However, the greater part of military operation in present days is noteworthy for the extreme diversity and complexity of its parts, and instead of becoming more simplified, the trend is toward greater elaboration. It is obviously absurd to expect that any officer could know more about radio repair than his repairman, more about mapping than his cartographical section, more about moving parts than a gunsmith, more about radar than a specialist in electronics and more about cypher than a cryptographer. If the services were to set any such unreasonable standard for the commissioned body, all would shortly move over into the lunatic fringe. Science has worked a few wonders for the military establishment but it hasn't told us how to produce that kind of man. Plainly, there must be a somewhat different approach to the question of what kind of knowledge an officer is expected to possess, or the requirement would be unreasonable and unworkable. _The distinction lies in the difference between the power to do a thing well and that of being able to judge when it is well done._ A man can say that a book is bad, though not knowing how to write one himself, provided he is a student of literature. Though he has never laid an egg, he can pass fair judgment on an omelette, if he knows a little about cookery, and has sampled many good eggs, and detected a few that were overripe. "He who lives in a house," said Aristotle, "is a better judge of it being good or bad than the builder of it. He can say not only these things, but wherein its defects consist. Yet he might be quite unable to cure the chimney, or to draw out a plan for his rooms which would suit him better. Sometimes he can even see where the fault is which caused the mischief, and yet he may not know practically how to remedy it." Adjustment to a job, and finally, mastery of it, by a service officer, comes of persistent pursuit of this principle. The main technique is study and constant reexamination of criteria. To take the correct measure of standards of performance, as to the value of the work itself, and as to the abilities of personnel, one must become immersed in knowledge of the nature, _and purpose_, of all operations. There is no shortcut to this grasp of affairs. The sack is filled bean by bean. Patient application to one thing at one time is the first rule of success; getting on one's horse and riding off in all directions is the prelude to failure. All specialists like to talk about their work; the interest of any other man is flattering; all men grow in knowledge chiefly by picking other men's brains. Book study of the subject, specialized courses in the service schools, the instructive comments of one's superiors, the informed criticism of hands further down the line and the weighing of human experience, at every source and by every recourse, are the means of an informed judgment. It was the scientist, Thomas Huxley who reminded us that science is only "organized common sense."