The man who cannot wonder, who does not habitually wonder, is but a pair of spectacles behind which there is no eye.—Carlyle.

Up to now I have treated exclusively of how to think, but have made no mention of what to think. I have treated of the best methods of dealing with different subjects and questions; I have not considered what subjects or problems are most worth dealing with.

Of course the important thing is that you do think. It is not absolutely essential that the results of your thinking are results which can be directly made use of. Thinking is an end in itself. Most men imagine that “thinking for the sake of thinking” may appeal to philosophers, but means nothing to them, as they like to think only when by so doing they can forward some practical end. These people do themselves an injustice.

Perhaps you, O reader, are among them. If so, let me appeal to your personal experience. Have you ever tried to solve a toy puzzle, tried to take the two wire hooks apart without bending them? Or have you ever stopped to tackle a problem on the family page of your evening or Sunday newspaper? “A grocer buys fifteen dozen eggs, he sells—” you know what I mean. You admit that you have. Exactly. You have been thinking for the mere sake of thinking.

If you protest that you didn’t care about the thinking, that you took no pleasure in the thinking, which was merely incidental, but that what really urged you on and gave you pleasure was the solution of the puzzle, you are again deceiving yourself. The thinking was not incidental. Thinking and problem solving are identical. The fact is that you set yourself to solving a problem, to removing a mental hindrance, for the mere sake of getting the answer, with absolutely no thought of what you were going to do with the answer when you got it.

But if you can derive so much pleasure from thinking which you cannot put to use, how much greater should be your pleasure when your conclusions can be utilized? For when you think of something useful, you have not only the present pleasure of solving your problem, but the ulterior pleasure of applying your solution to action, or to the solution of some further problem. And while I again admit that thinking is an end in itself, this does not prevent it from being at the same time a means to some further end. After all is said there is really no reason why we should be prejudiced against problems or subjects that are useful.

The mere decision that we should think of useful questions is insufficient. Very few questions are without some use. Even the solution of the family page puzzle might some day be useful in solving a similar problem arising in your own business; and even if this never came to pass you might spring the puzzle on your friends, and make yourself socially more interesting. Thought given to a question in a debating book now before me, “Resolved, that Ferocious Wild Beasts are more to be dreaded than Venomous Reptiles,” might result in knowledge which would come handy in selecting equipment if one decided to journey to the wilderness of South America. But there are millions of problems of as much use as these; and it is not within the power of one lone mortal, of years three score and ten, to compass even a corner of them. Our question is not—what problems are of use?, but—of how much use are certain problems?, or stated in another way,—what is the relative utility of problems?

Any adequate con-si-der-a-tion of this question would involve the selection of some criterion for utility, and the testing of individual problems by that criterion. But to treat such a question with anything like justice is beyond the scope of this book; it would require almost a volume in itself. It is almost the same as the problem, What knowledge is of most worth?, and the most masterly treatise on that question which has ever been written can be found in Herbert Spencer’s epoch-making little work, Education. I sincerely hope that the reader study this. But I hope even more earnestly that before he does so he first think the problem out in-de-pen-dently, for it is one of the most important he can put before himself.

But our present question—that of the relative importance of problems—is slightly different from that of the relative importance of knowledge. The first deals with thought and the second with information, or the materials of thought; the first with a process of getting knowledge and the second with knowledge itself.

I believe for example that a knowledge of his own body and of the laws of health is the most valuable a man can have, but there are few problems concerning the body which I would include in the first rank. There are several reasons for this. In the first place, while it may be true that such questions taken as a whole are more important than any other class of questions, taken separately they are relatively minor; there are no one or two questions of all-encompassing importance to which all the others are subsidiary. Moreover, such questions, while they undoubtedly require thought for their solution, depend to a relatively great extent on observation and experiment. No sane medical student would sit down and follow out a lengthy course of reasoning as to where the heart is; he would merely observe or dissect, or consult the book of a man who had dissected, and save mental fatigue. Not least of all, questions of physiology require extensive, highly technical and detailed information—information which requires years of special study to acquire—before any thinking that is at all safe can be put upon them. So in estimating the relative value of problems, there are other con-si-der-a-tions besides the value of knowledge.

