Education is the oversight and guidance of the development of the immature with certain ethical and social ends in view. Pedagogy, therefore, is based partly on psychology--which, as we have seen in the preceding chapter, is closely related to the biological sciences--and partly on ethics, or the study of morals, closely related to the social sciences. These two aspects of education, the psychological and the sociological, were treated respectively in Rousseau's _Emile_ and Plato's _Republic_. The former ill-understood work, definitely referring its readers to the latter for the social aspect of education, applies itself as exclusively as possible to the study of the physical and mental development of the individual child. Rousseau consciously set aside the problem of nationality or citizenship; he was cosmopolitan, and explicitly renounced the idea of planning the education of a Frenchman or a Swiss. Neither did he desire to set forth the education of a wild man, free and unrestrained. He wished rather to depict the development of a natural man in a state of society; but he emphasized the native hereditary endowment, while expressing his admiration for Plato's _Republic_ as the great classic of social pedagogy. The titles of the two works, one from the name of an individual child, the other from a form of government, should serve to remind us of the purpose and limitations of each. Plato's thought was centered on the educational and moral needs of the city-state of Athens. He was apprehensive that the city was becoming corrupted through the wantonness and lack of principle of the Athenian youth. He strove to rebuild on reasoned foundations the sense of social obligation and responsibility which had in the earlier days of Athens rested upon faith in the existence of the gods. As a conservative he hoped to restore the ancient Athenian feeling for duty and moral worth, and he even envied some of the educational practices of the rival city-state Sparta, by which the citizen was subordinated to the state. The novel feature of Plato's pedagogy was the plan to educate the directing classes, men disciplined in his own philosophical and ethical conceptions. He was, in fact, an intellectual aristocrat, and spoke of democracy in very ironical terms, as the following sentences will show:--