POLITICAL ECONOMY 293 POLITICAL SCIENCE varied at proper intervals with massage and auxiliary movement of the affected limb. The further methods in vogue in- clude the removal of the cerebrospinal fluid, followed by injection of the virus serum. This treatment is supplemented by calisthenics directed to bringing life and movement into the dormant parts. Where the malady affects an adult the course is similar but more severe, and calls for similar treatment, but is more likely to end in death. 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 ol" 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. POLITICAL PARTIES, division of people in a State marked off by the par- ticular views they hold as to the public policy to be pursued in the best interests of the people at large. POLITICAL SCIENCE, the study which treats of the life, organization, and principles of the state. Its primary purpose is to investigate and trace the history of the various political institu- tions of the state, showing what useful purposes they serve, the interests which called them into being, and attempting to show how they may be modified to suit changing social conditions. In serv- ing these purposes the need is now felt of having a wide range of historical data in order that vague generalizations may be avoided, and also artificial con- structions. The latter has been the partic- ular purpose of the science in the period preceding the rise of historical criticism in the nineteenth century. The method of study now used is the comparative one, an extensive examination and criti- cism of the existing institutions in many different modern states and a deduction of principles from the facts gathered. Still another purpose of the science, and one which is not nor ever can be fully achieved, is the derivation of sound prin- ciples for the conduct of political life. As the nature of the subject is certainly not wholly mathematical, but dependent in great measure on the complex psy- chology of human beings, until more ac- curacy is possible in this latter field, sound principles in political science will not be laid down very dogmatically. Like many of the sciences the complex nature of society and the increasing amount of data at the disposal of modern scholars has brought about many sub- divisions of political science. Among the divisions earliest to be made was the set- ting apart of the study of political theory and ethics from that of the field of con- stitutional and administrative law. A later division has created international law and diplomacy as subjects apart from comparative study of party politics and legislation. Aristotle's "Politics" is among the first works on political science, and in the field of political theory holds its own against many later treatises. A long space of time elapses before we come to another work which at all ranks with it, not in fact until Jean Bodin, a French- man of the 16th century. In the 17th century Hobbes and Locke contributed to the literature of the subject, their elab- orate theories revolving around the "social contract." Montesquieu and Rousseau are the leading political theorists of the eighteenth century. In the philosophy of Kant and especially of Hegel is found a considerable amount of political theory interwoven with their general
