We have spoken of the social sciences as if they were independent and distinct one from the other. Such, however, is not the case, for they are merely different aspects of the same science, each regarding society from its own particular viewpoint. Yet, since the human mind cannot grasp the social field as a unit, it has been found desirable to treat them as distinct sciences. In other words, we deal with the various social sciences as independent subjects of study for the sake of convenience and a clearer understanding. Consequently, in our colleges and universities, where ample opportunity is given for research and specialization, they have been developed independently under the direction and guidance of highly trained specialists. We must remember, however, that in spite of this development the study of society and social relationships is in itself a complete and single science.

Numerous examples of this close relationship are to be found on every hand. Foreign immigration, to illustrate, commands the attention of the historian, the political scientist, the sociologist, and the economist. The historian accounts for the events and developments that have caused millions of men, women, and children to migrate from their old homes in Europe to America. The political scientist is chiefly concerned with the immigrant's knowledge of the forms and purposes of government, with his attitude toward American democracy, and with his influence on American politics. The sociologist studies the more distinctly social questions connected with immigration, such as housing conditions, standards of living, morals, education, and entertainment. Lastly, the economist approaches the subject from the standpoint of industry, concerning himself with the effect of immigration on such things as wages, production of wealth, and foreign trade. Each specializes on a small portion of the subject - too often as if it were the whole subject - but it requires the combined labors of all to produce a complete and accurate account.

Some subjects, such as the Constitution of the United States, or negro slavery, for example, belong so exclusively to one or another social science as to make it appear that treatment under any other one is impossible. Obviously, the political scientist has the chief interest in the former, while the historian claims the latter. Nevertheless the economist must not neglect either. Without a proper understanding of the Constitution he could not account clearly for the various economic developments in such fields as labor legislation, interstate commerce, the protective tariff, money and banking; and no description of negro slavery can ever be complete which fails to take in consideration the economic environment in which it developed, its profitableness and unprofitableness, or its effect on the free labor with which it competed.