The practical life montessori lesson activities correspond to the psychical principle of "liberty of movement." Much of this work is suitable for little children, who must "exercise themselves in order to learn to coordinate their movements.
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.
The field thus opened to the free activity of the child will enable him to exercise himself and to form himself as a person. It is not movement for its own sake that he will derive from these exercises, but a powerful co-efficient in the complex formation of his personality. His social sentiments in the relations he forms with other free and active children, his collaborators in a kind of household designed to protect and aid their development; the sense of dignity acquired by the child who learns to satisfy himself in surroundings he himself preserves and dominates--these are the co-efficients of humanity which accompany "liberty of movement."
From his consciousness of this development of his personality the child derives the impulse to persist in these tasks, the industry to perform them, the intelligent joy he shows in their completion. In such an environment he undoubtedly _works himself_ and fortifies his spiritual being, just as when his body is bathed in fresh air and his limbs move freely in the meadows, he works at the growth of his physical organism and strengthens it.