This article is about Avicenna’s account of syllogisms comprising opposite premises. We examine the applications and the truth conditions of these syllogisms. Finally, we discuss the relation between these syllogisms and the principle of non-contradiction.

Brian Loar attempted to provide the Gricean program of intention-based semantics with an account of expression-meaning. But the theory he presented, like virtually every other foundational semantic or meta-semantical theory, was an idealization that ignored vagueness. What would happen if we tried to devise theories that accommodated the vagueness of vague expressions? I offer arguments based on well-known features of vagueness that, if sound, show that neither Brian’s nor any other extant theory could successfully make that adjustment, and this because, (...) if sound, the arguments show not only that nothing can be the content of a vague expression, but also that no spoken language has a compositional semantics. This raises the question of what, really, are the facts about a language whose explanation might seem to require the language to have a compositional semantics, and whether there might not be a way to explain those facts on the assumption that the language doesn’t have a compositional semantics. In response to this question I offer a rough sketch of a view designed to suggest how what needs to be explained might be explained without appeal to compositional semantics. (shrink)

In this paper we explain our pretense account of truth-talk and apply it in a diagnosis and treatment of the Liar Paradox. We begin by assuming that some form of deflationism is the correct approach to the topic of truth. We then briefly motivate the idea that all T-deflationists should endorse a fictionalist view of truth-talk, and, after distinguishing pretense-involving fictionalism (PIF) from error- theoretic fictionalism (ETF), explain the merits of the former over the latter. After presenting the basic framework (...) of our PIF account of truth-talk, we demonstrate a few advantages it offers over T-deflationist accounts that do not explicitly acknowledge pretense at work in the discourse. In turning to the Liar Paradox, we explain how the quasi-anaphoric functioning that our account attributes to truth-talk provides a diagnosis of the Liar Paradox (and other instances of semantic pathology) as having no content—in the sense of not specifying any of what we call M-conditions. At the same time, however, we vindicate the intuition that we can understand liar sentences, thereby avoiding one standard objection to “meaningless strategy” responses to the Liar Paradox. With this diagnosis in place, we then, by way of treatment, introduce a new predicate, ‘semantically defective’, and show how the explanation we give for its application allows for a consistent, yet revenge-immune, (dis)solution of the Liar Paradox, and semantic pathology generally. (shrink)

Functionalism faces a problem in accounting for the semantic powers of beliefs and other mental states. Simple causal considerations will not solve this problem, nor will any appeal to the social utility of semantic interpretations. The correct analysis of semantic representation is a teleological one, in terms of the biological purposes of mental states: whereas functionalism focuses, so to speak, only on the structure of the cognitive mechanism, the semantic perspective requires in addition that we consider the purposes of the (...) cognitive mechanism's parts. (shrink)

Correspondence theories are frequently charged with being either implausible—metaphysically troubling and overly general—or trivial—collapsing into deflationism's “‘P’ is true iff P.” Philip Kitcher argues for a “modest” correspondence theory, on which reference relations are causal relations, but there is no general theory of denotation. In this article, I start by showing that, understood this way, “modest” theories are open to charges of triviality. I then offer a refinement of modesty, and take the first steps toward articulating a modest correspondence theory, (...) giving a particular account of the relation between predicates, properties, and extensions. Finally, I argue that my account does not collapse into a deflationary one. (shrink)

Correspondence theories are frequently charged with being either implausible -- metaphysically troubling and overly general -- or trivial -- collapsing into deflationism's "'P' is true iff P." Philip Kitcher argues for a "modest" correspondence theory, on which reference relations are causal relations, but there is no general theory of denotation. In this paper, I start by showing that, understood this way, "modest" theories are open to charges of triviality. I then offer a refinement of modesty, and take the first steps (...) toward articulating a modest correspondence theory, giving a particular account of the relation between predicates, properties, and extensions. Finally, I argue that my account does not collapse into a deflationary one. (shrink)

