The Art of Thinking; H. Hazlitt

The author began his career as a reporter for The Wall Street Journal. He became Literary Editor of the New York Sun in 1925, of The Nation in 1930, and succeeded H. L. Mencken as Editor of the American Mercury in 1933. He subsequently wrote the financial and economic editorials for The;tVew York Times until September of 1946 when he became writer of the "Business Tides" column for N eW8 week. His twice-a-week column for the Los Angeles Times syndicate be gan in 1966. But before all that, when he was 21, Henry Hazlitt's first book had been published - Thinking as a Sci ence. It was written, he explains, because "I primarily wanted to teach myself how to think more efficiently, independently, and, if possible, origi nally. I had already sensed that 'he who teaches, learns.' " When the book was republished 53 years later, in 1969, by Nash Publish ing Corporation, 9255 Sunset Boule vard, Los Angeles, California 90069 ($4.95) , instead of extensive revision of the original text, the author pre pared an Epilogue, reproduced here by permission. Hopefully, the reader will want to review the Introductory Course - read the entire book.

486 THE ART OF I HAVE LEFT the text of the first edition of this book practically un altered. But I promised in the Pref ace that I would outline in an epilogue the-changes I would make today if I were writing an entirely new book on the same subject. Here is that outline. As thinking is primarily an ac tivity, an art, the new book would probably not be called Thinking as a Sc'ience, but, perhaps, The Art of Thinking Scient'ifically, or, simply, The Art of Thinking. There would be one or two maj or changes from the present book, at least in emphasis. I am more and more impressed, as I grow older, with how little the individual could accomplish in any direction what ever if he had to depend entirely on his own unaided efforts. He could not survive his first few years of life without the help of his parents or guardians. He could HENRY HAZLITT THINKING not think at all (or only at the level of a chimpanzee) if he did not inherit from the society and civilization in which he was born the priceless gift of an already created language. Without this he would not only be unable to reason logically, he would have nothing worthy to be called a "concept."

He could not frame a sentence; he could not even name things. We think in words, even in conver sations. Our language, concepts, and logic are part of the social inheritance of all of us. This has several important cor ollaries. One of them is that be fore the individual can even dream of "thinking for himself," or solv ing a simple problem, he must first acquire at least an elementary knowledge of what mankind has already learned, discovered, or in vented before him. Even if he re ceives what is called a good modern education, it will take him. till the age of eighteen or more to acquire even the rudiments of what he needs to know. So my new book would empha size far more than my previous one the need of extensive reading and study before the reader can profitably launch on "thinking for himself" or arriving at "indepen dent" conclusions. That, of course, should always be his goal; but the road to that goal is long, hard, and often roundabout.

How to Study My new book would therefore have a chapter on "How to Study." One of the topics considered in it would be the possibility of increas ing one's reading speed, and the methods of achieving this. But my new book would emphasize what some of the teachers of the new "speed reading" methods unfor488 THE FREEMAN August tunately do not - the necessity that the student learn to "change gears," Le., to learn to read differ ent matter at different speeds de pending on its nature, importance, and difficulty, as well as on the reader's purpose in reading it. One of the chief problems of study, in fact, is how often the student should reread a textbook or a particular passage of it, or how often he' should go over sub stantially the same material in other books. In studying a foreign language, for example, the reader may have to come across the same word or phrase again and again before he is able to translate it on sight, and he may have to see or hear it many more times before he can use it unprompted in a sentence framed by himself.

Knowledge of a foreign lan guage, in short, is not really knowl edge until it has been thoroughly assimilated,or worked in. This is no doubt widely recognized. But what is much less widely recog nized is that this is not merely true of a language but of practi-: cally any other subject. A doctor is seldom a good doctor when he has just graduated from medical school, even though he may already have been over much verbal ma terial with dreary repetition. Not until he has served as an intern, or been in private practice a cou ple of years, and so gone still more over the same ground and again and again encountered the same or similar problems, is he likely to achieve a quick and con fident recognition and interpre tation of symptoms. A student of algebra may ,be taught how to extract the square root of a polynominal, and may be intelligent enough to follow the demonstration the first time, but it will probably not be until he has extracted many square roots of many polynominals that he will really feel confident he knows how.

The student of languages, as well as the student of math, or a doc tor, or a pianist, soon finds him self slipping backward if he ceases to study or practice. Our mem ories are not what they should be. A little of our knowledge is con stantly oozing away. Knowledge and skill cannot be retained,let alone .increased, except by con stant addition, renewal, and re freshment. I might also in this "How to Study" chapter give some hints to the reader on how to set up a study program to teach himself a particular subject, but in this epilogue I am postponing that to a later point. I may say here, how ever, that there are already some excellent books or pamphlets on how to study. The reader should find a wide range of choice in a college bookshop.

1970 THE ART O~.., THINKING 489 Language and Thought My new book would have a chapter on "Language and Thought." I pointed out earlier that without language we would hardly be able to think at all. As the great nineteenth century phi lologist Max Mueller put it: "To think is to speak low. To speak is to think aloud." The corollary of this is tremen dously important. A man with a scant vocabulary will almost cer tainly be a weak thinker. The richer and more copious one's vocabulary and the greater one's awareness of fine distinctions and subtle nuances of meaning, the more fertile and precise is likely to be one's thinking. Knowledge of things and knowledge of the words for them grow together. If you do not know the words, you can hardly know the thing. Weare told that the Tasmanian method of counting is: "One, two, plenty." This points to a very significant truth. Man could not even count, certainly not beyond the number of fingers on his hands, until he had invented na,mes and, symbols for nu,mbers. For in speaking of the need for language for thought, we must, of course, include symboIs as an integral pa.rt of lan guage. It is amazing how recent in human history are even the Arabic numerals, the denary system, and the elementary signs for addition, subtraction, multiplication, and division _. not to speak of the myriad symbols now constantly used in algebra, geometry, trig onometry, differential and integral calculus, vector analysis, and other branches of higher mathematics.

