It will help much any view in the field of philosophy to keep uppermost the thought of distinct classes, types, or kinds of things in nature; the thought of the corresponding class concepts, general notions or universals in the human mind; and the thought of original ideas in the mind of God, as constituting principles or laws or modes of action in nature. This is not a world of chaotic chance, it is a world of rational and progressive order, and we are compelled to seek for the architecture an architect and a plan embodying rational ideas. Plato’s ideas are eternal entities existing neither in nature nor in the mind of God, but nevertheless the archetypes, forms, or patterns after which every kind of things to which may be applied a common name was fashioned. Plato here held in an imperfect way the mighty truth of all philosophy, and the “Ideas” have reappeared in many guises,—as the forms or essences of Aristotle, existing only as realized in nature, as ideas in the mind of God, as the self-evolving categories of Hegel, as the perfecting principle and the fashioning laws in the doctrine of evolution.
Man in his preëxistent state dwelt in the region of immaterial ideas and gazed on the fulness of their truth. At his human birth he was made oblivious of his past existence, and growth in wisdom was a gradual realization in the consciousness of the eternal verities formerly known. As in Wordsworth, man’s birth was but a “sleep and a forgetting;” growth in knowledge was a remembering. “Trailing clouds of glory do we come from God, who is our home.” The truth in this metaphor of philosophy, we may believe, is that man is of divine origin, and hence may know the divine revelations in his own being and in the material world. Here was foreshadowed in rough outlines the spiritual idealism which in its fresh form appears to be gaining new ground to-day. God writes the book of nature; man is the son of God and reads and vaguely understands the meaning of the mighty volume.
Sensations are not knowledge, but the signs of knowledge, as words are the signs of thought, and the mind is innately active and rational, else there could be no interpretation of those signs. This appears to be the true explanation of the fact that we are educated by contact with nature. Without the signs, no communication of knowledge; without the native power of the reader, no reception of knowledge.
Plato held that the ideas were manifest in nature and were also innate in the mind; hence by self-examination and comparison with the copies of the ideas in nature, man arrived at essential truth which was the work of philosophy.
Plato identified the Idea of Ideas with Cause, Mind, the Good or God. God was a personality and supreme above the gods. He was named by his chief attribute, the Good, and of this the True and the Beautiful were qualities. Cousin says, “The True, the Beautiful, and the Good are only revelations of the same Being; that which reveals them to us is reason.” “If all perfection belongs to the perfect being, God will possess beauty in its plenitude. The father of the world, of its laws, of its ravishing harmonies, the author of forms, colors, and sounds, he is the principle of beauty in nature. It is he whom we adore without knowing it, under the name of the ideal, when our imagination, borne on from beauties to beauties, calls for a final beauty in which it may find repose.” This passage is thoroughly Platonic in spirit and throws much light on the meaning of these absolute ideas of Plato. With change of terms the same passage would apply to Truth and Goodness. We trace them as they appear in the conscious reason and disposition, as they are manifested in the relations of society or are suggested by the reality and beneficence of the world, and we are led to the conception of the perfect ideals whose truth exists in God.
Plato has four principles whose interrelation and process of the active elements determine the world, as the laws of modern evolution are conceived to work out the results discovered by science: (1) unlimited, unformed, or chaotic nature; (2) law, imposing limits and forms upon nature; (3) the resulting, definite types and ideas of a rational world; (4) the Cause which effects these results.
The Good is that which imparts truth to the object and knowledge to the perceiving subject, and is the cause of science and truth; hence, to know the Good is the ethical aim, for to know the Good is to act in harmony with it, and knowledge is virtue.
Plato was fully aware that the philosopher, then as to-day, was regarded by the many as a useless star-gazer, and in the celebrated Allegory of the Cave he shows the relation of true insight to the common view of life and the world. He imagines dwellers in a cave so placed that they see only the shadows of passing objects and hear only the echoes of sounds from the outer world. If released and brought to the full light of the sun they are dazzled and pained, and think they are in a world of false appearance, and believe the realities are the familiar shadows in the cave. After a while they become accustomed to the day and the real objects, and see their truth and beauty. And if they return to the cave, they are half blind and appear ridiculous to the dwellers there. He concludes, “Whether I am right or not, God only knows; but, whether true or false, my opinion is that in the world of knowledge the idea of good appears last of all, and is seen only with an effort; and, when seen, is also inferred to be the universal author of all things beautiful and right, parent of light and lord of light in this world, and the source of truth and reason in the other: this is the first great cause which he, who would act rationally either in public or private life, must behold.”
To the Sophist, who follows the opinion of the many instead of regarding fixed principles of truth, he pays his respects with the searching satire of a Carlyle.