But it is not my purpose here to discuss the general principles upon which the selection of worth-while questions should be made. That task I leave to the reader. I have chosen rather the concrete path of suggesting a list of questions which I consider of great import. I believe that no matter how much thought the reader gives to any one of them he will not be losing his time.

I have elsewhere pointed out that the more knowledge a man has the more problems he will have. It is equally true that unless a man has some knowledge on a subject he will not be able to appreciate or even understand some of its most important problems. It is only when we begin to think of subjects that we discover problems and realize their significance. In stating most of the following problems, therefore, I have often thought it necessary to add a few sentences in explanation, and have sometimes stated a question in a variety of forms in order to more clearly convey the thought.

Are specific char-ac-ter-is-tics, acquired during the life-time of an in-di-vi-dual, in-herited by his off-spring? I have re-ferred so often to this problem and its im-por-tance that further ex-pla-na-tion is hardly nec-es-sary. “Char-ac-ter-is-tics” of course refer to in-tel-lec-tual and moral as well as physical char-ac-ter-is-tics.

What is the influence of the individual mind on society and of social environment on the individual?

Does the form of government determine the character of a people, or does the character of a people determine their form of government? Or do government and character react on each other, and how? The same question may be asked of all other social institutions. Does the religion of a people determine their character, or does the character of a people determine their religion? This whole problem is somewhat similar to that immediately preceding, regarding the interaction of the individual and the social mind.

Is society for the benefit of the individual or is the individual for the benefit of society?

Should the jurisdiction of the government be extended or curtailed? Or should it be extended in some directions and curtailed in others? Does the answer to this problem depend on the answer to the previous one? Another form of the same problem is: What is the proper sphere of government?

Should the government grant monopolies? Patents, for example?

What would be the most practicable plan for abolishing or minimizing war? Those who do not wish to beg the previous question may first ask whether it is always desirable to prevent war, whether war is always an evil. What is the effect of war on the physical future of the race? on national and individual character? on government? on national liberty? on personal liberty? What are the ethics of war? for aggression? for territorial conquest? for “national honor”? for defense of a weaker nation? for defense against invasion? What is the ef-fect of pre-pared-ness? of un-i-versal pre-pared-ness? of pre-pared-ness of an in-di-vi-dual nation? In each case what are the principles on which the extent of pre-pared-ness should be de-termined? What are the fun-da-men-tal causes of war? How can they be removed? Is it pos-sible to remove all of them?

Which is the rightful owner of land, the community or the individual? To state the problem in another form: Should private land ownership be abolished?

Who should be entitled to vote? This of course is a question similar to woman suffrage, but it is much broader. It deals not only with the qualification of sex, but of age. Should any one under twenty-one have the vote? The validity of property and educational qualifications should also be considered.

How should the relations of the sexes be regulated? Put in slightly narrower and perhaps less objectionable form: What would be just laws governing marriage and divorce?

What is the effect of attempted State interference with the law of supply and demand? Does the un-re-strict-ed working out of this law forward ultimate justice? Just what is the validity and the meaning of the expression “The law of supply and demand”? The question could be taken up in connection with minimum wage laws, railroad rate regulations, “extra crew” laws, etc.

Which is the best policy: free trade, rev-enue tar-iff, or pro-tec-tive tar-iff? Or under what con-ditions is each best? With what classes of com-mo-dities?

What would be an equitable and sound currency system? This question is somewhat technical, and would have to be considered in the form of a number of subsidiary problems. Ought money to have an intrinsic value? What is the effect of “fiat” paper currency on money of intrinsic value and on prices? The effect of credit? The effect of fluctuations in the supply of gold? Ought there be a double standard or a multiple standard? etc.

Should conduct be judged by the pleasure or happiness it yields? Stated in another form, almost a different problem: Is utility a good moral guide?