A single tiny symbol or formula - like that for zero, or pi, or a function, or the square root of minus one, or dy/dx, or Einstein's famous E = mc2 ( energy equals the quantity of matter multiplied by .the square of the speed of light) - can condense, sum up, fix, and hold forever a discovery that it may have taken mankind centuries to arrive at. Words Sharpen Observation A vocabulary increases and sharpens our observation, as sharp observation in turn leads us to increase our vocabulary. The stu dent of nature who is learning to recognize bushes and trees finds his observation increasingly shar pened as he is told how to identify respectively an oak, maple, elm, 490 THE FREEMAN August beech, pine, spruce, or hemlock. The name both fastens down the results of observation and tells him what distinguishing traits to look for. As a result of his knowledge, a countryman very seldom calls a specific tree simply a tree. The professional forester or nursery man habitually makes even finer distinctions, such as that between red oaks, black oaks, and white oaks, or between Norway maples, Schwedler maples, and sugar ma ples.

Once again, when a student of nature has a leaf described to him, or wants to describe one, he finds himself immeasurably aided by a specialized vocabulary of descrip tion for certain characteristics of edge or form - dentate, crenate, serrate, ovate, obovate, lanceolate, oblanceolate, sagittate, orbicular, and so on. The more names that are mastered, the more is obser vation sharpened. This intimate interdependence of language and thought exists in all fields of knowledge, from the simple and concrete to the most abstru'se and abstract. The highest thrill of the ama teur bird watcher comes when he identifies a new species for the first time. He usually does this by comparing the new bird he has just seen with the pictures or de scriptions in a bird book. But to be able to do this he has to observe very sharply everything he can - its size, shape, color, and markings, down to the minutest details, like the color and shape of its bill, its peculiarities of flight and song, and so forth.

When the bird student knows the name of the new species or its verbal description in a book he knows what to look for. His ob servation becomes keener not only for that time, but for the next time. By this process. he finds his observation becoming ever more acute as his knowledge becomes fuller. The professional ornitholo gist, by a refinement of the same method, knows when he has dis covered a species hitherto unrec ognized by anyone. Whereupon he preserves his discovery, and makes it accessible to all, by giving the new species a name, accompanied by a full and precise pictorial and verbal description. Identifying the Parts Let us turn to still another field. The first thing the student of medicine is asked to do is to study anatomy. This means, at the be ginning, to learn to recognize and name the hundreds of parts of the human body, from the anulu8 in guinalis profundus to the vesicula seminalis. It requires the dreary memorization of hundreds of names even to master what is called gross anatomy. When the 1970 THE ART OF THINKING 491 student comes to some special part, like the nervous system (not to mention microscopic anatomy), he must learn hundreds of more names. And he must learn this special vocabulary if for no other reason than to know what his pro fessors are talking about. Later on, as, say, a medical researcher, he must know this vocabulary not only to explain his findings in a medical journal, but to make them in the first place.

One of the things that used to puzzle me as a youth was why even the greatest painters and sculptors, like Leonardo da Vinci and Michelangelo, thought it nec essary to study artistic anatomy. Their eyes were sharp enough: couldn't they have painted just what they saw? The answer, as I have now come to realize, is that by learning the names, position, and description of the muscles, tendons, and veins in the normal human body they knew' what to look for and where to look for it, and their naturally acute vision was sharpened still more. What is true for the supreme genius is true for those of us who are less gifted. In a charming in troduction to his book on birds, John Kiernan tells the reader that he had never seen a white-breast ed nuthatch until he saw, on a bird card, a picture of one going down a fence post headfirst. The next day he saw five different nut hatches at different places. They had always been around, but he had never before looked for them.

He had been blind! The reader has perhaps had the experience of looking at some ob ject through binoculars or a mag nifying glass and seeing details that he could not previously see with his naked eye; but on remov ing the glass he could still see them, because now he knew they were there. The Arabian Nights story, telling how Ali Baba could not open the door to the robbers' den until he had learned to say "open sesame," contains a pro found moral. To be admitted to the realms of knowledge we must learn the right passwords. Symbols of Communication I remarked earlier that when I speak of "language" I do not have in mind merely words and sen tences, but symbols, signs, and signals of all kinds used in human intercommunication. There are special symbols in every science; but I have particularly in mind numbers, notation, and other sym bols of mathematics by which the results of mathematicians are made known to each other and without which, in fact, the mathematicians themselves could not even think mathematically. One authority, To bias Dantzig, has written a book 492 THE FREEMAN August called Number: The Langu,age of Science.

There are still further corol laries to be drawn from the inex tricable interdependence of thought and language. He who seeks to be a clear and precise thinker must also seek to be a clear and precise wri tel"'. Good writing is the twin of good think ing. He who would learn to think should learn to write. One of the most important steps, to repeat, is to enlarge one's vocabulary. The way most often consciously adopted for doing this is to study long lists of assorted words, usually polysyllabic. This may be better than nothing, but it is not the method to be preferred. It is generally more advisable to go from things and concepts to the names for them than to go from miscellaneous names to things and concepts. Vocabularies tend to grow with knowledge in general, and particularly with increasing knowledge of special subjects. Each science, discipline, art, sport, or branch of knowledge has its own special vocabulary, which is acquired with study or experience of that branch of knowledge or activity.

