If any one dissent from this, he must give a regular proof of these two propositions, viz. that there is A peculiar act of the mind, annext to promises; and that consequent to this act of the mind, there arises an inclination to perform, distinct from A sense of duty. I presume, that it is impossible to prove either of these two points; and therefore I venture to conclude that promises are human inventions, founded on the necessities and interests of society.
In order to discover these necessities and interests, we must consider the same qualities of human nature, which we have already found to give rise to the preceding laws of society. Men being naturally selfish, or endowed only with a confined generosity, they are not easily induced to perform any action for the interest of strangers, except with a view to some reciprocal advantage, which they had no hope of obtaining but by such a performance. Now as it frequently happens, that these mutual performances cannot be finished at the same instant, it is necessary, that one party be contented to remain in uncertainty, and depend upon the gratitude of the other for a return of kindness. But so much corruption is there among men, that, generally speaking, this becomes but a slender security; and as the benefactor is here supposed to bestow his favours with a view to self-interest, this both takes off from the obligation, and sets an example to selfishness, which is the true mother of ingratitude. Were we, therefore, to follow the natural course of our passions and inclinations, we should perform but few actions for the advantage of others, from distinterested views; because we are naturally very limited in our kindness and affection: And we should perform as few of that kind, out of a regard to interest; because we cannot depend upon their gratitude. Here then is the mutual commerce of good offices in a manner lost among mankind, and every one reduced to his own skill and industry for his well-being and subsistence. The invention of the law of nature, concerning the stability of possession, has already