Part 3

What we will do next depends on the nature of the question. In the example “What knowledge is of most worth?” we proceeded to look for a criterion of worthiness. And this was really a re-stating of the question. For instead of asking ourselves “What knowledge is of most worth?,” we began asking “What knowledge best prepares for complete living?”

Our next move was to classify. This is essential not only to systematic reasoning but to thinking of any kind. Classification is the process of grouping objects according to common qualities. But as almost all objects differ in some qualities and almost all have some qualities in common, it follows that, contrary to common belief, there is no one classification absolutely essential to any group of objects. An infinite number of classifications may be made, because every object has an infinite number of attributes, depending on the aspect we take of it. Nor is any one aspect of a thing “truer” than any other. The aspect we take depends entirely on the purpose we have in mind or the problem we wish to solve. As William James pointed out:

“Now that I am writing it is essential that I conceive my paper as a surface for inscription. If I failed to do that I should have to stop my work. But if I wished to light a fire and no other materials were by, the essential way of conceiving the paper would be as combustible material; and I need then have no thought of any of its other destinations. It is really all that it is: a combustible, a writing surface, a thin thing, a hydrocarbonaceous thing, a thing eight inches one way and ten another, a thing just one furlong east of a certain stone in my neighbor’s field, an American thing, etc., etc., ad infinitum.”

And if the reader insist that these qualities are merely “accidental,” and that what the thing really is, is just paper and nothing else, the reply is that the reader is intellectually petrified; that though “paper” may be our commonest title for it and may suggest our usual purpose with it, yet that purpose and this title and the properties which this title suggest have in reality nothing sacramental about them.

So because you have classified something from one aspect do not imagine that you are necessarily precluded from classifying it from any other. A man who is studying the theory of money may divide the medium of exchange into standard money and credit currency. But this need not keep him from viewing it as coins, government notes, and bank currency, nor should it prevent him from classifying it into, say (1) hand-to-hand money, (2) written or printed orders of one party to pay specified sums to another, and (3) book accounts. All these classifications will be true; all may be useful for a full comprehension. Every classification should of course be logical; but it is far more essential that it be utilizable.

And while we are treating of utility, we might note that this pragmatic method can be applied with profit to nearly all our positive problems. Before starting to solve a question—while deciding, for instance, on the validity of some nice distinction in logic—we should ask ourselves, “What practical difference will it make if I hold one opinion or the other? How will my belief influence my action?”—(using the word “action” in its broadest sense). This may often lead our line of inquiry into more fruitful channels, keep us from making fine but needless distinctions, help us to word our question more relevantly, and lead us to make distinctions where we really need them.

We are now ready to consider in order a number of constructive methods in thinking.

One method applicable to almost all problems is what we may call either the deductive or the à priori method. This method reaches a conclusion without observation or experiment. It consists in reasoning from previous experience or from established principles to particular facts. It may, however, be used to confirm observation and experiment as well as to take their place. Take the all important questions in biology of whether or not specific characteristics acquired by an animal during its life time are inherited by offspring. The a priori method would examine the structures of the body, the germ plasm from which the offspring develops, and the relation between them, and would ask just how a specific change in the body could affect the germ. If it were found that the tissues that are to continue the race were set off so completely from the structures of the body as to make inconceivable any manner by which they could be influenced by changes in these structures, then this method would decide that acquired characteristics are not transmitted.

Let us take another example. Both the supporters and opponents of woman suffrage have often decided the question without consulting at all the actual results achieved in the States where women vote. They have settled the question to their own satisfaction merely on a priori grounds. They have considered woman’s supposed mental qualities as compared with man’s, and have decided on her fitness for the ballot solely from these considerations. It must be remembered, however, that before women were admitted to suffrage anywhere, deductive or a priori reasoning was the only kind possible.

It is often helpful to look at a problem from the viewpoint of different sciences. A problem in political science will very likely have an economic aspect, whether it concerns taxation, tariff, trusts or the ownership of land, and so we may look at the question solely from the viewpoint of economics. But the problem may also have an ethical aspect. If it is proposed to pass a universal prohibition law, you may ask, “Has the Government the right to interfere in this way with personal liberty?” Again, we could take a psychological view: we would decide from our knowledge of human nature just what the effect of an alcohol prohibition law would be—whether it would not drive men to even more dangerous drugs, such as morphine and opium.

And now we come to a whole host of effective methods, all of which may be classed as comparative. The comparative method is as old as thought itself, but it is strange that even scientists did not begin to use it consciously and consistently until almost the present generation. Nowhere is it better illustrated than in modern psychology. Most of the so-called branches of psychology are merely different forms of the comparative method of treatment. “Abnormal psychology” is merely a comparison of abnormal mental types with normal mental types for the light they throw on each other. “Child study” is a comparison of the mind of the child with that of the adult. “Animal psychology” is a comparison of the actions of animals with each other and with those of man. And none of these methods is of any value except in so far as it makes use of comparison.

