knowledge of Mars represents a baby's acquaintance with the room in which he stays. In the second place, the method of organization of the material of achieved scholarship differs from that of the beginner. It is not true that the experience of the young is unorganized—that it consists of isolated scraps. But it is organized in connection with direct practical centers of interest. The child's home is, for example, the organizing center of his geographical knowledge. His own movements about the locality, his journeys abroad, the tales of his friends, give the ties which hold his items of information together. But the geography of the geographer, of the one who has already developed the implications of these smaller experiences, is organized on the basis of the relationship which the various facts bear to one another—not the relations which they bear to his house, bodily movements, and friends. To the one who is learned, subject matter is extensive, accurately defined, and logically interrelated. To the one who is learning, it is fluid, partial, and connected through his personal occupations. The problem of teaching is to keep the experience of the student moving in the direction of what the expert already knows. Hence the need that the teacher know both subject matter and the characteristic needs and capacities of the student.
2. The Development of Subject Matter in the Learner.—It is possible, without doing violence to the facts, to mark off three fairly typical stages in the growth of subject matter in the experience of the learner. In its first estate, knowledge exists as the content of intelligent ability—power to do. This kind of subject matter, or known material, is expressed in familiarity or acquaintance with things. Then this material gradually is surcharged and deepened through communicated knowledge or information. Finally, it is enlarged and worked
- Since the learned man should also still be a learner, it will be understood that these contrasts are relative, not absolute. But in the earlier stages of learning at least they are practically all-important.