A Few Principles. - The aim of education is the development of power beneficent to the social organism.

To have power in a certain field of activity is equivalent to reacting in the proper way on stimuli pertaining to that field. We may therefore think of education as having a twofold aim: first, to teach how to react; and second, to secure the taking place of the proper reaction. In other words, the result of education should be knowledge plus will-power.

Let us examine very briefly the role interest in the stimulation plays in regard to these two aspects.

A few quotations from Baldwin's "Mental Development" will throw some light upon how new accommodations are secured, and the relation of interest to the acquisition of knowledge.

The accommodation of an organism to a new stimulation is secured, apart from happy accidents, by the continued or repeated action of that stimulation. We must suppose the development of a function of coordination by which the two regions excited respec-tivelv by the original suggestion and the reaction first made coalesce in a common more voluminous and intense stimulation of the motor centre. A movement is thus produced which, by reason of its greater mass and diffusion, includes more of the elements of the movement seen and copied. This is again reported by eye orear, giving a new excitement which is again coordinated with the original stimulation, and with the after effects of earlier stimulations. The result is yet another stimulation or effort of still greater mass and diffusion which includes yet more elements of the "copy." And so on until simply by its increased mass, including the motor excitement of attention itself, by the greater range and variety of the motor elements thus enervated, - in short, by the excess discharge, - the copy is completely reproduced, the effort being successful. Observe a child trying to accomplish a difficult exercise. His "whole physical personality becomes concentrated, followed by convulsive' dicharge upon the member which, by habit or previous use, is nearest to the copy requirement He rolls his tongue, bites his lip. sways his body, works his legs, winks his eyes, etc., until every scheming nerve and tendon bends to the task.

An examination of the child's earliest voluntary movements shows the growth in mass, diffusion, and lack of precision which this theory requires. In acquiring the associations of elements involved in successful handwriting, for instance, the young child uses hand, then hand and arm, then hand, arm. tongue, face, and finally the whole body.

The effort thus succeeds by the simple fact of increased mass and diffusion of reaction, the useless elements fall away because they have no emphasis. The desired motor elements, on the other hand. are reinforced by their agreement with the copy, by the dwelling of the attention upon them, by the pleasure which accompanies success. Or to restate the above principle of development in another sentence of Baldwin's, it reads: Our organism begins with a susceptibility to certain organic stimulations such as food, oxygen, etc.; these when present give pleasure, the pleasure is, physiologically considered, a heightened vitality in the central nuclear processes; this heightened central vitality issues in a motor discharge; from the resultant, abundant, and varied movements of this exeess discharge, those are selected which bring more of these vital stimulations again, and these finally keep up the vitality of the organism and by the repeated excess movements provide for constantly progressive adaptations.

Pleasure, he says, is physiologically considered a heightened vitality in the central nuclear processes, and this increased nervous vitality means, of course, a greater facility for accommodation, that is, a greater facility for acquiring new ideas.

This throws some light in a mosl general way upon the role interesl in the stimulation plays in acquiring knowledge.

The other phase of power is the part played by the will. What significance has interest in the training of the will ?.

Through the fact that some stimulations appear pleasurable and others painful, there exists on the part of the organism a desire to repeat certain movements or reactions which brought about the pleasurable stimuli. Thus we secure the voluntary repetition of certain reactions through the attitude of the organism toward previous stimulations.

This shows the intimate relation of interest to the development of will-power. The development of power is therefore conditioned, in the first place, by the attitude of the child toward the stimulation. We have seen that interest means a greater mental activity, and also the possible voluntary repetition of the reaction in the future. The acquisition of knowledge and the training of the will are both to a great extent conditioned by this attitude of interest.

The question how to insure a continued interest is therefore of vital importance. What are the conditions underlying this attitude; in other words, what is interesting?

In a general way it is true that the useful reactions are the interesting ones. If it were not so life would soon disappear. But this general statement helps us little, as we continually see apparent exceptions to that rule.

We may distinguish three stages of interest in the child's life. What gives pleasure at one stage may not at another.

In the earliest childhood the chief source of interest or pleasure, giving rise to innumerable movements, is the healthy activity of function. At a later stage the result of the movement is the vital point. If it is successful, it gives pleasure. The consciousness of power is beginning to appear at that stage, and the organism is beginning to strive for self-realization. That which manifests his power is interesting. At a still later stage past pleasures attained through a certain activity, together with the ease with which the reaction takes place through habits previously formed, will strengthen the impulse to be reacted upon again. In other words, we are interested in what we can do easily and well. Thus interest depends upon power.