In this paper a logic for reasoning disquotationally about truth is presented and shown to have a standard model. This work improves on Hartry Field's recent results establishing consistency and omega-consistency of truth-theories with strong conditional logics. A novel method utilising the Banach fixed point theorem for contracting functions on complete metric spaces is invoked, and the resulting logic is shown to validate a number of principles which existing revision theoretic methods have heretofore failed to provide.

It is part of the current wisdom that the Liar and similar semantic paradoxes can be taken care of by the use of certain non-classical multivalued logics. In this paper I want to suggest that bivalent logic can do just as well. This is accomplished by using a non-deterministic matrix to define the negation connective. I show that the systems obtained in this way support a transparent truth predicate. The paper also contains some remarks on the conceptual interest of (...) such systems. (shrink)

This paper develops the idea that valid arguments are equivalent to true conditionals by combining Kripke’s theory of truth with the evidential account of conditionals offered by Crupi and Iacona. As will be shown, in a first-order language that contains a naïve truth predicate and a suitable conditional, one can define a validity predicate in accordance with the thesis that the inference from a conjunction of premises to a conclusion is valid when the corresponding conditional is (...) true. The validity predicate so defined significantly increases our expressive resources and provides a coherent formal treatment of paradoxical arguments. (shrink)

A unified answer is offered to two distinct fundamental questions: whether a nonclassical solution to the semantic paradoxes should be extended to other apparently similar paradoxes and whether a nonclassical logic should be expressed in a nonclassical metalanguage. The paper starts by reviewing a budget of paradoxes involving the logical properties of validity, inconsistency, and compatibility. The author’s favored substructural approach to naive truth is then presented and it is explained how that approach can be extended in a very (...) natural way so as to solve a certain paradox of validity. However, three individually decisive reasons are later provided for thinking that no approach adopting a classical metalanguage can adequately account for all the features involved in the paradoxes of logical properties. Consequently, the paper undertakes the task to do better, and, building on the system already developed, introduces a theory in a nonclassical metalanguage that expresses an adequate logic of naive truth and of some naive logical properties. (shrink)

In a recent series of papers, I and others have advanced new logical approaches to familiar paradoxes. The key to these approaches is to accept full classical logic, and to accept the principles that cause paradox, while preventing trouble by allowing a certain sort ofnontransitivity. Earlier papers have treated paradoxes of truth and vagueness. The present paper will begin to extend the approach to deal with the familiar paradoxes arising in naive set theory, pointing out some of the (...) promises and pitfalls of such an approach. (shrink)

This paper develops the idea that valid arguments are equivalent to true conditionals by combining Kripke’s theory of truth with the evidential account of conditionals offered by Crupi and Iacona. As will be shown, in a first-order language that contains a naïve truth predicate and a suitable conditional, one can define a validity predicate in accordance with the thesis that the inference from a conjunction of premises to a conclusion is valid when the corresponding conditional is (...) true. The validity predicate so defined significantly increases our expressive resources and provides a coherent formal treatment of paradoxical arguments. (shrink)

Critics of attempts to explain meaning in terms of truth-conditions have tended to charge their opponents with misconceptions regarding truth. I shall argue that the 'naïve' version of the truth-conditional theory which best accounts for its resilience fails for a different and more basic reason, namely, circularity arising from the contingency of meaning. One reason why this problem has been overlooked is a tendency (noted by Dummett in a different connection) to assimilate the naïve (...) truth-conditional theory to an idealized verificationism. (shrink)

Nonclassical theories of truth that take truth to be transparent have some obvious advantages over any classical theory of truth. But several authors have recently argued that there’s also a big disadvantage of nonclassical theories as compared to their “external” classical counterparts: proof-theoretic strength. While conceding the relevance of this, the paper argues that there is a natural way to beef up extant internal theories so as to remove their proof-theoretic disadvantage. It is suggested that the (...) resulting internal theories are preferable to their external counterparts. (shrink)

This paper extends Kripke’s theory of truth to a language with a variably strict conditional operator, of the kind that Stalnaker and others have used to represent ordinary indicative conditionals of English. It then shows how to combine this with a different and independently motivated conditional operator, to get a substantial logic of restricted quantification within naive truth theory.

