Generating possibilities

Our knowledge of the most basic alternative possibilities can be thought of as generated recursively from what we know about the actual world. But what are the generating principles? According to one view, they are recombinational: roughly, alternative possibilities are generated by “patching together” parts of distinct worlds or “blotting out” parts of worlds to yield new worlds. I argue that this view is inadequate. It is difficult to state in a way that is true and non-trivial, and anyway fails to account for our knowledge that there might have been other things, properties, relations, and combinations of these than there actually are. I sketch and defend an alternative view based on the distinction between determinable and determinate properties: roughly, alternative possibilities are generated by “intra-determinable” variation, variation from one determinate to another of the same determinable.     

Contrastivism and Lucky Questions

There’s something deeply right in the idea that knowledge requires an ability to discriminate truth from falsity. Failing to incorporate some version of the discrimination requirement into one’s epistemology generates cases of putative knowledge that are at best problematic. On the other hand, many theories that include a discrimination requirement thereby appear to entail violations of closure. This prima facie tension is resolved nicely in Jonathan Schaffer’s contrastivism, which I describe herein. The contrastivist take on relevant alternatives is implausible, however, and this then threatens to undermine contrastivism’s anti-skeptical results.

Paradigms and possibilities

This paper is a excursus into a philosophy of science for deployment in the study of sport. It argues for the virtues of Thomas Kuhn's account of the philosophy of science, an argument conducted strategically by contrasting that account with one derived from views of Karl Popper. In particular, it stresses, first, that Kuhn's views have been widely misunderstood; second, that a rectified Kuhnianism can give due weight to truth in science, while recognising that social sciences differ in crucial ways from natural sciences. For, as Kuhn recognised, social sciences do not function in the paradigm-relative way characteristic of natural sciences. Yet there Kuhn's jargon, and especially misguided talk of ‘paradigms’, is almost ubiquitous.

These thoughts have relevance for three groups. First, as both sports scientists and exercise scientists come to grips with the claims to scientificity of their work, they will need increasingly to locate it within an epistemological framework provided by philosophy of science. So they must begin to take Kuhn's view seriously. Second, social scientists of sport – faced with the predominant scientism of colleagues in sport and exercise science – must also recognise alternatives to a postmodernist rejection of the concept of truth, where Kuhn's picture of natural science clarifies one such. Finally, philosophers writing on sport must not let antipathy to scientism close off the options they present or the terms in which they (we!) present them. And that may require debate among ourselves on abstract issues not immediately connected with sport.     

Relevant identity

We begin to fill a lacuna in the relevance logic enterprise by providing a foundational analysis of identity in relevance logic. We consider rival interpretations of identity in this context, settling on the relevant indiscernibility interpretation, an interpretation related to Dunn's relevant predication project. We propose a general test for the stability of an axiomatisation of identity, relative to this interpretation, and we put various axiomatisations to this test. We fill our discussion out with both formal and philosophical remarks on identity in relevance logic.     

Ultimacy and alternative possibilities

I explore a key feature of Robert Kane’s libertarianism (about which I have been puzzled for some time). Kane claims that we should separate issues of alternative possibilities from issues of ultimacy, but he further argues that they are connected in a certain way. I call into question this connection, and I continue to argue for a strict separation of considerations pertaining to alternative possibilities and “actual-sequence” considerations.

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.     

General information in relevant logic

This paper sets out a philosophical interpretation of the model theory of Mares and Goldblatt (The Journal of Symbolic Logic 71, 2006). This interpretation distinguishes between truth conditions and information conditions. Whereas the usual Tarskian truth condition holds for universally quantified statements, their information condition is quite different. The information condition utilizes general propositions. The present paper gives a philosophical explanation of general propositions and argues that these are needed to give an adequate theory of general information.     

Morally Relevant Features

This article summarizes the account of morality presented in Morality: Its Nature and Justification (Oxford, 1998), with emphasis on that aspect of morality that deals with justifying violations of the moral rules. Such justification requires a two-step procedure; the first is describing the situation using only morally relevant features. I list these features, noting how diverse they are, and describe their characteristics. The second step is estimating the consequences of publicly allowing a violation with the same morally relevant features, that is, allowing a violation when everyone knows that it is allowed to violate the rule in the same circumstances, and comparing this to the estimated consequences of not publicly allowing that kind of violation. I then explain why fully informed, impartial rational persons can sometimes disagree about whether a violation should be publicly allowed and note that such weakly justified violations are the controversial cases.     

