Completeness in Science by Richard Schlegel (review)

BOOK REVIEWS of action leads to terror and constitutes a dangerous threat to human dignity." This is also why the Soviets make no pretence at liking Dupre's view of" Marx the existentialist" (cf. V. V. Lazarev, "Ekzistenvialistskaja koncepcija celoveka v SsA," in Voprosy filosofii No.3, [1967], pp. 160-169). Professor Dupre's book is an indispensable prolegomenon for the understanding of contemporary Marxism and Marxism-Leninism. It could be profitably followed up by Richard T. DeGeorge's Patterns of Soviet Thought (University of Michigan Press, 1966) and the publications of the Institute of East-European Studies, which specializes in dealing with what Marx has become in the form of contemporary Soviet philosophy. THOMAS J. BLAKELEY Boston College Cheatnut Hill, Mass. Completeness in Science. By Richard Schlegel. New York: AppletonCentury -Crofts, 1967. Pp. ~80. $7.50. Richard Schlegel has investigated the notion and the possibility of completeness in science. His work is especially valuable for distinguishing the various types of completeness. Our description of nature can never be complete because of the countless facts that can be discovered, and also because we could never hope to completely describe every act of description (i. e., we always need another new description to describe the present act of description-and this leads to an infinity of descriptions). Scientific explanations are likewise incomplete for two reasons: any given theory is concerned only with a limited aspect of the universe, and any theory must begin with certain assumptions unexplainable within the theory. The most obvious example of incompleteness arises from quantum mechanics; the Uncertainty Principle is a statement of the limitations on our knowledge of subatomic phenomena. It is quite generally agreed that the physicist is unable to gather a complete description of these microparticles due to the fact that the very act of measurement alters the properties of the particles. Schlegel draws an analogy between: (1) the scientist's inability to describe his own descriptive acts; (~) the indecisiveness (incompleteness) stated in Gi:idel's Theorem; (3) the loss by atomiclevel entities of properties that may be described in macroscopic physics. There is also a section discussing possible completeness in cosmology. I think that Schlegel's attempt to give a complet6 analysis of completeness leads to some rather meaningless conclusions. This is especially true of his discussion of complete descriptions. Common sense tell us that it is impossible to describe every property of every single atom and particle in BOOK REVIEWS 528 the universe; no detailed philosophical discussion is needed to know this. The book would have been more profitable had Schlegel investigated in greater detail generalized descriptions (e. g., "all sodium atoms in the unexcited state have eleven electrons ") ; generalization always gives us a degree of completeness. A complete description might imply an enumeration of all properties of a particular entity, or it might be a statement valid for all the entities of a similar nature. It is these latter generalized statements which are the usual material of a science, and it is only here that we need look for any complete descriptions. This weakness is totally overshadowed by Schlegel's excellent treatment of incompleteness in quantum theory. He very clearly exposes the allimportant role of the observer in quantum measurements. The reader must be familiar with the concepts of quantum mechanics in order to follow this section, but there is no need for a special competency in the mathematics. There can be no doubt that science gives us an incomplete knowledge of nature. The lesson of Schlegel's book is that we should look to other, non-scientific, types of knowledge in order to learni more. In our scientific age we tend to think that, if we wait long enough, some scientist will find the answer. Schlegel reminds us that the non-scientists should also give some answers. Dominican House of Studies Waakington, D. C. JoRDAN FINAN, 0. P. The Domain of Logic According to Saint Thomas Aquinas. By Robert W. Schmidt, S. J. The Hague: Martinus Nijho:ff, 1967. Pp. 368 with bibliography and index. 4ii! guilders. The precise subject of Logic has been problematic since the era of Aristotle, its recognized founder. Attempts at the solution of this multidimensioned...