An abundant vocabulary is usu ally a by-product of wide knowl edge. One good rule, both in thinking and writing, is never to use a word if you have only a vague and uncertain knowledge of its meaning. Look it up first in the dictionary to find its exact denotations and connotations - not to speak of its correct pron uncia tion! Writing Improves Thinking The reader who seeks to write well and think well should aim first at the essential qualities coherence, clarity, precision, sim plicity, and brevity. Euphony and rhythm are of course also desir able, but they are like the final rubbing on a fine piece of furni ture - finishing touches justified only if the piece has been soundly made. As a method of procedure, the apprentice writer may often find it advisable first of all to root out his faults. He should try to ac quire the Five Virtues of Coher ence, Clarity, Precision, Simplic ity, and Brevity by vigilant ab stention from the Five Vices of Incoherence, Obscurity, Vague ness, Pedantry, and Circumlocu tion.

For those who ask why writing is important to the thinker, one reply would be that it may be of crucial importance when the think er wishes to present the res ults of his thinking to his professional colleagues or directly to the public. Newton and Leibnitz each invent ed the calculus independently, and 1970 THE ART OF THINKING 493 Newton's discovery was earlier. But it was the calculus as present ed by Leibnitz that other mathe maticians began to use, mainly be cause Leibnitz devised a better no tation. The Abbe J. G. Mendel's bio logical experiments and theories on heredity, propounded in 1866, were of epoch-making importance, comparable to Darwin's theory of evolution published in The Origin of Species in 1859. Darwin's book brought him instant world fame, but neither Mendel nor his con tribution received any recognition until 1900, thirty-four years after he had published his results and sixteen years after his death. Rec ognition came only when other botanists independently obtained results similar to Mendel's and in searching the literature found that both the experimental data and the general theory had been published by him a third of a cen tury before. Mendel's original pa per had reached the principal Ii braries in Europe and America.

But it was so sparely and obscure ly written that even eminent bot anists at the time failed to grasp its implications. A book on the art of thinking is not the place to dwell in detail on the art of writing. The most illu minating discussion of its length written on the subject is still Her bert Spencer's essay on "The Phi losophy of Style" published in 1871. (Unfortunately, its' own style is somewhat stilted and pompous.) A helpful little manual is The Elements of Style by Wil liam Strunk, Jr., first published in 1918 and then republished with a delightful introduction and added chapter by Strunk's former stu dent, E. B. White, in 1959. Every professional writer ought to have, in addition to at least one good dictionary, four style books in his study: The King's English, by H. W. Fowler and F. G. Fowler, A Dictionary oj Modern English Usage, by H. W. Fowler, Usage and Abusage, by Eric Partridge, and Modern American Usage, by Wilson Follett.

A Notebook or Journal And every serious thinker, espe cially if he hopes to be a profes sional writer, should keep a note book or a journal. I pointed out, in the first edition of this book, that good ideas are often elusive and must be captured in flight - in 494 THE FREEMAN August other words, that it is excellent practice always to have a pencil and pad handy, so as to jot down a good thought the moment after it lights up your mind. The com placentassumption that once a bright idea or happy phrase occurs to you it is a permanent acquisi tion, to be called upon only when needed, too often proves false. Even Nietzsche, one of the great seminal minds of the nineteenth century, found that: "A thought comes when it wishes, not when I wish." When we write out our ideas, we are at the same time testing, developing, arranging, crystalliz ing, and completing them. We imagine ourselves not only making these ideas clear to others, but making them seem as important to others as they do to ourselves.

So we try to make what was vague in our minds precise and definite; what was implicit, explicit; what was disconnected, unified; what was fragmentary, whole. We frame a generalization, then try to make it as plausible as we' can; we try to think of concrete illustrations of it. And as we do this, we also expose it to ourselves - and some times, alas, find that it is empty, untenable, or sheer nonsense. A lot of ideas that cannot be tested by formal experiments can be at least partly tested by writ. ing them out. A great teacher of my acquaintance, when a student bothered him once too often by persisting in some silly proposal of his own on a subject, would suggest that the student write a paper on his idea and bring it in at the next. seminar. The student seldom did so; perhaps because he was mentally lazy, but more likely because, when he attempted to write it out and to prove its valid ity, he found it to be hopelessly vague or a self-contradiction.

Writing Aids Concentration One incidental advantage of the habit of writing out one's ideas is that it promotes concentration as almost no other practice does. As one who has written daily news paper editorials or weekly maga zine columns for many years, I can testify that nothing forces one to pull one's thoughts together more than deciding on a topic, sit ting before the typewriter, feeding in a clean sheet of paper, and then trying to frame one's exact theme, title, and opening paragraph. Francis Bacon summed it up with unsurpassable conciseness: "Reading maketh a full man, con ference a ready man, and writing an exact man." If the reader wants to know what the best and most stimulat ing notebooks and journals are like, I suggest, for a starting as sortment: The Meditations of 1970 THE ART OF THINKING 495 Marcus Aurelius, Pascal's Pensees, \ The Heart of Emerson's Journals, Samuel Butler's Notebooks, and Charles Horton Cooley's Life and the Student. All of these, of course, can be sampled rather than read through; they are admirable bedside books.

