The goal of evolutionary theory is to (a) specify the general causal structure of evolving systems and (b) analyze evolutionary consequences that are expected to result from the proposed structure of the model systems. Biologists frequently emphasize the hypothetico-deductive method in evolutionary theory. I will show that this method primarily provides a tactical device for (b), while evolutionary synthesis requires a foundation of a unifying conceptual model for (a). Therefore, any successful strategy for a new synthesis requires both a new conceptual insight of evolving systems, and tactical devices for analyzing new specific aspects of the evolutionary process.

In his The Foundations of Psychoanalysis (1984) Grünbaum compliments Freud on the development of the Tally Argument as an answer to a number of serious methodological criticisms, “The epistemological considerations that prompted Freud to enunciate (this argument) make him a sophisticated methodologist” (p. 128). In contrast to this position I argue that the Tally Argument and the considerations for it are hardly sophisticated: They would equally well go to demonstrate the methodological sophistication of modern-day evangelists. Furthermore, I argue that the Tally Argument does not play the crucial role that Grünbaum assigns to it. It is one of many arguments Freud used to counter criticism, but not one to which Freud gave pride of place.

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.

Figuring prominently in their decisions regarding which theories to pursue are scientists' appeals to the promise or lack of promise of those theories. Yet philosophy of science has had little to say about how one is to assess theory promise. This essay identifies several indices that might be consulted to determine whether or not a theory is promising and worthy of pursuit. Various historical examples of appeals to such indices are introduced.

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”.

The fundamental problem of what is explained in science should be considered and clarified since it determines the way of solving the problem of how something is explained as well as the entire view of explanation. In the first section after the introduction, Hempel's models of explanation are criticized for their narrow concern with logical reconstruction. In the next section a broader epistemological approach to explanation is presented, and in the last section an historical example of Newtonian explanation as epistemic activity is discussed.

The work of Tversky, Kahneman and others suggests that people often make use of cognitive heuristics such as availability, salience and representativeness in their reasoning and decision making. Through use of a historical example—the recent plate tectonics revolution in geology—I argue that such heuristics play a crucial role in scientific decision making also. I suggest how these heuristics are to be considered, along with noncognitive factors (such as motivation and social structures) when drawing historical and epistemological conclusions. The normative perspective is community-wide, contextual, and instrumental.

We examine two approaches to functions: etiological and forward-looking. In the context of functions, we raise the question, familiar to philosophers of mind, about the explanatory role of properties that are not supervenient on the mere dispositional features of a system. We first argue that the question has no easy answer in either of the two approaches. We then draw a parallel between functions and goal directedness. We conclude by proposing an answer to the question: The explanatory importance of nonsupervenient properties (like having the function of doing something, or like being goal-directed) does not lie in any special causal mechanism through which these properties bring about their effects; it lies rather in the different classification of the explananda types that these properties generate.

This is an essay in the Bayesian theory of how opinions should be revised over time. It begins with a discussion of the principle that van Fraassen has dubbed “Reflection”. This principle is not a requirement of rationality; a diachronic Dutch argument, that purports to show the contrary, is fallacious. But under suitable conditions, it is irrational to actually implement shifts in probability that violate Reflection. Conditionalization and probability kinematics are special cases of the principle not to implement shifts that violate Reflection; hence these principles are also requirements of rationality under suitable conditions, though not universal requirements of rationality.

Naturalism implies unity of method—an application of the methods of science to the methodology of science itself and to value theory. Epistemological naturalists have tried to find a privileged discipline to be the methodological model of philosophy of science and epistemology. However, since science itself is not unitary, the use of one science as a model amounts to a reduction and distorts the philosophy of science just as badly as traditional philosophy of science distorted science, despite the fact that the central theme of naturalized philosophy of science is that methodology should be true to science as practiced. I argue that naturalized philosophy of science must apply a plurality of methods to epistemological issues.

In his important paper “1953 and All That: A Tale of Two Sciences” (1984), Philip Kitcher defends biological antireductionism, arguing that the division of biology into subfields such as classical and molecular genetics is “not simply … a temporary feature of our science stemming from our cognitive imperfections but [is] the reflection of levels of organization in nature” (p. 371). In a recent discussion of Kitcher's views, Alexander Rosenberg has argued, first, that Kitcher has shown that the reduction of classical to molecular genetics is impossible only because of our intellectual limitations and, second, that this kind of antireductionism supports an instrumentalist approach to biological theory. I argue that both of Rosenberg's claims should be rejected despite the fact that Kitcher misdiagnoses the central reason for the failure of reduction.

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.

This paper takes up the cause of species pluralism. An argument for species pluralism is provided and standard monist objections to pluralism are answered. A new form of species pluralism is developed and shown to be an improvement over previous forms. This paper also offers a general foundation on which to base a pluralistic approach to biological classification.

Various claims have been made, recently, that Darwin's argumentation in the Origin instantiates and so supports some general philosophical proposal about scientific theorizing, for example, the “semantic view”. But these claims are grounded in various incorrect analyses of that argumentation. A summary is given here of an analysis defended at greater length in several papers by the present author. The historical and philosophical advantages of this analysis are explained briefly. Darwin's argument comprises three distinct evidential cases on behalf of natural selection, cases, that is, for its existence, its adequacy and its responsibility. Theorizing, today, about evolution by natural selection involves a similar structure of evidential and explanatory concerns.

Brandon ([1982] 1984, 1990) has argued that Salmon's (1971) concept of screening-off can be used to characterize (i) the idea that natural selection acts directly on an organism's phenotype, only indirectly on its genotype, and (ii) the biological problem of the levels of selection. Brandon also suggests (iii) that screening-off events in a causal chain are better explanations than the events they screen off. This paper critically evaluates Brandon's proposals.

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.

Kincaid argues that molecular biology provides little support for the reductionist program, that biochemistry does not reveal common mechanisms, indeed that biochemical theory obstructs discovery. These assertions clash with biologists' stated advocacy of reductionist programs and their claims about the consequent unity of experimental biology. This striking disagreement goes beyond differences in meaning granted to the terms. More significant is Kincaid's misunderstanding of what biochemists do, for a closer look at scientific practice— and one of Kincaid's examples—reveals substantial progress toward explaining biological function with biochemical models. With the molecular detail emerge unifying generalizations as well as further aspects of the functional processes.

The main goal of this book, The Structure and Confirmation of Evolutionary Theory (Lloyd 1988), “is to introduce, develop, and demonstrate the usefulness of a precise analysis of the structure of evolutionary theory” (p. 23), an analysis that treats evolutionary theory as built up out of complexly interrelated mathematical models. The book has a second goal as well, namely, “to offer … evidence of the appropriateness and utility of the semantic view of scientific theories” (ibid.). The appropriate audience for the book is not obvious. It is well suited for graduate courses in philosophy of biology, though it demands substantial knowledge of both disciplines. Lloyd has attempted to make it accessible to wider biological and philosophical audiences by minimizing the technical treatment of mathematical models, but I doubt that she has succeeded in making the book accessible to those unfamiliar with the models of population genetics or to biologists previously unversed in the philosophy of science.

Roger Jones asks what Newtonian realists should be realists about, given that there are four empirically equivalent formulations of Newtonian mechanics which have different ontological commitments and explanatory mechanisms. A realist answer is sketched: Newtonians should be realists about what the best metaphysical considerations dictate, where the best metaphysical considerations are those which have yielded the best physics. Metaphysical considerations are required within physics, just as they are required to eliminate idealist and surrealist theories which are empirically equivalent to realist ones. Realists must reject the positivist assumption that empirically equivalent theories are explanatory and evidential equivalents, too.