"In truth, experience knows no division between human concerns and a purely mechanical physical world. Man's home is nature; his purposes and aims are dependent for execution upon natural conditions. Separated from such conditions they become empty dreams and idle indulgences of fancy. From the standpoint of human experience, and hence of educational endeavor, any distinction which can be justly made between nature and man is a distinction between the conditions which have to be reckoned with in the formation and execution of our practical aims, and the aims themselves. This philosophy is vouched for by the doctrine of biological development which shows that man is continuous with nature, not an alien entering her processes from without. It is reinforced by the experimental method of science which shows that knowledge accrues in virtue of an attempt to direct physical energies in accord with ideas suggested in dealing with natural objects in behalf of social uses. Every step forward in the social sciences — the studies termed history, economics, politics, sociology — shows that social questions are capable of being intelligently coped with only in the degree in which we employ the method of collected data, forming hypotheses, and testing them in action which is characteristic of natural science, and in the degree in which we utilize in behalf of the promotion of social welfare the technical knowledge ascertained by physics and chemistry. Advanced methods of dealing with such perplexing problems as insanity, intemperance, poverty, public sanitation, city planning, the conservation of natural resources, the constructive use of governmental agencies for furthering the public good without weakening personal initiative, all illustrate the direct dependence of our important social concerns upon the methods and results of natural science."