Page:Popular Science Monthly Volume 11.djvu/411

Rh where, how, and why, we are wrong, is the teacher's most indispensable function.

3. The only mode of arriving at a new constructive combination is to try and try again. The will initiates some movements; these are found not to answer, and are suppressed; others are tried, and so on, until the requisite combination has been struck out. The way to new powers is by trial and error. According as the first and second conditions above given are realized, the unsuccessful trials are fewer. If we have been well led up to the combination required, and if we have before us a very clear idea of what is to be done, we do not need many tentatives; the prompt suppression of the wrong movements ultimately lands us in the right.

The mastering of a new manual combination—as in writing, in learning to swim, in the mechanical arts—is a very trying moment to the human powers; success involves all those favorable circumstances indicated in discussing the retentive or receptive faculty. Vigor, freshness, freedom from distraction, no strong or extraneous emotions, motives to succeed—are all most desirable in realizing a difficult combination. Fatigue, fear, flurry, or other wasting excitement, does away with the chances of success.

Very often we have to give up the attempt for a time; yet the ineffectual struggles are not entirely lost. We have at least learned to avoid a certain number of positions, and have narrowed the round of tentatives for the next occasion. If, after two or three repetitions, with rest-intervals, the desired combination does not emerge, it is a proof that some preparatory movement is wanting, and we should be made to retrace the approaches. Perhaps we may have learned the prerequisite movements in a way, but not with sufficient firmness and certainty for securing their being performed in combination.

—In the accustomed routine of education, a number of separate studies and acquirements are prosecuted together; so that, for each day, a pupil may have to engage in as many as three, four, or more, different kinds of lessons.

The principles that guide the alternation and remission of our modes of exercise and application are apparently these:

1. Sleep is the only entire and absolute cessation of the mental and bodily expenditure; and perfect or dreamless sleep is the greatest cessation of all. Whatever shortens the due allowance of sleep, renders it fitful and disturbed, or promotes dreaming, is so much force wasted.

In the waking hours, there may be cessation from a given exercise, with more or less of inaction over the whole system. The greatest diversion of the working forces is made by our meals; during these the trains of thought are changed, while the body is rested.

Bodily or muscular exercise, when alternated with sedentary mental labor, is really a mode of remission accompanied with an expenditure requisite to redress the balance of the physical functions. The