An Inquiry into the Nature and Causes of the Wealth of Nations is the magnum opus of the Scottish economist Adam Smith, published on March 9, 1776 during the Scottish Enlightenment. It is a clearly written account of political economy at the dawn of the Industrial Revolution, and is widely considered to be the first modern work in the field of economics. The work is also the first comprehensive defense of free market policies. It is broken down into five books between two volumes. The Wealth of Nations was written for the average educated individual of the 18th century rather than for specialists and mathematicians. There are three main concepts that Smith expands upon in this work that form the foundation of free market economics: The Division of Labor, The Pursuit of Self Interest, and The Freedom of Trade.
The Wealth of Nations was published in 1776, during the Age of Enlightenment. It influenced not only authors and economists, but governments and organisations. For example, Alexander Hamilton was influenced in part by The Wealth of Nations to write his Report on Manufactures, in which he argued against many of Smith's policies. Interestingly, Hamilton based much of this report on the ideas of Jean-Baptiste Colbert, and it was, in part, to Colbert's ideas that Smith wished to respond with The Wealth of Nations. Many other authors were influenced by the book and used it as a starting point in their own work, including Jean-Baptiste Say, David Ricardo, Thomas Malthus and, later, Karl Marx and Ludwig von Mises. The Russian national poet Aleksandr Pushkin refers to The Wealth of Nations in his 1833 verse-novel Eugene Onegin.
Irrespective of historical influence, however, The Wealth of Nations represented a clear leap forward in the field of economics, similar to Sir Isaac Newton's Principia Mathematica for physics or Antoine Lavoisier's Traité Élémentaire de Chimie for chemistry. The Wealth of Nations is also important in a Scottish linguistic context on account of the fact the book is written in English and not in Scots Language, a somewhat rare occurrence for the time.
Smith addresses in The Wealth of Nations a problem that was torturing the best economic minds of his day. This problem was rooted in the means by which objects are valued. The two predominant theories of value in Smith's time were the so-called "Practical Theory of Value" and the labor theory of value, as delineated later by David Ricardo.