But the last and main reason why the theory is no good is that it doesn't square with human experience. A narrow classification system invites the danger of overspecialization and lessens the team play which is so indispensable to all military enterprise. It is possible for the machine to break down totally from lack of interchangeability in its parts. We learn much from war, but some of the most obvious lessons are disregarded. One of the things that it should teach us is the tremendous adaptability of the average intelligent man, his ability to take hold of work altogether remote from any prior experience, master it, and find satisfaction in it, provided he is given help and encouragement by those who already know. This is the great phenomenon of war--greater than the atomic bomb or supersonic flight. Former bookkeepers emerge as demolitions men. Divinity students become pharmacist's mates. School teachers operate tanks. Writing men turn into navigators. Woodsmen become lecturers. Longshoremen specialize in tactics. And all goes well. Then when it is all over, and everyone gets back in his well-worn groove, the social scientists explain that these miracles occurred because under the stimulus of great fear and excitement which attends a period of national emergency, individuals will sublimate their main drives, and adjust temporarily to what would be otherwise an onerous personal difficulty. Sheer poppycock! Normal men do not feel pressed by fear simply because a state of war exists; their chief emotions change scarcely at all. These transformations occur only because the man had the potential all along, and with someone backing him up _and giving him the feeling of success_, his incentives became equal, at least, to anything he had known in his peacetime occupation. That is the long-and-short of it. If our average man couldn't become a jack of many trades, and a master of several, the United States would never be able to meet a major war emergency. For these reasons, service concepts of how men should be fitted to jobs do not develop around the simple notion that it is all a matter of putting a square peg in a square hole--which is the one best way to deny the peg any room for expansion. The doctrine is that _men are many sided, that they learn their own powers and likes through experiment, that they are entitled to find what is best for them, and that having found it, their satisfactions will still derive mainly from intelligent and interested treatment by their superiors_. Every officer arrives sooner or later at the point where he has a direct hand in the placement of men. By way of preparation for that responsibility he should do two things mainly--learn all that he can from his superiors about its technical aspects, and in his own thinking, concentrate on principles to the exclusion of detail.