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The primary goals of this book, Replacing Truth, are to present and justify the view that truth is an inconsistent concept and to offer a pair of concepts that are to serve, for certain purposes, as replacements for truth. The positive proposal I offer is multi-faceted and does not fit neatly into established ways of classifying contemporary work on truth. For this reason, a substantial amount of stage setting is required. The book has three parts. Parts I and II present both the background information and the conditions on acceptable theories that are needed to understand and appreciate the positive account of truth given in Part III.

The primary goals of Replacing Truth are to present and justify the view that truth is an inconsistent concept and to offer a pair of concepts that are to serve, for certain purposes, as replacements for truth. The positive proposal I offer is multi-faceted and does not fit neatly into established ways of classifying contemporary work on truth. For this reason, a substantial amount of stage setting is required. The book has three parts. Parts I and II present both the background information and the conditions on acceptable theories that are needed to understand and appreciate the positive account of truth given in Part III.

Philosophical work on truth covers two streams of inquiry, one concerning the nature (if any) of truth, the other concerning truth-related paradox, especially the Liar. For the most part these streams have proceeded fairly independently of each other. In his Deflationary Truth and the Liar (JPL 28:455–488, 1999) Keith Simmons argues that the two streams bear on one another in an important way; specifically, the Liar poses a greater problem for deflationary conceptions of truth than it does for inflationist conceptions. We agree with Simmons on this point; however, we disagree with his main conclusion. In a nutshell, Simmons' main conclusion is that deflationists can solve the Liar only by compromising deflationism. If Simmons is right, then deflationists cannot solve the Liar paradox. In this paper we argue that, pace Simmons, there is an approach to the Liar that is available to deflationists, namely dialetheism.

One recently proposed solution to the Liar paradox is the contextual theory of truth. Tyler Burge (1979) argues that truth is an indexical notion and that the extension of the truth predicate shifts during Liar reasoning. A Liar sentence might be true in one context and false in another. To many, contextualism seems to capture our pre-theoretic intuitions about the semantic paradoxes; this is especially due to its reliance on the so-called Revenge phenomenon. I, however, show that Super-Liar sentences (where a Super-Liar sentence is a sentence which says of itself that it is not true in any context) generate a significant problem for Burge’s contextual theory of truth.

This book is about one of the most baffling of all paradoxes--the famous Liar paradox. Suppose we say: "We are lying now." Then if we are lying, we are telling the truth; and if we are telling the truth we are lying. This paradox is more than an intriguing puzzle, since it involves the concept of truth. Thus any coherent theory of truth must deal with the Liar. Keith Simmons discusses the solutions proposed by medieval philosophers and offers his own solutions and in the process assesses other contemporary attempts to solve the paradox. Unlike such attempts, Simmons' "singularity" solution does not abandon classical semantics and does not appeal to the kind of hierarchical view found in Barwise's and Etchemendy's The Liar. Moreover, Simmons' solution resolves the vexing problem of semantic universality--the problem of whether there are semantic concepts beyond the expressive reach of a natural language such as English.

Hartry Field’s book, Saving Truth from Paradox, is without question among the best works on truth and the liar paradox in the analytic tradition—it should become the standard reference on the liar paradox for years to come. Field offers lucid, technically accurate, but accessible discussions of most of the approaches to the liar paradox that are currently being debated in the literature. He also defends his favored approach, which requires a change from classical to paracomplete logic. After a brief flirtation with dialetheism around the turn of the century, he now offers a novel, powerful, and technically dazzling way of dealing with the liar paradox to accompany his influential version of disquotationalism.2 Together they provide a unified view of the nature and logic of truth.3 Field’s solution to the liar together with his fair and charitable discussion of the alternatives make this book required reading by anyone remotely interested in issues associated with truth, philosophical logic, and philosophy of language. The book covers much the same ground as several of Field’s recent papers on the liar paradox4, but this is not a collection; instead, Field has written the book from scratch in a way that informs the..

