In practising an art we must begin by procuring apparatus for it; and to use this apparatus to advantage, we must have it solid enough to bear use. In learning to think, we must therefore employ our members, our senses, our organs, all which are the apparatus of our understanding. And to use them to the best advantage, the body which furnishes them must be sound and robust. Our reason is therefore so far from being independent of the body, that a good constitution renders mental operations easy and accurate. In indicating how the long leisure of childhood ought to be employed, I am entering into particulars which maybe thought ridiculous. "Pretty lessons," you will tell me, "which you yourself criticize for teaching only what there is no need of learning! Why waste time in instructions which always come of their own accord, and cost neither care nor trouble? What child of twelve does not know all you are going to teach yours, and all that his masters have taught him besides?" Gentlemen, you are mistaken. I am teaching my pupil a very tedious and difficult art, which yours certainly have not acquired,--that of being ignorant. For the knowledge of one who gives himself credit for knowing only what he really does know reduces itself to a very small compass. You are teaching science: very good; I am dealing with the instrument by which science is acquired. All who have reflected upon the mode of life among the ancients attribute to gymnastic exercises that vigor of body and mind which so notably distinguishes them from us moderns. Montaigne's support of this opinion shows that he had fully adopted it; he returns to it again and again, in a thousand ways. Speaking of the education of a child, he says, "We must make his mind robust by hardening his muscles; inure him to pain by accustoming him to labor; break him by severe exercise to the keen pangs of dislocation, of colic, of other ailments." The wise Locke,[18] the excellent Rollin,[19] the learned Fleury,[20] the pedantic de Crouzas,[21] so different in everything else, agree exactly on this point of abundant physical exercise for children. It is the wisest lesson they ever taught, but the one that is and always will be most neglected. Clothing.