RELATION OF POLITICAL SCIENCE TO OTHER FIELDS OF KNOWLEDGE. The relation of politics to the general science of society has already been indicated; its field is more restricted and the eharacter of its methods teleological rather than eausative. (See SOCIOLOGY.) The difference be tween the purposes and methods of sociology and of politics might be further indicated by consid ering how either would treat the career of a statesman like Lincoln. The science of polities would study the principles and purposes em bodied in his character in a concrete manner; sociology, on the other hand, would attempt to trace these eomposile factors hack to their ulti mate causes, and, passing beyond the energies manifesting themselves in the political struggle, would probe into their psychological and physical origins. The relation of politics to psychology also is that of a teleological to a causative science. All political institutions may be looked upon as psychological facts having their existence only in the mind, although they may be of the greatest tenacity and are in turn productive of concrete facts such as public buildings and im provements. But psychology, like sociology, is a causative science, going back of the purpose or concept with which politics starts, and trying to investigate its psychic and physiological origins. The science of economics deals with a different set of social phenomena, which, however, have the closest bearing upon polities. Not only is political influence largely determined by economic power, but the constant interference of political agencies with economic interests and processes makes it necessary for political science to give special attention to economies. The field of his
tory, like that of sociology, embraces political action together with the other manifestations of social life. But history differs specifically from polities in that its purpose lies in tracing indi vidual chains of causation, whereas polities, by the use of the comparative method, establishes broader generalizations. The science of statis tics furnishes a basis of induction for all the social sciences. Both in the study of the composi tion of political forces and of the results of politi cal action regarded as experiments. the aid of statistics is indispensable. The knowledge of the material body and of the physical basis of State life is furnished by the sciences of ethnology and geography, the results of both of which form the most essential data of political science. Among the other natural sciences physiology and biology are of special importance to political science. Although the similarity of the life processes in the State and in the physical organism have been exaggerated in the organic theory of the State, the analogy of historic to organic development, as opposed to purely mechanical construction, will always remain valuable. The absolute iden tification of biological, social, and political laws of development is, however, being abandoned and is giving way to a tendency to view political phenomena under the aspect of psychological facts to be explained rather by the laws of asso ciation and imitation than by the principle of organic structure and growth.