In these few pages I shall try to demonstrate the emptiness of the most cumbersome piece of unexamined intellectual baggage at present being hauled about by English philosophers. I here cite one example to be going on with, at the end of the paper I shall give a handful more, and it would be easy to multiply the number by ten from the writings of reputable philosophers. The outstanding philosophical achievement of the ha1f-century which has just drawn to a close (...) [i.e. the period 1900-1950] has been an appreciation of the peculiar status of a priori judgments and of logically necessary or formally true propositions. . . . Though many problems remain unsolved, the main outline is now clear: formally true statements assert nothing about the world; instead, their function is to state principles according to which empirical propositions are deduced from other empirical propositions . . . (R. B. Braithwaite, ‘Moral Principles and Inductive Policies’, Proceedings of the British Academy 1950). What is wrong with this passage and with the myth of which it is an expression is its assumption that we have clear notions of what it is for a proposition to be logically necessary and of what it is for a proposition to assert something about the world, these notions being such that it is plausible to say that it has recently been discovered that every proposition having the first of these properties lacks the second. This assumption is wrong: there is no body of published theory giving a clear account of such notions, and despite fairly diligent searching I have so far failed to find, among the many philosophers who accept the myth, one who is able when challenged to supplement the literature on this vital point. Let me make it clear at once that I am not going to defend synthetic a priori truths - I am going to attack a popular mishandling of the truth that all necessary truths are analytic, and through this attack to draw right-wing conclusions from left-wing premisses.. (shrink)

This paper aims to explain how the Tractatus attempts to unifylogic by deriving the truth-functionality of logical necessityfrom the thesis that a proposition shows its sense. I first interpret the Tractarian notion of showing as the displaying ofwhat is intrinsic to an expression (or a symbol). Then I argue that, according to theTractatus, the thesis that a proposition shows its sense implies the determinacy of sense, the possibility of the complete elimination of non-primitive symbols, the analyticity thesis and the strong (...) analyticity thesis. The picture theory emerges as what provides the only acceptable account of an elementary proposition, subject to the constraint that a proposition must show its sense. The picture theory and the analyticity thesis then entail the contingency thesis (that an elementary proposition is contingent) and the independence thesis (that elementary propositions are mutually logically independent) which, together with the strong analyticity thesis, imply that all logical propositions are tautologies. (shrink)

Graham Oppy has argued that possible explanation entails explanation in order to object to Richard Gale and Alexander Pruss’s new cosmological argument that it does not improve upon familiar cosmological arguments. Gale and Pruss as well as Pruss individually have granted Oppy’s inference from possible explanation to explanation and argue that this inference provides a reason to believe that the strong principle of sufficient reason is true. In this article, I shall undermine Oppy’s objection to the new cosmological argument by (...) arguing that it is logically possible that some truths are merely possibly explained. (shrink)

This paper analyzes the logical truths as (very roughly) those truths that would still have been true under a certain range of counterfactual perturbations.What’s nice is that the relevant range is characterized without relying (overtly, at least) upon the notion of logical truth. This approach suggests a conception of necessity that explains what the different varieties of necessity (logical, physical, etc.) have in common, in virtue of which they are all varieties of necessity. However, this approach places the counterfactual conditionals (...) in an unfamiliar foundational role. (shrink)

An attempt is made to show that Wittgenstein's later philosophy of logic is not the kind of conventionalism which is often ascribed to him. On the contrary, Wittgenstein gives expression to a ?mixed? theory which is not only interesting but tends to resolve the perplexities usually associated with the question of the a priori character of logical truth. I try to show that Wittgenstein is better understood not as denying that there are such things as ?logical rules? nor as denying (...) that the results of applying such rules are ?logically necessary,? but as trying to understand what it is to appeal to a logical rule and what it means to say that the results of applying such a rule are ?necessary.? He is not so much overthrowing standard accounts of logical necessity as discovering the limits of the concept. (shrink)

Some philosophers, for example Quine, doubt the possibility of jointly using modalities and quantification. Simple model-theoretic considerations, however, lead to a reconciliation of quantifiers with such modal concepts as logical, physical, and ethical necessity, and suggest a general class of modalities of which these are instances. A simple axiom system, analogous to the Lewis systems S1 —S5, is considered in connection with this class of modalities. The system proves to be complete, and its class of theorems decidable.

