Unexpected a posteriori necessary laws of nature

In this paper I argue that it is not a priori that all the laws of nature are contingent. I assume that the fundamental laws are contingent and show that some non-trivial, a posteriori, non-basic laws may nonetheless be necessary in the sense of having no counterinstances in any possible world. I consider a law L_S (such as ‘salt dissolves in water’) that concerns a substance S. Kripke's arguments concerning constitution show that the existence of S requires that a certain deeper level law or variants thereof hold. At the same time, that law and its variants may each entail the truth of L_S. Thus the existence of S entails L_S. Consequently there is no world in which S exists and fails to obey L_S. I consider the conditions concerning the fundamental laws that would make this phenomenon ubiquitous. I conclude with some consequences for metaphysics.     

Deflationism about the necessary a posteriori and Twin Earth

Some necessary truths are a posteriori. That’s widely agreed and is presumed here. Their existence might appear to show that discoveries about how things are in fact—about how things actually are—can lead to discoveries about all the ways things might be, about the nature of logical space. I detail one way of resisting this conclusion for a number of examples, and the implications of Twin Earth for the issue. Central is the notion of a Cambridge discovery.

     

Kripke's sole route to the necessary a posteriori

In ‘Kripke on epistemic and metaphysical possibility: two routes to the necessary a posteriori’, Scott Soames identifies two arguments for the existence of necessary a posteriori truths in Naming and Necessity (NN). He argues that Kripke's second argument relies on either of two principles, each of which leads to contradiction. He also claims that it has led to ‘two-dimensionalist’ approaches to the necessary a posteriori which are fundamentally at odds with the insights about meaning and modality expressed in NN. I argue that the alleged second argument is not in NN. I identify the mistakes that lead to Soames' misinterpretation.     

Authority as a contingency plan

Humean constructivists object to Kantian constructivism that by endorsing the constitutivist strategy, which grounds moral obligations in rational agency, this position discounts the impact of contingency in moral life. In response to these charges, I argue that Humeans misrepresent the challenge of contingency and fail to provide adequate resources to cope with it. In its formalist variety, Humean constructivism fails to make sense of an important category of ethical judgments, which claim universal authority. The substantive varieties of Humean constructivism recognize that some ethical judgments aspire to universality, but fail to fully justify such an aspiration. These versions of constructivism represent a setback in regard to the achievements of Kantian constructivism. In conclusion, I briefly resume the advantages of advocating a Kantian conception of rational authority as a response to contingency.     

On the a priori and a posteriori assessment of probabilities

We argue that in spite of their apparent dissimilarity, the methodologies employed in the a priori and a posteriori assessment of probabilities can both be justified by appeal to a single principle of inductive reasoning, viz., the principle of symmetry. The difference between these two methodologies consists in the way in which information about the single-trial probabilities in a repeatable chance process is extracted from the constraints imposed by this principle. In the case of a posteriori reasoning, these constraints inform the analysis by fixing an a posteriori determinant of the probabilities, whereas, in the case of a priori reasoning, they imply certain claims which then serve as the basis for subsequent probabilistic deductions. In a given context of inquiry, the particular form which a priori or a posteriori reason may take depends, in large part, on the strength of the underlying symmetry assumed: the stronger the symmetry, the more information can be acquired a priori and the less information about the long-run behavior of the process is needed for an a posteriori assessment of the probabilities. In the context of this framework, frequency-based reasoning emerges as a limiting case of a posteriori reasoning, and reasoning about simple games of chance, as a limiting case of a priori reasoning. Between these two extremes, both a priori and a posteriori reasoning can take a variety of intermediate forms.     

Semantics and truth relative to a world

This paper argues that relativity of truth to a world plays no significant role in empirical semantic theory, even as it is done in the model-theoretic tradition relying on intensional type theory. Some philosophical views of content provide an important notion of truth at a world, but they do not constrain the empirical domain of semantic theory in a way that makes this notion empirically significant. As an application of this conclusion, this paper shows that a potential motivation for relativism based on the relativity of truth to a world fails.     

Necessity and contingency

The paper considers the question of when the operator L of necessity in modal logic can be expressed in terms of the operator meaning it is non-contingent that.This paper was presented by title at the 1986 Annual Conference of the Australasian Association of Logic in Auckland, 9–12 July, 1986.     

Strategy changes in human contingency judgments as a function of contingency tables.

Judgment strategies of 169 undergraduate students on problems to judge the contingency between two binary events were identified by the method of rule-based analysis to clarify whether or not the strategies the subjects used would be affected by the concrete nature of the contingency table. Problems were constructed along two factors: total cell frequency and width of range of objective contingencies. Although the factor of total cell frequency had no effect on subjects' strategies, the number of subjects who changed strategies corresponding with problem instances increased when the objective contingencies were set closer to zero or when problems became more difficult. These results are discussed in the context of previous studies of this issue in the literature.     

Revisiting the relation between contingency awareness and attention: Evaluative conditioning relies on a contingency focus

Although evaluative conditioning has occasionally been demonstrated in the absence of contingency awareness, many recent studies imply that its acquisition depends on the availability of attentional resources during conditioning. In previous experiments attention has typically been manipulated in a general way rather than looking at the particular focus of attention. The present study investigated the role of a focus on the CS–US contingency. Two separate distraction tasks were designed that either diverted attention from the stimuli or directed it to the stimuli while drawing attention away from the contingency between the stimuli. Both types of distraction were shown to eliminate evaluative conditioning. Significant evaluative conditioning was observed in a third group of participants who were required to attend the contingencies. A mediation analysis showed that the observed discrepancy in evaluative conditioning effects between groups was mediated by contingency awareness. The results imply that attention in terms of a stimulus focus is not sufficient for evaluative conditioning to occur. Rather, attention to the contingencies between stimuli appears to be crucial in evaluative conditioning, because it is supposed to foster the acquisition of contingency awareness.