The scientist or inventor works in his laboratory or in his shop, devoting his energies to investigation and research which are nothing more than the application of the principle of trial and error to the particular problems with which his science is confronted. Once the experimenter has discovered a way to compel mechanical power to toil for man, or to destroy the typhoid germ, or to talk across a continent without wires, the next task is to find a better way or an easier way. Far from decreasing the necessity for experiment, each new discovery in the realm of natural science opens the door to additional possibilities. To-day every important college, most cities, many industries, and public institutions maintain experimental laboratories in the various fields of applied knowledge, and employ highly trained experts whose sole duty it is to try things out. Inventors frequently hit upon new ideas or upon novel devices by chance, but for every such chance discovery, there are scores and probably hundreds of ideas and devices that have been carefully thought out, worked over, rejected, revised, modified, until they produced the desired results. There is a margin of chance in all experiment, but surrounding it there is a vast field of careful thinking and planning and of endless purposeful endeavor. These observations are commonplaces in the laboratory and in the department of research. They have filtered through to thinking people who begin to understand the part that experiment plays in all forms of scientific progress. There is a general agreement that if there is to be an increase in the knowledge that men possess regarding the mechanical forces, the only sure way of gaining this knowledge is to weigh, measure, describe and classify. This applies to solids, liquids, gases, rocks, plants, animals, and even to the structure and function of the human body. But when it comes to social institutions, even the wisest hesitate and question. Is it possible that social knowledge can be gained only in this way?