This anthology of the very latest research on truth features the work of recognized luminaries in the field, put together following a rigorous refereeing process. Along with an introduction outlining the central issues in the field, it provides a unique and unrivaled view of contemporary work on the nature of truth, with papers selected from key conferences in 2011 such as Truth Be Told, Truth at Work, Paradoxes of Truth and Denotation and Axiomatic Theories of Truth. Studying the nature of (...) the concept of ‘truth’ has always been a core role of philosophy, but recent years have been a boom time in the topic. With a wealth of recent conferences examining the subject from various angles, this collection of essays recognizes the pressing need for a volume that brings scholars up to date on the arguments. Offering academics and graduate students alike a much-needed repository of today’s cutting-edge work in this vital topic of philosophy, the volume is required reading for anyone needing to keep abreast of developments, and is certain to act as a catalyst for further innovation and research. (shrink)

It is a fundamental intuition about truth that the conditions under which a sentence is true are given by what the sentence asserts. My aim in this paper is to show that this intuition captures the concept of truth completely and correctly. This is conceptual deflationism, for it does not go beyond what is asserted by a sentence in order to define the truth status of that sentence. This paper, hence, is a defense of deflationism as a conceptual account of (...) truth. This defense is developed in four stages. In the first stage I present a distinction between two types of deflationism, conceptual and metaphysical. This is the central stage of the argument and its main conclusion is that conceptual deflationism when joined with the principle of bivalence is inconsistent with metaphysical deflationism, that is, conceptual deflationism together with bivalence entails a non-deflationary metaphysical account of truth. In the second and third stages of the argument I argue that the totality of the Tarskian biconditionals, when interpreted as definitional biconditionals, offers a description of the nature of truth. In the fourth, and final, stage of the argument I advance a positive case for conceptual deflationism. I explain how the revision theory of truth provides this sort of deflationism with its best evidence: a clear demonstration of its consistency and a compelling argument for its material adequacy. (shrink)

Correspondence theories are frequently either too vaguely expressed – “true statements correspond to the way things are in the world,” or implausible – “true statements mirror raw, mind-independent reality.” I address this problem by developing features and roles that ought to characterize what I call ldquo;modest” correspondence theories. Of special importance is the role of correspondence in directing our responses to cases of suspected non-factuality; lack of straightforward correspondence shows the need for, and guides us in our choice of, various (...) kinds of reconstrual projects. This, I argue, is in contrast to the approaches suggested by deflationism and coherence, and thus modest correspondence theories are appropriately distinct from rivals. (shrink)

This paper investigates the determinacy of mathematics. We begin by clarifying how we are understanding the notion of determinacy before turning to the questions of whether and how famous independence results bear on issues of determinacy in mathematics. From there, we pose a metasemantic challenge for those who believe that mathematical language is determinate, motivate two important constraints on attempts to meet our challenge, and then use these constraints to develop an argument against determinacy and discuss a particularly popular approach (...) to resolving indeterminacy, before offering some brief closing reflections. We believe our discussion poses a serious challenge for most philosophical theories of mathematics, since it puts considerable pressure on all views that accept a non-trivial amount of determinacy for even basic arithmetic. (shrink)

Alfred Tarski’s refinement of an account of truth into a formal system that turns on the acceptance of Convention-T has had a lasting impact on philosophical logic, especially work concerning truth, meaning, and other semantic notions. In a series of studies completed from the 1930s to the 1960s, Arne Næss collected and analysed intuitive responses from non-philosophers to questions concerning truth, synonymy, certainty, and probability. Among the formulations of truth studied by Næss were practical variants of expressions of the form (...) “p’ is true if and only if p’. This paper calls attention to a series of experimental results Næss overlooked in his original study. These data collectively suggest that acceptance of expressions of the form “p’ is true if and only if p’ varies according to what kind of statement p is. (shrink)

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)

The article explores the relationship between Tarski’s theory oftruth and modern deflationary or minimalist accounts of truth. The authornotes many similarites, but he also identifies an important difference betweenTarski’s theory and the various approaches of his modern followers: Tarskithought of his theory of truth as an elaboration of the classical correspondence notion. The heart of his theory is the definition of truth in terms ofsatisfaction. Truth is explicated in terms of a relation between language andaspects of external reality. It is (...) just this central component of his theorywhich is rejected by modern deflationism and minimalism. (shrink)

