POLITICAL ECONOMY, the science which investigates the nature of wealth and the laws of its production and dis tribution, including, directly or remotely, the operation of all the causes by which the condition of mankind, or of any society of human beings, in respect to this universal object of human desire, is made prosperous or the reverse. In quiries on these points must have existed from the earliest times in every nation, but political economy as a science is very modern. Crude views on the subject arose in the Middle Ages in the free Italian cities and the Hanseatic towns. Sir Walter Raleigh (1595), Sir William Petty (1667), and Sir Dudley North (1691) wrote on the subject with en lightenment for their age. Francois Quesnay, in France (1786), founded the school of the economists which held that the soil is the source of all wealth. Adam Smith (1723-1790) had made political economy a portion of his lectures while professor in Glasgow University from 1751 to 1764. Visiting Paris in
that year, he became acquainted with Quesnay and the leading economists, but the principles of his great work, the "Wealth of Nations," published after 10 years' retirement, in 1776, were in the main, thought out independently. Since Adam Smith's time, no work on the sub ject has appeared more original or influ ential than the "Principles of Political Economy," by John Stuart Mill. Prob ably the most notable political economist of the latter part of the century was Henry George, of New York City, whose views, to some extent, coincide with those of J. S. Mill, especially as regards the unearned increment of the land. Mr. George's theory has been popularly de nominated the single tax idea, and is best set forth in his work, "Progress and Poverty." The most important corollary of the single tax is unlimited free trade —these two principles forming, in fact, all of Mr. George's theory. See SINGLE TAX.