How to Solve a Problem In the first edition, I remarked that all thinking is problem-solv ing. My new book would contain a special chapter on "How to Solve a Problem." It would begin, perhaps, by rais ing the problem: how to recog nize a problem when you see it. The better informed, more intelli gent, and more intellectually curi ous you are, the more problems you will become aware of. In his Voyage of the Beagle, Darwin de scribes how the savages, at one harbor in which the Beagle an chored, immensely admired the small boats in which his party landed, but paid no attention whatever to the big ship. They took it for granted, like a fact of na ture. It was too far out of their experience. Feebleminded barbarians, no doubt. But most of us civilized laymen daily switch on the lights, or turn on our'television set, with out the slightest curiosity regard ing the cause of the miraculous result.

A question akin to this, which my chapter would raise, is "What is the problem?" Our modern so cial reformers are constantly pre occupied, for example, with the problem of poverty. But poverty is the original condition of man, from which he has sought to es cape by the sweat of his brow, by work, production, and saving. It was when Adam Smith asked him self not what causes the poverty but what causes the wealth of na tions that real progress on the problem began to be made. For centuries, in the same way, doc tors took health for granted and assumed that the only problem is what causes disease. It was not until surgeons tried to transplant kidneys, hearts, and other organs that they became acutely troubled by the problem of what causes im munity. There is always the pos sibili ty of learning more by ask ing ourselves the opposite ques tion. There are hundreds of books 496 THE FREEMAN August on How to Play Chess. Znosko Borowsky created a mild sensation by writing one called How Not to Play Chess.

Rules for Discovery I suspect that my chapter on problem-solving would be heavily obligated to a little book by George Polya, first published in 1945, called How to Solve It. Polya's book is devoted primar ily to the problem of solving prob lems in mathematics; but it is ap plicable over the whole field of in vention, discovery, and independ ent thinking. "A great discovery," the author tells us in the preface, "solves a great problem but there is a grain of discovery in the· solution of any problem. Your problem may be modest, but if it challenges your curiosity and brings into play your inventive faculties, and if you solve it by your own means, you may experience the tension and enjoy the triumph of discovery. Such experiences at a susceptible age may create a taste for mental work and leave their imprint on mind and character for a lifetime." Polya has all sorts of instruc tive things to say about what questions to ask - "What is the unknown ?" - about the uses of analogy, about "decomposing" and "recomposing" problems, about Descartes' rules for invention, about the indispensability of good symbols and good notation for mathematical thinking. He tells how, overnight or after a longer interval, our subconscious mind will often solve problems for us, but warns that "conscious effort and tension seem to be necessary to set the subconscious work going" otherwise everything would be too easy.

Palya calls his whole book an effort to teach Heuristic': "The aim of heuristic is to study the methods and rules of discovery and invention. . . . The most fa mous attempts to build up a sys tem of heuristic are due, to Des cartes and to Leibnitz, both great mathematicians and philosophers." Polya's own illustrations and ap plication are confined entirely to mathematics, for which his own enthusia.sm is contagious. The reader, he says, should at least try to find out whether he has a taste for mathematics, and he may find out that "a mathematics problem may be as much fun as a crossword puzzle, or that vigorous mental work may be an exercise as desirable as a fast game of tennis. Having tasted the pleasure in mathematics he will not forget it easily and then there is a good chance that mathematics will be come something for him: a hobby, or a tool of his profession, or his profession, or a great ambition."

1970 THE ART OF THINKING 497 Specialization, Perseverance, Analogy My new book would contain a chapter on "The Dilemma of Spe cialization." The dilemma is this. In the modern world knowledge has been growing so fast and so enormously, in almost every field, that the probabilities are immense ly against anybody, no matter how innately clever, being able to make a contribution in anyone field unless he devotes all his time to it for years. If he tries to be the Rounded Universal Man, like Leonardo da Vinci, or to take all knowledge for his province, like Francis Bacon, he is most likely to become a mere dilettante and dabbler. But if he becomes too specialized, he is apt to become narrow and lopsided, ignorant on every subject but his own, and per haps dull and sterile even on that because he lacks perspective and vision and has missed the cross-fertilization of ideas that can come from knowing something of other subjects.

I do not know the way out of this dilemma, or the exact com promise, but I hope to find it by the time I write my new book. My new book, like the present one, will have a cha.pter on con centration, but it is more likely to be called "Concentration and Per severance," for it will put far more emphasis on patience, plod ding, perspiration, pertinacity, de termination, effort, work - on again and again returning to an obstinate problem until it is solved. Scientists talk much nowa days of "serendipity" - the fac ulty of making desirable discover eries by accident. An example often cited is how Sir Alexander Fleming discovered penicillin be cause one of his laboratory techni cians had carelessly left the top off a dish in which a virulent in fectious organism, staphylococcus, was growing; a. number of fungi had floated into the open dish, overgrown the bacteria - and killed it. The accident led Fleming to his discovery. But these "acci dents" only seem to bear fruit when they happen to alert inde fatigable scientists who have al ready been working for years on a project. As Pasteur put it: "Chance favors the prepared mind."

