In The Wealth of Nations, Adam Smith argued that

The correct answer is people promote public interest through economic choices

"The Wealth of Nations" by Adam Smith was the first major milestone for the theoretical foundation in defending a market economy. At a time when the first industrial revolution in England was taking shape, Smith devised a series of new concepts and relationships that would completely change the way political economy was later analyzed. Among its main contributions, the relationship between labor specialization and productivity, the focus on the consumer rather than the accumulation of metals, and the efficiency generated by the selfishness of each producer and consumer (invisible hand), continue to this day ...