1 Plato 5 · On the Cave and the Light. Handed down at the Academy, from his Republic
From the Republic, written when Plato was about fifty, in ten books. It begins with one question — what is justice — and in answering it becomes the plan of a city and then a theory of knowledge. The cave is in the seventh book. This volume takes only the cave: the descent, the turning, the ascent, the return, and that by which one sees. For the man, see the Gospel of Plato. What is set down here runs from his fortieth year to his seventieth; in the fourth chapter he states plainly that he no longer agrees with himself, and does not strike out the older view. Where the Good is spoken of, the Order takes it in the smaller sense: that which makes each thing be what it is, and is not itself among things.
5.1Glaucon, you ask what the sun outside the cave is.
5.2Let me ask you something first. If the eye is sound and the thing is there, is that enough to see it?
5.3It is not. At night your eye is just as sound and the thing is just as there, and you see nothing.
5.4A third thing is needed.
5.5That third thing is not the eye and not the object. It is what lets the two of them meet.
5.6By day, it is the light.
5.7A man looking at a thing never looks at the light. He looks at the thing.
5.8The one thing that lets him see, he does not glance at once in his whole life.
5.9I called the sun outside the cave that by which all seeing and all knowing are possible.
5.10From this some have said: then it is the Good, the one above all things.
5.11When I was young I said so too.
5.12Now I say it more carefully. It is that which makes each thing what it is, and it is not itself one of the things.
5.13It does not flow, and it makes all things flow. (cf. Prologue 1.12)
5.14You need not kneel to it. Kneeling shows you no more than standing does.
5.15You need only turn around and walk toward it. By as much as you see, by that much you are larger.