Confirmation is commonly identified with positive relevance, E being said to confirm H if and only if E increases the probability of H. Today, analyses of this general kind are usually Bayesian ones that take the relevant probabilities to be subjective. I argue that these subjective Bayesian analyses are irremediably flawed. In their place I propose a relevance analysis that makes confirmation objective and which, I show, avoids the flaws of the subjective analyses. What I am proposing is in some ways a return to Carnap's conception of confirmation, though there are also important differences between my analysis and his. My analysis includes new accounts of what evidence is and of the indexicality of confirmation claims. Finally, I defend my analysis against Achinstein's criticisms of the relevance concept of confirmation.

This paper argues against the possibility of presenting a consistent version of the Copenhagen Interpretation of Quantum Physics, characterizing its founders' philosophical pronouncements including those on the realism-antirealism issue, as a contingent collection of local, often contradictory, moves in changing theoretical and sociopolitical circumstances. The paper analyzes the fundamental differences of opinion between Bohr and the mathematical physicists, Heisenberg and Born, concerning the foundational doctrine of the “indispensability of classical concepts”, and their related disagreements on “quantum reality.” The paper concludes with an explanation of how the appearance of consensus was achieved despite fundamental disagreements among the proponents. The paper undermines the adequacy of the notion of a general conceptual framework to describe the philosophical endeavors of working scientists.

Aristotelian ideas are presented in a favorable light in Duhem's historical works surveying the history of the notion of chemical combination (1902) and the development of mechanics (1903). The importance Duhem was later to ascribe to Aristotelian ideas as reflected in the weight he attached to medieval science is well known. But the Aristotelian influence on his own mature philosophical perspective, and more particularly on his concern for logical coherence and the development of his ontological views, is not generally acknowledged. There are, however, clear pointers in this direction in these two earlier books on the history of science, which are unashamedly written in such a way as to project the author's own view of what is important in the relevant areas. Thermodynamics was the pinnacle of Duhemian science, and its interpretation requires the reinstatement, in Duhem's view, of Aristotelian conceptions which have been unfashionable since the rise of certain ideas with the scientific revolution of the seventeenth century.

The present paper is not primarily an exposition of these Aristotelian views of Duhem's, but an attempt to pursue the interpretation of a macroscopic, thermodynamical perspective on chemical substances from an elementary viewpoint in the spirit of Duhem (1902), sometimes being more definite than Duhem seems to be, and occasionally taking issue with him on certain points. Some of his leading ideas will determine the general approach, but views and problems will also be taken from modern textbooks in an attempt to lay down the general lines along which an explicit ontology—in Quine's sense—of macroscopic theory might be developed.

Recently, biologists and computer scientists who advocate the “strong thesis of artificial life” have argued that the distinction between life and nonlife is important and that certain computer software entities could be alive in the same sense as biological entities. These arguments have been challenged by Sober (1991). I address some of the questions about the rational reconstruction of biology that are suggested by these arguments: What is the relation between life and the “signs of life”? What work (if any) might the concept of “life” (over and above the “signs of life”) perform in biology? What turns on scientific disputes over the utility of this concept? To defend my answers to these questions, I compare “life” to certain other concepts used in science, and I examine historical episodes in which an entity's vitality was invoked to explain certain phenomena. I try to understand how these explanations could be illuminating even though they are not accompanied by any reductive definition of “life.”

Recent work in the Philosophy of Mind has suggested that alternatives to reduction are required in order to explain the relationship between psychology and biology or physics. Emergence has been proposed as one such alternative. In this paper, I propose a precise definition of emergence, and I argue that chaotic systems provide concrete examples of properties that meet this definition. In particular, I suggest that being in the basin of attraction of a strange attractor is an emergent property of any chaotic nonlinear dynamical system. This shows that non-reductive accounts of inter-theoretic relations are necessary, and that non-reductive accounts of the mental are possible. Moreover, this work provides a foundation for future work investigating the nature of explanation, prediction, and scientific understanding of non-reductive phenomena.

I analyze a number of widespread misconceptions concerning species. The species category, defined by a concept, denotes the rank of a species taxon in the Linnaean hierarchy. Biological species are reproducing isolated from each other, which protects the integrity of their genotypes. Degree of morphological difference is not an appropriate species definition. Unequal rates of evolution of different characters and lack of information on the mating potential of isolated populations are the major difficulties in the demarcation of species taxa.

Biographical studies have shown that visual mental imagery plays a significant role in the conduct of scientific research, particularly in the generation of hypotheses. But the nature of visual mental imagery and its participation in abductive inference is not systematically understood. This paper discusses examples of visual abductive reasoning by archaeologists, analyzing them according to the visual information and the process of inference employed. This work supports the conclusion that visual abduction is useful to scientists under certain conditions and that it is amenable to detailed study.

Paul Teller's (1995) new book, “An Interpretive Introduction to Quantum Field Theory”, is a pioneering work. To the best of our knowledge it is the first book by a philosopher devoted not only to explaining what quantum field theory (QFT) is, but to clarifying the conceptual issues and puzzles to which the theory gives rise (though Auyung 1995 treats some different issues in QFT). As such it is an important book, which we hope will greatly stimulate work in the area as other philosophers and physicists react to it.