A basic aim of E. Beth's work in philosophy of science was to explore the use of formal semantic methods in the analysis of physical theories. We hope to show that a general framework for Beth's semantic analysis is provided by the theory of semi-interpreted languages, introduced in a previous paper. After developing Beth's analysis of nonrelativistic physical theories in a more general form, we turn to the notion of the 'logic' of a physical theory. Here we prove a result (...) concerning the conditions under which semantic entailment in such a theory is finitary. We argue, finally, that Beth's approach provides a characterization of physical theory which is more faithful to current practice in foundational research in the sciences than the familiar picture of a partly interpreted axiomatic theory. (shrink)

Several paleontologists have recently challenged the explanatory adequacy of the modern synthetic theory of evolution. Their position is that, contrary to the prevailing view that evolutionary change is gradual, the fossil record manifests long periods of species stasis (equilibrium) punctuated by periods of rapid species formation. And, they argue, this punctuated equilibria pattern challenges the gradualist, adaptationist and extrapolationist assumptions of the modern synthetic theory of evolution and supports a hierarchical, non-extrapolationist (non-reductionist) view of evolution. In this paper I argue (...) that the challenge rests on an inadequate characterization of the modern synthetic theory and that, even accepting punctuated equilibria and an irreducible evolutionary hierarchy, the modern synthetic theory is adequate to explain evolutionary change at all levels of the hierarchy. (shrink)

Achinstein, Putnam, and others have urged the rejection of the received view on theories (which construes theories as axiomatic calculi where theoretical terms are given partial observational interpretations by correspondence rules) because (i) the notion of partial interpretation cannot be given precise formulation, and (ii) the observational-theoretical distinction cannot be drawn satisfactorily. I try to show that these are the wrong reasons for rejecting the received view since (i) is false and it is virtually impossible to demonstrate the truth of (...) (ii). Nonetheless, the received view should be rejected because it obscures a number of epistemologically important features of scientific theorizing. I show this by sketching an alternative analysis which reveals some of these features and gives a more faithful picture of scientific theorizing. (shrink)

The question of the levels at which natural selection can be said to operate is much discussed by biologists today and is a key factor in the recent controversy about sociobiology. It is shown that this problem is one to which Charles Darwin addressed himself at some length. It is argued that apart from some slight equivocation over man, Darwin opted firmly for hypotheses supposing selection always to work at the level of the individual rather than the group. However, natural (...) selection's co-discoverer, Alfred Russel Wallace, endorsed group selection hypotheses. (shrink)

When natural selection theory was presented, much active philosophical debate, in which Darwin himself participated, centered on its hypothetical nature, its explanatory power, and Darwin's methodology. Upon first examination, Darwin's support of his theory seems to consist of a set of claims pertaining to various aspects of explanatory success. I analyze the support of his method and theory given in the Origin of Species and private correspondence, and conclude that an interpretation focusing on the explanatory strengths of natural selection theory (...) accurately reflects neither Darwin's own self-consciously held views, nor the nature of his support. Darwin's methodological and philosophical arguments were at once consistently empiricist and more sophisticated than such interpretations credit to him. (shrink)

A precise formulation of the structure of modern evolutionary theory has proved elusive. In this paper, I introduce and develop a formal approach to the structure of population genetics, evolutionary theory's most developed sub-theory. Under the semantic approach, used as a framework in this paper, presenting a theory consists in presenting a related family of models. I offer general guidelines and examples for the classification of population genetics models; the defining features of the models are taken to be their state (...) spaces, parameters, and laws. The suggestions regarding the various aspects of the characterization of population genetics models provide an outline for further detailed research. (shrink)