This paper examines the “causal theory of reference”, according to which science aims at the discovery of “essences” which are the objects of reference of natural kind terms (among others). This theory has been advanced as an alternative to traditional views of “meaning”, on which a number of philosophical accounts of science have relied, and which have been criticized earlier by the present author. However, this newer theory of reference is shown to be equally subject to fatal internal difficulties, and to be incompatible with actual science as well. Indeed, it rests on assumptions which it shares with the purportedly opposing theory of meaning. Behind those common assumptions is the supposition that the nature of science can be illuminated by an examination of alleged necessities of language which are independent of the results and methods of scientific inquiry. An alternative view of science is proposed, according to which the goals and language of science develop as integral parts of the process of demarcating science from non-science, a process in which the notion of a “reason” gradually assumes a decisive role. On this view, the comparability, competition, and development of scientific ideas are understood without reliance on either common “meanings” or common “references” as fundamental tools of analysis.

The aim of this paper is to describe a methodology for revising logical principles in the light of empirical psychological findings. Historical philosophy of science and wide reflective equilibrium in ethics are considered as providing possible models for arguing from the descriptive to the normative. Neither is adequate for the psychology/logic case, and a new model is constructed, employing criteria for evaluating inferential systems. Once we have such criteria, the notion of reflective equilibrium becomes redundant.

Bell's Theorem is proved for locality and conservation formulated in terms of subjunctive conditionals with chance consequents, rather than the usual conditional probability formulation. This brings into sharp focus the minimal counterfactual assumptions needed for Bell's theorem.

This paper discusses different interpretations of probability in relation to determinism. It is argued that both objective and subjective views on probability can be compatible with deterministic as well as indeterministic situations. The possibility of a conceptual independence between probability and determinism is argued to hold on a general level. The subsequent philosophical analysis of recent advances in classical statistical mechanics (ergodic theory) is of independent interest, but also adds weight to the claim that it is possible to justify an objective interpretation of probabilities in a theory having as a basis the paradigmatically deterministic theory of classical mechanics.

Essentialism—understood as the doctrine that there are natural kinds—can be sustained with respect to the most fundamental physical entities of the world, as I elsewhere argue. In this paper I take up the question of the existence of natural kinds among complex structures built out of these elementary ones. I consider a number of objections to essentialism, in particular Locke's puzzle about the existence of borderline cases. A number of recent attempts to justify biological taxonomy are critically examined. I conclude that theory partially justifies such taxonomies but supports only a weaker form of essentialism.

Many have claimed that split-brain patients are actually two persons. I maintain that both the traditional separation argument and the more recent sophistication argument for the two persons interpretation are inadequate on conceptual grounds. An autonomy argument is inadequate on empirical grounds. Overall, theoretical and practical consequences weigh heavily in favor of adopting a one person interpretation.

Standard accounts of the micro-reduction of phenomenological to kinetic thermostatics, based on the postulate relating empirical absolute temperature to mean kinetic energy (ū = (3/2)kT), face two problems. The standard postulate also allows ‘reduction’ in the other direction and it can be criticized from the point of view that reduction postulates need to be ontological identities.

This paper presents a detailed account of the reduction, based on the postulate that thermal equilibrium is ontologically identical to having equal mean kinetic energy. In particular, it is shown that this postulate enables reduction only in the appropriate direction, but leaves room for ‘evidence transport’ in the other. Moreover, it makes possible the derivation (explanation) of the standard postulate, using the existential kinetic hypothesis and phenomenological laws with which it turns out to be laden.

In a book and a series of articles (1977a, 1977b, 1977c, 1978) Harold I. Brown has presented “the new theory of science”, which he characterizes as a “modest historicism”. I propose to examine Brown's contribution to the current debate on scientific method, and to show the inadequacy of his proposals. In particular, I want to concentrate on a fundamental concern of Brown's, namely, rationality.

There is often substantial disparity between philosophical ideals and scientific practice. Philosophical reductionism is motivated by a drive for ontological austerity. The vehicle is conceptual parsimony: the fewer our conceptual primitives, the less are our ontological commitments. A general moral to be drawn from my “Functionalism and Reductionism” (1979) is that scientific reduction does not, and should not be expected to, facilitate conceptual economy; yet reduction it still is, and in the classical mold. Those who press for the irreducibility of a functional psychology have been seduced by an inadequate account of scientific reduction. Patricia Kitcher (1980) is unhappy with my argument because it fails to live up to her philosophical ideals. “The claim that psychology is irreducible to neurophysiology,” she suggests, “rests to a large extent on the fact that, even in principle, neurophysiology is not capable of carrying out the explanatory work of a functional psychology” (1980, p. 140).