While non-classical theories of truth that take truth to be transparent have some obvious advantages over any classical theory that evidently must take it as non-transparent, several authors have recently argued that there's also a big disadvantage of non-classical theories as compared to their “external” classical counterparts: proof-theoretic strength. While conceding the relevance of this, the paper argues that there is a natural way to beef up extant internal theories so as to remove their proof-theoretic disadvantage. It (...) is suggested that the resulting internal theories should seem preferable to their external counterparts. (shrink)

In their recent paper, “Epistemology for Beginners: Two to Five-Year-Old Children’s Representation of Falsity,” Olivier Mascaro and Olivier Morin study the ontogeny of a naïve understanding of truth in humans. Their paper is fascinating for several reasons, but most striking is their claim (given a rather optimistic reading of epistemology) that toddlers as young as two can, at times, recognize false from true assertions. Their Optimistic Epistemology Hypothesis holds that children seem to have an innate capacity to represent (...) a state of affairs truthfully. In the following paper, I investigate the problems this research poses for deflationist theories of truth. Richard Rorty and Huw Price hold that the best way to understand truth or “the truth” is to understand the necessary conditions required for assertoric practice. Both philosophers present unique and very different deflationary theories when it comes to construing truth. I argue that neither philosopher’s approach is successful because they focus on truth and fail to recognize truthfulness as a norm of assertoric practice. I show that truthfulness is the elusive third norm of claim-based discourse and is consistent with Mascaro and Morin’s findings. (shrink)

I show that the logic $\textsf {TJK}^{d+}$, one of the strongest logics currently known to support the naive theory of truth, is obtained from the Kripke semantics for constant domain intuitionistic logic by dropping the requirement that the accessibility relation is reflexive and only allowing reflexive worlds to serve as counterexamples to logical consequence. In addition, I provide a simplified natural deduction system for $\textsf {TJK}^{d+}$, in which a restricted form of conditional proof is used to establish conditionals.

ABSTRACT In our response Field's ‘Properties, Propositions and Conditionals’, we explore the methodology of Field's program. We begin by contrasting it with a proof-theoretic approach and then commenting on some of the particular choices made in the development of Field's theory. Then, we look at issues of property identity in connection with different notions of equivalence. We close with some comments relating our discussion to Field's response to Restall’s [2010] ‘What Are We to Accept, and What Are We to (...) Reject, While Saving Truth from Paradox?’. (shrink)

The naive structuralist definition of truthlikeness is an idealization in the sense that it assumes that all mistaken models of a theory are equally bad. The natural concretization is a refined definition based on an underlying notion of structurelikeness.In Section 1 the naive definition of truthlikeness of theories is presented, using a new conceptual justification, in terms of instantial and explanatory mistakes.

Kripke’s theory of truth, 690–716; 1975) has been very successful but shows well-known expressive difficulties; recently, Field has proposed to overcome them by adding a new conditional connective to it. In Field’s theories, desirable conditional and truth-theoretic principles are validated that Kripke’s theory does not yield. Some authors, however, are dissatisfied with certain aspects of Field’s theories, in particular the high complexity. I analyze Field’s models and pin down some reasons for discontent with them, focusing on (...) the meaning of the new conditional and on the status of the principles so successfully recovered. Subsequently, I develop a semantics that improves on Kripke’s theory following Field’s program of adding a conditional to it, using some inductive constructions that include Kripke’s one and feature a strong evaluation for conditionals. The new theory overcomes several problems of Kripke’s one and, although weaker than Field’s proposals, it avoids the difficulties that affect them; at the same time, the new theory turns out to be quite simple. Moreover, the new construction can be used to model various conceptions of what a conditional connective is, in ways that are precluded to both Kripke’s and Field’s theories. (shrink)

Theories where truth is a naive concept fall under the following dilemma: either the theory is subject to Curry’s Paradox, which engenders triviality, or the theory is not trivial but the resulting conditional is too weak. In this paper we explore a number of theories which arguably do not fall under this dilemma. In these theories the conditional is characterized in terms of non-deterministic matrices. These non-deterministic theories are similar to infinitely-valued Łukasiewicz logic in that they are (...) consistent and their conditionals are quite strong. The difference is the following: while Łukasiewicz logic is \-inconsistent, the non-deterministic theories might turn out to be \-consistent. (shrink)

