Facts or Fancies1 STEWART J . LLOYD University of Alabama, University, Alabama
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FEEL rather embarrassed after listening on Monday to all those interesting and profound papers on chemical thermodynamics. I feel rather embarrassed, I repeat, to be talking about so elementary a matter as the proper use of words, for that is what my small effort really amounts to. Some of you, however, have no doubt read Stuart Chase's entertaining little book, "The Tyranny of Words," and may recall his illustrations of the disastrous effects upon economics and philosophy produced by an unfortunate choice of words and phrases. His discussion of the relation between language and the natural sciences is perhaps not so penetrating, though well worth reading. Personally, in the course of a fairly long life of teaching chemistry to college students, I have been impressed by the confusion existing in their minds about the underlying basis of our knowledge of the natural sciences, and I attribute that confusion largely to the misleading language used by many of our natural science texts, both high-school and college. Of course, i t is easy to find fault with a textbook, but it is not so easy to sit down and write a better one, and I have much respect for the man who finds time and patience to put one together. However, I want to point out that we as chemistry instructors owe it to both classes of students, to those who study the natural sciences as a part of a liberal education, and to those who study them to help make a living, we owe it to both of these groups to use language in our texts and in our classes which will not give them a distorted view of the present state of our knowledge, and will make them realize the inherent limitations of that knowledge. This general subject, the philosophical basis of natural science, sometimes called epistemology, has been left pretty much to the philosophers and the psychologists, with the natural result that i t has been smothered in long words. A few experimenters haae workedon it, however; among them are Kirchhoff; Karl Pearsou in his "Grammar of Science"; Ostwald; Stallo in his "Concepts of Modern Physics"; Ernest Mach in "Die W h e l e h r e " ; Poincar6; Einstein; and P. W. Bridgman in "The Logic of Modern Physics." The general subject of "communication by languageu-that is, the proper choice of words to convey meaning, or the logic of language-has been given lately the name "sePaper presented before the Division of Chemical Education of the American Chemical Society, 108th meeting, New York City, September 13.1944.
mantics" or the science of meaning, and is discussed in Stuart Chase's book already mentioned. The language used in many modern texts of chemistry and physics is misleading. Let me give you a few illustrations of this, and of the effect it has upon the student. A useful and popular college text in chemistry begins by mentioning primitive man, and his lamentable ignorance of the "causes" of natural phenomena. I quote: "Water flowed down hill, but he, primitive man, did not know why," the inference being, of course, that we in this age of enlightenment do know. Well I, for one, do not, though I am inclined to associate i t with the fact that the moon continues to revolve around the earth, instead of shooting off into space, and with other well-known verifiable facts, but this is as far as I can go. Out of sheer curiosity, I actually asked a student why water flowed down hill, and he answered, with evident satisfaction, that it was due to the law of gravitation, a good case of inverted reasoning. Another paragraph (from the same book, I think) makes this astonishing statement: "The reason iron displaces copper from a solution of a copper salt is that iron stands above copper in the electrochemical series." The student promptly gets the idea that there exists in nature something called an electrochemical series, and that the elements therein have to obey orders, or else. It does not occur to him that iron stands above copper in this series because, among other things, i t precipitates copper from solution. In still another text the author sticks his neck out thus. I quote again: "Only recently has the true nature of solutions been discovered." So nothing is left for the future, and even Arrhenius, Van't Hoff, Ostwald, and all their distinguished company of the past must take a back seat; it has been reserved for the present illustrious generation to discover the "true" nature of things. What the author meant, no doubt, was that a more convenient and useful way had recently been found of describing the behavior of those common things we call solutions. But consider the effect upon the student of the word "true." The subject is closed after we use it. Perhaps the greatest sinner of all in producing misunderstanding and mental confusion is the word exfilmin as commonly used. It has its legitimate uses, of course, but nine times out of ten i t is employed merely as a synonym of "describe." Kirchhoff it was, I think, who pointed out many years ago that mechanics was merely
the accurate description of the motion of bodies, and natural science today in general is little more than close and accurate description. Unfortunately though, the student who is asked to explain something when we really mean describe it, often believes he has solved a problem instead of merely exercising his memory. I recall wandering quite a few years ago into a classroom where a history examination had just been held, and on picking up there one of the mimeographed sheets containing the questions, I found the following gem: "Explain Mary Queen of Scots." I suppose the instructor intended his victims to tell something about Queen Mary's life, her times, her contemporaries, and her tragic fate, but he surely did not ask for that. We have plenty of such cases nearer home, however. Last spring I deleted from an examination paper given by one of our own junior staff members the question: "Explain the manufacture of sulfuric add." Of course, no student could do that, but he ought to be able to describe the manufacture of this acid with some precision, and that was what the questioner really wanted. I pick out the following additional examples, taken a t random from various chemistry textbooks. (a) "Explain the meaning of the following state-, ment." What the writer meant was of course "state" the meaning, or "give" the meaning. (b) "Explain how carbon monoxide is produced in a stove or furnace." Surely he meant describe or state. (c) "Expiain destructive distillation as applied to coal and wood." Surely again this means describe, or discuss. And still worse, (d) "Explain chemical energy," whatever that may mean. The frequent use of this word explain is no doubt due to mental laziness, to a disinclination