Adam Smith (1723-1790) is one of the most important theorists of the eighteenth century period. His book, An Inquiry into the Nature and Causes of the Wealth of Nations (1776), was the first book to systematically theorize capitalism (see link below) and stands as the book that pretty much invented economics in the Western world.

       Smith has one and only one concern in the book: to explain how nations as a collective grow wealthier. While other eighteenth century thinkers were concerned about improvements in knowledge and society, Smith believed that human progress largely consisted in the steady improvement of human life through the increasing wealth of a nation as a whole. The Wealth of Nations is a systematic attempt to explain the     processes whereby the collective wealth of a nation grows.

       Smith identifies several characteristics of growing economies. The first and most foremost is division of labor. The revolution in labor in the seventeenth and eighteenth centuries, in which productive tasks were divided among a number of workers each doing a single task, produced a revolution in production in which output was increased a hundredfold. Smith's foundational argument is that all meaning and value in human life is to be found in productive labor; the exponential increase of production, then, not only resulted in more wealth for the nation, but greater meaning and value for human life. Second, all monopolies and regulations stifle productive labor. Human beings work for their own profit; regulations and monopolies do away with the profit incentive and so discourage human productivity. In place of these regulations, Smith proposed a natural system of economic liberty, in which each individual in a society is free to choose how to expend their productive labor and their capital. This economic liberty was called laissez faire (let them do as they please); if individuals were allowed to pursue their own selfish aims, then the wealth of the nation as a whole would increase. This selfishness, though, would not result in social injustice; behind this natural economic     liberty lay an "invisible hand" which guided people into right action. Thirdly, the material world was an infinite store of resources that could be exploited for the benefit of human kind. It was incumbent on humans to approach material resources, not as scarce, but as infinitely abundant. The idea that the world is an infinite storehouse of resources that should be exploited by us is such a common aspect of our lives, that it's hard to realize that it's a modern idea that can be dated back to Smith's book.