As part of an approach to the liar paradox and the other paradoxes affecting truth, I have proposed replacing our concept of truth with two concepts: ascending truth and descending truth.1 I am not going to discuss why I think this is the best approach or how it solves the paradoxes; instead, I concentrate on the theory of ascending and descending truth. I formulate an axiomatic theory of ascending truth and descending truth (ADT) and provide a possible-worlds semantics for it (which I dub xeno semantics). Xeno semantics is a generalization of the familiar neighborhood semantics, which itself is a generalization of the standard relational semantics. Once the details of ADT have been presented, it is easy to show that neither relational semantics nor neighborhood semantics will work for it; thus, the move to a more general framework is required. The main result is a fixed point theorem that guarantees the existence of an acceptable first-order constant-domain xeno model. From this result it follows that ADT is sound with respect to the class of such models. The upshot is that ADT is consistent relative to the background set theory.

I propose a solution to the aletheic paradoxes on which truth predicates are assessment-sensitive. Truth is not an antecedently plausible topic for a semantic relativist treatment; nevertheless, the aletheic paradoxes give us good reason to think that truth is an inconsistent concept, and there are good reasons to think that semantic relativism is appropriate for inconsistent concepts, especially those that display what I call empirical inconsistency. Thus, I show that a promising version of the best approach to the paradoxes is an application of semantic relativism to truth itself—arguing from results about the paradoxes and general considerations about language use to aletheic assessment-sensitivity. The paper is divided into three parts, the first on the aletheic paradoxes, the second on semantic relativism, and the third on assessment-sensitivity with respect to truth predicates. The first contains an overview of my preferred approach to the paradoxes, which entails that truth is an inconsistent concept that that should be replaced (for certain purposes) by a team of consistent concepts that can do its work without causing troubling paradoxes. The second part provides an overview of semantic relativism and its rivals. The third considers which treatment is most appropriate for inconsistent concepts in general and truth in particular. In it, I propose an assessment-sensitivity view of truth, discuss some prominent objections to semantic relativism, and review some issues that arise for approaches to the aletheic paradoxes.

Thinking about truth can be more dangerous than it looks. Of course, our concept of truth is the source of one of the most frustrating and impenetrable paradoxes humans have ever contemplated, the liar paradox, but that is just the beginning of its treachery. In an effort to understand why one of the most beloved and revered members of our conceptual repertoire could cause us so much trouble, philosophers have for centuries proposed “solutions” to the liar paradox. However, it seems that our concept of truth takes offense to our efforts to understand it because it appears to retaliate against those who propose “solutions” to the liar. It takes its revenge on us by creating new paradoxes from our own attempts to find resolution. That is, most proposed solutions to the liar paradox give rise to new, more insidious paradoxes—often called revenge paradoxes. For our attempts at understanding, truth rewards us with inconsistent theories, untenable logics, and a deep feeling of bewilderment. It is as if our concept of truth lashes out at us because it wants to remain a mystery. After a few run-ins with truth, many philosophers have the good sense to keep their distance. Far from being the serene, profound concept most people take it to be, those of us who think much about the liar paradox know truth to be a vengeful bully—a conceptual misanthrope.

An inconsistency approach to the liar and related paradoxes takes the non-logical principles involved in the derivation of the paradoxes to be constitutive of our concept of truth. That is, it is our very competence with the concept of truth that leads us to accept the non-logical premises or inferences involved in the derivation. One who endorses an approach of this type should not be content to diagnose the problem; rather, such a theorist should propose a way of changing our conceptual scheme by introducing new concepts that do the work we ask of truth without giving rise to paradoxes. I offer a pair of concepts, ascending truth and descending truth, for this purpose. Here, I present a formal theory of ascending and descending truth (ADT), explore some of its features, and propose a semantics for it. I show how ADT avoids the liar paradox, Curry’s paradox, and Yablo’s paradox. Moreover, ADT is consistent, fully compatible with classical logic, and does not require any kind of expressive limitation, so it does not give rise to any revenge paradoxes. Finally, I compare ADT to some other views in the literature.