Widespread deflationistic readings of Quine misrepresent his view of disquotation’s significance and the truth predicate’s utility. I demonstrate this by answering a question that philosophers have not directly addressed: how does Quine understand the philosophical problem of truth? A primary thesis of this paper is that we can answer this question only by working from within Quine’s naturalistic framework. Drawing on neglected texts from Quine's corpus, I defend the view that, for Quine, the problem of truth emerges from the development (...) of science, in particular, from logical theorizing. I show that disquotation itself, from this Quinean point of view, is the problematic phenomenon calling for philosophical reflection. I conclude by arguing that Quine does not envisage the kind of explanatory role for disquotation taken up by contemporary deflationists, and he shows no interest in the task that animates deflationism, namely, to show that concerns with truth’s nature are fundamentally confused. (shrink)

One of the main logical functions of the truth predicate is to enable us to express so-called ‘infinite conjunctions’. Several authors claim that the truth predicate can serve this function only if it is fully disquotational, which leads to triviality in classical logic. As a consequence, many have concluded that classical logic should be rejected. The purpose of this paper is threefold. First, we consider two accounts available in the literature of what it means to express infinite conjunctions with a (...) truth predicate and argue that they fail to support the necessity of transparency for that purpose. Second, we show that, with the aid of some regimentation, many expressive functions of the truth predicate can actually be performed using truth principles that are consistent in classical logic. Finally, we suggest a reconceptualisation of deflationism, according to which the principles that govern the use of the truth predicate in natural language are largely irrelevant for the question of what formal theory of truth we should adopt. Many philosophers think that the paradoxes pose a special problem for deflationists; we will argue, on the contrary, that deflationists are in a much better position to deal with the paradoxes than their opponents. (shrink)

Philosophy and Phenomenological Research, EarlyView.

Tarski’s Convention T is often taken to claim that it is both sufficient and necessary for adequacy in a definition of truth that it imply instances of the T-schema where the embedded sentence translates the mentioned sentence. However, arguments against the necessity claim have recently appeared, and, furthermore, the necessity claim is actually not required for the indefinability results for which Tarski is justly famous; indeed, Tarski’s own presentation of the results in the later Undecidable Theories makes no mention of (...) an assumption to the effect that the definition of truth implies the biconditionals. This raises a question: was Tarski in fact committed to the necessity claim in the important papers of the 1930s and 40s? I argue that he was not. The discussion of this apparently esoteric interpretive issue in fact gets to the heart of many important questions about truth, and in the final sections of the paper I discuss the importance of the T-biconditionals in the theory of meaning and the relation of deflationary and inflationary theories of truth to the semantic paradoxes. (shrink)

Controversy has arisen of late over the claim that deflationism about truth requires that we explain meaning in terms of something other than truth-conditions. This controversy, it is argued, is due to unclarity as to whether the basic deflationary claim that a sentence and a sentence that attributes truth to it are equivalent in meaning is intended to involve the truth- predicate of the object language for which we develop an account of meaning, or is intended to involve the truth- (...) predicate of the metalanguage in which we develop an account of meaning. The former view is compatible with the truth-conditional theory of meaning for the object language, the latter is incompatible with it. However, the former view is also trivially true; hence we should endorse the claim that any form of deflationism worth being interested in is incompatible with understanding meaning truth-conditionally. (shrink)

A number of recent writers have argued that we should explain mental representation teleologically, in terms of the biological purposes of beliefs and other mental states.A rather older idea is that the truth condition of a belief is that condition which guarantees that actions based on that belief will succeed.What I want to show in this paper is that these two ideas complement each other. The teleological theory is inadequate unless it incorporates the thesis that truth is the guarantee of (...) successful action. Conversely, the success-guaranteeing account of truth conditions is incomplete until it is placed in a teleological context. (shrink)

A number of recent writers have argued that we should explain mental representation teleologically, in terms of the biological purposes of beliefs and other mental states.A rather older idea is that the truth condition of a belief is that condition which guarantees that actions based on that belief will succeed.What I want to show in this paper is that these two ideas complement each other. The teleological theory is inadequate unless it incorporates the thesis that truth is the guarantee of (...) successful action. Conversely, the success-guaranteeing account of truth conditions is incomplete until it is placed in a teleological context. (shrink)

