关于克里普克模态性的一个自然主义解释

The Kripkean metaphysical modality (i.e. possibility and necessity) is one of the most important concepts in contemporary analytic philosophy and is the basis of many metaphysical speculations. These metaphysical speculations frequently commit to entities that do not belong to this physical universe, such as merely possible entities, abstract entities, mental entities or qualities not realizable by the physical, which seems to contradict naturalism or physicalism. This paper proposes a naturalistic interpretation of the Kripkean modality, as a naturalist’s response to these metaphysical speculations. It will show that naturalism can accommodate the Kripkean metaphysical modality. In particular, it will show that naturalism can help to resolve the puzzles surrounding Kripke’s a posteriori necessary propositions and a priori contingent propositions. __________ Translated from Zhexue yanjiu 哲学研究 (Philosophical Researches), 2008, (1): 18–26     

Dicing with Saul Kripke

Everyone knows what David Lewis’ possible worlds are, what role they play in his account of possibility and necessity, and Saul Kripke’s criticisms. But what, instead, are Kripke’s possible worlds, and what role do they play in his account of possibility and necessity? The answers are not so obvious. Recently, it has even been claimed that, contrary to what is standardly assumed, Kripke’s approach to modality has not always been consistently metaphysical. In particular, an interpretation of the famous passage in the preface to Naming and Necessity with Kripke’s discussion of the dice example has been put forward, according to which he purports there to clarify the modal notions in terms of that of possible world, model-theoretically construed, in a way which is reminiscent of Carnap’s. In this paper, I shall point out some internal difficulties of this interpretation, and offer a different one, according to which in the dice passage Kripke is trying, consistently with his metaphysical approach, to legitimize the technically useful notion of possible world starting from modal notions, to be accounted for in another way (arguably, in an essentialistic framework). My final goal, however, will be philosophical elucidation rather than mere exegesis. Indeed, I am interested in shedding some light on what possible worlds might possibly be, if something like Kripke’s metaphysical approach is on the right track.     

The metaphysics of rule-following

This paper proposes a causal–dispositional account of rule-following as it occurs in reasoning and intentional agency. It defends this view against Kripke’s (Wittgenstein on rules and private language, Harvard University Press, Cambridge, 1982) objection to dispositional accounts of rule-following, and it proposes a solution to the problem of deviant causal chains. In the first part, I will outline the causal–dispositional approach. In the second part, I will follow Martin and Heil’s (Philos Perspect 12:283–312, 1998) realist response to Kripke’s challenge. I will propose an account that distinguishes between two kinds of rule-conformity and two kinds of rule-following, and I will defend the realist approach against two challenges that have recently been raised by Handfield and Bird (Philos Stud 140:285–298, 2008). In the third part, I will turn to the problem of deviant causal chains, and I will propose a new solution that is partly based on the realist account of rule-following.     

Antecedent-Relative Comparative World Similarity

In “Backward Causation and the Stalnaker–Lewis Approach to Counterfactuals,” Analysis 62:191–7, (2002), Michael Tooley argues that if a certain kind of backward causation is possible, then a Stalnaker–Lewis comparative world similarity account of the truth conditions of counterfactuals cannot be sound. In “Tooley on Backward Causation,” Analysis 63:157–62, (2003), Paul Noordhof argues that Tooley’s example can be reconciled with a Stalnaker–Lewis account of counterfactuals if the comparative world similarity relation on which the Stalnaker–Lewis account relies is allowed to be antecedent-relative. In this paper I show that taking comparative world similarity to be antecedent-relative results in a formal semantics which is a comparative world similarity semantics in name only.     

A Pinch of Salt for Frege

Michael Dummett has argued that a formal semantics for our language is inadequate unless it can be shown to illuminate to our actual practice of speaking and understanding. This paper argues that Frege’s account of the semantics of predicate expressions according to which the reference of a predicate is a concept (a function from objects to truth values) has exactly the required characteristics. The first part of the paper develops a model for understanding the distinction between objects and concepts as an ontological distinction. It argues that, ontologically, we can take a Fregean function to be generated by a property detection device that can register for any object the presence or absence of that property. This provides a direct connection between the semantics of sentences and the structure of perceptual judgment. The second part of the paper deals with arguments that have been mounted against the coherence of Frege’s semantics. It argues that some of these are question begging, while others are correct in so far as Frege’s claim is untenable if we assume that the syntactic categories singular term and predicate are primary, and the ontological categories are simply projections of these syntactic categories. However, the objections dissipate once we recognize that an independent ontological characterization of the distinction is available.     

