Abstract

Part three attempts to analyze a number of key concepts in the modern synthetic theory in light of the preceding historical and methodological investigations. The concepts of adaptation and progress have proven particulary recalcitrant to conceptual explication by biologists and philosophers interested in the synthetic theory. It is argued that neither notion poses any difficulties for scientific use in the modern synthetic theory once they have been correctly defined and understood. ;Part Two is devoted primarily to an analysis of some standard methodological issues in the philosophy of science concerning scientific theories. After presenting a brief synopsis of the assumptions and premises of the modern theory, an attempt is made to illuminate the structure of the theory as well as the nature of the laws and explanations invoked on the basis of the theory. Special attention is directed toward understanding the nature of the 'synthesis' that has been achieved by contemporary evolutionary biologists. It is also claimed that the comparative method, which plays a dominant role in the thinking of many biologists engaged in research in evolutionary biology, raises no special difficulties for standard philosophical conceptions of the nature of laws and explanations in science. ;The discussion in this essay is divided into three parts. Part one is devoted to an analysis of the historical development of evolutionary theory. The changes and modifications that have occurred in evolutionary biology from Darwin's day to the present are highlighted with an eye toward demonstrating the incorrectness of the view that it is impossible to test evolutionary theories. The discussion will show, not only is it possible to test Darwinian theory, but, at various times, many biologists felt that Darwinian theory had been shown to be false. An attempt is also made to illustrate the logical character of the explanations and laws proferred by early evolutionists as well as to give some substance to the concept of 'synthesis' which is so frequently invoked by evolutionary biologists in discussing their theory