating the accuracy argument in a way that manifestly does not depend on the coding of truth-values. (...) Along the way, I will explain how to formulate the laws of probability and rational expectation in a scale-invariant way, and how to properly understand the values of the credence functions that we use to represent rational degrees of confidence. (shrink)

Truth is a value in that sense that a belief is good (or successful, or correct) just in case it is true. But it does not follow that truth is a good-making property, nor does it follow that the nature of truth explains its value. Instead, this paper argues that the nature of belief explains its value.

The four-valued semantics of Belnap–Dunn logic, consisting of the truth values True, False, Neither, and Both, gives rise to several nonclassical logics depending on which feature of propositions we wish to preserve: truth, nonfalsity, or exact truth. Interpreting equality of truth values in this semantics as material equivalence of propositions, we can moreover see the equational consequence relation of this four-element algebra as a logic of material equivalence. In this paper, we axiomatize all combinations of these (...) four-valued logics, for example, the logic of truth and exact truth or the logic of truth and material equivalence. These combined systems are consequence relations which allow us to express implications involving more than one of these features of propositions. (shrink)

This chapter focuses on the question of whether true belief can have final value because it answers our ‘intellectual interest’ or ‘natural curiosity’. The idea is that sometimes we are interested in the truth on some issue not for any ulterior purpose, but simply because we are curious about that issue. It is argued that this approach fails to provide an adequate explanation of the final value of true belief, since there is an unbridgeable gap between our (...) valuing the truth on some issue for its own sake, and that truth's being valuable for its own sake. (shrink)