Hedonic possibilities and heritability statistics

Several influential psychologists have attempted to estimate to what extent human happiness levels are directly controlled by genes by comparing the happiness levels of identical twins raised apart. If we discover that the happiness levels of identical twins raised apart tend to be closer than the happiness levels of fraternal twins raised apart, this is taken as evidence that average happiness levels are largely controlled by genes. However, if it turns out that identical twins' happiness levels tend to be substantially different, as different as fraternal twins raised apart, it has been argued that this implies that the environment largely determines happiness levels. I contend that this interpretation of the data rests on a set of questionable, closely related assumptions: a) that pairs of identical twins raised apart are raised in substantially different environments; b) that genetically identical twins aren't identical in other pertinent ways; and c) that average levels of affect that are correlated with certain sets of genes in the environments the twin studies were conducted in will be correlated with those genes in other relevant environments because those genes govern average affect levels. In this paper, I will show that these assumptions are false and explain how to properly go about investigating the contingent causal links between genes and happiness. In the end, I argue that there is no good evidence that our genes delimit our hedonic potential and that the fact that this misinterpretation of the data has been widely disseminated is potentially harmful to human well-being.     

Effects of the discriminability of alternatives in three-alternative concurrent-schedule performance

Six pigeons were trained on two- and three-alternative concurrent schedules in which the alternatives were signaled by different wavelengths of light on the main pecking key. The schedules were arranged according to a switching-key procedure in which pecks on a white side key produced a 3-s blackout and, intermittently, a change in the variable-interval schedule of food programmed on the main (center) key after the blackout. In Part 1, a two-alternative concurrent variable-interval schedule was arranged in which the alternatives were signaled by 560 nm and 630 nm. Parts 2 and 3 arranged three-alternative concurrent variable-interval schedules with the alternatives signaled by 560 nm, 600 nm, and 630 nm (Part 2) and 560 nm, 623 nm, and 630 nm (Part 3). Within each part, the relative rate of food reinforcers available on the alternatives was varied across a wide range. In all parts of the experiment, the ratios of responses emitted between pairs of alternatives were more extreme than the ratios of reinforcers obtained on the pairs of alternatives, a result termed overmatching. In Parts 2 and 3, generalized matching sensitivities between pairs of alternatives were found to be higher when the reinforcer rate on the third alternative was low than when it was high—an apparent failure of the constant-ratio rule. The data were well described by an extension of the Davison and Jenkins (1985) model, which assumes differing discriminabilities between concurrent-schedule alternatives in combination with a punishing effect of blackout following changeovers.     

Using logical relevance for question answering

We propose a novel method of determining the appropriateness of an answer to a question through a proof of logical relevance rather than a logical proof of truth. We define logical relevance as the idea that answers should not be considered as absolutely true or false in relation to a question, but should be considered true more flexibly in a sliding scale of aptness. This enables us to reason rigorously about the appropriateness of an answer even in cases where the sources we are getting answers from are incomplete or inconsistent or contain errors. We show how logical relevance can be implemented through the use of measured simplification, a form of constraint relaxation, in order to seek a logical proof than an answer is in fact an answer to a particular question. We then give an example of such an implementation providing a set of specific rules for this purpose.     

Local Change

An agent can usually hold a very large number of beliefs. However, only a small part of these beliefs is used at a time. Efficient operations for belief change should affect the beliefs of the agent locally, that is, the changes should be performed only in the relevant part of the belief state. In this paper we define a local consequence operator that only considers the relevant part of a belief base. This operator is used to define local versions of the operations for belief change. Representation theorems are given for the local operators.     

The Relevant Equivalence Property

The pure implicational and the multiplicative fragments of arange of propositional relevant (and other) logics are shownto have the property that any two formulas equivalent in sucha logic are constructed from exactly the same propositionalvariables – as opposed to merely having (as the definitionof relevance itself would require) some propositional variablein common.     

