an idea suggested by Adam Smith in Wealth of Nations (1776) that when people trade voluntarily, all parties expect to benefit. He also explained that because people trade, each person's actions affect other people. Even selfish actions often help other people. He explained that the butcher and the baker provide food for our dinner not because of their generosity, but because of their own self-interests. Smith explained that even in acting selfishly, people are often "led by an invisible hand to promote an end which was no part" of their intentions 1