to spend the effort necessary in finding the proper word. Of course we have a right to define a term as we see fit, andif the scientific fraternity wishes to use "explain" as a synonym of "state" or "describe," or "give," no one can say them nay. But the stndent invariably attaches a deeper meaning to it. We have other undesirable words, of course, besides true, and explain. False, the opposite of true, is one of them. A good textbook of my acquaintance speaks of the old phlogiston theory as "false." Well, maybe it was, but this word "false" is associated in most minds with some moral obliquity, and the stndent who hears it used to describe a theory almost unconsciously imputes either moral delinquency or intellectual stupidity to those who used that theory. Incidentally, the concept of "phlogiston" was quite useful in its day, it stimulated and directed chemical study very well for a long time. I don't like to use the word "false" for it, I prefer to say we have outgrown it, just as we have outgrown Arrhenius' simple theory of aqueous solutions. Other words to be used with great caution are the words "law," and particularly the word "obey." It is hard for the young student to separate the scientific meanings of these words from the common ones. The
idea of moral obligation arises in his mind when you speak of "hydrogen obeying Boyle's law," and he naively thinks of this behavior of hydrogen as something laudable or creditable. The same confusion, unavoidable, perhaps, appears in the word "work" as used in common speech, and in thermodynamics. Indeed all technical words which appear also in the language of the street are to be carefully watched and, if possible, avoided. The use of ambiguous and misleading words is, however, only one phase of a defect which goes deeper than words. The extraordinarily fruitful results of research in the last 40 years, in physics, chemistry, and indeed in most of the natural sciences, with the unbelievable practical applications resulting therefrom, have led to an overestimation perhaps of the real status of our knowledge. We are constantly personifying and believing, so to speak, in the concrete existenceof things whichare pure concepts and have no objective existence so far as we know. I recall the indimation shown bv a student in thermodynamics when I suggested that ierhaps the formal treatment of that subject might be simplified if we ceased to classify heat as a form of energy, and instead set up the coordinate trinity of Matter-EnergyHeat. "But," he said, "heat is a form of energy." The idea that our concepts such as heat, energy, and matter have an objective existence, instead of being mere useful tools which we can modify as we will, is hard to destroy. I have had students ask me how we could tell what comoounds an element could form until we knew its "valence." Apparently they thought of valence as an actual entity, so to speak, attached to each element, instead of a useful concept which may be abandoned altogether, or radically modified, as i t has been of late years. It seems supeduous a t this late day to insist again that chemistry is an experimental science after all, that experimental facts, e. g., that chlorine and hydrogen when mixed explode vigorously in the sunlight, that strong H2S04takes the moisture out of air, that these are the building bricks of the world structure, the invariants, and that our numerous laws, concepts, hypotheses, theories, etc., constitute the scaffolding used in construction, a scaffolding which is torn down and rebuilt repeatedly as the building grows. If we assume, as many do, that our future material prosperity will depend largely upon our scientificinvestigators, i t becomes particularly necessary that the sound point of view be presented and maintained in the high schools. Excluding geniuses, who are subject to no laws, our future research men will carry with them tenaciously the impressions and points of view taken from their high-school instructors. How necessary i t is then that these high-school science teachers be competent and well informed, and especially that they have the scientific approach to their subject, so that our future researchers may acquire from the very first that open, tolerant, flexible cast of mind so necessary for investigation. One of the most forward-looking steps taken by the
American Chemical Society for some time is the decision to have its Educational Committee study and improve high-school teaching of chemistry. Most of us are accustomed to think that the teaching of natural science, since it deals so largely with objects and materials, is free, like mathematics, from the human factors which make literature, history, and economics so troublesome, as well as free from the arbitrary eccentricities of language study. We are accustomed to think it should be especially adapted to teaching correct habits of thought, and of reasoning, and I suspect that the usual science teacher is inclined to regard his subject as intrinsically more "scientific" than other studies, except perhaps mathematics. If this belief is to be justifiably maintained we need to be very careful of our methods and language. Let me suggest, therefore, to all high-school and college science teachers, that they look carefully into their texts and into their minds to see whether or not their teaching is founded on the solid rock of experimental data, or whether these data are regarded merely as a fortunate c o n b a t i o n of some current theory. This is no mere academic question. An acquaintance of mine, a chemical engineer, once told me he had decided
not to try out a certain scheme, which if successful would have achieved a very desirable end, because it was contrary to one of the laws of chemistry. Someone else, by the way, who was not frightened by the word law,did try it later, and patented the result. It had not occurred to my friend apparently that the laws of chemistry are not handed down from high, but are set up by man and can be changed as often as it is found convenient to change them. George Claude, the famous French engineer, the man really responsible for ow neon lamps, once said he never allowed theoretical considerations to prevent him from trying to do something he wanted to do. When high-school and college students once get the idea that natural science is a well-settled fixed subject governed by laws, which in turn are merely illustrated by experiments, it is a hard job to turn them later into research men. Quoting Bridgman, "The experimental f a d has always been for the physicist, and of course the chemist, the one ultimate thing from which there is no appeal, and in the face of which the only possible attitude is a humility almost religious." We have a choice of showing by our language in class and in text whether we preferfacts orfancies.
