The Elimination of Self-Reference: Generalized Yablo-Series and the Theory of Truth

Although it was traditionally thought that self-reference is a crucial ingredient of semantic paradoxes, Yablo (1993, 2004) showed that this was not so by displaying an infinite series of sentences none of which is self-referential but which, taken together, are paradoxical. Yablo’s paradox consists of a countable series of linearly ordered sentences s(0), s(1), s(2),... , where each s(i) says: For each k > i, s(k) is false (or equivalently: For no k > i is s(k) true). We generalize Yablo’s results along two dimensions. First, we study the behavior of generalized Yablo-series in which each sentence s(i) has the form: For Q k > i, s(k) is true, where Q is a generalized quantifier (e.g., no, every, infinitely many, etc). We show that under broad conditions all the sentences in the series must have the same truth value, and we derive a characterization of those values of Q for which the series is paradoxical. Second, we show that in the Strong Kleene trivalent logic Yablo’s results are a special case of a more general fact: under certain conditions, any semantic phenomenon that involves self-reference can be emulated without self-reference. Various translation procedures that eliminate self-reference from a non-quantificational language are defined and characterized. An Appendix sketches an extension to quantificational languages, as well as a new argument that Yablo’s paradox and the translations we offer do not involve self-reference.     

Dynamic Deontic Logic and its Paradoxes

In Meyer’s promising account [7] deontic logic is reduced to a dynamic logic. Meyer claims that with his account “we get rid of most (if not all) of the nasty paradoxes that have plagued traditional deontic logic.” But as was shown by van der Meyden in [4], Meyer’s logic also contains a paradoxical formula. In this paper we will show that another paradox can be proven, one which also effects Meyer’s “solution” to contrary to duty obligations and his logic in general. Presented by Hannes Leitgeb     

Against Stepping Back: A Critique of Contextualist Approaches to the Semantic Paradoxes

A number of philosophers have argued that the key to understanding the semantic paradoxes is to recognize that truth is essentially relative to context. All of these philosophers have been motivated by the idea that once a liar sentence has been uttered we can ‘step back’ and, from the point of view of a different context, judge that the liar sentence is true. This paper argues that this ‘stepping back’ idea is a mistake that results from failing to relativize truth to context in the first place. Moreover, context-relative liar sentences, such as ‘This sentence is not true in any context’ present a paradox even after truth has been relativized to context. Nonetheless, the relativization of truth to context may offer us the means to avoid paradox, if we can justifiably deny that a sentence about a context can be true in the very context it is about.     

Grelling’s Paradox

Grelling’s Paradox is the paradox which results from considering whether heterologicality, the word-property which a designator has when and only when the designator does not bear the word-property it designates, is had by ‘ ȁ8heterologicality’. Although there has been some philosophical debate over its solution, Grelling’s Paradox is nearly uniformly treated as a variant of either the Liar Paradox or Russell’s Paradox, a paradox which does not present any philosophical challenges not already presented by the two better known paradoxes. The aims of this paper are, first, to offer a precise formulation of Grelling’s Paradox which is clearly distinguished from both the Liar Paradox and Russell’s Paradox; second, to offer a solution to Grelling’s Paradox which both resolves the paradoxical reasoning and accounts for unproblematic predications of heterologicality; and, third, to argue that there are two lessons to be drawn from Grelling’s Paradox which have not yet been drawn from the Liar or Russell’s Paradox. The first lesson is that it is possible for the semantic content of a predicate to be sensitive to the semantic context; i.e., it is possible for a predicate to be an indexical expression. The second lesson is that the semantic content of an indexical predicate, though unproblematic for many cases, can nevertheless be problematic in some cases.     

