75. The primitive or original attention depends primarily on the strength of the sense-impression. Bright colors and loud speaking are more easily noticed than dark colors and low tones. It would be an error, however, to infer that the strongest sense-perceptions are at the same time the most adequate. These quickly blunt the receptivity, while weak sense-impressions may, in the course of time, engender ideation as energetic as that produced by originally obtrusive perceptions. For this reason, a middle course must be chosen from the first. For children, however, the direct sense-perception, even of a picture, if the object itself is not to be had, is altogether preferable to mere description. The presence in the minds of children of ideas--those supplied by instruction itself not excepted--contrary to the new representations to be mastered, acts as a hindrance or check. This very fact explains why clearness of apprehension is not gained where instruction piles up one thing upon another in too rapid succession. It is essential, therefore, in the case of beginners, so to single out each fact, to separate part from part, and to proceed step by step, that apprehension may be rendered easy for them. A second hindrance to attention is of a more temporary character, but may nevertheless work much mischief. It makes a vast difference whether the ideas aroused are in a state of equilibrium or not. Long sentences in speech and in books are less easily apprehended than short ones. They excite a movement of many albeit connected thoughts, which do not at once subside into their proper places. Now, just as in reading and writing pauses must be observed, which is done more easily in short than in long sentences, instruction in general must have its chosen stopping-places and resting-points at which the child may tarry as long as may be necessary. Otherwise the accumulation of thoughts will become excessive, crowding in upon what follows, and this upon the next new element, until finally the pupils arrive at a state where they no longer hear anything. 76. The four essentials then for primitive attention are: strength of sense-impression, economy of receptivity, avoidance of harmful antitheses to existing ideas, and delay until the aroused ideas have recovered their equilibrium. But in actual teaching it will be found difficult to do justice to all of these requirements simultaneously. Sameness of presentation should not be carried too far lest the child’s receptivity be taxed too heavily. Monotony produces weariness. But a sudden change of subject frequently discloses the fact that the new is too remote from what has preceded, and that the old thoughts refuse to give way. If the change is delayed too long the lesson drags. Too little variety causes ennui. The pupils begin to think of something else, and with that their attention is gone completely.