When the beginner approaches the study of politics, one of the most natural questions for him to ask is: what is it that political science studies? This is a way of asking what is the political scientist's conception of reality. More often than not, the teacher finds the student looking for an objective physical structure, simplified yet concrete, like the astronomer's reduced-scale construction of the solar system, the biologist's photographic reproduction of microscopic cellular organisms, or the physicist's diagram of atomic structure. It is important for the student of human affairs to realize that while individuals, small groups, mass meetings, and even whole cities can be photographed or diagrammed, social scientists have never succeeded in reproducing satisfactory physical models of such concepts as personality, social structure, bureaucratic organization, the price system, or government. Nor do the ends and criteria of government, like order, justice, freedom, welfare or security, lend themselves to analysis in terms of physical or chemical elements like oxygen, carbon, iron, or uranium. Perhaps the closest physical analogy to politics and government is an automobile engine or an electric power plant; but no one would claim that the driver of a car has learned the principles of the engine if all he knows is how to operate it, any more than the power plant engineer understands generation if all he learns is how to read dials and pull switches. Theory is required, and its function is to identify and abstract from total reality the essential minimal concepts and to formulate statements describing the relationships between those concepts whereby the world of experience becomes comprehensible. Theory is never identical with the totality of phenomenal experience; the propositions and principles of theory provide a means by which aspects of reality can be explicitly analyzed and verified, in the hope that some synthesizing minds will make the efforts toward a synthetic reconstruction of reality on the basis of understood principles.