The physician, for example, does not bake his own bread, or manufacture his own instruments, or weave or make his own coat. Others do these things for him, and in return he treats the diseases with which his patients are afflicted. The more numerous, severe, and frequent these diseases are, the more others consent, and are obliged, to do for his personal comfort. Regarding it from this point of view, disease, that general obstacle to human happiness, becomes a cause of material prosperity to the individual physician. The same argument applies to all producers in their several departments. The shipowner derives his profits from the obstacle called _distance_; the agriculturist from that called _hunger_; the manufacturer of cloth from that called _cold_; the schoolmaster lives upon _ignorance_; the lapidary upon _vanity_; the attorney on _cupidity_; the notary upon possible _bad faith_,--just as the physician lives upon the diseases of men. It is quite true, therefore, that each profession has an immediate interest in the continuation, nay in the extension, of the special obstacle which it is its business to combat. Observing this, theorists make their appearance, and, founding a system on their individual sentiments, tell us: Want is wealth, labour is wealth, obstacles to material prosperity are prosperity. To multiply obstacles is to support industry. Then statesmen intervene. They have the disposal of the public force; and what more natural than to make it available for developing and multiplying obstacles, since this is developing and multiplying wealth? They say, for example: If we prevent the importation of iron from places where it is abundant, we place an obstacle in the way of its being procured. This obstacle, keenly felt at home, will induce men to pay in order to be set free from it. A certain number of our fellow-citizens will devote themselves to combating it, and this obstacle will make their fortune. The greater the obstacle is--that is, the scarcer, the more inaccessible, the more difficult to transport, the more distant from the place where it is to be used, the mineral sought for becomes--the more hands will be engaged in the various ramifications of this branch of industry. Exclude, then, foreign iron, create an obstacle, for you thereby create the labour which is to overcome it. The same reasoning leads to the proscription of machinery.