(_a_) _Reality_ he disposes of as “not strictly an item by itself, but a characteristic of all the items that follow.” Of (_b_), _Solidity or Impenetrability_, he writes that “here our feelings of effort come specially into play. They are not entirely absent in those movements of exploration by which we attain a knowledge of space; but it is when these movements are definitely realized, or are only possible by increased effort, that we reach the full meaning of body as that which occupies space.” Dr. Ward goes on to add as “in the highest degree essential,” that muscular effort should meet with something which seems to be “making an effort the counterpart of our own.” Besides telling the mother to give the required definite resistance, by opposing her hand or chest to the little trampling feet, Froebel gives a “new play, a new perception of the object,” when he tells the mother that “as soon as the child is sufficiently developed to perceive the ball as a thing separate from himself,” she should tie a string to it and pull gently. “The child will hold the ball fast, the arm will rise as you lift the ball, and as you loosen the string the hand and arm will sink back from their own weight; the feeling of the utterance of force, as well as the alternation of the movement, will delight the child. From this, however, soon springs a quite new play, that is also something new to the child, when, through a suitable drawing and lifting, the ball escapes from the child’s hand and then quietly moves freely before him as an individual object. Through this play is developed in the child a new feeling, the new perception of the object as a something now clasped, grasped and handled, and now as a freely active opposite something.”--_P., p. 36._ _Unity and Complexity_, “the remaining factors in the psychological constitution of things,” says Dr. Ward, “might be described in general terms as the time-relations of their opponents.…” And Froebel, going straight on from “the opposite something,” comes in like manner to time-relations.