This whole development has been the work, not so much of a spontaneous creative evolution, as of blind natural selection. The statesman, the executive, the party leader, the head of a voluntary association, found that if he had to discuss two dozen different subjects in the course of the day, somebody would have to coach him. He began to clamor for memoranda. He found he could not read his mail. He demanded somebody who would blue-pencil the interesting sentences in the important letters. He found he could not digest the great stacks of type-written reports that grew mellow on his desk. He demanded summaries. He found he could not read an unending series of figures. He embraced the man who made colored pictures of them. He found that he really did not know one machine from another. He hired engineers to pick them, and tell him how much they cost and what they could do. He peeled off one burden after another, as a man will take off first his hat, then his coat, then his collar, when he is struggling to move an unwieldy load.
Yet curiously enough, though he knew that he needed help, he was slow to call in the social scientist. The chemist, the physicist, the geologist, had a much earlier and more friendly reception. Laboratories were set up for them, inducements offered, for there was quick appreciation of the victories over nature. But the scientist who has human nature as his problem is in a different case. There are many reasons for this: the chief one, that he has so few victories to exhibit. He has so few, because unless he deals with the historic past, he cannot prove his theories before offering them to the public. The physical scientist can make an hypothesis, test it, revise the hypothesis hundreds of times, and, if after all that, he is wrong, no one else has to pay the price. But the social scientist cannot begin to offer the assurance of a laboratory test, and if his advice is followed, and he is wrong, the consequences may be incalculable. He is in the nature of things far more responsible, and far less certain.
But more than that. In the laboratory sciences the student has conquered the dilemma of thought and action. He brings a sample of the action to a quiet place, where it can be repeated at will, and examined at leisure. But the social scientist is constantly being impaled on a dilemma. If he stays in his library, where he has the leisure to think, he has to rely upon the exceedingly casual and meager printed record that comes to him through official reports, newspapers, and interviews. If he goes out into "the world" where things are happening, he has to serve a long, often wasteful, apprenticeship, before he is admitted to the sanctum where they are being decided. What he cannot do is to dip into action and out again whenever it suits him. There are no privileged listeners. The man of affairs, observing that the social scientist knows only from the outside what he knows, in part at least, from the inside, recognizing that the social scientist's hypothesis is not in the nature of things susceptible of laboratory proof, and that verification is possible only in the "real" world, has developed a rather low opinion of social scientists who do not share his views of public policy.