To begin at the beginning, we may start from the commonplace that every form of economic labor in the workshop and in the factory, in the field and in the mine, in the store and in the office, must first be learned. How far do the experiments of the psychologist offer suggestions for securing the most economic method of learning practical activities? Bodily actions in the service of economic work are taught and learned in hundreds of thousands of places. It is evident that one method of teaching must reach the goal more quickly and more reliably than another. Some methods of teaching must therefore be economically more advantageous, and yet on the whole the methods of teaching muscular work are essentially left to chance. It is indeed not difficult to observe how factory workers or artisans have learned the same complex motion according to entirely different methods. The result is that they carry out the various partial movements in a different order, or with different auxiliary motions, or in different positions, or in a different rhythm, or with different emphasis, simply because they imitate different teachers, and because no norm, no certainty as to the best methods for the teaching, has been determined. But the process of learning is still more fluctuating and still more dependent upon chance than the process of teaching. The apprentice approaches the instruction, in any chance way, and the beginner usually learns even the first steps with a psychophysical attitude which is left to accident. An immense waste of energy and a quite anti-economic training in unfit movements is the necessary result.