If there is one service greater than another that Herbart has rendered to education, it is in bringing clearly to our consciousness the supreme importance of the principle of apperception, or mental assimilation, as a working basis for educative processes. So long as a fact or a principle or system of knowledge stands as an end in itself, just so long is it a thing apart from the real mental life of the child. Even a formally correct method of presentation, should it even appeal at once to all ‘six’ classes of interest, will fail to create more than a factitious mental enthusiasm. It is like conversation that is ‘made’ interesting; it may suffice to lighten a tedious hour, but it awakens no vital response. When, however, the natural love of novelty or inborn response to the true is reinforced by a sense of warm personal relationship, when the facts of forest, or plain, or mine, or animal life flood the mind with unexpected and significant revelations concerning either the present or the past in close personal touch with the learner, then instruction rests upon an apperceptive basis. Abstractions that before were pale, beauties that were cold, now receive color and warmth because they get a new subjective valuation that before was impossible. A sedate sheep nibbling grass or resting in the shade, a skipping lamb gambolling on the green, are suitable objects of nature study. Their pelts, their hoofs, their horns, their wool, are worthy of note as scientific facts. A diluted interest may even be added by recitation of the nursery rhymes about “Little Bo-Peep” and “Mary had a Little Lamb.” But these are devices for the feeble-minded. If the teacher can reveal to the pupil the function of wool in making garments for the race, and can lead him to repeat the processes by which, from time immemorial, the wool has been spun into yarn and woven into cloth; if, at the same time, the influence of this industry upon the home life, both of men and women, can be shown, the study of the sheep becomes worthy the attention even of a boy who can play foot-ball or of a girl who can cook. The literature of the sheep is no longer infantile or fatuous. We have a gamut reaching from Penelope to Priscilla. In the words of Professor Dewey: “The child who is interested in the way in which men lived, the tools they had to do with, the transformation of life that arose from the power and leisure thus gained, is eager to repeat like processes in his own action; to make utensils, to reproduce processes, to rehandle materials. Since he understands their problems and their successes only by seeing what obstacles and what resources they had from nature, the child is interested in field and forest, ocean and mountain, plant and animal.... The interest in history gives a more human coloring, a wider significance, to his own study of nature.”[34]