  By nature human beings have many desires but are individually ill-equipped with strength, natural weapons, or natural skills to satisfy them. We can remedy these natural defects by means of social cooperation: shared strength, division of labor, and mutual aid in times of individual weakness. It occurs to people to form a society as a consequence of their experience with the small family groups into which they are born, groups united initially by sexual attraction and familial love, but in time demonstrating the many practical advantages of working together with others. However, in the conditions of moderate scarcity in which we find ourselves, and given the portable nature of the goods we desire, our untrammeled greed and naturally “confined generosity” (generosity to those dear to us in preference to others) tends to create conflict or undermine cooperation, destroying collaborative arrangements among people who are not united by ties of affection, and leaving us all materially poor. No remedy for this natural partiality is to be found in “our natural uncultivated ideas of morality” (T 3.2.2.8); an invention is needed.