The vast range of his thought we will touch only at two points. In the Symposium and the Phaedrus he discusses in his most brilliant vein the problem of love. To the reader who has inherited the ethical ideal of Christianity, Plato's love will seem like the image in Nebuchadnezzar's vision,—the head of gold, the feet of miry clay. He has a toleration for some aspects of sensuality of which Paul said, "it is a shame even to speak;" and this tolerance, in the greatest of the classic philosophers, is the most pregnant suggestion of the cleansing work which it was left for Christianity to undertake. Yet Plato teaches most impressively the subordination of sense to spirit in love, and the struggle of the two in man has seldom been set forth more powerfully than in his figure of the two yoked horses: the white, celestial steed struggling upward; the black, unruly one plunging down, while Reason, the charioteer, strives to guide. In the description of Love which Socrates professes to quote from the wise woman of Mantineia, there is the very height of the Platonic philosophy,—the gradual sublimation of human passion to the recognition of all noble forms and ideas, and at last to the vision of the Divine Beauty which is one with Wisdom and with Love.
"The true order of going or being led by another to the things of love is to use the beauties of earth as steps along which he mounts upwards for the sake of that other beauty, going from one to two, and from two to all fair forms, and from fair forms to fair actions, and from fair actions to fair notions, until from fair notions he arrives at the notion of absolute beauty, and at last knows what the essence of beauty is.
"What if man had eyes to see the true beauty—the divine beauty, I mean, pure and clear and unalloyed, not clogged with the pollution of mortality, and all the colors and vanities of human life—thither looking and holding converse with the true beauty divine and simple, and bringing into being and educating true creations of virtue, and not idols only? Do you not see that in that communion only, beholding beauty with the eye of the mind, he will be enabled to bring forth, not images of beauty, but realities; for he has hold not of an image but of a reality,—and will be enabled, bringing forth and educating true virtue, to become the friend of God and be immortal, if mortal man may." [1]
It is largely to Plato that we owe the idea of immortality as it exists in the mind of the civilized world to-day. The belief in a continued existence beyond death is much older; it is seen in the Iliad, where the appearance of the dead Patroclus to Achilles in a dream is accepted as the assurance of a shadowy and forlorn hereafter; and in the Odyssey the visit of the hero to the land of shades is portrayed with a free and gloomy imagination. It was a belief which among the earlier Greeks had little power either to console or to guide. In the age of Socrates, it seems to have signified little in the minds of the orthodox and pious. The great tragedians, who sublimate the popular mythology, for the most part regard the after-life as only a sad inevitable sequel; and to be snatched back from it for even a brief reprieve, like Alkestis, is miraculous good fortune. The greatest of the tragedians in his highest reach, Sophocles in Oedipus at Colonus, invests the departure of the hero, who has been purified by suffering, with a mystic radiance, a "light that never was on sea or land," the promise as it were of some future too sublime for mortal words. But the philosophy of Socrates was directed rather to the clear penetration of the method and secret of earthly life, than to any vision of the hereafter. It is noticeable that Xenophon, the loyal disciple and biographer of Socrates, himself of the best type of orthodox piety, and zealous to vindicate his master from the charge of irreligion,—Xenophon, in all the story of the master's life and death, gives not a hint of any future hope. But Plato developed the idea that in man there resides an essential, indestructible principle, superior to the physical frame which is its home and may be either its servant or master—a principle which manifests itself in thought, aspiration, virtue; which has existed before the body and will exist after it; which chooses for itself an upward or downward path; and which rightly tends to a celestial and immortal destiny. The thought never won universal acceptance even among philosophers; it had only an indirect and slight effect on the Stoicism which was the best religious product of ancient philosophy. But it wrought by degrees all effect on the thinking of mankind. While the lofty faith of the Egyptian passed away leaving no visible fruit, the idea of Plato slowly suffused with its light and warmth the current of human aspirations. Meantime, the later Jewish belief in a hereafter—in its form a much cruder conception of a physical revival from the grave—flamed up in a passionate ardor, as the sequence of the life and teaching of Jesus. The Platonic and the Christian belief sprang from a like source. Each was born from the death of a man so great and so beloved as to give the impression of some imperishable quality.
Socrates, with his noble character and aim, was put to death as a criminal. Was that the end of it all? Impossible—monstrous—never, if this world be indeed a cosmos. The one firm certainty which Socrates seems to have held, "No evil can happen to a good man in life or death,"—flashes in Plato's mind into a glorious hope of immortality, embodied in his loftiest passage, the picture of the dying Socrates.
The soul when withdrawn from all outward objects and rapt in contemplation is nearest to the divine,—this is the central thought of the Phaedo. It is pursued with much subtle argumentation, of which the essential residuum is this: the soul's action is purest and most intense when farthest withdrawn from the visible and tangible world,—and hence we guess that her true and eternal home is in that invisible realm of which all this material universe is but the veil and symbol.
But more impressive than the argument, more moving to the human heart, is the picture which is given of Socrates himself as the hour of death comes on,—the exaltation of all his familiar traits, the playfulness so exquisitely blent with seriousness, the searching thought, the frank human desire to be convinced by his own argument,—the charm of his friendly ways, the hand playing with Phaedo's hair, the taking of the cup "in the easiest and gentlest manner, without the least fear or change of color, looking at the man with all his eyes as his manner was,"—the last word, of calm reminder of a trivial obligation,—the whole scene of majestic and tender peace, like a sunset. It is a scene which reconciles us to life, and makes us no longer impatient even of our uncertainties. It speaks with a voice like that of Landor's verse:—
"Death stands above me, whispering low,
I know not what into my ear,
Of his strange language all I know
Is,—there is not a word of fear."
To the modern reader there is a singular contradiction between the doctrine of Lucretius and his temper. The denial of any divine supervision of human life, or any hereafter for man; the dominion over all existence of purely material law,—this seems to us to destroy man's dearest faith and hope. This is the teaching of Lucretius, yet on this road he marches with a step so firm and buoyant, an eye so awake to all beauty and grandeur, a spirit so elate, that as we read we catch the energy and elation. The reading of the riddle is this: the religion against which Lucretius made his attack was not the soaring idealism of Plato, nor the inspiring and consolatory faith of Christianity, but an outworn mythology in which this world was ruled by capricious and unworthy despots, and the next world was gloomy with terrors and almost unlighted by hopes. Such had become the popular mythology in its later day, and as contrasted with this the view and temper of Lucretius are rational and manly. His message went far beyond a negation; he announced one of the greatest discoveries of the human spirit—the uniformity of nature. Well might the genius of poetry and the vigor of manhood unite to make the message impressive and splendid. Not caprice, but order,—not conflict, but harmony,—not deified partialities and spites and lusts, but exalted and unchanging law, rules the universe!
When Lucretius essayed to define in what this law consists, he fell hopelessly short of the mark. In his revulsion from the chaos and pettiness of man-like divinities, he fixed on material forces,—clearly to be seen and permanent in their operation,—as the only and sufficient cause and order. Those forces, by a brilliant guess, he resolved into an interplay of atoms. From this basis he projected a physical theory, which we know now was quite inadequate even for material phenomena, while the application of it to human thought and will was hopelessly insufficient. Viewed from this standpoint, the spectacle of human life takes on a sadness which the poet's genius cannot dispel, and sometimes intensifies. To man's inner world Lucretius has no serviceable key. But he is to be judged not by what he missed but by what he gained. He above all others stands as the discoverer of one of the few cardinal truths by which to-day we interpret the universe,—the constancy of nature.