The Paradox of Inference and the Non-Triviality of Analytic Information

The classical theory of semantic information (ESI), as formulated by Bar-Hillel and Carnap in 1952, does not give a satisfactory account of the problem of what information, if any, analytically and/or logically true sentences have to offer. According to ESI, analytically true sentences lack informational content, and any two analytically equivalent sentences convey the same piece of information. This problem is connected with Cohen and Nagel’s paradox of inference: Since the conclusion of a valid argument is contained in the premises, it fails to provide any novel information. Again, ESI does not give a satisfactory account of the paradox. In this paper I propose a solution based on the distinction between empirical information and analytic information. Declarative sentences are informative due to their meanings. I construe meanings as structured hyperintensions, modelled in Transparent Intensional Logic as so-called constructions. These are abstract, algorithmically structured procedures whose constituents are sub-procedures. My main thesis is that constructions are the vehicles of information. Hence, although analytically true sentences provide no empirical information about the state of the world, they convey analytic information, in the shape of constructions prescribing how to arrive at the truths in question. Moreover, even though analytically equivalent sentences have equal empirical content, their analytic content may be different. Finally, though the empirical content of the conclusion of a valid argument is contained in the premises, its analytic content may be different from the analytic content of the premises and thus convey a new piece of information.     

Drawing inferences from semantically positive and negative implicative predicates

Subjects were timed while they drew inferences from syntactically affirmative and negative sentences containing the semantically positive and negative implicative predicates remember/forget and bother/neglect, under different linguistic contexts that met the presuppositions of the sentences at varying levels of generality. Different patterns of inference latencies were obtained for the two implicative predicates studied, suggesting that there are important differences among semantically negative implicative predicates that influence their representation and processing. Regardless of these differences, inference latencies for all sentences decreased when they were presented in contexts that met some of their presuppositions, indicating that context can facilitate inferential processing.     

Agamben,Badiou, and Russell

Giorgio Agamben and Alain Badiou have both recently made central use of set-theoretic results in their political and ontological projects. As I argue in the paper, one of the most important of these to both thinkers is the paradox of set membership discovered by Russell in 1901. Russell’s paradox demonstrates the fundamentally paradoxical status of the totality of language itself, in its concrete occurrence or taking-place in the world. The paradoxical status of language is essential to Agamben’s discussions of the “coming community,” “whatever being,” sovereignty, law and its force, and the possibility of a reconfiguration of political life, as well as to Badiou’s notions of representation, political intervention, the nature of the subject, and the event. I document these implications of Russell’s paradox in the texts of Agamben and Badiou and suggest that they point the way toward a reconfigured political life, grounded in a radical reflective experience of language.     

Liar-type Paradoxes and the Incompleteness Phenomena

We define a liar-type paradox as a consistent proposition in propositional modal logic which is obtained by attaching boxes to several subformulas of an inconsistent proposition in classical propositional logic, and show several famous paradoxes are liar-type. Then we show that we can generate a liar-type paradox from any inconsistent proposition in classical propositional logic and that undecidable sentences in arithmetic can be obtained from the existence of a liar-type paradox. We extend these results to predicate logic and discuss Yablo’s Paradox in this framework. Furthermore, we define explicit and implicit self-reference in paradoxes in the incompleteness phenomena.     

Paradox and Mystery in Theology

The question of paradox in Christian theology continues to attract attention in contemporary philosophical theology. Much of this attention understandably centers on the epistemological problems paradoxical claims pose for Christian faith. But even among those who conclude that certain points of Christian theology are paradoxical and that belief in paradoxical points of doctrine is epistemically supportable, concepts of the nature and function of paradox in Christian theology differ significantly. In this essay, after briefly noting the diversity of phenomena that count as paradoxes in contemporary discourse, I critique two of the most helpful accounts of paradox in Christian theology available – James Anderson's and C. Stephen Evans's – on the way to proposing an alternative definition. That definition combines the most helpful features of those two accounts while correcting certain weaknesses in each. The result is a definition of paradox as a particular kind of mystery that fits the Reformed strand of Christian theology particularly well and involves a compelling analysis of the spirituality of the phenomenon of paradox in theology.     

Against classical dialetheism

Dialetheism is the view that there are true contradictions. Classical dialetheism holds further the view that the law of excluded middle is indeed a logical law. Most famous dialetheists, such as G. Priest and J. Beall, are classical dialetheists; they take classical dialetheism to be the only plausible solution to the semantic paradoxes. The main contention of the paper is, however, that their views should be rejected. Based on inspecting Priest’s and Beall’s dialetheist theories from a special perspective, this paper contends that classical dialetheism has no natural and plausible way to assign truth values to various truth-ineliminable sentences, i.e., sentences whose truth-conditions essentially involve the property of being true. Several examples of such truth-ineliminable sentences are given in the paper, and two classical dialetheist strategies for assigning them truth values are inspected. This paper argues that none of these strategies is successful.     

