9. All the food, clothing, and fuel required by men, can be produced by the labour of their own arms on the earth and sea; all food is appointed to be so produced, and must be so produced, at their peril. If instead of taking the quantity of exercise made necessary to their bodies by God, in the work appointed by God, they take it in hunting or shooting, they become ignorant, irreligious, and finally insane, and seek to live by fighting as well as by hunting; whence the type of Nimrod in the circle of the Hell-towers, which I desired you to study in Dante. If they do not take exercise at all, they become sensual, and insane in worse ways. And it is physically impossible that true religious knowledge, or pure morality, should exist among any classes of a nation who do not work with their hands for their bread. Read Letter XI. carefully. 10. The use of machinery [57] in agriculture throws a certain number of persons out of wholesome employment, who must thenceforward either do nothing, or mischief. The use of machinery in art destroys the national intellect; and, finally, renders all luxury impossible. All machinery needful in ordinary life to supplement human or animal labour may be moved by wind or water: while steam, or any modes of heat-power, may only be employed justifiably under extreme or special conditions of need; as for speed on main lines of communication, and for raising water from great depths, or other such work beyond human strength. 11. No true luxury, wealth, or religion is possible to dirty persons; nor is it decent or human to attempt to compass any temporal prosperity whatever by the sacrifice of cleanliness. The speedy abolition of all abolishable filth is the first process of education; [58] the principles of which I state in the second group of aphorisms following. 12. All education must be moral first; intellectual secondarily. Intellectual, before—(much more without)—moral education, is, in completeness, impossible; and in incompleteness, a calamity. 13. Moral education begins in making the creature to be educated, clean, and obedient. This must be done thoroughly, and at any cost, and with any kind of compulsion rendered necessary by the nature of the animal, be it dog, child, or man. 14. Moral education consists next in making the creature practically serviceable to other creatures, according to the nature and extent of its own capacities; taking care that these be healthily developed in such service. It may be a question how long, and to what extent, boys and girls of fine race may be allowed to run in the paddock before they are broken; but assuredly the sooner they are put to such work as they are able for, the better. [59] Moral education is summed when the creature has been made to do its work with delight, and thoroughly; but this cannot be until some degree of intellectual education has been given also.