Furniture for children, their tables and chairs, should be light, not only that they may be easily carried about by childish arms, but because their very fragility is of educational value. The same consideration leads us to give children china plates and glass drinking-vessels, for these objects become the _denouncers_ of rough, disorderly, and undisciplined movements. Thus the child is led to correct himself, and he accordingly trains himself not to knock against, overturn, and break things; softening his movements more and more, he gradually becomes their perfectly free and self-possessed director. In the same way the child will accustom himself to do his utmost _not to soil_ the gay and pretty things which enliven his surroundings. Thus he makes progress in his own perfection, or, in other words, it is thus he achieves the perfect coordination of his voluntary movements. It is the same process by which, having enjoyed silence and music, he will do all in his power to avoid discordant noises, which have become unpleasant to his educated ear. On the other hand, when a child comes into collision a hundred times with an enormously heavy iron-bound desk, which a porter would have difficulty in moving; when he makes thousands of invisible ink-stains on a black bench; when he lets a metal plate fall to the ground a hundred times without breaking it, he remains immersed in his sea of defects without perceiving them; his environment meanwhile is so constructed as to hide and therefore to encourage his errors, with Mephistophelean hypocrisy. * * * * * =Free movement=.--It is now a hygienic principle universally accepted that children require movement. Thus, when we speak of "free children," we generally imply that they are free to move, that is, to run and jump. No mother nowadays fails to agree with the children's doctor that her child should go into parks and meadows, and move about freely in the open air. When we talk of liberty for children in school, some such conception of physical liberty as this rises at once in the mind. We imagine the free child making perilous leaps over the desks, or dashing madly against the walls; his "liberty of movement" seems necessarily to imply the idea of "a wide space," and accordingly we suppose that, if confined to the narrow limits of a room, it would inevitably become a conflict between violence and obstacles, a disorder incompatible with discipline and work.