Naïve realism, often overlooked among philosophical theories of perception, has in recent years attracted a surge of interest. Broadly speaking, the central commitment of naïve realism is that mind-independent objects are essential to the fundamental analysis of perceptual experience. Since the claims of naïve realism concern the essential metaphysical structure of conscious perception, its truth or falsity is of central importance to a wide range of topics, including the explanation of semantic reference and representational content, the (...) nature of phenomenal consciousness, and the basis of perceptual justification and knowledge. One of the greatest difficulties surrounding discussions of naïve realism, however, has been lack of clarity concerning exactly what affirming or denying it entails. In particular, it is sometimes unclear how naïve realism is related to the claim that perceptual experience is in some sense direct or unmediated, and also to what extent the view is compatible with another widely discussed thesis in the philosophy of perception, the claim that perceptual experiences are states with representational content. In this essay, I discuss how recent work on these issues helps to clarify both the central commitments of naïve realism, as well as its relation to representationalist theories of perception. Along the way, I will attempt to shed light on the different ways in which each approach tries to address the various theoretical challenges facing a philosophical theory of perception, and also to assess the prospects for views that attempts to combine features of each approach. (shrink)

The paper is concerned with a logical difficulty which Lionel Shapiro’s deflationist theory of logical consequence (as well as the author’s favoured, non-deflationist theory) gives rise to. It is argued that Shapiro’s non-contractive approach to solving the difficulty, although correct in its broad outlines, is nevertheless extremely problematic in some of its specifics, in particular in its failure to validate certain intuitive rules and laws associated with the principle of modus ponens. An alternative non-contractive theory is offered (...) which does not suffer from the same problem. (shrink)

This paper expands upon a way in which we might rationally doubt that there are multiple sizes of infinity. The argument draws its inspiration from recent work in the philosophy of truth and philosophy of set theory. More specifically, elements of contextualist theories of truth and multiverse accounts of set theory are brought together in an effort to make sense of Cantor’s troubling theorem. The resultant theory provides an alternative philosophical perspective on the transfinite, but (...) has limited impact on everyday mathematical practice. (shrink)

A theory of truth is usually demanded to be consistent, but -consistency is less frequently requested. Recently, Yatabe has argued in favour of -inconsistent first-order theories of truth, minimising their odd consequences. In view of this fact, in this paper, we present five arguments against -inconsistent theories of truth. In order to bring out this point, we will focus on two very well-known -inconsistent theories of truth: the classical theory of symmetric truth FS (...) and the non-classical theory of naïve truth based on ᴌukasiewicz infinitely valued logic: PAᴌT. (shrink)

Paul Horwich (1990) once suggested restricting the T-Schema to the maximally consistent set of its instances. But Vann McGee (1992) proved that there are multiple incompatible such sets, none of which, given minimal assumptions, is recursively axiomatizable. The analogous view for set theory---that Naïve Comprehension should be restricted according to consistency maxims---has recently been defended by Laurence Goldstein (2006; 2013). It can be traced back to W.V.O. Quine(1951), who held that Naïve Comprehension embodies the only really intuitive (...) conception of set and should be restricted as little as possible. The view might even have been held by Ernst Zermelo (1908), who,according to Penelope Maddy (1988), subscribed to a ‘one step back from disaster’ rule of thumb: if a natural principle leads to contra-diction, the principle should be weakened just enough to block the contradiction. We prove a generalization of McGee’s Theorem, anduse it to show that the situation for set theory is the same as that for truth: there are multiple incompatible sets of instances of Naïve Comprehension, none of which, given minimal assumptions, is recursively axiomatizable. This shows that the view adumbrated by Goldstein, Quine and perhaps Zermelo is untenable. (shrink)