亨佩尔确证悖论及其解决方案探析

To solve the highly counterintuitive paradox of confirmation represented by the statement, “A pair of red shoes confirms that all ravens are black,” Hempel employed a strategy that retained the equivalence condition but abandoned Nicod’s irrelevance condition. However, his use of the equivalence condition is fairly ad hoc, raising doubts about its applicability to this problem. Furthermore, applying the irrelevance condition from Nicod’s criterion does not necessarily lead to paradoxes, nor does discarding it prevent the emergence of paradoxes. Hempel’s approach fails to adequately resolve the paradox. __________ Translated from Ziran Bianzhengfa Yanjiu 自然辩证法研究 (Studies in Dialectics of Nature), 2005, (8): 33–37     

On Reduction Rules,Meaning-as-use,and Proof-theoretic Semantics

The intention here is that of giving a formal underpinning to the idea of ‘meaning-is-use’ which, even if based on proofs, it is rather different from proof-theoretic semantics as in the Dummett–Prawitz tradition. Instead, it is based on the idea that the meaning of logical constants are given by the explanation of immediate consequences, which in formalistic terms means the effect of elimination rules on the result of introduction rules, i.e. the so-called reduction rules. For that we suggest an extension to the Curry– Howard interpretation which draws on the idea of labelled deduction, and brings back Frege’s device of variable-abstraction to operate on the labels (i.e., proof-terms) alongside formulas of predicate logic. Presented by Heinrich Wansing     

In Defense of Imperative Inference

“Surrender; therefore, surrender or fight” is apparently an argument corresponding to an inference from an imperative to an imperative. Several philosophers, however (Williams 1963; Wedeking 1970; Harrison 1991; Hansen 2008), have denied that imperative inferences exist, arguing that (1) no such inferences occur in everyday life, (2) imperatives cannot be premises or conclusions of inferences because it makes no sense to say, for example, “since surrender” or “it follows that surrender or fight”, and (3) distinct imperatives have conflicting permissive presuppositions (“surrender or fight” permits you to fight without surrendering, but “surrender” does not), so issuing distinct imperatives amounts to changing one’s mind and thus cannot be construed as making an inference. In response I argue inter alia that, on a reasonable understanding of ‘inference’, some everyday-life inferences do have imperatives as premises and conclusions, and that issuing imperatives with conflicting permissive presuppositions does not amount to changing one’s mind.     

Moore’s Paradox and Moral Motivation

Assertions of statements such as ‘it’s raining, but I don’t believe it’ are standard examples of what is known as Moore’s paradox. Here I consider moral equivalents of such statements, statements wherein individuals affirm moral judgments while also expressing motivational indifference to those judgments (such as ‘hurting animals for fun is wrong, but I don’t care’). I argue for four main conclusions concerning such statements: 1. Such statements are genuinely paradoxical, even if not contradictory. 2. This paradoxicality can be traced to a form of epistemic self-defeat that also explains the paradoxicality of ordinary Moore-paradoxical statements. 3. Although a simple form of internalism about moral judgment and motivation can explain the paradoxicality of these moral equivalents, a more plausible explanation can be provided that does not rely on this simple form of internalism. 4. The paradoxicality of such statements suggests a more credible understanding of the thesis that those who are not motivated by their moral judgments are irrational.     

An entirely non-self-referential Yabloesque paradox

Graham Priest (Analysis 57:236–242, 1997) has argued that Yablo’s paradox (Analysis 53:251–252, 1993) involves a kind of ‘hidden’ circularity, since it involves a predicate whose satisfaction conditions can only be given in terms of that very predicate. Even if we accept Priest’s claim that Yablo’s paradox is self-referential in this sense—that the satisfaction conditions for the sentences making up the paradox involve a circular predicate—it turns out that there are paradoxical variations of Yablo’s paradox that are not circular in this sense, since they involve satisfaction conditions that are not recursively specifiable, and hence not recognizable in the sense required for Priest’s argument. In this paper I provide a general recipe for constructing infinitely many (in fact, continuum-many) such noncircular Yabloesque paradoxes, and conclude by drawing some more general lessons regarding our ability to identify conditions that are necessary and sufficient for paradoxically more generally.     