In my new book I would treat Analogy less cavalierly than I did 498 THE FREEMAN August earlier in this one, and perhaps have a separate chapter with that title. I did mention analogy in my first edition as a constructive method of making discoveries, but then went on to talk almost exclu sively about its dangers and pit falls. A. Wolf, in his Textbook of Logic (1938), emphasizes its achievements: "One need only think of the most important discoveries in the history of science, in order to re alize the enormous value of anal ogy. Our conception of the solar system (the helio-centric theory) owes a great deal to the analogy of the miniature system of Jupiter and the Medicean satellites. Some of the most important discoveries in modern mathematics are due to the analogy, discovered by Des cartes, between algebra and geom etry. The wave-theory of sound was suggested by the observation of water-waves; and the undula tory theory of light was suggested by the analogous air-waves which transmit sound. The theory of natural selection by the struggle for existence was suggested to Darwin by his knowledge of the artificial selection by which breed ers have produced the many varie ties of domestic animals. And so forth."

Like the first edition of the present volume, my new book would contain chapters on "Subjects Worth Thinking About" and on "Books on Thinking." Subjects Worth Thinking About But the former chapter, instead of containing a list of important but very miscellaneous problems, would call the reader's attention to some of the innumerable sciences or disciplines in which he could en joyably and profitably interest himself - agriculture, astronomy, atomic physics, biology, building, chemistry, crystallography, elec tricty, engineering, fossils, gar dening, geography, geology, math ematics, medicine, metallurgy, me teorology, minerology, pathology, physics, physiology, and zoology. These are all physical sciences. I name so many here because my first edition rather neglected them in its emphasis on social questions. But, of course, in my new book the reader would still be invited to consider the attractions of the social disciplines - political sci ence, jurisprudence, economics, ethics, psychology, anthropology, or archeology.

In choosing subjects to think about or problems to solve, I must confess a personal preference for those that are useful. I admire disinterested curiosity and the achievements of "pure" science and "pure" research as much as anyone; but I cannot share the snobbery of those who seem able 1970 THE ART OF 1~HINKING 499 to express their esteem of pure science only by disparaging its practical applications. Both are admirable; and they are mutually dependent. The partisans of pure science chronically talk as if there were only a one-way dependency, and as if inventors were men of a lower order than pure scientists. They never tire of reminding us how the inventions of Marconi in wireless telegraphy and de Forest in radio were dependent on the previous theoretical discoveries of Clerk Maxwell and Hertz. All very true. But how far would pure re search have been able to go in a hundred fields if it had not been for the invention, say, of the mi croscope? Or, for that matter, of the printing press?

As Karl R. Popper has pointed out, in his Poverty of H'istoricism (1957), one need not espouse a narrow pragmatism in order to ap preciate Kant's saying: "To yield to every whim of curiosity, and to allow our passion for inquiry to be restrained by nothing but the limits of our ability, this shows an eagerness of mind not unbe coming to sc'holarship. But it is wisdom that has the merit of selecting, from among the innumer able problems which present them selves, those whose solution is im portant to mankind." The Study of Economics The reader of my new book 'would receive some guidance in how to take up a subject new to him, and there would be some specific illustrations. Suppose, for example, that he wanted to take up economics in a systematic way. :He would be advised to begin with some short elementary text. An excellent one for the beginner to day would be, say, Essentials of IEconomics, a book of only one hundred pages by Faustino Ballve (Irvington-on-H udson, N. Y.: Foundation for Economic Educa tion). A collection of essays, Plan ning for Freedom, by Ludwig von Mises, is less systematic but enor mously stimulating. (1 would be less than mercenary if I failed to mention here also my own Econ omics in One Lesson, available both in hard -cover by Harper & Rowand in paperback by Mac fadden-Bartell.) The next step would be to read a book of intermediate length. One 500 THE FREEMAN August of the best is A Humane Economy by the late Wilhelm Roepke (Reg nery) .

The student would now be ready to tackle one of the most compre hensive and advanced books on the subject, of which I will mention only three. Human Action: A Treatise on Economic'S by Ludwig von Mises (Regnery, 907 pages) extends the logical unity and pre cision of economics beyond any other work. Some readers seem to find this excessively difficult. For these I can strongly recommend Man, Economy, and State, by Murray N. Rothbard (D. Van Nostrand, two volumes, 987 pages) which is equally comprehensive, and along Misesian lines, but in which the reader may find the ar rangement and exposition easier to follow. Finally, I would include in this triad an older book, Philip Wicksteed's The Common Sense of PoliUcal Ec'onomy (1910, new edi tion 1933, two volumes, 871 pages) , as remarkable for the ease and lucidity of its style as for the penetration and power of its reasoning. When the reader has finished even one of the books in this ad vanced triad, perhaps after a couple of introductory volumes, he will be prepared to choose his own further reading in economics, and may browse among the great writ ers and thinkers who created the science - Hume, Adam Smith, Ricardo, Mill, J evons, Menger, Boehm-Bawerk, Wicksell, Mar shall, John Bates Clark - an en viable feast. Adam Smith's Wealth of Nations, though published in 1776, can still be ardently recom mended no less for its literary se ductiveness than for the brilliant light it still can throw even on the economic life of today.

General Rules for Exploring Any New or Strange Subject Of course, my book could only include such specific recommenda tions on one or two subjects. For others there would have to be gen eral rules. One would be to ask an expert in the subject. Another would be to consult the article on the subject in an encyclopedia and to see whether that included, as it ought to, a good list of references. A third rule would be to consult such a book as Good Reading, a paperback published by The New American Library. This is a vol ume sponsored by the College Eng lish Association and prepared by the Committee on College Read ing. I happen to have the nine teenth printing which came out in 1964, but revisions have been' ap pearing every year or two. The volume lists selected books on ev ery conceivable subject - history, fiction, poetry, drama, biography, essays, philosophy, religion, and 1970 THE ART OF THINKING 501 all the leading arts and sciences.