This paper presents a range of new triviality proofs pertaining to naïve truth theory formulated in paraconsistent relevant logics. It is shown that excluded middle together with various permutation principles such as A → (B → C)⊩B → (A → C) trivialize naïve truth theory. The paper also provides some new triviality proofs which utilize the axioms ((A → B)∧ (B → C)) → (A → C) and (A → ¬A) → ¬A, the fusion (...) connective and the Ackermann constant. An overview over various ways to formulate Leibniz’s law in non-classical logics and two new triviality proofs for naïve set theory are also provided. (shrink)

Church’s type theory, aka simple type theory, is a formal logical language which includes classical first-order and propositional logic, but is more expressive in a practical sense. It is used, with some modifications and enhancements, in most modern applications of type theory. It is particularly well suited to the formalization of mathematics and other disciplines and to specifying and verifying hardware and software. It also plays an important role in the study of the formal semantics of natural (...) language. When utilizing it as a meta-logic to semantically embed expressive non-classical logics further topical applications are enabled in artificial intelligence and philosophy. A great wealth of technical knowledge can be expressed very naturally in it. With possible enhancements, Church’s type theory constitutes an excellent formal language for representing the knowledge in automated information systems, sophisticated automated reasoning systems, systems for verifying the correctness of mathematical proofs, and a range of projects involving logic and artificial intelligence. Some examples and further references are given in Sections 1.2.2 and 5 below. Type theories are also called higher-order logics, since they allow quantification not only over individual variables, but also over function, predicate, and even higher order variables. Type theories characteristically assign types to entities, distinguishing, for example, between numbers, sets of numbers, functions from numbers to sets of numbers, and sets of such functions. As illustrated in Section 1.2.2 below, these distinctions allow one to discuss the conceptually rich world of sets and functions without encountering the paradoxes of naive set theory. Church’s type theory is a formulation of type theory that was introduced by Alonzo Church in Church 1940. In certain respects, it is simpler and more general than the type theory introduced by Bertrand Russell in Russell 1908 and Whitehead & Russell 1927a. Since properties and relations can be regarded as functions from entities to truth values, the concept of a function is taken as primitive in Church’s type theory, and the λ-notation which Church introduced in Church 1932 and Church 1941 is incorporated into the formal language. Moreover, quantifiers and description operators are introduced in a way so that additional binding mechanisms can be avoided, λ-notation is reused instead. λ-notation is thus the only binding mechanism employed in Church’s type theory. (shrink)

The paper offers a critical examination of a prominent, “quasi-deflationist” argument advanced in the contemporary debate on the semantic paradoxes against non-naive and non-transparent theories of truth. The argument claims that truth unrestrictedly fulfils certain expressive functions, and that its so doing requires the unrestricted validity of naivety and transparency principles. The paper criticises the quasi-deflationist argument by considering some kinds of cases in which transparency and naivety arguably fail. In some such cases truth still fulfils the (...) relevant expressive functions without being transparent or naive; in some other such cases, truth does not fulfil the relevant expressive functions and other conceptual resources must be called upon. Thus, in different ways, all such cases belie the quasi-deflationist argument’s insistence that naivety and transparency should be unrestrictedly valid for truth unrestrictedly to fulfil the relevant expressive functions. There might however be other reasons for solving the semantic paradoxes by revising classical logic, and the paper in effect closes by offering versions of the liar paradox that rely on compelling but opacity-friendly truth-theoretic principles. (shrink)

Gila Sher approaches knowledge from the perspective of the basic human epistemic situation—the situation of limited yet resourceful beings, living in a complex world and aspiring to know it in its full complexity. What principles should guide them? Two fundamental principles of knowledge are epistemic friction and freedom. Knowledge must be substantially constrained by the world (friction), but without active participation of the knower in accessing the world (freedom) theoretical knowledge is impossible. This requires a grounding of all knowledge, empirical (...) and abstract, in both mind and world, but the fall of traditional foundationalism has led many to doubt the viability of this ‘classical’ project. Sher challenges this skepticism, charting a new foundational methodology, foundational holism, that differs from others in being holistic, world-oriented, and universal (i.e., applicable to all fields of knowledge). Using this methodology, Epistemic Friction develops an integrated theory of knowledge, truth, and logic. This includes (i) a dynamic model of knowledge, incorporating some of Quine’s revolutionary ideas while rejecting his narrow empiricism, (ii) a substantivist, non-traditional correspondence theory of truth, and (iii) an outline of a joint grounding of logic in mind and world. The model of knowledge subjects all disciplines to demanding norms of both veridicality and conceptualization. The correspondence theory is robust and universal yet not simplistic or naive, admitting diverse forms of correspondence. Logic’s grounding in the world brings it in line with other disciplines while preserving, and explaining, its strong formality, necessity, generality, and normativity. (shrink)

