The greater, the more serious, the more stringent may be this obstacle, the more he is remunerated for the conquering of it, by those who are relieved by his labors.
A physician, for instance, does not busy himself in baking his bread, or in manufacturing his clothing and his instruments; others do it for him, and he, in return, combats the maladies with which his patients are afflicted.

The more dangerous and frequent these maladies are, the more others are willing, the more, even, are they forced, to work in his service.

Disease, then, which is an obstacle to the happiness of mankind, becomes to him the source of his comforts.

The reasoning of all producers is, in what concerns themselves, the same.

As the doctor draws his profits from disease, so does the ship owner from the obstacle called _distance_; the agriculturist from that named _hunger_; the cloth manufacturer from _cold_; the schoolmaster lives upon _ignorance_, the jeweler upon _vanity_, the lawyer upon _quarrels_, the notary upon _breach of faith_.