There is also an instructive list of "100 Significant Books." One last general piece of advice. No practice excels that of brows ing along a library shelf contain ing books on the subject that has awakened your interest, and sam pling them. If I may be permitted a per sonal note, it seems to me, looking back, that the hours of purest happiness in my own youth were spent in just this way. I would avidly sample one book after an other, and when the bell rang, and the library closed for the night, and I was forced to leave, I would leave in a state of mental intoxi cation, with my new-found knowl edge and ideas whirling in my head. I would speculate eagerly on what solutions the authors I had -read had come to in the passages I hadn't had time to finish. I think now that these unpremedi tated efforts to anticipate an au thor's conclusions stimulated my thinking far more than any con tinuous uninterrupted reading would have done. In fact, when I came back to one of these same books the next evening, I most often felt let down. The night be fore, the author had seemed on the verge of some marvelous breakthrough, opening new vistas to the soul, and now he seemed to fizzle out in a truism.

Books on Thinking The final chapter in my new book, like the final chapter in the first edition of this one, would be about "Books on Thinking." My new references would sup plement, rather than displace, those in my first edition. For ex ample, I cited there only two "classics" on the art of thinking - John Locke's Conduct of the Un derstanding, and Arthur Schopen hauer's Thinking for Oneself. I should also have included the three classics mentioned in my present preface: Bacon's Novum Organ um, Desca.rtes' Rules for the Di rection of the Mind, and Spinoza's Improvement of the Understand ing. My new bibliography would of course also include a handful of good books written specifically on the art of thinking since the orig inal edition of Thinking as a Sci ence appeared. One of these would surely be The Art of Thought, by Graham Wallace (1926). Another would be Thinking to Some Pur pose, by the late British logician L. Susan Stebbing. Her chief em phasis is on how to detect illogi calities in other people's thinking and how to avoid them in our own.

In addition, my new bibliog raphy would refer the reader to passages, paragraphs, and even single sentences, widely scattered through the works of many au502 THE FREEMAN August thors, that throw light on the art of thinking. Some of these can be found in the biographies or auto biographies of great thinkers. My first edition cited material of this nature from the autobiographies of John Stuart Mill and Herbert Spencer. But there are illuminat ing passages in many writers less well known. I quote here a few lines, for ex ample, from Charles Horton Cool ey's admirable notebook, Life and the Student (1927) : "Let our struggle be with facts, with life, rather than with other writers. We cannot have the spirit of truth and the spirit of contro versy at the same time. "A writer whose aim is to be unlike others is liable to a sub servience of contradiction. That is, he after all gets his cue from them, takes the other end of the same rope. Originality raises new questions."

Though it starts apparently in contradiction, the advice of Morris R. Cohen in the preface to his Reason and Nature (1931) rein forces that of Cooley: "The philosopher whose primary interest is to attain as much truth as possible must put aside as a snare the effort at originality. In deed, it seems to me that the mod ern penchant for novelty in philos ophy is symptomatic of restless ness or low intellectual vitality .... The principle of polarity calls at tention to the fact that the tradi tional dilemmas, on which people have for a long time taken oppo site stands, generally rest on dif ficulties rather than real contra dictions, and that positive gains in philosophy can be made not by simply trying to prove that one side or the other is the truth, but by trying to get at the difficulty and determining in what respect and to what extent each side is justified. This may deprive our results of sweep and popular glamour, but will achieve the more permanent satisfaction of truth."

Lessons in Logic The art of thinking, like engi neering or medicine, is based on several distinct sciences. One of these is psychology. I referred in the first edition of this book to John Dewey's How We Think, which is still useful. But great experimental as well as theoretical progress has been made since Dewey's book was published. The reader could bring himself abreast of this by consulting the article on Thinking and Problem Solving, Psychology of in the 1965 edition of the Encyclopedia Britannica. The article itself includes an ex tensi ve list of books for further reading. Logic, the study of the general condi tions of valid inference, is of 1970 THE ART OF 1 l HINKING 503 course the chief established sci ence on which the art of thinking must be based. My recommenda tion for initial reading in my first edition was Stanley Jevons' Ele mentary Lessons in Logic. Because Jevons was an excellent writer as well as a first-rate thinker, this can still be read with pleasure and profit. But today I would prefer to recommend as an introductory volume A. Wolf's Textbook of Logic (first edition 1930, but often republished). More advanced, but still not too difficult, is L. Susan Stebbing's Modern Introduction to Logic (1940). Still more advanced, longer, and more difficult is An Introduction to Logic and Scien tific Method, by Morris R. Cohen and Ernest Nagel (1934).

Scientific method is closely con nected with logic. In fact, it is usual for modern books on logic (and this is true of the three just mentioned - the last explicitly in its title) to treat traditional logic in the first half of the book as "formal" or "deductive" logic, and then to devote the second half to "inductive" logic and to "scien tific method" in general. This sec ond subject includes discussions of such subjects as circumstantial evidence, the evolutionary and comparative methods, the simpler inductive methods (Mill's "five canons"), the statistical method, the deductive-inductive method, probability, laws of nature, scien tific explanation, and so on. Long established as a standard work in this field is F. W. Westaway's Scientific Method (1919), but the literature is now very extensive. A brilliant and penetrating book, for those who have the intel lectual background, capacity, and ambition to read it, is The Logic of Scientific Discovery by Karl R.

