The main puzzle about theoretical definitions is that nothing seems to decide which assumptions contribute to such definitions and which do not. I argue that theoretical definitions are indeed imprecise, but that this does not normally matter, since the definitional imprecision does not normally produce indeterminacy of referential value. Sometimes, however, the definitional imprecision is less benign, and does generate referential indeterminacy. In these special cases, but not otherwise, it is necessary to refine the term's definition.

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.

In this paper we first briefly review Bell's (1964, 1966) Theorem to see how it invalidates any deterministic “hidden variable” account of the apparent indeterminacy of quantum mechanics (QM). Then we show that quantum uncertainty, at the level of DNA mutations, can “percolate” up to have major populational effects. Interesting as this point may be it does not show any autonomous indeterminism of the evolutionary process. In the next two sections we investigate drift and natural selection as the locus of autonomous biological indeterminacy. Here we conclude that the population-level indeterminacy of natural selection and drift are ultimately based on the assumption of a fundamental indeterminacy at the level of the lives and deaths of individual organisms. The following section examines this assumption and defends it from the determinists' attack. Then we show that, even if one rejects the assumption, there is still an important reason why one might think evolutionary theory (ET) is autonomously indeterministic. In the concluding section we contrast the arguments we have mounted against a deterministic hidden variable account of ET with the proof of the impossibility of such an account of QM.

This paper argues that there are powerful similarities between cognitive development in children and scientific theory change. These similarities are best explained by postulating an underlying abstract set of rules and representations that underwrite both types of cognitive abilities. In fact, science may be successful largely because it exploits powerful and flexible cognitive devices that were designed by evolution to facilitate learning in young children. Both science and cognitive development involve abstract, coherent systems of entities and rules, theories. In both cases, theories provide predictions, explanations, and interpretations. In both, theories change in characteristic ways in response to counterevidence. These ideas are illustrated by an account of children's developing understanding of the mind.

While endorsing Gopnik's proposal that studies of the emergence and modification of scientific theories and studies of cognitive development in children are mutually illuminating, we offer a different picture of the beginning points of cognitive development from Gopnik's picture of “theories all the way down.” Human infants are endowed with several distinct core systems of knowledge which are theory-like in some, but not all, important ways. The existence of these core systems of knowledge has implications for the joint research program between philosophers and psychologists that Gopnik advocates and we endorse. A few lessons already gained from this program of research are sketched.

We propose that the generalizations of linguistic theory serve to ascribe beliefs to humans. Ordinary speakers would explicitly (and sincerely) deny having these rather esoteric beliefs about language—e.g., the belief that an anaphor must be bound in its governing category. Such ascriptions can also seem problematic in light of certain theoretical considerations having to do with concept possession, revisability, and so on. Nonetheless, we argue that ordinary speakers believe the propositions expressed by certain sentences of linguistic theory, and that linguistics can therefore teach us something about belief as well as language. Rather than insisting that ordinary speakers lack the linguistic beliefs in question, philosophers should try to show how these empirically motivated belief ascriptions can be correct. We argue that Stalnaker's (1984) “pragmatic” account—according to which beliefs are dispositions, and propositions are sets of possible worlds—does just this. Moreover, our construal of explanation in linguistics motivates (and helps provide) responses to two difficulties for the pragmatic account of belief: the phenomenon of opacity, and the so-called problem of deduction.

Darwinists classify biological traits either by their ancestry (homology) or by their adaptive role. Only the latter can provide traditional natural kinds, but only the former is practicable. Process structuralists exploit this embarrassment to argue for non-Darwinian classifications in terms of underlying developmental mechanisms. This new taxonomy will also explain phylogenetic inertia and developmental constraint. I argue that Darwinian homologies are natural kinds despite having historical essences and being spatio-temporally restricted. Furthermore, process structuralist explanations of biological form require an unwarranted assumption about the space of developmental possibility.

Plausibly, when we adopt a probabilistic standpoint any measure Cb(h, e) of the degree to which evidence e confirms (or is evidentially relevant to) hypothesis (or theory) h relative to background knowledge b should meet these five desiderata:

(1) Cb(h,e) > 0 when P(h/eb) > P(h/b; Cb(h,e) < 0 when P(h/eb) < P(h/b); Cb(h,e) = 0 when P(h/eb) = P(h/b).

(2) Cb(h,e) is some function of the values P(·/b) and P(·/·b) assume on the at most sixteen truth-functional combinations of e and h.

(3) If P(e/hb) < P(f/hb) and P(e/b) = P(f/b) then Cb(h,e) ≤ Cb(h,f); if P(e/hb) = P(f/hb) and P(e/b) < P(f/b) then Cb(h,e) ≥ Cb(h,f).