The structure of lexical concepts

Jerry Fodor (Concepts: Where cognitive science went wrong. New York: Oxford University Press, 1998) famously argued that lexical concepts are unstructured. After examining the advantages and disadvantages of both the classical approach to concepts and Fodor’s conceptual atomism, I argue that some lexical concepts are, in fact, structured. Roughly stated, I argue that structured lexical concepts bear a necessary biconditional entailment relation to their structural constituents. I develop this account of the structure of lexical concepts within the framework of Pavel Tichy’s (The foundations of Frege’s logic. Berlin, New York: De Gruyter, 1988) theory of constructions. I argue that concepts are constructions which can be combined by way of Tichy’s construction-forming operations of composition and closure and an additional operation, simplification, which I propose in section 6. The last of these construction-forming operations plays a central role in my account of lexical concept structure. Stated generally, structured lexical concepts are a result of simplifying their structural constituents.     

Comparing Fixed-Point and Revision Theories of Truth

In response to the liar’s paradox, Kripke developed the fixed-point semantics for languages expressing their own truth concepts. (Martin and Woodruff independently developed this semantics, but not to the same extent as Kripke.) Kripke’s work suggests a number of related fixed-point theories of truth for such languages. Gupta and Belnap develop their revision theory of truth in contrast to the fixed-point theories. The current paper considers three natural ways to compare the various resulting theories of truth, and establishes the resulting relationships among these theories. The point is to get a sense of the lay of the land amid a variety of options. Our results will also provide technical fodder for the methodological remarks of the companion paper to this one.     

The Logic of Theory Assessment

This paper starts by indicating the analysis of Hempel’s conditions of adequacy for any relation of confirmation (Hempel, 1945) as presented in Huber (submitted). There I argue contra Carnap (1962, Section 87) that Hempel felt the need for two concepts of confirmation: one aiming at plausible theories and another aiming at informative theories. However, he also realized that these two concepts are conflicting, and he gave up the concept of confirmation aiming at informative theories. The main part of the paper consists in working out the claim that one can have Hempel’s cake and eat it too — in the sense that there is a logic of theory assessment that takes into account both of the two conflicting aspects of plausibility and informativeness. According to the semantics of this logic, α is an acceptable theory for evidence β if and only if α is both sufficiently plausible given β and sufficiently informative about β. This is spelt out in terms of ranking functions (Spohn, 1988) and shown to represent the syntactically specified notion of an assessment relation. The paper then compares these acceptability relations to explanatory and confirmatory consequence relations (Flach, 2000) as well as to nonmonotonic consequence relations (Kraus et al., 1990). It concludes by relating the plausibility-informativeness approach to Carnap’s positive relevance account, thereby shedding new light on Carnap’s analysis as well as solving another problem of confirmation theory. A precursor of this paper has appeared as “The Logic of Confirmation and Theory Assessment” in L. Běhounek & M. Bílková (eds.), The Logica Yearbook 2004, Prague: Filosofia, 2005, 161–176.     

On Permutation in Simplified Semantics

This note explains an error in Restall’s ‘Simplified Semantics for Relevant Logics (and some of their rivals)’ (Restall, J Philos Logic 22(5):481–511, 1993) concerning the modelling conditions for the axioms of assertion A → ((A → B) → B) (there called c6) and permutation (A → (B → C)) → (B → (A → C)) (there called c7). We show that the modelling conditions for assertion and permutation proposed in ‘Simplified Semantics’ overgenerate. In fact, they overgenerate so badly that the proposed semantics for the relevant logic R validate the rule of disjunctive syllogism. The semantics provides for no models of R in which the “base point” is inconsistent. This problem is not restricted to ‘Simplified Semantics.’ The techniques of that paper are used in Graham Priest’s textbook An Introduction to Non-Classical Logic (Priest, 2001), which is in wide circulation: it is important to find a solution. In this article, we explain this result, diagnose the mistake in ‘Simplified Semantics’ and propose two different corrections.     