Quine and Davidson employ proxy functions to demonstrate that the use of language (behaviouristically conceived) is compatible with indefinitely many radically different reference relations. They also believe that the use of language (behaviouristically conceived) is all that determines reference. From this they infer that reference is indeterminate, i.e. that there are no facts of the matter as to what singular terms designate and what predicates apply to. Yet referential indeterminacy yields rather dire consequences. One thus does wonder whether one can (...) hold on to a Quine--Davidson stance in semantics-cum-metaphysics and still avoid embracing referential indeterminacy. I argue that one can. Anyone adhering to the behaviouristic account pivotal to the Quine--Davidson stance is bound to acknowledge certain facts about verbal behaviour -- that some utterances are tied to situations, that some utterances are tied to segments in situations, that some predicates have non-contextualised conditions of application, and that use involves causal dependencies. The restrictions from these facts ensure that only reference relations generated by means of rather exceptional proxy functions are compatible with verbal behaviour. I conclude that this allows one to rebuff the Quine--Davidson argument for the indeterminacy of reference, as it were, from within. I moreover tentatively conclude that the line of thought laid out provides good reason for just about anyone to hold that there are facts about reference after all. (shrink)

Deflationists about truth typically deny that truth is a causal-explanatory property. However, the now familiar 'success argument' attempts to show that truth plays an important causal-explanatory role in explanations of practical success. Deflationists have standardly responded that the truth predicate appears in such explanations merely as a logical device, and that therefore truth has not been shown to play a causal-explanatory role. I argue that if we accept Jackson and Pettit's account of causal explanations, the standard deflationist response is inconsistent, (...) for on this account even logical properties can be causally explanatory. Therefore the deflationist should remain neutral as to whether truth is a causal-explanatory property, and focus instead on the claim that truth, if it is a property, is a merely logical one. (shrink)

Recently, Paul Horwich has developed the minimalist theory of truth, according to which the truth predicate does not express a substantive property, though it may be used as a grammatical expedient. Minimalism shares these claims with Quine’s disquotationalism; it differs from disquotationalism primarily in holding that truth-bearers are propositions, rather than sentences. Despite potential ontological worries, allowing that propositions bear truth gives Horwich a prima facie response to several important objections to disquotationalism. In section I of this paper, disquotationalism is (...) given a careful exegesis, in which seven known objections are traced to the disquotational schema, and two new objections are raised. A version of disquotationalism which avoids two of the seven known objections is recommended. In section II, an examination of minimalism shows that it faces eight of the nine objections facing disquotationalism, plus a new objection. In section III, a finite formulation of minimalism proposed by Ernest Sosa is shown to meet five of the nine objections facing disquotationalism as well as the objection new to minimalism, though it faces another new objection. (shrink)

On an expressivist view, ethical claims are not fact stating; instead they serve the alternative function of expressing our feelings, attitudes and values. On a deflationary view, truth is not a property with a nature to be analyzed, but merely a grammatical device to aid us in endorsing sentences. Views on the relationship between expressivism and deflationism vary widely: they are compatible; they are incompatible; they are a natural pair; they doom one another. Here I explain some of these views, (...) extract some necessary distinctions, and put these to use for understanding expressivism. I argue that contrary to the opinions of some, deflationism doesn’t help with problems of objectivity, knowledge and reasoning in ethics. I suggest alternative expressivist treatments of these problems, and show how expressivism as a metaethical view must have consequences for our ethical lives and beliefs. In particular it must affect the way we deal with ethical consistency—when norms or beliefs conflict—and ethical incompleteness—when ethical questions have no right answer. (shrink)

In this paper, I argue (a) that the predicate "true" is ambiguously used to express a deflationary and a substantial concept of truth and (b) that the two concepts are systematically related in that substantial truths are deflationary truths of a certain kind. Claim (a) allows one to accept the main insights of deflationism but still take seriously, and participate in, the traditional debate about the nature of truth. Claim (b) is a contribution to that debate. The overall position is (...) not new and it has previously been defended by supervaluationists about vagueness. However, the position is here motivated in a new, independent way, and an explanation is offered why some uses of "true" do not seem to require disambiguation. (shrink)

Hartry Field has argued that Alfred Tarski desired to reduce all semantic concepts to concepts acceptable to physicalism and that Tarski failed to do this. In the two succeeding decades, Field has been charged with being too lenient with Tarski; but it has been almost universally accepted that an objection at least as strong as Field's is telling against Tarski's theory. Close examination of the relevant literature, most of it printed in this journal in the 1930s, reveals that Field's conception (...) of physicalism is anachronistic. Tarski did succeed in furthering the sort of physicalist program he had in mind. (shrink)

