last chapter with the following allusion: "Many years ago I met with a quotation from a German author to the effect that the æsthetic sentiments originate from the play-impulse. I do not remember the name of the author; and if any reasons were given for this statement, or any inferences drawn from it, I can not recall them. But the statement itself has remained with me, as being one which, if not literally true, is yet the adumbration of a truth." The author referred to is the poet Schiller, and the writing in which the idea cited by Spencer occurs is Schiller's Letters on the Æsthetic Education of Man. What Schiller is attempting to explain is not the origin of the "æsthetic sentiments," but the nature of man as an art-producing being. This nature, he thinks, grows out of the union of two impulses: (1) The sense-impulse (Stofftrieb), which determines that there shall be constant change, that time shall have a content; and (2) the form-impulse (Formtrieb), which determines that time shall be abolished, that there shall be no change. From the union of these two impulses in man results the play-impulse (Spieltrieb), which tends to abolish time in time, and to unify becoming with absolute being, change with identity. But we must not expose ourselves too long in the rarefied air of even a poet's metaphysics. Spencer, without knowing his teacher, and kindling his torch with the stray spark of Schiller's flash upon the clouds, has shed more light upon the origin of art than the poet himself.
"The activities we call play," he says, "are united with the æsthetic activities, by the trait that neither subserve, in any direct way, the processes conducive to life. . . . Inferior kinds of animals have in common the trait, that all their forces are expended in fulfilling functions essential to the maintenance of life. They are unceasingly occupied in searching for food, in escaping from enemies, in forming places of shelter, and in making preparations for progeny. But, as we ascend to animals of high types, having faculties more efficient and more numerous, we begin to find that time and strength are not wholly absorbed in providing for immediate needs. Better nutrition, gained by superiority, occasionally yields a surplus of vigor. The appetites being satisfied, there is no craving which directs the overflowing energies to the pursuit of more prey, or to the satisfaction of some pressing want. The greater variety of faculty, commonly joined with this greater efficiency of faculty, has a kindred result. When there have been developed many powers adjusted to many requirements, they can not all act at once; now the circumstances call these into exercise and now those; and some of them occasionally remain unexercised for considerable periods. Thus it happens that, in the more evolved creatures, there often recurs an energy somewhat in excess of immediate needs, and there comes also such