THE ALLEGORY OF THE CAVE

by Plato

The following is an excerpt from Plato’s dialogue called “The Republic.” In this section of the

dialogue called the “Allegory of the Cave,” Socrates creates an allegory to help illustrate his

theory of knowledge.

“Now then,” Socrates said, “let me tell you a story about ignorance and education which

will explain the condition of man’s nature. Imagine that there is an underground cave with a

long entrance open to the light. In this cave men have been chained from birth, fettered by the

neck and legs so they cannot move. They cannot turn their heads around; they can only look

forward at the wall of the cave. A light comes to them from a fire burning some distance behind

them. Between the fire and the chained men is a raised platform on which a low wall has been

built. Behind the wall are people, like puppeteers, who carry all sorts of articles like statues of

men and other living things which they hold above the wall. Some of the bearers speak and

others are silent, as you might expect.”

“I see,” said Glaucon [Socrates’ student]. “Truly a strange place and strange sort of

people.”

“Actually, they are just like ourselves.” Socrates explained, “What do you think these

chained men would know of themselves or each other or anything else? They will know only the

shadows which the firelight casts on the opposite wall of the cave.”

“They could not know anything else if they were chained so that they could never turn

their heads,” exclaimed Glaucon.

“True; and what about the things being held above the wall? Would not they only know

the shadows of these things?” asked Socrates.

“Of course,” Glaucon answered.

“Suppose the prisoners could talk to each other; and they named the passing shadows.

Would they believe they were naming real things?”

“They would.”

“Then suppose the cave had an echo so that when one of the people passing behind the

wall spoke, the chained prisoners would think that the sounds originated with the shadows.

Would they not think that the shadows of the objects were real?”

“Surely they would,” said Glaucon.

“Now consider what would happen,” Socrates continued, “if one of the prisoners would

be released from his chains. He would be forced to stand up and turn around, to walk and look at

the firelight. Would he not find this painful? Would he not be too dazzled by the light to see

clearly those things whose shadows he had seen on the wall? What do you think he would say if

someone told him all that he had seen before was merely an illusion, but now he could see more

clearly being closer to reality? What if he were shown each of the items which cast the shadows;

would he not be confused and be sure that what he had seen before was more real than what was

being shown him now?”

“He would surely be confused,” Glaucon exclaimed.

Socrates went on. “Then suppose he were made to look towards the great light coming

from the entrance to the cave; would that not hurt his eyes? Would he not prefer to look upon

those things being shown him?”

“Of course,” answered Glaucon.

“Now, let us suppose that someone would force him to approach the light and then

dragged him up the steep and rugged pathway and out into daylight. Would he not then be

distressed? When he came into the light of the sun the brilliance would blind him. He would not

be able to see any of the things that we would call real.”

“No,” Glaucon said, “not at first.”

Socrates continued, “He would surely have to get used to the light. At first he would

most easily look at the shadows, then at reflections in the water, and finally he would find it

easier to study the night sky and the light of the stars and the moon, than to look at things in the

glare of the sunlight.”

“Just so,” said Glaucon.

“Last of all he could look at the sun itself, in its own place, and understand what it is like

in itself, not as it is reflected in water or some other medium. And, after all this, he might reason

that it is the sun which creates the seasons and the course of the year, and it is the cause of all

things seen in the visible world.”

“Yes,” Glaucon nodded, “he would come to that conclusion.”

“Very good,” Socrates encouraged. “Now let us remind the released man of his former

dwelling place and what had passed for knowledge among those chained in the cave. Do you

think he would prefer his present state and pity those still in the cave?”

“He surely would prefer his present state,” Glaucon agreed.

“And what if there had been honors and prizes for those chained men who would name

the most shadows and remember the order in which they appeared, do you think he would want

to return to his chains and gain those rewards? Would he envy those who won the honors? Or

would he not say like Homer’s hero, Achilles, that he would far prefer to be the servant of a poor

man in the world above than to be the king of the land of the shadows below?”

“Oh yes, he would indeed!” Glaucon exclaimed.

“Consider then, what would happen if this released prisoner should return to his former

seat in the cave; would he not be unable to see clearly, coming into the darkness so suddenly?”

“Yes, he would find it hard to see,” said Glaucon.

“Then what would happen if he had to compete with those who had never left the cave

and he was asked to name the passing shadows? It would take him a long time to get used to this

again. Would the others not mock him and say that he had ruined his eyesight by leaving the

cave? They would say it was not worthwhile even to try to go up and if someone tried to force

them to leave, they would kill him.”

“They probably would,” Glaucon said morosely.

Socrates went on to explain his allegory: “The world that we see, my dear Glaucon, may

be compared to the cave, and the firelight to the light of the sun. The ascent out of the world of

the shadows is like the journey of the mind into the realm of knowledge. Do you understand? If

you do you will not be far from knowing what I think, since that is what you asked, but Lord

only knows if it is really true. Anyway this is how it appears to me; in the realm of knowledge,

the last thing to be known and most difficult to understand is the idea of the good, the true, the

essential form. Once understood it becomes obvious that this is the source of all that is right and

just, beautiful and true. This is what has given birth to the light and to the Lord of light, both in

the world of sight and in the world of the mind. This is what produces truth and reason. This is

what must be known and understood by anyone who is to act with reason either publicly or

privately.”

“I believe that you are right, Socrates,” Glaucon said, “if I understand you correctly.”

“Then believe me when I say that those who come to this point of knowledge grow

disinterested in the petty affairs of man and their souls seek to remain in the upper realms.”

“Quite so,” Glaucon agreed.

“Well then, do you think it is surprising if one, who has just left the contemplation of

divine wisdom and returned to the concerns of men, appears to be foolish? Although he has not

yet become accustomed to the darkness around him, he is compelled to struggle in law courts

about shadows of justice or to debate with others who have never seen the true form of justice.”

“It would be difficult for him,” Glaucon said.

“But any man of sense,” Socrates continued, “would remember that his eyes were

confused from two different causes—from moving from darkness to light and from light to

darkness. He would know that the same thing happens to the mind. Whenever he saw a person

confused and unable to understand something, he would not scoff but would try to discern if that

person had come from a more brilliant life and was puzzled by the darkness of this life, or if that

person had been in the darkness and now was dazzled by the brighter light here. Then he would

know if he should console or congratulate that man.”

“That would be the prudent course,” agreed Glaucon.

“If all that we have been saying is true,” Socrates said, “presently held theories about the

nature of education must be false. It cannot be, as some say, the filling of empty minds with

wisdom, like putting sight into blind eyes. Our reasoning indicates that the power of knowledge

is already in each mind. It is the instrument by which every man learns. Thus, if the eye of the

chained man could not really see until his whole body was turned towards the light, so too the

instrument of knowledge, the mind, must be turned away from the distractions of this world of

Becoming until it learns to endure the sight of the brilliant light of Being, that which we call the

Good.

“The business of those of us who are founders of the ideal Republic will be to compel

those with the best minds to attain that knowledge of the Good, which we have shown is the

greatest of all knowledge, and then they must be made to descend again among the prisoners in

the cave, and partake of their honors and prizes whether they think them worthwhile or not.”