The exercise of any organ or faculty takes place by converting its latent force into active force, which is then given off in the form of "function" (i.e., the action appropriate to the organ or faculty). That this exercise strengthens instead of weakening our faculties, is due to the fact that the withdrawal of latent force by exercise creates an immediate receptivity for new force, which then becomes latent. And, under all ordinary conditions, the new supply taken in is in excess of that given off. This new supply ought to come from extra-human sources (including, of course, but not exclusively consisting of, food and air). A sound method in Education means, chiefly, a method which secures that the recuperation shall come from these extra-human sources. But a teacher may be brilliantly successful at Examinations without understanding how to effect this, or caring to try. There are several non-legitimate ways by which he may be securing his apparent success. He may be draining either the physical vitality of his pupils, or those intellectual faculties which are not needed for the pursuit of his own subject, or the moral faculties, especially those for the exercise of which school-life affords no great scope, but which will be needed for the conduct of adult life. Now when a faculty is thus passively drained at second hand, it suffers the same loss of force as if it were itself exercised; and it is not stimulated to healthy recuperation. Therefore the "successful" teacher may, in reality, be either destroying the physical health of his pupils, or preventing more conscientious and less showy colleagues from attaining the amount of success which they deserve, or preparing his pupils to be bad men and women, and a source of moral corruption; or he may be