A repair of Frege’s theory of thoughts

Frege’s writings contain arguments for the thesis (i) that a thought expressed by a sentence S is a structured object whose composition pictures the composition of S, and for the thesis (ii) that a thought is an unstructured object. I will argue that Frege’s reasons for both (i) and (ii) are strong. Frege’s explanation of the difference in sense between logically equivalent sentences rests on assumption (i), while Frege’s claim that the same thought can be decomposed differently makes (ii) plausible. Thoughts are supposed to do work that requires that they be structured and work that requires that they be unstructured. But this cannot be! While the standard response to this problem is to reject either (i) or (ii), I propose a charitable repair in the spirit of Frege’s theory that accepts both. The key idea can be found in Frege’s Basic Laws of Arithmetic(BL, GGA). Frege argues that the thought expressed by a sentence is determined by the truth-conditions that can be derived from the semantic axioms for the sentence constituents. The fact that the same axiomatic truth-condition can be derived in different ways from different semantic axioms suggests a Fregean solution of the dilemma: A thought is a type that is instantiated by all sequences of senses (decomposed thoughts) that have the same axiomatic truth-conditions. This allows for multiple decomposability of the same thought (for different decomposed thoughts can have the same axiomatic truth-conditions) and for a notion of containment (the decomposed thought contains those senses whose semantic axioms are needed in the derivation of the truth-conditions). My proposal combines the virtues of (i) and (ii) without inheriting their vices.     

Hume’s Principle and Axiom V Reconsidered: Critical Reflections on Frege and His Interpreters

In this paper, I shall discuss several topics related to Frege’s paradigms of second-order abstraction principles and his logicism. The discussion includes a critical examination of some controversial views put forward mainly by Robin Jeshion, Tyler Burge, Crispin Wright, Richard Heck and John MacFarlane. In the introductory section, I try to shed light on the connection between logical abstraction and logical objects. The second section contains a critical appraisal of Frege’s notion of evidence and its interpretation by Jeshion, the introduction of the course-of-values operator and Frege’s attitude towards Axiom V, in the expression of which this operator occurs as the key primitive term. Axiom V says that the course-of-values of the function f is identical with the course-of-values of the function g if and only if f and g are coextensional. In the third section, I intend to show that in Die Grundlagen der Arithmetik (1884) Frege hardly could have construed Hume’s Principle (HP) as a primitive truth of logic and used it as an axiom governing the cardinality operator as a primitive sign. HP expresses that the number of Fs is identical with the number of Gs if and only if F and G are equinumerous. In the fourth section, I argue that Wright falls short of making a convincing case for the alleged analyticity of HP. In the final section, I canvass Heck’s arguments for his contention that Frege knew he could deduce the simplest laws of arithmetic from HP without invoking Axiom V. I argue that they do not carry conviction. I conclude this section by rejecting an interpretation concerning HP suggested by MacFarlane.     

Non-cognitivism and rational inference

Non-cognitivism might seem to offer a plausible account of evaluative judgments, at least on the assumption that there is a satisfactory solution to the Frege–Geach problem. However, Cian Dorr has argued that non-cognitivism remains implausible even assuming that the Frege–Geach problem can be solved, on the grounds that non-cognitivism still has to classify some paradigmatically rational inferences as irrational. Dorr’s argument is ingenious and at first glance seems decisive. However, in this paper I will show that Dorr’s argument equivocates between two different notions of evidence, and that once this equivocation is noted there is no reason to doubt that non-cognitivism is consistent with the rationality of such inferences, at least if it is assumed that the Frege–Geach problem can be solved. In particular, I will show that non-cognitivists can endorse the same explanation of the rationality of such inferences that cognitivists should endorse, and that there is thus no need for non-cognitivists to offer any sort of idiosyncratic account of the epistemology of such cases, in contrast to what other commentators on Dorr’s argument have thought.     

FREGE PUZZLES?