(4) Cb(h,ef) – Cb(h,eg) is fully determined by Cb(h,e) and Cbe(h,f) – Cbe(h,g); if Cb(h,ef) = 0 then Cb(h,e) + Cbe(h,f) = 0.

(5) If P(e/hb) = P(e/tb) then Cb(h,e) = Cb(t,e).

This paper examines the problem of founding irreversibility on reversible equations of motion from the point of view of the Brussels school's recent developments in the foundations of quantum statistical mechanics. A detailed critique of both their ‘subdynamics’ and ‘transformation’ theory is given. It is argued that the subdynamics approach involves a generalized form of ‘coarse-graining’ description, whereas, transformation theory cannot lead to truly irreversible processes pointing to a preferred direction of time. It is concluded that the Brussels school's conception of microscopic temporal irreversibility, as such, is tacitly assumed at the macroscopic level. Finally a logical argument is provided which shows, independently of the mathematical formalism of the theory concerned, that statistical reasoning alone is not sufficient to explain the arrow of time.

Alexander Rosenberg (1994) claims that the omniscient viewpoint of the evolutionary process would have no need for the concept of random drift. However, his argument fails to take into account all of the processes which are considered to be instances of random drift. A consideration of these processes shows that random drift is not eliminable even given a position of omniscience. Furthermore, Rosenberg must take these processes into account in order to support his claims that evolution is deterministic and that evolutionary biology is an instrumental science.

In this paper, I argue that accurate indexical representations have been crucial for the survival and reproduction of homo sapiens sapiens. Specifically, I want to suggest that reliable processes have been selected for because of their indirect, but close, connection to true belief during the Pleistocene hunter-gatherer period of our ancestral history. True beliefs are not heritable, reliable processes are heritable. Those reliable processes connected with reasoning take the form of Darwinian Algorithms: a plethora of specialized, domain-specific inference rules designed to solve specific, recurrent, adaptive problems in social exchange contexts. Humans do not reason logically, but adaptively.

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.

Child's play? Certainly Alison Gopnik is in good company in pointing to connections between science and child development. To mention just a few luminaries: in psychology, Freud (followed by Erikson and Piaget) looked at the developmental connection between children's play and adult work; in philosophy, Thomas Reid may have been the first to ground the faculty of reasoning in developmental stages that “unfold themselves by degrees; so that it [the child] is inspired with the various principles of common sense” (1764, V, 7). As for connecting commonsense reasoning and science, according to Einstein, “The whole of science is nothing more than a refinement of everyday thinking” (1954, 290). Quod erat demonstrandum.

Predictivism asserts that where evidence E confirms theory T, E provides stronger support for T when E is predicted on the basis of T and then confirmed than when E is known before T's construction and ‘used’, in some sense, in the construction of T. Among the most interesting attempts to argue that predictivism is a true thesis (under certain conditions) is that of Patrick Maher (1988, 1990, 1993). The purpose of this paper is to investigate the nature of predictivism using Maher's analysis as a starting point. I briefly summarize Maher's primary argument and expand upon it; I explore related issues pertaining to the causal structure of empirical domains and the logic of discovery.

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.

Cognitive scientists often employ the notion of innateness without defining it. The issue is, how is innateness defined in biology? Some critics contend that innateness is not a legitimate concept in biology. In this paper I will argue that it is. However, neither the concept of high heritability nor the concept of flat norm of reaction (two popular accounts in the biology literature) define innateness. An adequate account is found in developmental biology. I propose that innateness is best defined in terms of C. H. Waddington's concept of canalization.

My concern is with the possible implications of research in developmental psychology for understanding the workings of modern science. I agree both with Gopnik's general naturalistic orientation and with her more specific claims about scientists as cognitive agents. Neither the formal structure of propositions nor the social structure of scientific communities provides sufficient resources for the understanding we seek. So I agree that the empirical study of human cognition is not only relevant, but necessary, for understanding how science works (Giere 1988, 1989).

In order to judge whether a theory is empirically adequate one must have epistemic access to reliable records of past measurement results that can be compared against the predictions of the theory. Some formulations of quantum mechanics fail to satisfy this condition. The standard theory without the collapse postulate is an example. Bell's reading of Everett's relative-state formulation is another. Furthermore, there are formulations of quantum mechanics that only satisfy this condition for a special class of observers, formulations whose empirical adequacy could only be judged by an observer who records her measurement results in a special way. Bohm's theory is an example. It is possible to formulate hidden-variable theories that do not suffer from such a restriction, but these encounter other problems.