16. Philosophical Teaching. -- Socrates is before all else a teacher of morals. He was convinced that his predecessors had followed a false track in neglecting the phenomena of the moral life. The root principle of Socratic ethics is the reduction of virtue to knowledge: to possess science, that is, universal notions, is to act righteously. Knowledge is not alone, as with Plato and Aristotle, the prerequisite condition of all moral conduct; the possession of genuine universal ideas (as opposed to the commonplace and erroneous ideas of the crowd) actually constitutes the morality of our conduct. His meaning is, according to Piat,^{1} that reason should rule supreme over human conduct and that the full and healthy development of the nous will always secure a righteous will. "Know Thyself" is the first practical precept of conduct, for all reasoning involves growth in self-knowledge, and this knowledge is the first and most potent factor of morality. According to others,^{2} it is the knowledge itself of the good, as a thing known, an object of science, that Socrates identifies with virtue. He, then, would be good and just, who knows what is good and just. But behind this lies the further question: what is the good? It is the universal notion regarded as end or aim of our activity; to do good is to conform our conduct to this universal knowledge. He thus returns to his earlier formula identifying knowledge and virtue, but neither explains nor justifies it. We find him formulating here and there, especially in Xenophon, another concept of goodness at variance with the preceding one: he reduces both the good and the beautiful to the useful -- in deference to the popular idea of virtue. And it is on this idea that he bases his defence of the immortality of the soul.

The study of the external world occupies a place of minor importance in the philosophy of Socrates. He could not well neglect it altogether, since man is in constant touch with his external surroundings. But it is only on account of these relations of man to the visible world that he gives it any consideration, and with a view to arriving at this conclusion: that the external universe, by the order which reigns in it, gives manifest evidence of the intervention of a supreme guiding intelligence, which has appointed and destined the whole universe for the well-being of man. As regards the Divinity, he shows little or no anxiety to speculate about the nature of the Divine Being, but very much for the discovery of motives, in the contemplation of the Divinity, to elevate man to a higher and loftier moral plane.

{1} Socrate (Paris, 1901), pp. 97 sqq.

{2} ZELLER, op. cit., ii., 149.