Richard Jeffrey and Michael Goldstein have both introduced systematic approaches to the structure of opinion changes. For both approaches there are theorems which indicate great generality and width of scope. The main questions addressed here will be to what extent the basic forms of representation are intertranslatable, and how we can conceive of such programs in general.

Gödel began to seriously study Husserl's phenomenology in 1959, and the Gödel Nachlass is known to contain many notes on Husserl. In this paper I describe what is presently known about Gödel's interest in phenomenology. Among other things, it appears that the 1963 supplement to “What is Cantor's Continuum Hypothesis?”, which contains Gödel's famous views on mathematical intuition, may have been influenced by Husserl. I then show how Gödel's views on mathematical intuition and objectivity can be readily interpreted in a phenomenological theory of intuition and mathematical knowledge.

This paper examines Wesley Salmon's “process” theory of causality, arguing in particular that there are four areas of inadequacy. These are that the theory is circular, that it is too vague at a crucial point, that statistical forks do not serve their intended purpose, and that Salmon has not adequately demonstrated that the theory avoids Hume's strictures about “hidden powers”. A new theory is suggested, based on “conserved quantities”, which fulfills Salmon's broad objectives, and which avoids the problems discussed.

Davidson's principle of the anomalousness of the mental was instrumental in discrediting once-popular versions of mind-brain reductionism. In this essay I argue that a novel account of intertheoretic reduction, which does not require the sort of cross-theoretic bridge laws that Davidson's principle rules out, allows a version of mind-brain reductionism which is immune from Davidson's challenge. In the final section, I address a second worry about reductionism, also based on Davidson's principle, that survives this response. I argue that new reductionists should revise some significant details of the program, particularly the conception of theories, to circumvent this more potent Davidson-inspired worry.

Scientific realists contend that theory-conjunction presents a problem for empiricist conceptions of scientific knowledge and practice. Van Fraassen (1980) has offered a competing account of theory-conjunction which I argue fails to capture the mercenary character of epistemic dependence in science. Representative cases of theory-conjunction developed in the present paper show that mercenary reliance implies a “principle of epistemic symmetry” which only a realist can consistently accommodate. Finally, because the practice in question involves the conjunction of theories, a version of realism more robust than the “entity realism” of Cartwright (1983, 1989) and Hacking (1983) is required to explain the success of theory-conjunction.

My purpose here is to elaborate the reasons I maintain that Salmon has not been completely successful in reporting the history of work on explanation. The most important limitation of his account is that it does not emphasize the critical necessity to embrace a suitable conception of probability in the development of the theory of probabilistic explanation.

Some irrational numbers are “random” in a sense which implies that no algorithm can compute their decimal expansions to an arbitrarily high degree of accuracy. This feature of (most) irrational numbers has been claimed to be at the heart of the deterministic, but chaotic, behavior exhibited by many nonlinear dynamical systems. In this paper, a number of now classical chaotic systems are shown to remain chaotic when their domains are restricted to the computable real numbers, providing counterexamples to the above claim. More fundamentally, the randomness view of chaos is shown to be based upon a confusion between a chaotic function on a phase space and its numerical representation in R”.

Kary (1990) defends the view that evolution by natural selection can be adequately explained in terms of a theory incorporating only a single level of selection. Here I point out some of the inherent inadequacies of such a theory.

In his recent work, Michael Redhead (1986, 1987, 1989, 1990) has introduced a condition he calls robustness which, he argues, a relation must satisfy in order to be causal. He has used this condition to argue further that EPR-type correlations are neither the result of a direct causal connection between the correlated events, nor the result of a common cause associated with the source of the particle pairs which feature in these events. Andrew Elby (1992) has used this same condition as a premise in an independent argument for the conclusion that EPR-type correlations cannot be causally explained (except, perhaps, by a nonlocal hidden variable theory). I wish to argue here that robustness is itself too fragile a notion to support such conclusions.

In his article “The Concept of Observation in Science and Philosophy” (1982), Dudley Shapere argues for an analysis of what it is for an object to be directly observed (observable). He does so by presenting two contrasting ways of observing the center of the sun. However, his examples, which are probabilistic in nature, are at odds with his analysis, which is absolute. I argue that of the three features of the examples which could serve as the basis for the analysis only one—the amount of alteration to the information being transmitted—can plausibly do so. Having reworked Shapere's analysis on the basis of this feature, I show that the analysis still fails to provide a sufficient condition for observation.

Itamar Pitowsky's book (1989), published in the Springer-Verlag Lecture Notes in Physics series, brings together several extremely interesting component investigations concerning the foundations of quantum mechanics. All deal with issues of probability including, in one case, the relation of probability to logic. It is a significant contribution, offering both new, nontrivial mathematical results, and provocative philosophical remarks about their significance.

This is an important book: It is the most sustained defense of a minimalist conception of truth in print. It systematically deals with all of the usual objections to minimalist views of truth (redundancy theories and their ilk), in most cases providing devastating replies to them; and it contains interesting things to say about many issues that are or have been thought to be connected to the topic of truth. Its arguments are lucid and of high quality, and it is broad in scope. I recommend it with enthusiasm.