Often consciously used in the consideration of problems is the so-called historical method. This method, as its name implies, consists in obtaining knowledge of a thing by considering its past record. The word history is popularly used in so narrow a sense, however, being restricted only to the history of nations, and often merely to the political history of nations, that we can avoid confusion by calling this method the evolutionary. In the final analysis the method is comparative, for it really consists in comparing a thing at one period of development with itself at another period.

Let us take our example from political science. The historical method, in its popular sense, has been so much used here, even to the exclusion of other methods, that it would seem needless to speak of it. But often the method has been abused and often it has not been given broad enough treatment. It traces the growth of an institution, or of an idea—personal liberty, say,—through successive periods. It notes what the path has been, and judges of the probable future tendency. But a far broader outlook than we get from this narrowly conceived “historical” method is furnished by evolutionary sociology. Here we inquire into the origin of society and of the various trades, industries, professions and pursuits of all kinds, and to do this we go far into prehistoric times.

Nowhere is the evolutionary method more strikingly seen than in biology. Since Darwin’s great theory was promulgated the science has gone forward by leaps and bounds. We have derived untold benefit from a comparison of man and animals in the light of this hypothesis; even study of the development of individual man has been aided. The discovery of the fact of evolution constituted an incalculable advance, but the method for study which it furnished was of even greater importance.

I have spoken of the comparison of man and animals “in the light of this (evolutionary) hypothesis.” This brings us to a point which must be kept in mind in practically all observation. We are often exhorted to “observe.” Presumably we are to do this “on general principles.” Such advice is about as foolish as asking us to think on general principles. Imagine for the moment what would happen if you started right now to “observe” as much as you could. You might begin with this book and notice the size of the type, the amount of margin, the quality of the paper, the dimensions of the page, the number of pages. But you have by no means exhausted the number of properties possessed by this book. You must observe that it is also combustible, that it is destructible, that it is machine made, that it is American printed, that it is such and such a price, that it weighs so many ounces, that it is flat, that it is rectangular, that its thickness is so much. . . .

The absurdity is obvious. If we started out merely to observe, with no definite purpose in mind, we could keep it up forever. And get nowhere. Nine out of every ten observations would never be put to use. We would be sinfully wasting our time. To observe most profitably, just as to think most profitably, we must have a definite purpose. This purpose must be to test the truth of a supposition. A concrete example will make this clear.

A man has been shipwrecked on an island and believes himself to be alone there. One day, as he is walking along the beach, he discovers footprints. How did they get there? His first assumption is that they are his own. It occurs to him, however, that he had not been near this spot for over a week, and that yesterday’s storm would have washed any footprints away. This objection is confirmed by making a footprint himself and comparing it with the one observed, and noticing that they differ markedly. The footprints being those of some one else, how did the man who made them get there? The first supposition is that he came in a boat. The idea of a small boat is dismissed because of the assumed great distance of this island from other land. Therefore the man must have come in a large vessel. But the footprints lead to a wet part of the sand and the tide is just going down. In this case they are very recent—made not more than a half hour ago. This being so the man who made them could not have had time to get back to any ship and sail out of sight. If he came in a ship it should be still in view. The discoverer of the footprints climbs a tree from which he can view the sea around the entire island. He can sight no vessel. The supposition or hypothesis that the unknown came in a ship is abandoned. Then the suggestion comes that the unknown has been on the island during the entire time that the shipwrecked man thought himself alone. This suggestion is tested in a manner similar to the others. . . .

The example sums up roughly the general process of all thought, and brings out the motive and value of observation. Let us analyze it.

The first thing to happen is the arousal of a feeling of perplexity, the appearance of a problem. The man has been shambling along, doubtless “thinking” in that loose sense referred to. He has perhaps kicked several stones loose that would have set a geologist worrying, and has picked branches from bushes which would have puzzled a botanist. But this man has not had his curiosity aroused until he has come to these footprints. His thinking starts with his perplexity. After this doubt has been aroused the most obvious solution suggests itself—“my own footprints.” But if true, this suggestion involves the co-existence of other facts, some of which are known and some of which may be determined. Thus, if they were his own footprints, it must, among other things, necessarily follow (1) that he had been at that spot before, (2) that nothing had happened since that time to remove the prints, (3) that the footprints corresponded to his own. The first consequence involved—that he had been there before—was a fact, but the others were not, and so the suggestion was dropped. Then a second hypothesis occurred—“the man came in a ship”—and this was tried out in a similar way. Notice that in each case the consequences dependent on the truth of the suggestion are tried out (1) by memory, (2) by observation or experiment. Memory came when he thought of the last time he had walked near the beach and of yesterday’s storm. Observation came when he compared his footprint with the one seen, when he followed the footprints along the sand and noticed where they led, when he climbed a tree and looked for a ship. There were a number of other things which he could have observed. He might have noticed the texture of the sand, what kind of a tree he was climbing, what sort of clouds were in the sky. But he did not observe these interesting things simply because they would throw no light on the truth or falsity of his supposition. In another problem one of these facts might have been of value.