The article is based upon the following starting position. In this post-modern time, it seems that no scholar in Europe supports what is called “Enlightenment Project” with its naïve objectivism and Correspondence Theory of Truth1, - though not being really hostile, just strongly skeptical about it. No old-fasioned “classical” academical texts; only His Majesty Discourse as chain of interpretations and reinterpretations. What was called objectivity “proved to be” intersubjectivity; what was called Object (in Latin and German and Russian (...) tradition) now is related to as a phenomenon; what was called Subject either is looked upon as Cartesian “cogito” or disappeares at all; what was called Truth turned to be either method of demonstration (by positivists) or the author’s sincerity (by existentialists); what was called Essence is now merely a joke. Alternatively, we speak about Sense, Meaning, and Value. (shrink)

In their recent paper, “Practical Knowledge without Luminosity,” Bob Beddor and Carlotta Pavese (2022) claim that the doctrine of essentially intentional actions, or “essentialism,” is false. Essentialism states that some actions are essentially intentional, such that, “whenever they are performed, they are performed intentionally” (2022, p. 926). Beddor and Pavese work to reject essentialism, which figures as a key premise in Juan Piñeros Glasscock’s anti-luminosity argument against the knowledge condition for intentional action (Piñeros Glasscock, p. 1240). Historically, essentialism has received (...) little attention from philosophers since its inception in Elizabeth Anscombe’s Intention (2000, §47). However, I believe that essentially intentional actions can play an important role in an ontology of action. In my paper, I develop and argue for a variety of essentialism in the context of naive action theory, which I call naive essentialism. Naive essentialism is a two-fold thesis, which claims that (1) essentially intentional actions exist, and (2) that essentially intentional actions ground accidentally intentional actions. My paper has four parts. In the first part, I distinguish between essentially and accidentally intentional actions, and unpack the relevant principles of naive action theory. Second, I present the grounding thesis that accidentally intentional actions are grounded in essentially intentional actions. Next, I provide an argument for the existence of essentially intentional actions. Lastly, I briefly respond to a possible objection to my argument. The upshot of my arguments is that essentially intentional actions form the metaphysical and explanatory bedrock in a naive ontology of action, and that there are good reasons for accepting a key premise in Piñeros Glasscock’s anti-luminosity argument. (shrink)

Therapists and their patients must deal with the negative sequelae of short term mating strategies. Implications for therapy of Gangestad & Simpson's strategic pluralism theory are compared with those of Buss's sexual strategies theory and Eagly's social role theory. Naive theories held by therapists and patients, as well as prevailing societal views, are posited as influential in determining the course and outcome of therapy.

Kant is known for having said relatively little about truth in Critique of Pure Reason. Nevertheless, there are important lessons to be learned from this work about truth, lessons that apply to the contemporary debate on the nature and structure of truth and its theory. In this paper I suggest two such lessons. The first lesson concerns the structure of a substantive theory of truth as contrasted with a deflationist theory; the second concerns (...) the structure of a correspondence theory of truth. The first lesson warns us against conceiving of a substantive theory of truth in a way that led Kant to conclude that such a theory is unviable. In so doing it indirectly suggests what a viable substantive theory of truth would be like. The second lesson teaches us that a correspondence theory of truth need not be as naive and overly simplistic as it is usually thought to be, but can, and should be, far more complex. This lesson is based on a correspondence theory of truth incipient in the Critique, one whose structure reflects the complexity of the relation between mind and world in Kant’s theory. (shrink)

