Methodological Foundations of Relativistic Mechanics by Spector Marshall, and: The Field Concept in Contemporary Science by Mendel Sachs, and: Philosophical Problems of Space and Time by Adolf Grünbaum (review)

BOOK REVIEWS 427 Methodological Foundations of Relativistic Mechanics. By MARSHALL SPECTOR. Notre Dame, Indiana: University of Notre Dame Press, 1972. Pp. 192. $10.95. The Field Concept in Contemporary Science. By MENDEL SAcHs. American Lecture Series, M. Farber, ed. Springfield, Illinois: Charles C. Thomas, 1973. Pp. 132. Philosophical Problems of Space and Time. Second, enlarged edition. By ADOLF GRUNBAUM. Boston Studies in the Philosophy of Science, Vol. XII, R. S. Cohen & M. W. Wartofsky, eds. Dordrecht and Boston: D. Reidel Publishing Company, 1973. Pp. 907. $17.90. The three titles listed above are recent works in the philosophy of science, similar in their addressing scientific topics that are somewhat esoteric for the ordinary philosopher and yet quite different in their levels of approach and degrees of sophistication. While none of the three offers a definitive solution to current problems in the philosophy of science, all are worthy of notice as providing useful background and for suggesting new insights that may help decide substantive issues within this discipline. In their editorial introduction to Griinbaum's work Robert Cohen and Marx Wartofsky agree that this is "one of the few major works in the philosophy of the natural sciences in this generation " and go on to praise the author for his admirable exemplification of the "Aristotelian devotion to the intimate and useful dependence of actual science and philosophical understanding ." (p. xiii) All three of the works under review show a deep awarenes of such mutual interdependence between science and philosophy, an awareness that was shared also by Thomas Aquinas when he had reached the peak of his intellectual career, and for this reason alone merit being called to the attention of readers of The Thomist. * * * Spector's analysis of relativistic mechanics is the work of a philosopher who is concerned with the methodological foundations of the special theory of relativity, who can and does employ sufficient mathematics to state his position unambiguously, and who is concerned to go beyond positivist interpretations of Einstein's special theory to suggest a conceptual understanding of that theory more sympathetic to realism. Unlike many popular expositions of special relativity, which concentrate on its kinematic aspects and treat such well-worn topics as simultaneity, light cones, world lines, and the four-dimensional manifold, Spector's work by-passes most of this material and focuses instead on the dynamical aspects of the special theory, paying particular attention to the changes induced in the concepts of force, mass, and energy in the transition from classical to relativistic dynamics. 4~8 BOOK REVIEWS The author is concerned exclusively with the special theory, mentioning Einstein's general theory only in passing. Spector's book may be roughly divided into three parts. The first deals with the methodological foundations of classical mechanics, with primary emphasis on dynamics and on delineating the paradigm this provides for mechanical explanation. The second part goes into the foundations of classical electrodynamics, introduces the concepts of frame of reference and Galilean transformation, and delineates the crisis situation that developed towards the end of the nineteenth century as proposed mechanical models of the ether proved unsatisfactory. The third part then explains how special relativity arose as a response to the crisis situation in classical mechanics and electrodynamics, and how Einstein's laws of mechanics differ from those of Newton, tracing the implications of this for understanding various force functions and the famous equation, E = mc2• Some of Spector's distinctive theses include the following: that F = ma represents the essential content of Newton's second law of motion, and that the first law of motion is actually a consequence of, and not a propadeutic to, the second law; that mechanical explanations in the classical sense are causal explanations made through the application of Newton's second law and particular force laws; that an element of conventionality enters into classical mechanics through the constraints that are placed on the kinds of force laws regarded as allowable; that the luminiferous ether was originally conceived to supply a mechanical explanation of light phenomena ; that the failure of the program to reduce electrodynamics to classical mechanics did not automatically entail the rejection of an ether, nor did it necessitate the identification of an ether...