I argue that a popular brand of deflationism about truth, disquotationalism, does not adequately account for some central varieties of truth ascription. For example, given Boyle’s Law is “The product of pressure and volume is exactly a constant for an ideal gas”, disquotationalism does not explain why the blind ascription “Boyle’s Law is true” implies that the product of pressure and volume is exactly a constant for an ideal gas, and given Washington said only “Birds sing”, disquotationalism does not explain (...) why the existentially quantified ascription “Something Washington said is true” implies that birds sing. Thus disquotationalism fails to account for all the facts about truth. (shrink)

It is often argued that the combination of deflationism about truth and the truth-conditional theory of meaning is impossible for reasons of circularity. I distinguish, and reject, two strains of circularity argument. Arguments of the first strain hold that the combination has a circular account of the order in which one comes to know the meaning of a sentence and comes to know its truth condition. I show that these arguments fail to identify any circularity. Arguments of the second strain (...) hold that the combination has a circular explanation of the ideas or concepts of meaning and truth. I show that these arguments identify a genuine, but acceptable, circularity. (shrink)

According to Field’s influential incompleteness objection, Tarski’s semantic theory of truth is unsatisfactory since the definition that forms its basis is incomplete in two distinct senses: (1) it is physicalistically inadequate, and for this reason, (2) it is conceptually deficient. In this paper, I defend the semantic theory of truth against the incompleteness objection by conceding (1) but rejecting (2). After arguing that Davidson and McDowell’s reply to the incompleteness objection fails to pass muster, I argue that, within the constraints (...) of a non-reductive physicalism and a holism concerning the concepts of truth, reference and meaning, conceding Field’s physicalistic inadequacy conclusion while rejecting his conceptual deficiency conclusion is a promising reply to the incompleteness objection. (shrink)

This paper has three main concerns. First, it proposes a deflationary theory of the concept of truth, arguing thatthe concept can be explicitly defined in terms of substitutionalquantification. Second, it attempts to describe and explainthe intuitions that have traditionally been thought tofavor correspondence theories of truth over deflationarytheories. And third, it argues that these intuitions areultimately compatible with deflationism, maintaining,among other things, that the relation of semantic correspondence can itself be characterized in terms ofsubstitutional quantification.

In recent discussions of the problem of truth, Austin's views have been largely overlooked. This is unfortunate, since many of his criticisms aimed at Strawson's redundancy theory carry over to more recent incarnations of deflationism. And unlike contemporary versions of the correspondence theory of truth, Austin's manages properly to situate truth in its conceptual neighbourhood wherein it belongs to “a whole dimension of different appraisals which have something or other to do with the relation between what we say and the (...) facts.” A proper analysis of truth cannot be given apart from a broader study of speech acts. (shrink)

I argue that semantics is the study of the proprietary database of a centrally inaccessible and informationally encapsulated input–output system. This system’s role is to encode and decode partial and defeasible evidence of what speakers are saying. Since information about nonlinguistic context is therefore outside the purview of semantic processing, a sentence’s semantic value is not its content but a partial and defeasible constraint on what it can be used to say. I show how to translate this thesis into a (...) detailed compositional-semantic theory based on the influential framework of Heim and Kratzer. This approach situates semantics within an independently motivated account of human cognitive architecture and reveals the semantics–pragmatics interface to be grounded in the underlying interface between modular and central systems. (shrink)

This paper aims to show that truth is neutral with respect to metaphysics and epistemology. In other words, the paper states that in order to make an analysis about our daily use of truth discourse, it is not necessary to refer to neither the nature of the world nor the nature of our epistemic capacities. The text is composed by three sections. In the first one, it makes explicit the common-sense intuitions which seem to bring truth to either metaphysics or (...) epistemology. In the second one, the text analyzes the role of the predicate «is true» in our natural languages. In the third section, the intuitions aforementioned are considered with the purpose of examining its intuitive status and its alleged relationship with both metaphysics and epistemology. (shrink)

The infinitary function of the truth predicate consists in its ability to express infinite conjunctions and disjunctions. A transparency principle for truth states the equivalence between a sentence and its truth predication; it requires an introduction principle—which allows the inference from “snow is white” to “the sentence ‘snow is white’ is true”—and an elimination principle—which allows the inference from “the sentence ‘snow is white’ is true” to “snow is white”. It is commonly assumed that a theory of truth needs to (...) satisfy a transparency principle to fulfil the infinitary function. Picollo and Schindler (Erkenntnis 83:899–928, 2017) argue against this idea. They prove that, given certain assumptions, an elimination principle is sufficient for the purpose. Then, they pose a challenge: to show why we should incorporate introduction principles to our theory of truth. In this essay I take on the challenge. I show that, given the authors’ assumptions, an introduction principle is also sufficient to perform the infinitary function. (shrink)

