BOOK REVIEWS 265 On Understanding Science. By JAMES B. CoNANT. New Haven: Yale University Press, 1947. Pp. 157. $~.00. This book must not be considered another of the scientific works that have appeared since the atom bomb focussed public attention upon the rapid progress made in atomic physics. It is a professedly popular approach, written by a scientist and educator, to clarify for the layman the meaning of science and its method of development. Dr. Conant's purpose in understaking this work is the assimilation of a scientific spirit of knowledge into social and political life. When that has been accomplished, and when we no longer fear the discoveries of science, we shall have been led one step nearer to peaceful living. In the Author's own words (pp. ~. 3) : When what we now roughly designate as science has been fully assimilated into our cultural stream, we shall perhaps no longer use the word as we do today. When that time arrives, as I have no doubt it will, the subject of t!his book will be fused into the age-old problem of understanding man and his works: in short, secular education . . . My argument, therefore, runs as follows: we need a widespread understanding of science in this country, for only thus can science be assimilated into our secular cultural pattern. When that has been achieved, we shall be one step nearer the goal which we now desire so earnestly, a unified, coherent culture suitable for our American democracy in this new age of machines and experts. The immediate necessity of such an assimilation is found in the pressing problem of international control of atomic energy. Since national policy rests ultimately upon the people, and since a government should be guided by its citizens rather than by a handful of scientific experts, the people should have an understanding of science when faced with a future largely dependent upon the advance of science. The method of this work is by far its most interesting feature. For Dr. Conant, understanding science means understanding the advance of thinking in the field of science. Hence, understanding science does not mean understanding the contents of the physical sciences as much as understanding the evolution of scientific thinking. In order to clarify his point, and in order to avoid technicalities difficult to the layman, he adopts an historical explanation. He shows how scientific thinking proceeds by way of a dialectic, namely, the dissatisfaction with an old theory or hypothesis, the toying with an alternative, the investigation of the alternative under the compelling force of new data accidentally discovered or planned experimentally. He illustrates his history by three case histories: (1) the evolution of the water pump into the vacuum pump, involving entirely new concepts of the weight and resiliency of air; (~) the transition from Galvani's 'animal magnetism' to the Voltaic pile; (3) the overthrow of the ' Phlogisten ' theory of combustion. In this section, the book is especially interesting, written in a clear and limpid style. It flashes with 266 BOOK .REVIEW.,S·humor when Dr. Conant shows the historian's tendency to read into history and to score the scientist's natural reluctance to abandon an old theory. Of atomic physics, the author has little to say, since his purpose is to avoid technicalities rather than to investigate them. On this point, it is, perhaps, necessary to differ with the author. Taken in connection with other popular presentations of science, it has value as an exposition of specialized, scientific thinking. In itself, however, it adds little to man's information about science. The every term ' science ' connotes content-value, knowledge of things in their causes and principles, not merely a method of reasoning which, after all, is as common to the mechanic as to the scientist. If some of the scientists at work on the Manhattan Project have been able, successfully, to present a popular understanding of nuclear physics, surely this work, if it is to give an understanding of science, and if it is to contribute to the education of the ordinary layman in an atomic world, should have more of a content-value than three case histories. Furthermore, when the author includes in...