According to some philosophers, the Liar paradox arises because of a mistaken theory of truth. Its lesson is that we must reject some instances of the naive propositional truth-schema \It is true that \ if and only if \\. In this paper, I construct a novel semantic paradox in which no principle even analogous to the truth-schema plays any role. I argue that this undermines the claim that we ought to respond to the Liar by revising (...) our theory of truth. (shrink)

The main formal notion involved in qualitative truth approximation by the HD-method, viz. ‘more truthlike’, is shown to not only have, by its definition, an intuitively appealing ‘model foundation’, but also, at least partially, a conceptually plausible ‘consequence foundation’. Moreover, combining the relevant parts of both leads to a very appealing ‘dual foundation’, the more so since the relevant methodological notions, viz. ‘more successful’ and its ingredients provided by the HD-method, can be given a similar dual foundation. According to (...) the resulting dual foundation of ‘naive truth approximation’, the HD-method provides successes (established true consequences) and counterexamples (established wrongly missing models) of theories. Such HD-results may support the tentative conclusion that one theory seems to remain more successful than another in the naive sense of having more successes and fewer counterexamples. If so, this provides good reasons for believing that the more successful theory is also more truthlike in the naive sense of having more correct models and more true consequences. (shrink)

What MacKinnon offers here is a provocative and original analysis of the meaning of the word "true." His applications are in the areas of statements in general, scientific theories, and theological propositions. One reason for the interest of the book can be found in MacKinnon’s intellectual odyssey. Setting out from a starting-point of standard neo-scholastic textbook philosophy and theology, MacKinnon has come to a highly personal synthesis to which he is willing at least tentatively to apply the label, "ontological pragmatism." (...) Stages along the way—and elements in the synthesis—include Bernard Lonergan’s transcendental Thomism, Wilfrid Sellars’ neo-Kantian version of analytical epistemology, and much detailed work of MacKinnon’s own in analytical philosophy of science. The provocative character of Truth and Expression is likely to bring criticism of the author for misuse of his sources. Wittgensteinian philosophical therapists are likely to bemoan MacKinnon’s relapse into ontologism, even if he qualifies it as a "pragmatic" version. Sellars is likely to object to being lumped with Lonergan, and the latter would probably be upset with the uses to which his former student has put his insights. It may also be worthwhile here to express a demur or two with respect to MacKinnon’s use of his Thomistic sources, e.g., concerning his theory of meaning. It seems that MacKinnon has accepted too naively what might best be called "textbook Thomism." It is true that Aquinas offers a mentalist view, and true also that both Aristotle and Aquinas speak of words as signs of concepts. While this can give rise to a private-language mentalism of the kind Wittgenstein would criticize, it must be recalled that Aristotle and Aquinas were writing not only before Wittgenstein but also before Kant. Whatever can be said of Aquinas’ "mentalism," it is certainly true that in other contexts Aquinas has a social theory of learning that is, at least on the surface, incompatible with a private language theory. Again, with respect to theological truth it seems likely that MacKinnon has been misled by Thomistic manuals, at least when he claims that what Aquinas offers is "a geometrically ordered deductive system" in which "the primacy of Jesus as a revelation of God does not fit." Historical studies of the function of his Summa Theologiae in Aquinas’ scheme for theological education do not support the view of Aquinas as a theological deductive system builder. Nor is it true, as MacKinnon seems to hold, that Aquinas’ view of theological truth is more Aristotelian than biblical. Aside from these qualifications on his use of sources, MacKinnon’s book offers an abundance of critical thinking, analytical insight, and systematic ability. For instance, the reader interested in MacKinnon’s original approach to an adequate epistemology of science will here, in chapter three of Truth and Expression, find the best summary yet of his many contributions in that area. Whether or not, in the last analysis, MacKinnon’s synthesis will be historically significant remains to be seen. What seems likely now is that if it does, the ingredient elements of Lonergen, [[sic]] Sellars, Wittgenstein, Quine, etc., will be more muted, and MacKinnon’s own synthesis will stand on its own. Meanwhile, Truth and Expression will serve as the best guide, pointing in the direction we can expect MacKinnon to follow in the future.—P. T. D. (shrink)