The first page of Frege’s classic “Uber Sinn und Bedeutung” sets for more than a hundred years now the agenda for much of semantics and the philosophy of mind. It presents a purported puzzle whose solution is said to call upon the “entities” of semantics (meanings) and psychological explanation (Psychological states, beliefs, concepts). The paper separates three separate alleged puzzles that can be read into Frege’s data. It then argues that none are genuine puzzles. In turn, much of the Frege-driven theoretical development, motivated as an inevitable “solution”, is thrown into doubt.     

SUPERVALUATION FIXED-POINT LOGICS OF TRUTH

Michael Kremer defines fixed-point logics of truth based on Saul Kripke’s fixed point semantics for languages expressing their own truth concepts. Kremer axiomatizes the strong Kleene fixed-point logic of truth and the weak Kleene fixed-point logic of truth, but leaves the axiomatizability question open for the supervaluation fixed-point logic of truth and its variants. We show that the principal supervaluation fixed point logic of truth, when thought of as consequence relation, is highly complex: it is not even analytic. We also consider variants, engendered by a stronger notion of ‘fixed point’, and by variant supervaluation schemes. A ‘logic’ is often thought of, not as a consequence relation, but as a set of sentences – the sentences true on each interpretation. We axiomatize the supervaluation fixed-point logics so conceived.     

Thomason’s Paradox for Belief,and Two Consequence Relations

Thomason (1979/2010)’s argument against competence psychologism in semantics envisages a representation of a subject’s competence as follows: he understands his own language in the sense that he can identify the semantic content of each of its sentences, which requires that the relation between expression and content be recursive. Then if the scientist constructs a theory that is meant to represent the body of the subject’s beliefs, construed as assent to the content of the pertinent sentences, and that theory satisfies certain ‘natural assumptions’, then it implies that the subject is inconsistent if the beliefs include arithmetic. I challenge the result by insisting that the motivation for Thomason’s principle (ii), via Moore’s Paradox, leads to a more complex representation, in which stating the facts and expressing one’s beliefs are treated differently. Certain logical connections among expressions of assent, and between expression and statement, are a matter of consequence on pain of pragmatic incoherence, not consequence on pain of classical logical inconsistency. But while this salvages the possibility that a modification of the above sort of representation could be adequate, Thomason’s devastating conclusion returns if the scientist identifies himself as the subject of that representation, even when paying heed to the requirement of pragmatic coherence of the sort highlighted by Moore’s Paradox.     

A defense of contingent logical truths

A formula is a contingent logical truth when it is true in every model M but, for some model M, false at some world of M. We argue that there are such truths, given the logic of actuality. Our argument turns on defending Tarski’s definition of truth and logical truth, extended so as to apply to modal languages with an actuality operator. We argue that this extension is the philosophically proper account of validity. We counter recent arguments to the contrary presented in Hanson’s ‘Actuality, Necessity, and Logical Truth’ (Philos Stud 130:437–459, 2006).     

Behind Our I’s: Grief and Loss in the Poetry of Li-Young Lee

This article uses Kenneth R. Mitchell and Herbert Anderson’s (1983) six modalities of grieving as presented in Donald Capps’ (1993) The Poet’s Gift to bring a pastoral theological perspective to bear on Li-Young Lee’s Behind My Eyes (2008), a collection of thirty-nine poems. In specifically focusing on Lee’s poem “To Hold,” it makes the case for a seventh grieving modality, that of preemptive loss. Employing Mitchell and Anderson’s distinction between faithful and unfaithful grieving, it argues that preemptive loss is an unfaithful form or expression of grieving, and notes the irony and sadness in this regard, as this unfaithful response to grief is informed by what is widely considered to be a faithful Judeo–Christian perspective, rooted in the inescapable sinfulness of humanity.     

Amending Frege’s <Emphasis Type="Italic">Grundgesetze der Arithmetik</Emphasis>

Frege’s Grundgesetze der Arithmetik is formally inconsistent. This system is, except for minor differences, second-order logic together with an abstraction operator governed by Frege’s Axiom V. A few years ago, Richard Heck showed that the ramified predicative second-order fragment of the Grundgesetze is consistent. In this paper, we show that the above fragment augmented with the axiom of reducibility for concepts true of only finitely many individuals is still consistent, and that elementary Peano arithmetic (and more) is interpretable in this extended system.