=Expression at Times Inhibited.=--It is to be noted that the child should early learn to form intelligent plans of action and postpone or even condemn them as forms of expression. In other words, a child should early learn to select and co-ordinate ideas into an orderly system independently of their actual expression in physical action. Without this power to suppress, or inhibit, expression, the child would be unable adequately to weigh and compare alternative courses of action and suppress such as seem undesirable. Such indeed is the weakness of the man who possesses an impulsive nature. Although, therefore, it is true that all knowledge is intended to serve in meeting actual needs, or to function in the control of expression, it is equally true that not every organized experience should find expression in action. Part at least of man's efficiency must consist in his ability to organize a new experience in an indirect way and condemn it as a rule of action. While, therefore, we emphasize the importance, under ordinary conditions, of having the child's knowledge function as directly as possible in some form of actual expression, it is equally important to recognize that in actual life many organized plans should not find expression in outer physical action. This being the case, the divorce between organized experience, or knowledge, and practical expression, which at times takes place in school work, is not necessarily unsound, since it tends to make the child proficient in separating the mental organizing of experience from its immediate expression, and must, therefore, tend to make him more capable of weighing plans before putting them into execution. This will in turn habituate the child to taking the necessary time for reflection between "the acting of a thing and the first purpose." This question will be considered more fully in Chapter XXX, which treats of the development of voluntary control. It should be noted in conclusion that the law of expression as a fourth stage of the learning process differs in purpose from the use of physical action as a means of creating interest in the problem, as referred to on page 62. When, for instance, we set a pupil who has no knowledge of long measure to use the inch in interpreting the yard stick, expressive action is merely a means of putting the problem before the child in an interesting form on account of his liking for physical action. When, on the other hand, the child later uses the foot or yard as a unit to measure the perimeter of the school-room, he is applying his knowledge of long measure, which has been acquired previously to this expressive act. CHAPTER XIII FORMS OF LESSON PRESENTATION