The seven sins of consumer psychology

Consumer psychology faces serious issues of internal and external relevance. Most of these issues originate in seven fundamental problems with the way consumer psychologists plan and conduct their research—problems that could be called “the seven sins of consumer psychology.” These seven “sins” are (1) a narrow conception of the scope of consumer behavior research; (2) adoption of a narrow set of theoretical lenses; (3) adherence to a narrow epistemology of consumer research; (4) an almost exclusive emphasis on psychological processes as opposed to psychological content; (5) a strong tendency to overgeneralize from finite empirical results, both as authors and as reviewers; (6) a predisposition to design studies based on methodological convenience rather than on substantive considerations; and (7) a pervasive confusion between “theories of studies” and studies of theories. Addressing these problems (“atoning for these sins”) would greatly enhance the relevance of the field. However, this may require a substantial rebalancing of the field's incentives to reward actual research impact rather than sheer number of publications in major journals.     

Striving for optimal relevance when answering questions

When people are asked "Do you have the time?" they can answer in a variety of ways, such as "It is almost 3", "Yeah, it is quarter past two", or more precisely as in "It is now 1:43". We present the results of four experiments that examined people's real-life answers to questions about the time. Our hypothesis, following previous research findings, was that people strive to make their answers optimally relevant for the addressee, which in many cases allows people to give rounded, and not exact, time responses. Moreover, analyses of the non-numeral words, hesitations, and latencies of people's verbal responses to time questions reveal important insights into the dynamics of speaking to achieve optimal relevance. People include discourse markers, hesitation marks, like "uh" and "um", and pauses when answering time questions to maximize the cognitive effects (e.g., a rounded answer is adequate) listeners can infer while minimizing the cognitive effort required to infer these effects. This research provides new empirical evidence on how relevance considerations shape collaborative language use.     

Equivalents of Mingle and Positive Paradox

Relevant logic is a proper subset of classical logic. It does not include among its theorems any ofpositive paradox A (B A)mingle A (A A)linear order (A B) (B A)unrelated extremes (A ) (B B¯)This article shows that those four formulas have different effects when added to relevant logic, and then lists many formulas that have the same effect as positive paradox or mingle.     

An Incomplete Relevant Modal Logic

The relevant modal logic G is a simple extension of the logic RT, the relevant counterpart of the familiar classically based system T. Using the Routley–Meyer semantics for relevant modal logics, this paper proves three main results regarding G: (i) G is semantically complete, but only with a non-standard interpretation of necessity. From this, however, other nice properties follow. (ii) With a standard interpretation of necessity, G is semantically incomplete; there is no class of frames that characterizes G. (iii) The class of frames for G characterizes the classically based logic T.     

物质主义及其相关研究

物质主义一般被看作是一种强调拥有物质财富重要性的个人价值观,它已成为很多不同学科研究者感兴趣的课题。文章从物质主义的基本概念、结构及测量开始,重点论述了其成因、影响尤其是对幸福感的影响,并简介了跨文化研究的成果,最后指出了未来的研究方向,一是对物质主义采用量表测量时应考虑社会称许性反应偏见或者开发内隐测量方法,二是关于物质主义与幸福感的研究方法需要改进,三是物质主义在中国的研究有待于加强     

Restricted Arrow

In this paper I present a range of substructural logics for a conditional connective ↦. This connective was original introduced semantically via restriction on the ternary accessibility relation R for a relevant conditional. I give sound and complete proof systems for a number of variations of this semantic definition. The completeness result in this paper proceeds by step-by-step improvements of models, rather than by the one-step canonical model method. This gradual technique allows for the additional control, lacking in the canonical model method, that is required.     

Frege's Content-Principle and Relevant Deducibility

Given the harmony principle for logical operators, compositionality ought to ensure that harmony should obtain at the level of whole contents. That is, the role of a content qua premise ought to be balanced exactly by its role as a conclusion. Frege's contextual definition of propositional content happens to exploit this balance, and one appeals to the Cut rule to show that the definition is adequate.We show here that Frege's definition remains adequate even when one relevantizes logic by abandoning an unrestricted Cut rule. The proof exploits the fact that in the relevantized logic, which abandons the unrestricted rule of Cut, any failure of the transitivity of deduction is offset by the epistemic gain involved in learning that a stronger-than-expected result holds.