Experiments on fatigue have shown that work with an intelligent object is far less fatiguing than an equal quantity of aimless work. So much so, that the psychiatrists of to-day recommend, not "exercise in the open air," but "work in the open air," to restore the individuality of the neurasthenic. "Reconstructive" work--work, that is to say, which is not the product of a "mental effort," but tends to the coordination of the psycho-muscular organism. Such are the activities which are not directed to the _production_ of objects, but to their _preservation_, as, for instance, dusting or washing a little table, sweeping the floor, laying or clearing the table, cleaning shoes, spreading out a carpet. These are the tasks performed by a servant to _preserve_ the objects belonging to his master, work of a very different order to that of the artificer, who, on the other hand, _produced_ those objects by an intelligent effort. The two classes of work are profoundly different. The one is simple; it is a coordinated activity scarcely higher in degree than the activity required for walking or jumping; for it merely gives purpose to those simple movements, whereas _productive_ work entails a preliminary intellectual work of preparation, and comprises a series of very complicated motor movements, together with an application of sensory exercises. The first is the work suitable for little children, who must "exercise themselves in order to learn to coordinate their movements." It consists of the so-called exercises of practical life which correspond to the psychical principle of "liberty of movement." For this it will be sufficient to prepare "a suitable environment," just as we should place the branch of a tree in an aviary, and then to leave the children to follow their instincts of activity and imitation. The surrounding objects should be proportioned to the size and strength of the child: light furniture that he can carry about; low dressers within reach of his arms; locks that he can easily manipulate; chests that run on castors; light doors that he can open and shut readily; clothes-pegs fixed on the walls at a height convenient for him; brushes his little hand can grasp; pieces of soap that can lie in the hollow of such a hand; basins so small that the child is strong enough to empty them; brooms with short, smooth, light handles; clothes he can easily put on and take off himself; these are surroundings which invite activity, and among which the child will gradually perfect his movements without fatigue, acquiring human grace and dexterity, just as the little kitten acquires its graceful movement and feline dexterity solely under the guidance of instinct.