Should conduct be judged by its tendency to produce individual well-being, or should it be judged by its tendency to produce the well-being of all humanity, or of all sentient beings? This problem cannot be lightly dismissed in favor of universal well-being. This becomes apparent when we attempt to give an undogmatic and non-question-begging answer to the query: Why should a man act for the benefit of others?

No science is more provocative of thought than ethics. The question of whether acts should be declared good or bad as they tend to produce pleasure or happiness, either individual or in humanity as a whole, or whether “virtue” or “morality” is an end in itself, is one of the most subtle and elusive we can attempt to solve; no matter which answer we give we are brought into logical and psy-cho-log-i-cal dilemmas from which it seems impossible to escape. This is also true of the problem of whether our knowledge of what constitutes right and wrong comes from experience or from intuition.

The broadest form of the ethical problem, which includes the two preceding italicized problems, is:

What is the proper criterion for determining right and wrong conduct? Or even less dogmatic: Can there be a criterion for determining right and wrong conduct, and what is it?

Somewhat allied with the ethical problem is that problem of problems: how to live? By this is meant how to put the most into life and get the most out of it; what vocation to follow; what hobbies, amusements, avocations to take up; how to plan time by months, by weeks, by days, by hours. How much time and energy do certain activities deserve? How much can we afford to give them? Restated: what activities are of most worth?

Of course every one does think of problems connected with the art of living. But he thinks of them as little unconnected questions. Barely indeed does any one go about the solution of the general problem of living in an orderly, sys-tem-at-ic manner. To insist upon the broad practical bearings of the problem would be unnecessary, absurd. By its very nature it is the most “practical” question we can ask. Any par-tic-u-lar solution or treatment may be impractical, but this does not affect the question itself.

What are the respective influences of environment (education, experience, etc.) and innate tendencies in determining character? Which is the greater determinant?

Does pleasure depend upon the satisfaction of instinctive desires, or do desires for certain activities depend upon the pleasure accompanying the previous performance of such activities? Does an activity or the possession of an object give us pleasure because we have previously desired it, or do we desire an activity or an object because we have previously obtained pleasure from it? Or do pleasure and desire interact, and just how? The solution of this psy-cho-log-i-cal problem is of tremendous importance in ethics.

Does the mind depend entirely on the brain? That is, are all thoughts, emotions, feelings, due to material changes in the brain? The answer we give to this problem may determine our answer to the question of immortality.

What knowledge is of most worth? I have so fully discussed the importance of this question and the method of proceeding with its solution that further explanation is needless.

One sphere of thought where the thinker is compelled to be original; where it is practically impossible for him to fall into beaten tracks, is invention. But there is useless as well as useful invention. A man’s ambition may range all the way from inventing a machine to harness directly the limitless power of the sun, down to devising a tenacious tip for shoelaces. But he should be careful about inventing something already patented. He should be even more careful to avoid inventing something for which there is no demand. One of Edison’s first patents was for a machine to register quickly the votes of legislative assemblies. And it worked. But the legislative assemblies didn’t want it, because they didn’t want their votes quickly registered. That would have ended good old filibuster methods. Another invention of great uselessness which has been several times attempted is a machine to write words just like the human hand writes them. There are really so many useful things which do not exist and for which there is a demand, that it seems quite a pity nine out of ten patents in the files at Washington are for things inutile. If the would-be inventor cannot himself think of something really needed, almost any big patent attorney house will send him an entire book of sug-ges-tions on “What to Invent.”

Invention usually requires highly technical knowledge, not to speak of facilities for experiment and a well-supplied purse. But nothing gives more solid satisfaction to its creator than a successful appliance. While the conscientious philosopher is constantly harassed by doubts as to whether, after all, he has discovered truth; the inventor need not worry. His machine either works or it does not work, and he knows the truth of his thought thereby. On the other hand the philosopher will always have some thoughts. Be they true or not they may at least be interesting and worth recording, whereas the inventor may toil on for years and years with absolutely nothing to show for his exertion at the end. . . .

There are a number of problems that are not of great “practical” importance, but whose theoretic value is so transcendent as to compel attent............