Paradoxes in the Textual Development of the Laozi: A Closer Examination of Chapters Eight and Twenty-Four

In light of the recently published Western Han period bamboo-slip Laozi,now in the collection of Peking University,this paper explores several paradoxes in the textual development of the Laozi.Specifically,it presents two examples suggesting that since the wording in the Laozi was originally intended to be ambiguous and paradoxical,during the transmission of the text,the compilers or commentators modified some of the paradoxes to make better sense.Eventually those modifications came to replace the original text.In the first part of this article examines certain contrasting differences in Chapter Eight from the Beida Laozi,the Mawangdui Laozi,and the received Laozi.The second part,I examine certain other contrasting differences from these same versions from Chapter Twenty-Four are discussed.This paper argues that these differences among the various versions are not the product of transcribal error;rather,they are the result of compilers or commentators who revised these passages against their earliest versions in order to make the meaning clearer and more explicit.     

Hume’s Solution of the Goodman Paradox and the Reliability Riddle (Mill’s problem)

Many solutions of the Goodman paradox have been proposed but so far no agreement has been reached about which is the correct solution. However, I will not contribute here to the discussion with a new solution. Rather, I will argue that a solution has been in front of us for more than two hundred years because a careful reading of Hume’s account of inductive inferences shows that, contrary to Goodman’s opinion, it embodies a correct solution of the paradox. Moreover, the account even includes a correct answer to Mill’s question of why in some cases a single instance is sufficient for a complete induction, since Hume gives a well-supported explanation of this reliability phenomenon. The discussion also suggests that Bayesian theory by itself cannot explain this phenomenon. Finally, we will see that Hume’s explanation of the reliability phenomenon is surprisingly similar to the explanation given lately by a number of naturalistic philosophers in their discussion of the Goodman paradox.     

Moore’s Paradox is not just another pragmatic paradox

One version of Moore’s Paradox is the challenge to account for the absurdity of beliefs purportedly expressed by someone who asserts sentences of the form ‘p & I do not believe that p’ (‘Moorean sentences’). The absurdity of these beliefs is philosophically puzzling, given that Moorean sentences (i) are contingent and often true; and (ii) express contents that are unproblematic when presented in the third-person. In this paper I critically examine the most popular proposed solution to these two puzzles, according to which Moorean beliefs are absurd because Moorean sentences are instances of pragmatic paradox; that is to say, the propositions they express are necessarily false-when-believed. My conclusion is that while a Moorean belief is a pragmatic paradox, it is not just another pragmatic paradox, because this diagnosis does not explain all the puzzling features of Moorean beliefs. In particularly, while this analysis is plausible in relation to the puzzle posed by characteristic (i) of Moorean sentences, I argue that it fails to account for (ii). I do so in the course of an attempt to formulate the definition of a pragmatic paradox in more precise formal terms, in order to see whether the definition is satisfied by Moorean sentences, but not by their third-person transpositions. For only an account which can do so could address (ii) adequately. After rejecting a number of attempted formalizations, I arrive at a definition which delivers the right results. The problem with this definition, however, is that it has to be couched in first-person terms, making an essential use of ‘I’. Thus the problem of accounting for first-/third-person asymmetry recurs at a higher order, which shows that the Pragmatic Paradox Resolution fails to identify the source of such asymmetry highlighted by Moore’s Paradox.     

Conditionals and Curry

Curry’s paradox for “if.. then..” concerns the paradoxical features of sentences of the form “If this very sentence is true, then 2 + 2 = 5”. Standard inference principles lead us to the conclusion that such conditionals have true consequents: so, for example, 2 + 2 = 5 after all. There has been a lot of technical work done on formal options for blocking Curry paradoxes while only compromising a little on the various central principles of logic and meaning that are under threat. Once we have a sense of the technical options, though, a philosophical choice remains. When dealing with puzzles in the logic of conditionals, a natural place to turn is independently motivated semantic theories of the behaviour of “if... then...”. This paper argues that a closest-worlds approach outlined in previous work offers a philosophically satisfying reason to deny conditional proof and so block the paradoxical Curry reasoning, and can give the verdict that standard Curry conditionals are false, along with related “contraction conditionals”.