The “father of free markets”, Adam Smith is often quoted as having said:

In a free or laissez-faire market, an individual would work and interact with others in the economy on the basis of their self-interest. And the sum of all self-interests would make for a balanced, harmonious, and prosperous society.

His optimism for capitalism was very real, and it has been proven out over the history since his musings during the Enlightenment.

What is forgotten is that he opposed absolutism, urging concern for the overall well-being of society. In acknowledgement of the real harms possible through a laissez-fair market he argued for healing social policies.