They are the first stimulants that rouse the brain of infant man into sentient activity: and such seems to be the sluggishness of original matter, that unless, by a peculiar course of excitements, other wants, equally powerful, are generated, these stimulants seem, even afterwards, to be necessary, to continue that activity which they first awakened. The savage would slumber for ever under his tree, unless he were roused from his torpor by the cravings of hunger, or the pinchings of cold; and the exertions that he makes to avoid these evils, by procuring food, and building himself a covering, are the exercises which form and keep in motion his faculties, which otherwise would sink into listless inactivity. From all that experience has taught us concerning the structure of the human mind, if those stimulants to exertion, which arise from the wants of the body, were removed
