The Nature of Science and Other Essays by David Greenwood (review)

BOOK REVIEWS 671 The Nature of Science and Other Essays. By DAVID GREENWOOD. New York, Philosophical Library, 1959. Pp. xiii + 95, with index. $3.75. A current of analytical philosophy that has contributed heavily to the development of American ' scientific philosophy ' is that deriving from England through interest in linguistic analysis. The present volume is not completely representative of the British analytical movement, but it does contain several essays that will be of particular interest to Thomists. The first essay, from which the book takes its title, is refreshing in that the author does not make science the unique pathway to knowledge but allows for an independent approach on the part of the philosopher. In so doing, he reverts to the Greek concept of science as including both philosophy and science. Greenwood admits that it is difficult " to draw the dividing line exactly " between philosophy and science, and prefers to distinguish on the basis of method rather than . subject matter: " Both begin with phenomena which are sensibly observable, since all knowledge has its origin in sense perception. But the method of philosophy is to proceed from the observable phenomena to the real causes which underlie the phenomena, while the method of science is to proceed from the observable phenomena to a formula expressing a regular order in the occurrences of the phenomena, and eventually, through the application of this formula, to the prediction of future phenomena." (p. 2) The major part of the essay is concerned with a logical analysis of the nature of scientific method thus understood, and particularly with the problem of induction. He sees philosophical realism as supplying the ontological background against which logical analysis becomes meaningful: " The phenomena which the natural sciences study and the order which they discover among these phenomena have real causes, namely the essences which are manifested through the phenomena. The mathematical formulae and laws of the natural sciences do not express these essences, but they derive their validity from them. This view of the function of theories and laws in the natural sciences saves modern physics from the charge that it is not directly concerned with the real world at all. . . . The mathematical formulae of science are logical beings but the phenomena are real beings. Without this foundation in reality, no scientific prediction of events in the real order would be of any value" (p. 14) . The second paper, entitled "Concept Formation and Operational Definition ," continues the theme of the first essay. Greenwood is impatient with the view that quantitative or operational concepts are the only ones that are strictly scientific, and takes the position that even in the discourse of the scientist, classificatory and comparative concepts retain their fundamental importance without detracting in any way from the advantages of quantitative treatment (p. 19). He is also outspoken in his criticism of 672 BOOK REVIEWS Bridgman's attempt to describe concept formation in terms of operational analysis (p. flfl). Still he does allow for the utility of operationalism and even of conventionalism for clarifying the terminology of modern science, so that it need not be " encumbered by the consideration of preserving the prescientific use of conventional terms taken over into its vocabulary." (p. 31). Following these essays of a general, philosophical nature, are three papers, considerably more technical, in which Greenwood applies his ideas to particular difficulties in the philosophy of science. The most interesting of the three papers, from a Thomistic viewpoint, is the one entitled " Causality and the Counterfactual Conditional." Here Greenwood argues with telling force against the Humean concept of causality. His own conviction is that " the subjective postulate prejudices the whole issue as to the reality of causes before examination of the question even commences" (p. 51). He sees the linguistic representation of causality as bound up with the problem of counterfactual conditionals, and regards the work of Lewis, Quine and Reichenbach as having contributed towards its elucidation, although he is most impressed by the modal method of Burks. " It would seem that the infant procedures of modal logic have much to offer in the clarification of problems of causality for the future. . . . To define 'cause,' 'causality,' 'causal law,' etc., comprehensively, the formulation of both the deductive...