It is almost possible to sum up the whole process of thinking as the occurrence of suggestions for the solution of difficulties and the testing out of those suggestions. The suggestions or suppositions are tested by observation, memory, experiment. Supposition and observation alternate. The first facts observed—in the case foregoing, the footprints—make the problem, they suggest the supposition. A supposition is that the man came in a boat. If the man came in a boat such and such would be the case—the boat would still be visible, etc. If the boat is not visible the supposition is given up and another one made; if the boat is visible the supposition is confirmed. This is a case of simple and rudimentary thinking, but it illustrates roughly the process of thought on even the most complicated problems of science. The methods we have been discussing may all be considered simply as means for helping good suggestions occur to us.

Let us illustrate by considering a few methods of rather restricted application. We are often aided in the solution of a problem by asking its opposite. If we ask ourselves “What constitutes gracefulness?” we may find ourselves at a loss for suggestions, because gracefulness always seems “so natural.” But if we ask its opposite, “What constitutes awkwardness?,” suggestions are more apt to occur. If we find, for instance, that awkwardness consists in undue bodily effort in making a movement, we may assume that gracefulness consists in ease of movement. In the same way the question of what makes us forget may be helped by asking ourselves what makes us remember, and light may be thrown on the causes of success in business and in life by a study of the causes of failure.

The method of analogy likewise encourages suggestions. Analogy consists in noting certain likenesses between things, and assuming that they also possess other common qualities. Striking use of analogy is made in dealing with the planet Mars. At each pole there are great white patches. The size of these varies markedly with the seasons, which suggests that like the earth, Mars has great areas of ice and snow at its two poles which melt and re-form. The general surface is reddish, but three-eighths of it is covered by blue-green tracts, and these are usually inferred to be seas. These again are connected by an intricate system of blue-green lines, which some scientists believe to be canals, but on this there is much controversy. In Mars we have at once an illustration of the possibilities and dangers of analogy.

In the whole discussion of constructive method thus far, I have left out the two most common and useful methods of all. The first of these we may designate by a somewhat formidable title: empirical observation. Empirical, at least for our present purposes, means merely that which comes within experience. But the term is generally opposed to scientific. Thus Dewey gives an example: “A says, ‘It will probably rain to-morrow.’ B asks, ‘Why do you think so?’ And A replies, ‘Because the sky was lowering at sunset.’ When B asks, ‘What has that to do with it?’ A responds, ‘I do not know, but it generally does rain after such a sunset.’ He does not perceive any connection between the appearance of the sky and the coming rain; he is not aware of any continuity in the facts themselves—any law or principle, as we usually say. He simply, from frequently recurring conjunction of the events, has associated them so that when he sees one he thinks of the other.”

This, however, is not what I mean to imply by the term empirical observation. I mean rather thinking on the basis merely of facts which occur in the natural course of events, which have not been systematically produced by ourselves or others for the purpose of solving a problem. Logicians usually call this method simply observation, and oppose it to experiment. But I object to calling this simply observation because experiment itself is really observation, only in one case we observe merely events which happen to occur, and in the other we observe the results of events which we have made occur. The true way of distinguishing these two methods would be to call one empirical observation, and the other experimental observation.

This empirical method—if indeed I am justified in calling it a method—is the most common in all thinking. To give examples of it would be to show how men generally think. But the method has real value, and may even be the most important of all, for if we thought without it our ideas would doubtless be original, but very dangerous. Let us apply it to some of the problems considered under other methods.

Empirical observation is used where experiment is impossible—often, unfortunately, where experiment is merely inconvenient. In political science the empirical method would consist in noting the effect of certain laws,—e.g., tariffs of different countries and of the same country at different periods—and noting economic conditions at the time the different tariffs were in effect. Allowance would be made for other factors which could influence the country’s economic condition and the effect of the tariff could then be determined.

The empirical method of dealing with meteorology, the science of weather, would consist in making a study of cloud formations, wind velocity, moisture in the air, temperature, etc., and noting what conditions usually or perhaps invariably followed certain of these conditions. From this, conclusions could be drawn as to what weather to expect following certain conditions.

But valuable as empirical observation is, and often as we must use it, it should never be employed when we can experiment. When the empirical method is rightly used allowance always has to be made for certain irrelevant factors. But “making allowances” is always sheer guess work. The experimental method consists not in making allowances for certain factors, but in eliminating those factors. In our example from political science experiment is practically impossible, because the factors which may influence economic conditions are innumerable, and even were they few, no country could survive the dangers of being experimented upon—to say nothing of its permitting it. Experiment is similarly impossible in dealing with weather conditions directly. It is impossible in astronomy.