And for the common moral life of the world there is a profound teaching in this Socratic doctrine which makes knowledge the spring of virtue.[501] There is in knowledge, in insight, in the clear recognition of the relation of man’s highest good to virtue, an impelling force and authority. As the world advances in true knowledge, it will advance in true morality. The Renaissance is ever the precursor of the Reformation. It is this fact which should make optimists of us all, for the unceasing advance of the world in knowledge is well assured.

In the ethical system of Socrates we have a good illustration of the truth that great men are the product of their age. With all his originality and profound spiritual insight, Socrates could not and did not rise much above the plane of the common moral consciousness of his contemporaries. He stood on essentially Greek ground. His morality was the morality of his time and place. In his practical code of morals he made the Greek virtue of self-control or moderation a cardinal virtue; he laid the Greek emphasis upon the civic virtues, dying rather than disobey or evade the decree of his city; he entertained the common Greek ideas respecting the family and the domestic virtues; he saw nothing to disapprove in the life of the hetæra; he viewed the beautiful from a standpoint wholly Greek, almost identifying beauty with goodness; he was thoroughly Greek in the aristocratic tendency of his ethical teachings, making the practice of true virtue the prerogative of the cultured class alone; he had the ordinary Greek conscience in regard to slavery; and he never detached himself from that narrow Greek prejudice which saw in the Hellenes the elect race. He never proclaimed, as did many a later Greek and Roman moralist, the essential unity of the human race.

Plato and his ethical system

Socrates made virtue and man’s moral nature the subject of philosophic reflection. His pupil, Plato, systematized his master’s teachings, and, reducing these and the common ethical notions of his time to scientific form laid the basis of the science of ethics.

Plato agreed with Socrates in teaching that to know the good is necessarily to seek it. He accordingly makes wisdom the first of the virtues, by wisdom meaning insight, the clear recognition of what constitutes the highest good. Issuing from this primary virtue of wisdom, like a stream from a fountain, are the virtues of courage, temperance, and justice.

From wisdom comes courage, for perfect knowledge of good and evil casts out fear; and moderation, for knowledge of higher and lower, of the penalty that awaits all excess, leads to prudence and self-control; and justice, for knowledge of one’s relations to one’s fellows creates consideration for the rights of others. Plato here simply systematizes and reduces to scientific form those various virtues which the common Greek conscience recognized as constituting moral excellence.

Particularly noteworthy is Plato’s doctrine that virtue in the state is the same as virtue in the individual. There is need of emphasis being laid anew upon this teaching at the present time, when the disciples of Machiavelli would give fresh vogue to the doctrine of a double standard of morality, one for the individual and another for the state. The modern world might well sit at Plato’s feet and learn that virtue is ever one and the same, and that the moral law can no more be traversed with impunity by a nation than by a single individual.

In many of his ethical teachings Plato anticipated and deeply influenced Christian doctrines. He has been called the precursor of the Fathers of the Church. “His ideas on virtue,” as Denis observes, “take us far from Greece and antiquity; they seem addressed rather to the saints and anchorites than to the citizens of Sparta and Athens.”[502] His doctrines that the way of approach to God is through contemplation; that withdrawal from the turmoil of public life is a furtherance of the true life; that the body is a “prison house” of the soul; that the soul is immortal and that there awaits it in the after life recompense for deeds done in the flesh; that expiation for sin is an ethical necessity; that punishment is not a deterrent and restraint but a remedy that restores to health the sin-diseased soul[503]—all these ideas and principles were in exact accord with the Christian moral consciousness, and through St. Augustine and other Fathers of the Church came to enrich and reënforce the ethical system of the monastic and the papal Church of the medieval age.

Perhaps what is the most admirable of Plato’s teachings is embodied in this petition: “And may I, being of sound mind, do to others as I would that they should do to me.”[504] The significance of this lies in the fact that it is a prayer, and that the petitioner asks that he may be of sound mind when he reflects on what he would like to have others do to him.

Yet notwithstanding the loftiness and nobility of much of Plato’s ethical thought, still, like Socrates, he stood almost wholly on Greek ground. His ethics is scarcely more than a justification of the common Greek morality of his time. He destroys the family in the interest of the state; he approves of the exposition of ill-formed, unpromising infants; he makes morality to be a class thing—only select and cultured souls are with him capable of genuine virtue. He accepts slavery as a necessary institution of the state; he practically shuts out the non-Greek world from the sphere of morality;[505] and with the common Greek he believes that to do evil to one’s enemies is an imperative duty.[506] Nor does Plato, like Hebrew seer, rise high enough above the general Greek viewpoint to discern the great law of moral progress, and to prevision the historical goal—ethical world unity.