Popper (1961 edition). Digression on Mathematics It was one of the shortcomings of my first edition that it did not contain any explicit discussion of the enormously important field of mathematics. Yet at least an ele mentary knowledge of mathe matics is essential for solving most of our daily practical prob lems as well as for most scientific thinking. We need arithmetic to buy and sell, to count our change, to read the time or the tempera ture, or to perform a hundred 504 THE FREEMAN August other daily operations. Mathe matics has been called the "queen" and even the "mother" of sciences, because every science has its mathema.tical aspect. The acceler ative development of mathematics in the last century has been both cause and consequence of the tre mendous progress in the same period in the whole realm of the sciences, physical and social. And - what was strangely not recognized until the last century - there is an inextricable connec tion between logic and mathe matics. Mathematics may be called the quantification of logic. Mathe matical logicians consider it a branch of logic. A formidable literature has grown up in the last few decades on "mathematical logic," "the algebra of logic," and "symbolic logic."

I do not mean to discourage or frighten the nonmathematical reader at this point by any impli cation that unless he masters higher mathematics and symbolic logic he cannot hope to contribute anything to science, philosophy, or the higher realms of thought. Great contributions to science and other knowledge will be made in the future, as they have been made in the past, by persons innocent of mathematics beyond simple arithmetic. But I do want to sug gest that, other things being equal, the more you know of mathematics the more you will be likely to accomplish in science or original thought. And mathematics can be fun. Few things can give greater en joyment than mathematical prob lems, in fact, to those who relish mental exercise for its own sake. The reader may be, like myself, one who grew up with a deep aversion to mathematics. This was chiefly, I am now convinced, be cause of the way it was then taught. Algebra was thrown at most of us who are now over forty simply as something that had to be learned if we didn't want to flunk. I never remember any teacher telling me anything about the engrossing history of algebra, or even explaining why algebra was necessary in solving any prob lem except the artificial ones that were specially invented for the textbooks. The course in algebra seemed to me mainly a malicious contrivance to cut down the time I could give to handball.

But now, I can assure any reader who doesn't know, all is changed. There are now so many fascinating introductions to mathematics (at least for adults) that it seems almost invidious to name only a handful. For a short introduction covering the whole field, I would especially recom mend David Bergamini's Mathe matics (1963) in the admirable 1970 THE ART OF THINKING 505 Life Science Library series. Mathematician's Delight by W. W. Sawyer (1943) is a charming in troduction available in paperback. Two single volumes that teach the actual operations of the conven tional part of the field are Mathe matics for the Pra,ctical Man by George Howe (1957), and Lance lot Hogben's best-selling Mathe matics for the Million (1937) if you don't mind its belligerent Marxism. There is an excellent five-volume set on Malhematics for Self-Study (1931, 1962) by J. E. Thompson, covering in sep arate volumes arithmetic, algebra, geometry, trigonometry, and cal culus. Finally there are the mag nificent four volumes of The World of Ma,thematics edited by James R. Newman (1956).

Sdence, Philosophy, and Log;c I am still talking, the reader will remember, about studies that are directly likely to help him in the art of thinking - though the dis cussion inevitably splashes over into the domain of the chapter on "Subjects Worth Thinking About." To continue with aids to the art of thinking: The reader will get both knowledge and stimulation from reading histories of science, lives of great scientists and in ventors and discussions of their methods; histories of engineering, and histories of inventions and discoveries. Again I can mention only a few books. Two more from the handsomely illustrated Life Science Library series: The Engi neer, by C. C. Furnas, Joe Mc Carthy and others (1966), and The Scientist, by Henry Marge nau, David Bergamini, and the editors of Life (1964) ~ The latter book will introduce the reader to a wide variety of sciences. In the realm of technology the reader may consult anything from the five-volume History of Technology (1954-58), edited by C. Singer to the Popular History of American Invention (1924), edited by W.

Kaempffert. Of course I should include phi losophy also among the subjects whose study would contribute di rectly to the stimulation and im provement of one's thinking. But my list of recommendations has already grown so long that I shall here mention only two. The first is Bertrand Russell's brilliant History of Western Philosophy (1945). The second is AnIntroduction to Philosophical Analysis (second edition, 1967), by John Hospers. This text will bring the reader abreast of the kind of problems that professional philoso phers now discuss. At this point some reader may ask, earnestly or skeptically: But if I do some or all of this reading, will it really make me a better 506 THE FREEMAN August thinker than if I devote my leisure wholly to detective stories or golf? To this I can confidently reply: Yes. But to the further question: How much will it help me?, I can not reply with any confiden~e at all. The answer depends on the native intelligence of the indi vidual reader, the nature of his gifts and interests, and a score of other factors.

Improving the Prospects Is it really necessary to study formal logic, for example? Tris tram Shandy, Lawrence Sterne's hero, commenting on the gap be tween his father's argumentative powers and his ignorance of formal logic, says: "It was a mat ter of just wonder with my worthy tutor, and two or three fellows of that learned society, that a man who knew not so much as the names of his tools, should be able to work after that fashion with them." In 1685, in the great hall of Dublin University, the young Jonathan Swift, having failed once before to take his bachelor's degree on account of his ignorance of logic, came up again without having conde scended to read logic. He was asked how he could reason well without rules, and replied that he did reason pretty well without them. Reluctantly, though as the outcome proves, justifiably, his examiners gave him the degree. On the reverse side of the coin we may cite examples of even great professional logicians, like John Stuart Mill, sometimes falling into logical howlers.