Tenseless theories of time entail that earlierthan, later than and simultaneous with (i.e.,McTaggart's `B-series') are the only temporalproperties exemplified by events. Such theories oftencome under attack for being unable to satisfactorilyaccount for tensed language. In this essay I arguethat tenseless theories of time are capable of twofeats that critics, such as Quentin Smith, argue arebeyond their grasp: (1) They can coherently explainthe impossibility of translating all tensed sentencesby tenseless counterparts; (2) They can account forcertain obviously valid entailment relations betweentensed sentence (...) types. In analyzing tensed entailmentrelations tenselessly, I favor a date analysis oftensed language over a token-reflexive theory. Theupshot is that tenseless theories of time are notundermined by the linguistic facts. (shrink)

In this paper I argue that Kierkegaard's theory of change is motivated by a robust notion of contingency. His view of contingency is sharply juxtaposed with a strong notion of absolute necessity. I show that how he understands these notions explains certain of his claims about causation. I end by suggesting a compatibilist interpretation of Kierkegaard's philosophy.

Critical (necessary or sufficient) features in categorisation have a long history, but the empirical evidence makes their existence questionable. Nevertheless, there are some cases that suggest critical feature effects. The purpose of the present work is to offer some insight into why classification decisions might misleadingly appear as if they involve critical features. Utilising Tversky's (1977) contrast model of similarity, we suggest that when an object has a sparser representation, changing any of its features is more likely to lead to (...) a change in identity than it would in objects that have richer representations. Experiment 1 provides a basic test of this suggestion with artificial stimuli, whereby objects with a rich or a sparse representation were transformed by changing one of their features. As expected, we observed more identity judgements in the former case. Experiment 2 further confirms our hypothesis, with realistic stimuli, by assuming that superordinate categories have sparser representations than subordinate ones. These results offer some insight into the way feature changes may or may not lead to identity changes in classification decisions. (shrink)

Critical (necessary or sufficient) features in categorisation have a long history, but the empirical evidence makes their existence questionable. Nevertheless, there are some cases that suggest critical feature effects. The purpose of the present work is to offer some insight into why classification decisions might misleadingly appear as if they involve critical features. Utilising Tversky's (1977) contrast model of similarity, we suggest that when an object has a sparser representation, changing any of its features is more likely to lead to (...) a change in identity than it would in objects that have richer representations. Experiment 1 provides a basic test of this suggestion with artificial stimuli, whereby objects with a rich or a sparse representation were transformed by changing one of their features. As expected, we observed more identity judgements in the former case. Experiment 2 further confirms our hypothesis, with realistic stimuli, by assuming that superordinate categories have sparser representations than subordinate ones. These results offer some insight into the way feature changes may or may not lead to identity changes in classification decisions. (shrink)

The issues of just what laws of nature are and what makes statements law-like have been more discussed than advanced. After exploring the general area and uncovering some difficulties which, I suspect, make the case even knottier than generally imagined, I argue that certain resources available only to the theist---in particular, counterfactuals of God’s freedom---may provide the materials needed for constructing solutions.

