Plato, Republic

[523a] that it is one of those studies which we are seeking that naturally conduce to the awakening of thought, but that no one makes the right use¹ of it, though it really does tend to draw the mind to essence and reality.” “What do you mean?” he said. “I will try,” I said, “to show you at least my opinion. Do you keep watch and observe the things I distinguish in my mind as being or not being conducive to our purpose, and either concur or dissent, in order that here too we may see more clearly² whether my surmise is right.” “Point them out,” he said. “I do point them out,” I said, “if you can discern that some reports of our perceptions [523b] do not provoke thought to reconsideration because the judgement³ of them by sensation seems adequate,⁴ while others always invite the intellect to reflection because the sensation yields nothing that can be trusted.⁵” “You obviously mean distant⁶ appearances,” he said, “and shadow-painting.⁷” “You have quite missed my meaning,⁸” said I. “What do you mean?” he said. “The experiences that do not provoke thought are those that do not [523c] at the same time issue in a contradictory perception.⁹ Those that do have that effect I set down as provocatives, when the perception no more manifests one thing than its contrary, alike whether its impact¹⁰ comes from nearby or afar. An illustration will make my meaning plain. Here, we say, are three fingers, the little finger, the second and the middle.” “Quite so,” he said. “Assume that I speak of them as seen near at hand. But this is the point that you are to consider.” “What?” “Each one of them appears to be [523d] equally a finger,¹¹ and in this respect it makes no difference whether it is observed as intermediate or at either extreme, whether it is white or black, thick or thin, or of any other quality of this kind. For in none of these cases is the soul of most men impelled to question the reason and to ask what in the world is a finger, since the faculty of sight never signifies to it at the same time that the finger is the opposite of a finger.” “Why, no, it does not,” he said. “Then,” said I, “it is to be expected that such a perception will not provoke or awaken¹² [523e] reflection and thought.” “It is.” “But now, what about the bigness and the smallness of these objects? Is our vision's view of them adequate, and does it make no difference to it whether one of them is situated¹³ outside or in the middle; and similarly of the relation of touch, to thickness and thinness, softness and hardness? And are not the other senses also defective in their reports of such things? Or is the operation of each of them as follows?