3. The Metaphysician

There is no system in Plato, and if here, for order’s sake, his ideas are summarized under the classic heads of logic, metaphysics, ethics, esthetics, and politics, it should be remembered that Plato himself was too intense a poet to shackle his thought in a frame. Because he is a poet he has most difficulty with logic; he wanders about seeking definitions, and loses his way in perilous analogies; “then we got into a labyrinth, and, when we thought we were at the end, came out again at the beginning, having still to see as much as ever.”⁷⁹ He concludes: “I am not certain whether there is such a science of science” as logic “at all.”⁸⁰ Nevertheless he makes a beginning. He examines the nature of language, and derives it from imitative sound.⁸¹ He discusses analysis and synthesis, analogies and fallacies; he accepts induction, but prefers deduction;⁸² he creates, even in these popular dialogues, technical terms—essence, power, action, passion, generation—which will be useful to later philosophy; he names five of the ten “categories” that will make up part of Aristotle’s fame. He rejects the Sophist view that the senses are the best test of truth, that the individual “man is the measure of all things”; if that were so, he argues, any man’s, any sleeper’s, any madman’s, any baboon’s report of the world would be as good as any other.⁸³

All that the “rabble of the senses” gives us is a Heracleitean flux of change; if we had only sensations, we should never have any knowledge or truth at all. Knowledge is possible through Ideas, through generalized images and forms that mold the chaos of sensation into the order of thought.⁸⁴ If we could be conscious only of individual things thought would be impossible. We learn to think by grouping things into classes according to their likenesses, and expressing the class as a whole by a common noun; manenables us to think of all men, table of all tables, light of every light that ever shone on land or sea. These Ideas (ideai, eida) are not objective to the senses but they are real to thought, for they remain, and are unchanged, even when all the sense objects to which they correspond are destroyed. Men are born and die, but man survives. Every individual triangle is only imperfectly a triangle, sooner or later passes away, and therefore is relatively unreal; but triangle—the form and law of all triangles—is perfect and everlasting.⁸⁵ All mathematical forms are Ideas, eternal and complete;* everything that geometry says of triangles, circles, squares, cubes, spheres would remain true, and therefore “real,” even if there had never been, and never would be, any such figures in the physical world. Abstractions also are real in this sense; individual acts of virtue have a brief existence, but virtue remains as a permanent reality for thought, and an instrument of thought; so with beauty, largeness, likeness, and so forth; these are as real to the mind as beautiful, large, or like things are real to the sense.⁸⁷ Individual acts or things are what they are by partaking of, and more or less realizing, these perfect forms or Ideas. The world of science and philosophy is composed not of individual things, but of Ideas;†⁸⁸ history, as distinct from biography, is the story of man; biology is the science not of specific organisms, but of life; mathematics is the study not of concrete things but of number, relation, and form independently of things and yet as valid for all things. Philosophy is the science of Ideas.

Everything in Plato’s metaphysics turns upon the theory of Ideas. God, the Prime Mover Unmoved, or Soul of the World,⁹¹ moves and orders all things according to the eternal laws and forms, the perfect and changeless Ideas which constitute, as the Neo-Platonists would say, the Logos, or Divine Wisdom or Mind of God. The highest of the Ideas is the Good. Sometimes Plato identifies this with God himself;⁹² more often it is the guiding instrument of creation, the supreme form towards which all things are drawn. To perceive this Good, to vision the molding ideal of the creative process, is the loftiest goal of knowledge.⁹³ Motion and creation are not mechanical; they require in the world, as in ourselves, a soul or principle of life as their originative power.⁹⁴

Only that which has power is real;⁹⁵ therefore matter is not basically real (to me on), but is merely a principle of inertia, a possibility waiting for God or soul to give it specific form and being according to some Idea. The soul is the self-moving force in man, and is part of the self-moving Soul of all things.⁹⁶ It is pure vitality, incorporeal and immortal. It existed before the body, and has brought with it from antecedent incarnations many memories which, when awakened by new life, are mistaken for new knowledge. All mathematical truths, for example, are innate in this way; teaching merely arouses the recollection of things known by the soul many lives ago.⁹⁷ After death the soul or principle of life passes into other organisms, higher or lower according to the deserts it has earned in its previous avatars. Perhaps the soul that has sinned goes to a purgatory or hell, and the virtuous soul goes to the Islands of the Blest.⁹⁸ When through various existences the soul has been purified of all wrongdoing, it is freed from reincarnation, and mounts to a paradise of everlasting happiness.*⁹⁹