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?