Hume's arguments for the contention that causal necessity precludes logical necessity depend on the questionable principle that a cause must precede its effect. Hobbes' definition of entire cause, although it fails to account for causal priority, is not refuted by Hume. The objections of Myles Brand and Marshall Swain (Philosophical Studies, 1976) to my counterexample against Hume (Philosophical Studies, 1975) are ineffective. Their other objections to my criticisms of their argument against defining causation in terms of necessary and sufficient conditions (...) (Synthese, 1970) are also mostly ineffective. (shrink)

Myles Brand and Marshall Swain advocate the principle that if A is the set of conditions individually necessary and jointly sufficient for the occurrence of B, then if C is a set of conditions individually necessary for the occurrence of B, every member of C is a member of A. I agree with John Barker and Risto Hilpinen who each argue that this principle is not true for causal necessity and sufficiency, but I disagree with their claim that it is (...) true for logical necessity and sufficiency. The original appeal of the principle may be due to confusing two kinds of totality: to say that when every member of set A obtains, then every condition necessary for E obtains is not to say that every condition necessary for E is a member of A. All the authors mentioned believe that causal necessity precludes logical necessity. I deny this on the basis of an example from kinematics. Hume has not refuted definitions of causation in terms of logically necessary and sufficient conditions, nor have Brand and Swain. (shrink)

In this fascinating work, Scott Soames offers a new conception of the relationship between linguistic meaning and assertions made by utterances. He gives meanings of proper names and natural kind predicates and explains their use in attitude ascriptions. He also demonstrates the irrelevance of rigid designation in understanding why theoretical identities containing such predicates are necessary, if true.

Prior research shows that reasoners' confidence is poorly calibrated (Shynkaruk & Thompson, 2006). The goal of the current experiment was to increase calibration in syllogistic reasoning by training reasoners on (a) the concept of logical necessity and (b) the idea that more than one representation of the premises may be possible. Training improved accuracy and was also effective in remedying some systematic misunderstandings about the task: those in the training condition were better at estimating their overall performance than those who (...) were untrained. However, training was less successful in helping reasoners to discriminate which items are most likely to cause them difficulties. In addition we explored other variables that may affect confidence and accuracy, such as the number of models required to represent the problem and whether or not the presented conclusion was necessitated by the premises, possible given the premises, or impossible given the premises. These variables had systematically different relationships to confidence and accuracy. Thus, we propose that confidence in reasoning judgements is analogous to confidence in memory retrievals, in that they are inferentially derived from cues that are not diagnostic in terms of accuracy. (shrink)

This study investigated individual differences in the belief bias effect, which is the tendency to accept conclusions because they are believable rather than because they are logically valid. It was observed that the extent of an individual's belief bias effect was unrelated to a number of measures of reasoning competence. Instead, as predicted by mental models theory, it was related to a person's ability to generate alternative representations of premises: the more alternatives a person generated, the less likely they were (...) to show a belief bias effect. In contrast to belief effects, which were predicted by the number of alternatives generated, scores on logical reasoning tasks were predicted by an individual's understanding of the concept of logical necessity. These two mediating variables, ability to generate alternatives and understanding of logical necessity, were themselves predicted by similar variables, such as cognitive motivation and abstract reasoning ability. Our findings strongly support the mental models interpretation of the belief bias effect, and suggest that individual differences in this effect are associated with a specific ability to generate alternatives, rather than with a general logical competence. (shrink)

Prior research shows that reasoners' confidence is poorly calibrated (Shynkaruk & Thompson, 2006). The goal of the current experiment was to increase calibration in syllogistic reasoning by training reasoners on (a) the concept of logical necessity and (b) the idea that more than one representation of the premises may be possible. Training improved accuracy and was also effective in remedying some systematic misunderstandings about the task: those in the training condition were better at estimating their overall performance than those who (...) were untrained. However, training was less successful in helping reasoners to discriminate which items are most likely to cause them difficulties. In addition we explored other variables that may affect confidence and accuracy, such as the number of models required to represent the problem and whether or not the presented conclusion was necessitated by the premises, possible given the premises, or impossible given the premises. These variables had systematically different relationships to confidence and accuracy. Thus, we propose that confidence in reasoning judgements is analogous to confidence in memory retrievals, in that they are inferentially derived from cues that are not diagnostic in terms of accuracy. (shrink)

This article discusses how the words 'necessary' and 'analytic' are suitably used in philosophy. It is argued that analytic statements should not be called 'necessary'.