"Market fundamentalism" describes the view that it is desirable to leave all economic activity to a free market. This is because a free, competitive market is "efficient" or, more exactly, "cost-efficient," say advocates of this theory.
Adam Smith's "invisible hand" is equivalent to a market mechanism. He theorized that laissez faire -- the policy of allowing the free pursuit of self-interest -- would lead to the maximum well-being of society. This theory has been considered a basic tenet of economics based on market fundamentalism.
In "The Wealth of Nations" published in 1776, Smith convincingly contravened the then universally held view that the public good was the ultimate goal of society and that controlling the pursuit of self-interest would help achieve the goal.