The Rationality of Science by W. H. Newton-Smith (review)

478 BOOK REVIEWS The Rationality of Science. By W. H. NEWTON-SMrrH. Boston: International Library of Philosophy, 1981. Pp. 294. $19.50 cloth; $11.50 paper. The author's purpose in writing this book is "to vindicate a rationalist account of the scientific enterprise based on a realist construal of scientific theories" (19). His attempts at vindication are successful and admirably executed, but his attempt at establishing "a realist construal of scientific theories " is problematic. The weakness that surfaces in the latter undertaking -specifically, his failure to produce a realism that differs in any important sense from the blanket instrumentalism of Laudan, which he rejects-does not, however, invalidate his arguments for the rationality of science. I shall get back to this point later. The two poles of the enterprise in which Newton-Smith engages are described by him as " exciting " and " boring " attacks on the rationality of science. The exciting attacks are those launched by Kuhn and Feyerabend , the thrust of which is that science is nonrational in that shifts in the allegiance of the scientific community from one theory to another occur more as the result of psychological and sociological factors than as the result of factors pertaining to science and its goals. The boring attacks are those which maintain that science is indeed rational, but not so rational as the image it likes to project. Newton-Smith himself launches a boring attack, ending up with a view of science which he calls "temperate rationalism". The product is a thorough, rigorous, and sober picture of science. The book's most valuable contribution is its precise determination of the sense in which science is rational. In the course of his investigation, Newton-Smith offers his readers valuable assessments of the current leaders in the philosophy of science. The book itself is attractively designed; the print is clear and aesthetically pleasing; it has an extensive, up-to-date bibliography, and an index of subjects and proper names. I did not find any typographical errors. Although the writing is well organized and clear, Newton-Smith's habit of not using commas after introducing a sentence by a dependent clause left me initially confused more than once as to the sentence's meaning. The thrust of his argument comes down to this: It is obvious that science has been making steady progress. From Copernicus to Newton to Einstein, science has gained an increasing predictive power; but increasing predictive power means an increasing correspondence between the theories and the world; this increasing correspondence means that the truth-content of the theories is increasing. The central concept in New- BOOK REVIEWS 479 ton-Smith's argument is accordingly the theory of verisimilitude. He does not wish to argue, however, that science is getting more truth but instead that it is obtaining "increasing verisimilitude ", by which he means an increasing approximation to truth (38 and 221). His distinction between "verisimilitude" and "increasing verisimilitude" reflects his view that no one has yet come up with an acceptable set of criteria for determining verisimilitude (260). That agnosticism will return to haunt him, as it is intimately bound up with " the realist construal of scientific theories " which he insists is part and parcel of the defense of science's rationality . At all events, Newton-Smith insists that the shift in theories that occurs as science increases its predictive power testifies to the rationality of scientific change. For it is absurd to suppose that science has for its primary goal anything other than the truth; and since it is the promise of increasing predictive power that makes theory T2 more appealing than theory Tl, it is only reasonable to hold that the change in theories which occurs as science progTesses is rationally motivated. As Newton-Smith himself acknowledges, that argument in itself is not enough to answer the specific objections of nonrationalists such as Kuhn and Feyerabend. In his Structure of Scientific Revolutions, Kuhn advanced the thesis that science as it is practiced in any given era, is dominated by a paradigm which not only determines what good science is but confers meaning on the terms that comprise scientific theories. The paradigm is taken for granted until a theory...