Playfulness does not require the sacrifice of good sense or sound principle or serious purpose, but subjects them to certain conditions; and there is no form in which exalted characters or sacred truths are brought home more effectually to the hearts both of young and old than in the stones and dramas that make life speak for itself, and play themselves into the affections and fancy. It does require that the laws of attention and emotion, the unities and the varieties of aesthetic art, shall be observed; and as soon as the book is dull, and offers no sparkling waters nor fair flowers nor tempting fruits to lure the flagging reader over its intervals of dusty road or sandy waste, it is a failure, and not what it pretends to be. With children, play demands more the _varieties_ than the _unities_ of Art; and their first education deals with those spontaneous sensibilities and impulses that insist upon being played upon freely, with little regard to exact method. Those sports are most pleasing to young children, especially, that touch the greatest number of the keys of sensation and will, and make them answer to the pulse of Nature and companionship. One may learn a deal of philosophy from the most popular nursery rhymes; and Mother Goose, good old soul, who has sung many of those strange old verses to children for a thousand years, if the antiquaries are not mistaken, proves to us that the way to please little ears and eyes is by presenting a variety of images in the easiest succession, without any attempt at intellectual method or logical unity. Her style is that of the kaleidoscope, and she turns words and pictures over as rapidly, and with as little method, as that instrument shows in its handling of colors. As the child's development advances, the varieties need more of the unities, and the favorite sports rise into more method and sequence, nearer the rule of actual life: marbles give way to cricket, and blindman's bluff yields to chess. For a long time, however, anything like severe intellectual unity of plan is irksome, and even the toys that require careful thought and embody extraordinary workmanship are less agreeable than the rude playthings that can be knocked about at will, and made to take any shape or use that the changing mood or fancy may decree. The rag baby is more popular with the little girl than the mechanical doll; and a tin pot, with a stick to drum upon it, pleases little master more than the elegant music-box. As long as the child's mind is in a chaos of unsorted sensations and impulses, he does not like plays that are so utterly in advance of his position as to present a perfect order that calls up Kosmos within him before its time. There is a good Providence in this necessity, and Nature is servant of God in her attempt to touch and voice the separate keys of the great organ, before she tunes them together to the great harmonies and symphonies that are to be performed.