Logicians interested in naive theories of truth or set have proposed logical frameworks in which classical operational rules are retained but structural rules are restricted. One increasingly popular way to do this is by restricting transitivity of entailment. This paper discusses a series of logics in this tradition, in which the transitivity restrictions are effected by a determinacy constraint on assumptions occurring in both the major and minor premises of certain rules. Semantics and proof theory for 3-valued, continuum-valued (...) and surreal-valued semantics are given and the proof theory for the systems outlined. The framework is robust in the sense that no conditional, defined or primitive, which sustains the contraction principles underlying Curry paradoxes can be expressed. Classical recapture is smoothly achievable in the system which however is expressively limited and not semantically closed. The conclusion considers the issue of how to extend the system to capture full naive set theory. (shrink)

Restricted quantification poses a serious and under-appreciated challenge for nonclassical approaches to both vagueness and the semantic paradoxes. It is tempting to explain as ; but in the nonclassical logics typically used in dealing with vagueness and the semantic paradoxes (even those where thend expect. If we’re going to use a nonclassical logic, we need one that handles restricted quantification better.

After indicating why this is needed, the paper proves a non-triviality result for paraconsistent theory containing arithmetic, naive truth and denotation predicates, and descriptions. The result is obtained by dualising a construction of Kroon. Its most notable feature is that there is a trivial object- one that has every property.

A Naive Realist Theory of Colour defends the view that colours are mind-independent properties of things in the environment, that are distinct from properties identified by the physical sciences. This view stands in contrast to the long-standing and wide-spread view amongst philosophers and scientists that colours don't really exist - or at any rate, that if they do exist, then they are radically different from the way that they appear. It is argued that a naive realist theory of (...) colour best explains how colours appear to perceiving subjects, and that this view is not undermined either by reflecting on variations in colour perception between perceivers and across perceptual conditions, or by our modern scientific understanding of the world. A Naive Realist Theory of Colour also illustrates how our understanding of what colours are has far-reaching implications for wider questions about the nature of perceptual experience, the relationship between mind and world, the problem of consciousness, the apparent tension between common sense and scientific representations of the world, and even the very nature and possibility of philosophical inquiry. (shrink)

Naive set theory, as found in Frege and Russell, is almost universally believed to have been shown to be false by the set-theoretic paradoxes. The standard response has been to rank sets into one or other hierarchy. However it is extremely difficult to characterise the nature of any such hierarchy without falling into antinomies as severe as the set-theoretic paradoxes themselves. Various attempts to surmount this problem are examined and criticised. It is argued that the rejection of naive set (...) theory inevitably leads one into a severe scepticism with regard to the feasibility of giving a systematic semantics for set theory. It is further argued that this is not just a problem for philosophers of mathematics. Semantic scepticism in set theory will almost inevitably spill over into total pessimism regarding the prospects for an explanatory theory of language and meaning in general. The conclusion is that those who wish to avoid such intellectual defeatism need to look seriously at the possibility that it is the logic used in the derivation of the paradoxes, and not the naive set theory itself, which is at fault. (shrink)

The question "Why?" that is deployed in these exchanges evidently bears the "special sense" Elizabeth Anscombe has linked to the concepts of intention and of a reason for action; it is the sort of question "Why?" that asks for what Donald Davidson later called a "rationalization".2 The special character of what is given, in each response, as formulating a reason ── a description, namely, of the agent as actually doing something, and, moreover, as..

This paper aims to defend scientific realism against two versions of agnostic empiricism: a naive agnostic position, which suggests that the only rational option is to remain agnostic as to the truth of theoretical assertions, and van Fraassen's more sophisticated agnostic empiricism - which may be called "Hypercritical Empiricism". It first argues that given semantic realism, naive agnostic empiricism cannot be maintained: there is no relevant epistemic difference between theoretical assertions and observational ones. It then focuses on van Fraassen's (...) more sophisticated alternative to scientific realism and suggests that an attitude towards science which involves less than aiming at theoretical truth and believing in theories would be, in some concrete respect that empiricists should recognize, worse off than the recommended realist attitude. To this end, the paper develops the so-called conjunction argument into a diachronic argument for scientific realism. (shrink)