"Let’s compare our own education and understanding of the world to people in a cave -- to human beings in an underground, cave-like dwelling with a long and wide entrance open toward the light. From childhood on, the people who live in this cave have their legs and necks chained so that they can see only straight ahead in front of them. The chains keep them from turning their heads in any other direction.

"The only light in the cave is from a fire burning far above the people and behind them. Between the fire and the chained people there’s a road, built on a kind of stage structure such as you find in theaters—again above and behind the people—along which move other people and animals, some carrying things, some not, some speaking, some not."

"This is a bizarre image of bizarre prisoners," Glaucon said.

"But they’re just like us," I replied. "Do you think they can see anything of themselves and one another? Or do they merely see the images or shadows that fall on the side of the cave facing them, cast by the fire above them?"

"How could they see one another," Glaucon said, "if they’re forced to keep their heads turned in one direction throughout their whole lives?"

"And what about the shadows on the wall [the men and animals that the shadows on the wall represent that can’t be seen either]? Isn’t it the same with them?"


"And if the chained people happened to talk to each other, wouldn’t they think it right to give names and descriptions to the shadows they saw in front of them, projected on the cave wall?"

"Of course they would."

"And what if the cave had an echo, so that the side facing the chained people seemed to produce a sound? Whenever one of the men walking above and behind them spoke, would the chained people believe anything other than that the shadow on the wall was addressing them?"

"No, by Zeus," Glaucon said, "I don’t think they’d believe anything else."

"Then for sure," I said, "what the chained people held to be the truth would be nothing more than shadows."

"Certainly," Glaucon assented.

"Now let’s imagine," I said, "what freedom from their chains would be like. Suppose one of the chained people, a man, was released and immediately forced to stand up and look toward the light. He’d necessarily be doing this in pain, because the light would be dazzling. At first, he wouldn’t be able to make out the shapes of the men and animals walking up on the elevated road in front of him—which he’d seen before only as shadows.

"What do you suppose this man would say if someone told him that he’d only been looking at shadows and now he was seeing real things? And how would the man reply if he were asked to describe the nature of these real things [the shadows of which he’d been looking at all his life]? Wouldn’t he feel at a loss? And wouldn’t he be tempted to think that what he’d looked at all his life must be truer than what he’s seeing right now?"

"Yes," replied Glaucon.

"What if the man were forced to look right into the light of the fire? Wouldn’t it hurt his eyes? Wouldn’t he turn away from it? And further, wouldn’t he turn back to the shadows, thinking them more clear and therefore more true than the light itself?"

"Of course he would," Glaucon said.

"Now," I said, "what if someone were to drag that man up to the light, forcing him through a steep and rugged ascent into the light itself—where he couldn’t see anything and his eyes hurt? Wouldn’t the man be distressed, even angry? And wouldn’t he be unable to see anything, even what was being presented to him as the truth of things?

"At least at the beginning, he couldn’t see anything," Glaucon agreed.

"He’d need time and practice, perhaps learning to perceive the truth in stages—first seeing the dim images of things as he had with shadows before, maybe then seeing things reflected in water, and then finally being able to look at the real men and animals that had before just been shadows on his cave wall. As for the bright sky, he’d have to start by looking at it first at night, seeing only the light of the moon and stars, and that way gradually accustom his sight to the full light of day."

"Of course."

"Then as he was able to see the sun, he’d be able to contemplate its nature, to realize that it was the source of seasons and light and the shadows that he and his cave companions had been staring at all their lives."

"Yes, he’d no doubt arrive at this conclusion."

"And wouldn’t this man, being awake to the light, think that his original home lacked real knowledge? And wouldn’t he feel happy at his own transformation and pity those back in the cave?"

"Without a doubt."

"How do you think he’d feel as he thought back on the honors and awards given to those whose perception in the cave was sharpest? Do you think he’d want those honors and awards? Would he envy those cave-dwellers who received prizes because they could make out the shadows better than anyone else or see which shadow came first and which next? Or would he rather undergo anything, even menial labor, rather than think and live the way the cave-dwellers lived?"

"He’d probably rather suffer anything than go back to living the cave-dweller way," Glaucon said.

"Now, let’s imagine what would happen if that man returned to his place in the cave. Wouldn’t his eyes be blinded, as a man coming into darkness suddenly from sunlight?"

"Very much so."

"And what if the man—before his cave-sight returned—were to try to compete with other cave-dwellers about the shadows? Wouldn’t he seem ridiculous to the others? And during the time while his sight was adapting to the darkness, wouldn’t his former friends say that his sight had been ruined by going up to the light? And that he should never try to go back up to the light again, because it would destroy his sight again? Might not his friends even say that anyone who tried to lead him back to the light ought to be stopped, even killed if they could legally kill him?"

"There’s no question about it."

"All right, then. Let’s take this whole allegory and apply it to everything we’ve said so far. What we see with our eyes and experience through our senses is like the cave, while the sun, the center of the universe, is like the fire that illumines the cave. As you probably expect—and I agree with your expectations—the ascent from the cave is like the soul’s ascent to the Realm of Ideas. Of course, just because we agree on this doesn’t make it true; there may be some god or power somewhere who knows the truth about these things. But this is the way it appears to me: that of all the subjects of human knowledge, the last and most difficult to be seen is the Idea of the Good.

"But once seen, it is clear that the Idea of the Good is the source of everything. In the visible realm, it’s the source of physical light, and in the consciousness realm, it’s the source of truth and wisdom. And any person who wants to act with justice, either personally or publicly, must see it."


4th century BC