The political theory of Plato and, to a degree only slightly less, that of Aristotle also may be characterized as the rationalization and idealization of an existing political and social order. As philosopher, Plato is known especially for his so-called idealism, or theory of ideas. Like all philosophers, he engaged in a "quest for certainty," for absolute, final truth; and this endeavor he conceived as an effort to define ultimate reality. His solution of the problem was expressed in the theory that our general ideas or concepts reflect the ultimate reality of things; the apparent variety and change of the world of sense experience is a kind of illusion, due to the fallibility of human nature. The aim of philosophy is to discover and formulate accurately these "ideas" which are the true reality of the universe. In keeping with this general tendency of his philosophy, Plato's discussion of the state is, in effect, an attempt to describe the ideal state and to define the essence of political organization. To express the same thought somewhat differently, we may say that Plato conceived society as an artifact--something that man can shape artificially, within limits, in the light of intellectual knowledge. The underlying animus of Aristotle Politics is the same. In this respect, both men exemplify the preoccupation with ideal, stable form which is said by authorities to be so invariably characteristic of Greek culture. In other words, what Plato and Aristotle contributed to the development of social theory was, in the main, political philosophy rather than political science.

Both did, to be sure, attempt to describe a natural cycle of change in the constitution or general form of the government of a state; to this extent they anticipated the modern conception of natural process in the social order. They conceived of political change, however, as a process that went on in closed cycles; they seemed quite unable to imagine political change that would result in a form of government not actually known to them from the history of the Greek city-states. Even Plato's ideal polity is a sort of idealized abstraction from the traditional constitution of Sparta, modified by the inclusion of elements drawn from what he knew of other Greek states. States, in this view, simply swing around a circle of forms, eventually returning to a type of constitution that they have had before. The concept of evolution, in the post-Darwinian sense, and the concept of progress, as it had been cherished in the Western world since the eighteenth century, are entirely lacking in their writings. The same limitation of their thought is illustrated by the fact that, although according to tradition Aristotle was for some time the tutor of the Macedonian prince who became Alexander the Great, and although the rise of the Macedonian empire took place almost entirely within his lifetime, he did not recognize at any point in the Politics that such a form of government as empire could exist.

There is in the political dialogues of Plato, however, an implicit acknowledgment of the principle that governmental forms must be adapted to conditions set by human nature and other circumstances. This is indicated in the progressive modification of his ideas from the Republic through the Statesman to the Laws. In the Laws, which was written in the old age of Plato, there is much more concession to the demands of human nature and other empirical forces. The same tendency in Plato's social thought is suggested by the striking contrast between his description of a simple ideal community, in the early part of Book II of the Republic, and the much more elaborate ideal society depicted in the remainder of the dialogue. To this extent, Plato the idealist was a realist in the modern sense of the term.

To reiterate, the political writings of Plato, in spite of their preoccupation with the quest for an ideal, demonstrate to a certain extent the possibilities of considering political phenomena reflectively, critically, and objectively, instead of merely perpetuating the custom and tradition of the past. It is, then, unfair to say in response to the question What did Plato contribute to the development of modern social science? "He contributed nothing." The reflective and critical approach to human problems was a relatively new thing in the time of Plato and from the merely speculative and dialectic attack upon such problems to the systematic labor of checking concepts and theories against all available empirical evidence was a long road to travel. It has required over two thousand years for the thinkers of the Western world to travel as far as they have traveled on this road. We should give Plato credit for having helped to guide an early stage of the journey.

In considering the work of Plato, we have anticipated to some extent what may be said in a brief survey concerning the place of Aristotle in the development of social thought. The two philosophers can scarcely be thought of separately except to a limited extent and by abstraction, so to speak. The political theories of Aristotle may be regarded with almost no reservation as the direct continuation of those of Plato, whose pupil an associate he was for many years, and it has been aptly said the Aristotle was "a Platonist in spite of himself." It is in the Politics of Aristotle that one finds the earliest clear-cut example of systematic political theorizing after the manner of a modern university lecture--at least it is the earliest such treatise that has survived to our times; for there is some reason to think that Plato composed similar works which have been lost. In the Dialogues of Plato we have a polished literary, indeed almost dramatic, presentation of certain political speculations an reflections; while Aristotle Politics is, in form, if not altogether in substance, a scientific treatise. By temperament and habit, Aristotle seems to have been inclined to base his generalization upon the concrete facts known to him, but he had been so thoroughly indoctrinated with the "dialectic" of Plato--reasoning from highly generalized "ideas," or principles, to the more specific propositions that could be deduced from them--that he wrote his own works according to this pattern and referred to the facts only by way of illustration or secondary evidence in support of his theories. . .