Between the Manifest and the Scientific Image

Jul 7, 2001 - reviewed by A. Truman Schwartz. It is safe to assert that most chemists are not given to philosophical speculation. We are a pretty prag...
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Chemical Education Today

Book & Media Reviews Philosophy of Chemistry: Between the Manifest and the Scientific Image by J. van Brakel Leuven University Press: Leuven, Belgium, 2000. xiv + 246 pp. ISBN 90-5867-063-5. 700 BEF (17.35 eu). reviewed by A. Truman Schwartz

It is safe to assert that most chemists are not given to philosophical speculation. We are a pretty pragmatic bunch, and our pragmatism has proved to be fruitful. Physicists deal with the ultimate nature of matter and the origin of the universe. Biologists contemplate questions such as “what is life and how did it begin?” Chemists make paradichlorobenzene and drip-dry shirts. Not many of us ponder the ontological status of the compound we’re trying to synthesize or the epistemological assumptions inherent in the computer program we’re using to model molecular structure. Therefore, one might expect a book entitled Philosophy of Chemistry to be a slim volume. To be sure, the work at hand contains only 200 pages of text, but it is pretty concentrated stuff, with almost 500 footnotes and 31 closely packed pages of references. That’s not bad for a subdiscipline that, according to the author, didn’t really begin until 1994. If nothing else, this avalanche of information certainly appears to contradict the statement that van Brakel quotes from a physicist named Dingle: “Chemistry rightly figures prominently in the history of science; in the philosophy of science it should not figure at all.” van Brakel’s book consists of eight rather disparate chapters, many of them based on the author’s previously published papers. They are of varying interest and accessibility to a chemist. Chapter 1 provides an instructive overview of the emergence of the philosophy of chemistry, from Aristotle to modern times. Interestingly, the German Democratic Republic and other parts of the old Soviet block provided fertile soil for the flourishing of the subdiscipline. One of the more amusing features of this chapter is an account of the supposed ideological conflict between resonance theory and dialectical materialism. Chapters 2 and 6 provide heavy doses of philosophical terminology and arguments. I found them tough going and not essential for grasping the author’s central thesis. In stark contrast to all this philosophy, Chapter 6 also contains a technical analysis of various models for a wetting liquid advancing in a packed bed of rounded particles. The following chapter is even more technical—a detailed treatment of modeling in chemical engineering that emphasizes dimensional analysis. The connections between this topic and the rest of the book seem tenuous at best. I concluded that van Brakel, whose professional affiliation is not indicated, must have started his career as a chemical engineer with an interest in mass transport and capillary flow. To me, the most interesting parts of this book are Chapters 3, Chemical Substances; 4, Essentialistic Realism; and 5, The Alleged Reduction of Chemistry. At issue here is the validity of Dirac’s famous statement of 1929: The underlying laws necessary for the mathematical theory of a large part of physics and the whole of chem878

istry are thus completely known, and the difficulty is only that exact applications of these laws lead to equations which are too complicated to be soluble.

Those of us who like to mess around with matter have taken some solace in the second half of this sentence, but we are worried that modern computers are reducing the difficulty at an alarming rate. As a philosopher, van Brakel is concerned with the correctness of the first half of Dirac’s pronouncement. He musters philosophical and chemical evidence and arguments, supplemented with common sense, to conclude that chemistry is in fact not ultimately reducible to physics. For example, he points out that quantum mechanical calculations must be guided by chemical experience and intuition in order to achieve congruence with experimental observations. van Brakel also devotes considerable attention to the related issue of what he calls manifest images, substances, and properties and their scientific counterparts. Manifest water is defined by its familiar macroscopic properties—density, boiling point, viscosity, etc. Scientific water encompasses microscopic properties such as molecular structure and shape and submicroscopic concepts including molecular orbitals. The author very sensibly concludes that “scientific practice is involved in a co-production of macroscopic and manifest observables and ‘theoretical’ interpretations, models, and their intercalations.” However, if a choice must be made, van Brakel opts for the primacy of the manifest over scientific abstraction. In the reality game, ordinary wet water trumps an sp3 hybrid. The history and current practice of chemistry are largely based on operational definitions, phenomenological classification, and empirical methods. For these reasons, I suspect that most chemists will agree with van Brakel’s conclusion. For the same reasons, I suspect that reading Philosophy of Chemistry will have no influence whatsoever on how any chemist does his or her work. Nevertheless, the author does raise many interesting points about our discipline. For example, I now have a better appreciation of the complexity and ambiguity implicit in the deceptively simple statement, “water is H2O”; and I enjoyed the section examining the fascinating case of polywater—the water that wasn’t. The book has things to offer to both chemists and philosophers, as well as the small fraternity of chemical philosophers. van Brakel writes with a light informal touch, and when the philosophical concepts and terms get particularly dense, he often rescues the reader with a witty or commonsensical aside. Comprehensibility is enhanced by 65 “blocks” scattered throughout the text, which serve as extended notes and sometimes contain relevant quotations or definitions. I did not read with an eye for errors, typographical or otherwise, but I did note that F. Hund’s name is spelled Hundt on page 119. The philosophy of chemistry is a small but growing cottage industry. Because of this book’s narrow focus, it does not provide a comprehensive introduction to the field. What it does offer is a way to introduce a little speculation into that long tradition of pragmatism. A. Truman Schwartz is in the Department of Chemistry, Macalester College, Saint Paul, MN 55125; schwartz@ macalester.edu.

Journal of Chemical Education • Vol. 78 No. 7 July 2001 • JChemEd.chem.wisc.edu