Allegory of the Cave: Reality, Perception, and Enlightenment

In this article, we look at Plato’s Allegory of the Cave. Plato used this story, or thought experiment, to show us his understanding of reality and our ability to understand it. Throughout Western history, there has been general agreement that there is such a thing as an objective reality. You are reading this article. That would be seen by almost everyone in the Western intellectual tradition as objectively true. Some today reject objective reality, however, in favor of addressing your truth or my truth, which are to be regarded as having equal validity. Here, we view Plato’s understanding of an objective reality and the possible problems of correctly perceiving it.


Plato was a member of a prominent Athens family, His family was said to be descended from the great Athenian lawgiver Solon and from the god Poseidon. A truly noble heritage, indeed! Plato was born about 428, during the Peloponnesian War, which lasted for about 37 years between 431 BC and 404 BC. The war ended with Sparta achieving victory over Athens.

With the end of the war came great unrest in Athens. Athens was divided between support for oligarchy and support for a restoration of Athenian democracy. Some of Plato’s relatives were in the so-called Tyranny of the Thirty, a relatively brief period of oligarchic rule in 404 BC. Plato harbored a suspicion of democracy and in general leaned toward oligarchic views.

Plato was acquainted with Socrates. In fact, Plato is the best known student of Socrates. Plato’s philosophical works are dialogues with different characters presenting a variety of views. Socrates appears as a character in most of Plato’s dialogues. We can’t know for sure how much the Platonic character of Socrates matches the historical Socrates. Socrates wrote nothing. What we know about him comes from others writing about him.

Some of Plato’s earliest dialogues about Socrates are believed to better represent the historical Socrates than the later ones. Later dialogues seem to use Socrates as a character expressing Plato’s views. Not all scholars agree, of course, on this general interpretation.

In 399 BC, Socrates was executed under order of an Athenian court. He had been accused of impiety and corrupting the youth. Following the execution of his teacher, Plato left Athens for a while, then returned to start his Academy in 387 BC. The Academy was a philosophical school located in Athens. Many intellectuals, including Aristotle, studied at the Academy. Plato died in about 348 or 347 BC.

The Republic

The Republic is perhaps Plato’s best known dialogue. In the dialogue, the different characters (including Socrates, likely representing Plato’s position) are exploring the nature of justice. Is justice what we say it is, or is there an objective thing called justice? What is a just person? Early on, the discussion runs into problems. Socrates proposes that the discussion change course. Since it is hard to find justice in an individual, perhaps it will be easier to find justice in something larger, in the polis (the Greek city-state), for instance. The discussion at this point takes a definite political turn.

The title, The Republic, is somewhat misleading. The title comes not from Greek, but from Latin, res publica, literally meaning the public thing. While republican government today is understood to involve things like civic virtue, broad public participation, and division of power, that is not at all what Plato was writing about. It might have been better had the dialogue been known by a title more like Justice or The Just State, since that is the central concept being explored.

Allegory of the Cave

The Cave

In Book VII of The Republic, we see a new discussion unfold, with the Allegory of the Cave. The topic, broadly speaking is education. Socrates proposes a thought experiment.

Behold! Human beings live in an underground den, which has a mouth open towards the light and reaching all in the den; here they have all been from their childhood, and have their legs and necks chained so they cannot move, and can only see before them, being prevented by the chains from turning round their heads. Above and behind them a fire is blazing at a distance, and between the fire and the prisoners there is a raised way; and you will see, if you look, a low wall built along the way, like the screen which marionette players have in front of them, over which they show the puppets.

Let’s break this down, since this may seem a bit dense. Perhaps we can slightly update the imagery as well. Imagine you are in a large room with a screen at the front. For the modern reader, it might be useful to imagine a movie theater. Everyone in the theater is sitting in a seat and is bound to the seat. They have been confined in this way since childhood. No one in the audience can get up or turn their heads to look around. They can look only at the screen in front of them. Using the theater metaphor, there is a bright light coming from the back of the room that the audience can not turn around to see.

The Puppeteers

Socrates continues

And do you see . . . men passing along the wall carrying all sorts of vessels, and statues and figures of animals made of wood and stone and various materials, which appear over the wall? Some of them are talking and others silent.

Here, we see that people are walking in front of the light, carrying objects that cast shadows on the front of the cave. In our theater imagery, we can imagine the window in the projectionist’s booth where the a traditional film image would be projected. Instead of a film, there is just a bright light. People are walking under the projectionist’s window in the projectionist’s booth, carrying objects held up to pass between the light and the projectionist’s window.

Shadows Perceived as Reality

Let’s continue, speaking of the people in the cave.

They see only their own shadows, or the shadows of one another, which the fire throws on the opposite wall of the cave. . . .

And of the objects being carried in like manner they see only shadows. . . .

If they were able to converse one with another, would they not be suppose that they were naming what was actually before them? . . .

