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 consideration 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 independently, 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 considerations 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 characteristics, acquired during the lifetime of an individual, inherited by his offspring? I have referred so often to this problem and its importance that further explanation is hardly necessary. “Characteristics” of course refer to intellectual and moral as well as physical characteristics.