The only reply I can think of to these examples is that though ig norance of logic may not prevent correct reasoning, or knowledge of it guarantee correct thinking, that knowledge nonetheless helps. The probability is that in the long run a man who has studied formal logic will reason better, and make fewer errors, than if he had not. Remembering the tech nical names and descriptions of the more common fallacies, for ex ample, will help him to detect such fallacies in the reasoning of others and avoid them in his own. I have much less doubt about the usefulness of mathematics. True, even a prolonged study of higher mathematics will not make a man into an original or even effective thinker if he lacks the innate qualities. But a study of mathematics is of great impor tance in training a, man to think mathematically about a problem or a subject. On the negative side the im portance of mathematical study is overwhelming. Without a knowl edge of at least elementary arith metic none of us would be com petent to manage his daily affairs.

1970 THE ART OF 'rHINKING 507 Without a knowledge of double entry bookkeeping and cost ac counting, a business firm would never know just how much money it was making or losing. And without a knowledge of higher mathematics, few modern physical scientists could hope to make con tributions to their subjects, or even understand what had already been discovered. Morris R. Cohen tells us that in dealing with ex perimental physics, the lack of advanced mathematical knowledge discomforted the acute and power ful mind of Hobbes. Even if the case for the useful ness of mathematics were· not so overwhelming, its study could still be infinitely rewarding. In a fa mous fifteen-page essay, "The Study of Mathematics," included in his Mysticism and Logic (1918), Bertrand Russell writes: "Mathematics, rightly viewed, possesses not only truth, but su preme beauty ... sublimely pure, and capable of a stern perfection such as only the greatest art can show....

"For the health of the moral life, for ennobling the tone of an age or a nation, the austerer virtues have a strange power, exceed ing the power of those not in formed and purified by thought. Of these austerer virtues the love of truth is the chief, and in mathe matics, more than elsewhere, the love of truth may find encourage ment for waning faith. Every great study is not only an end in itself, but also a means of creating and sustaining a lofty habit of mind; and this purpose should be kept always in view throughout the teaching and learning of mathematics." The Joy of Thinking But I ought not to try to prose lytize for anyone subject, among the hundreds, indeed (as encyclo pedias and great libraries remind us) the thousands, that compete for the interest of the inquiring mind. Some of the world's most· brilliant intellects have had no gift for mathematics. Most of us, moreover, have neither the sur plus time nor energy to divert from the interests that already preoccupy our attention. And most of us, also, will feel less frustrated if we devote· ourselves to less abstract and abstruse subjects 508 THE FREEMAN August which are nonetheless rewarding and absorbing. Not everyone can be a Newton or a Darwin, but everyone, by a little effort and persistence, can improve his in tellectual attainments and satis factions - and his enjoyment of life.

I would like to end this epilogue where I began, and to repeat that if I were writing a new book on the art of thinking I would empha size, as I failed to do in my first edition, that no man can hope to do original work or even profitable thinking in any science or branch of knowledge until he has gone to the trouble to learn what has al ready been discovered in that branch of knowledge. He must know the previous state of the question. Then he will see whether he can make any contribution of his own. When the great Isaac Newton was asked how he had been able to make such tremendous contri butions to human knowledge and thought, and to see-so much far ther than other men, he answered modestly: "I stood on the shoul ders of giants." In other words, he was able to build on what his predecessors had discovered. We who live today are in one respect in a more enviable position than any other generation in his tory. We stand on the shoulders of giants, like Newton and his suc cessors, who stood on the shoul ders of other giants before them.

A thousand professional mathema ticians today, though they have nothing approaching his genius, know more mathematics than Newton, who invented the calcu lus. And they know it because Newton, Leibnitz, the Bernoullis, Euler, Lagrange, Gauss, Riemann, Hamilton, and a. hundred lesser figures have taught them. So an intelligent college student today is in a position to learn more about calculus than Newton, more about economics than Adam Smith, more about evolution than Darwin. The present generation has been pri vileged beyond all others in acquiring this great intellectual heritage. It is a cardinal sin for any individual to neglect to ac quire at least some small pa.rt of it for himself. It is more than a sin; it is a folly. It is a failure to take advanta.ge of one of the greatest sources of human enjoy ment. For we may say of thought in general what Tarrasch said of chess: Thinking, like Love, like Music, has the power to make men happy.

The way to this happiness is what I have tried to show in this book. f) A REVIEWER'S NOTEBOOK ~ ~qmmutable ~aM fJf'Ecollomics JOHN CHAMBERLAIN AL LAX'S Consumers' Capitalism and the Immutable Laws of Eco nomics (Charles Hallberg & Co., $5.95) is an adventure in shirt sleeve economics. What it tries to do - and succeeds very well in ac complishing - is to put the concept of marginal utility (a rather forbid ding phrase) into easily compre hensible terms. This is "Austrian economics" in homespun, or Men ger-for-the-Masses, which eschews all talk about "monopsony," or "oligopoly," or any of the manifold verbal barbarisms that the profes sional economists use as short hand. It is the work of a good sim plifier who knows how to be clear without becoming superficial. If it is Menger-for-the-Masses, an exposition of how the subjec tive desires of individuals result in personal lists of preferences re garding the utility of any and all the items that are offered in trade, it is also Mises-for-the-Multitudes.