And suppose further that the prison had an echo which came from the other side, would they not be sure to fancy when one of the passers-by spoke that the voice they heard came from the passing shadow? . . .

To them, . . . the truth would be literally nothing but the shadows of the images.

So, now we are discussing the shadows from the people moving on the wall behind the chained people. In the theater analogy, we are discussing the shadows that come from the objects passing in front of the projectionist’s light. These shadows are cast on the screen in front of the theater. From the perspective of the people chained in position, reality is the shadows cast on the screen (or the front of the cave), along with the voices echoing off the walls that seem to come from the shadows. The shadows are perceived not as shadows, but rather as what is really happening.


Now, imagine that something fantastic happens. The prisoners are released. They are free to go and discover the truth of their situation. When asked to stand and look around, what happens?

At first, when any of them is liberated and compelled suddenly to stand up and turn his neck round and walk and look towards the light, he will suffer sharp pains; the glare will distress him, and he will be unable to see the realities of which in his former state he had seen the shadows; and then conceive some one saying to him, that what he saw before was an illusion, but that now . . . his eye is turned towards more real existence . . . – what will be his reply? . . . Will he not fancy that the shadows which he formerly saw are truer than the objects which are now shown to him?

What we see here is rejection of reality in favor of the shadows to which the person was accustomed. In the theater analogy, imagine looking back at the projectionist’s window and being blinded by the brightness of the light. It would be painful and foreign. It would, indeed, seem very unreal.


Plato’s allegory goes on, though, to imagine that someone is taken out of the cave completely into a sunny day. The light of the sun would be even more painful than the light of the fire in the cave. Eventually, though, his eyes will adjust.

He will require and grow accustomed to the sight of the upper world. And first he will see the shadows best, next the reflections of men and other objects in the water, and then the objects themselves; then he will gaze upon the light of the moon and the stars and the spangled heaven; and he will see the sky and the stars by night better than the sun or the light of the sun by day. . . . he will see him[self] in his own proper place, and not in another; and he will contemplate him[self] as he is.

This person who has made it all the way out of the cave has acquired more complete knowledge about the reality of the world.

Rejection of Enlightenment

Will this newly enlightened person not remember his former companions still in the cave? Plato suggests he indeed will. When he returns to the cave, though, he will have a difficult time seeing because the cave is relatively dark, and his eyes have adjusted to the brightness outside the cave. When he returns he will stagger until his eyes can readjust. Socrates suggest that, “Men would say of him that up he went and down he came without his eyes; and that it was better not even to think of ascending.” Not only would the people who never left the cave be afraid to leave, they would “put to death” anyone who tried to force others to leave the cave.

So, what does this all mean? Socrates explains

the prison-house is the world of sight, the light of the fire is the sun, and you will not misapprehend me if you interpret the journey upwards to be the ascent of the soul into the intellectual world . . . my opinion is that in the world of knowledge the idea of good appears last of all and is seen only with an effort; and, when seen, is also inferred to be the universal author of all things beautiful and right, parent of light and the lord of light in this visible world, and the immediate source of reason and truth in the intellectual; and that this is the power upon which he who would act rationally either in public or private life must have his eye fixed.

He continues to note that ones who have been so enlightened “are unwilling to descend into human affairs; for their souls are ever hastening into the upper world where they desire to dwell. . .”

So, where does this leave us? Note that most people were unwilling to pursue the path out of the cave. Most people are unwilling to pursue enlightenment. There is a bit of an elitist undertone to the Allegory of the Cave; for instance, the enlightened philosopher is now above the concerns of the common people. Only the worthy are able to achieve a truer understanding of reality. Plato is a philosopher, and it may be no surprise that he sees a special elevated role for the philosopher in society.

Lessons from the Allegory of the Cave

What else can we learn from the Allegory of the Cave? The allegory illustrates a number of things.

The masses may be indeed be disillusioned. Just because “everyone knows,” something doesn’t mean it is true. We may be looking at a mere shadow of reality. To some degree, in fact, this is certainly true. We do not have perfect knowledge of anything. The people in the cave see shadows on the wall. Even from sitting in different positions in the cave, the perception of the shadows will be different for different people.

Enlightenment takes work. It may even involve pain. Enlightenment does not come by just waiting for it to happen. What does this work look like and how might it be painful? In the allegory, the pain came from the brightness of the light (the previously unknown knowledge). For us, the pain may come in confronting our own errors. It may come in developing a willingness to pursue truth over your current opinion. Enlightenment must include a willingness to reject your own ideas that are wrong and to adopt right ideas.

We believe that there is an objective reality. We believe that our perceptions of reality are fallible. While we may correctly see some aspects of reality, our perception is still partial. While we may see reality from one side, another person may see the same reality from another side. Both may be right about what they see, but they would also be incomplete or wrong in what they don’t see. It is also possible that both are completely wrong. We should be seeking not to reject objective reality (there really is not an apparent workable alternative), but to seek it.