Tim Maudlin’s Truth and Paradox is terrific. In some sense its solution to the paradoxes is familiar—the book advocates an extension of what’s called the Kripke-Feferman theory (although the definition of validity it employs disguises this fact). Nonetheless, the perspective it casts on that solution is completely novel, and Maudlin uses this perspective to try to make the prima facie unattractive features of this solution seem palatable, indeed inescapable. Moreover, the book deals with many important issues that most writers on (...) the paradoxes never deal with, including issues about the application of the Gödel theorems to powerful theories that include our theory of truth. The book includes intriguing excursions into general metaphysics, e.g. on the nature of logic, facts, vagueness, and much more; and it’s lucid and lively, a pleasure to read. It will interest a wide range of philosophers. (shrink)

This essay argues that deflationism is incompatible with the phenomenon of referential indeterminacy. This puts the deflationist in the difficult position of having to deny the possibility of what otherwise seems like a manifest and theoretically important phenomenon. Section 1 provides background on deflationism. Section 2 considers an intuitive argument by Stephen Leeds to the effect that deflationism precludes RI; the essay argues that this argument does not succeed. The rest of the essay presents its own, distinct argument for the (...) incompatibility of deflationism and RI. Section 3 argues that direct RI—RI that is not simply a derivative of some other, nonreferential instance of indeterminacy—is strictly incompatible with deflationism. Section 4 considers a couple of different ways the deflationist might try to achieve indirect RI—via indeterminate identity and indeterminate synonymy—and argues that each is unsatisfactory. (shrink)

Radical embodied cognitive science (REC) tries to understand as much cognition as it can without positing contentful mental entities. Thus, in one prominent formulation, REC claims that content is involved neither in visual perception nor in any more elementary form of cognition. Arguments for REC tend to rely heavily on considerations of ontological parsimony, with authors frequently pointing to the difficulty of explaining content in naturalistically acceptable terms. However, many classic concerns about the difficulty of naturalizing content likewise threaten the (...) credentials of intentionality, which even advocates of REC take to be a fundamental feature of cognition. In particular, concerns about the explanatory role of content and about indeterminacy can be run on accounts of intentionality as well. Issues about explanation can be avoided, intriguingly if uncomfortably, by dramatically reconceptualizing or even renouncing the idea that intentionality can explain. As for indeterminacy, Daniel Hutto and Erik Myin point the way toward a response, appropriating an idea from Ruth Millikan. I take it a step further, arguing that attention to the ways that beliefs’ effects on behavior are modulated by background beliefs can help illuminate the facts that underlie their intentionality and content. (shrink)

What is deflationism about truth? There are many questions that can be raised about this, given the numerous different characterizations of deflationism in the literature. Here I attend to questions about the characterization of deflationism that arise when we carefully distinguish between issues pertaining to concepts and issues pertaining to properties.

This paper begins by raising a puzzle about what function our use of the word ‘rational’ could serve. To solve the puzzle, I introduce a view I call Epistemic Communism: we use epistemic evaluations to promote coordination among our basic belief-forming rules, and the function of this is to make the acquisition of knowledge by testimony more efficient.

In section 1, I develop epistemic communism, my view of the function of epistemically evaluative terms such as ‘rational’. The function is to support the coordination of our belief-forming rules, which in turn supports the reliable acquisition of beliefs through testimony. This view is motivated by the existence of valid inferences that we hesitate to call rational. I defend the view against the worry that it fails to account for a function of evaluations within first-personal deliberation. In the rest of (...) the paper, I then argue, on the basis of epistemic communism, for a view about rationality itself. I set up the argument in section 2 by saying what a theory of rational deduction is supposed to do. I claim that such a theory would provide a necessary, sufficient, and explanatorily unifying condition for being a rational rule for inferring deductive consequences. I argue in section 3 that, given epistemic communism and the conventionality that it entails, there is no such theory. Nothing explains why certain rules for deductive reasoning are rational. (shrink)