Allegory of the cave

Plato's allegory of the cave is an allegory presented by the Greek philosopher Plato in his work Republic (514a–520a, Book VII) to compare "the effect of education (παιδεία) and the lack of it on our nature". It is written as a dialogue between Plato's brother Glaucon and his mentor Socrates and is narrated by the latter. The allegory is presented after the analogy of the Sun (508b–509c) and the analogy of the divided line (509d–511e).
In the allegory, Plato describes people who have spent their entire lives chained by their necks and ankles in front of an inner wall with a view of the empty outer wall of the cave. They observe the shadows projected onto the outer wall by objects carried behind the inner wall by people who are invisible to the chained “prisoners” and who walk along the inner wall with a fire behind them, creating the shadows on the inner wall in front of the prisoners. The "sign bearers" pronounce the names of the objects, the sounds of which are reflected near the shadows and are understood by the prisoners as if they were coming from the shadows themselves.
Only the shadows and sounds are the prisoners' reality, which are not accurate representations of the real world. The shadows represent distorted and blurred copies of reality we can perceive through our senses, while the objects under the Sun represent the true forms of objects that we can only perceive through reason. Three higher levels exist: natural science; deductive mathematics, geometry, and logic; and the theory of forms.
Socrates explains how the philosopher is like a prisoner freed from the cave and comes to understand that the shadows on the wall are not the direct source of the images seen. A philosopher aims to understand and perceive the higher levels of reality. However, the other inmates of the cave do not even desire to leave their prison, for they know no better life.
Socrates remarks that this allegory can be paired with previous writings, namely the analogy of the Sun and the analogy of the divided line.
Plato begins by having Socrates ask Glaucon to imagine a cave where people have been imprisoned from childhood. These prisoners are chained so that their legs and necks are fixed, forcing them to gaze at the wall in front of them and not to look around at the cave, each other, or themselves (514a–b). Behind the prisoners is a fire, and between the fire and the prisoners is a raised walkway with a low wall, behind which people walk carrying objects or puppets "of men and other living things" (514b).
The people walk behind the wall so their bodies do not cast shadows for the prisoners to see, but the objects they carry do ("just as puppet showmen have screens in front of them at which they work their puppets") (514a). The prisoners cannot see any of what is happening behind them; they are only able to see the shadows cast upon the cave wall in front of them. The sounds of the people talking echo off the walls; the prisoners believe these sounds come from the shadows (514c).
Socrates suggests that the shadows are reality for the prisoners because they have never seen anything else; they do not realize that what they see are shadows of objects in front of a fire, much less that these objects are inspired by real things outside the cave which they do not see (514b–515a).
Socrates then supposes that the prisoners are released. A freed prisoner would look around and see the fire. The light would hurt his eyes and make it difficult for him to see the objects casting the shadows. If he were told that what he is seeing is real instead of the other version of reality he sees on the wall, he would not believe it. In his pain, Socrates continues, the freed prisoner would turn away and run back to what he is accustomed to (that is, the shadows of the carried objects). The light "... would hurt his eyes, and he would escape by turning away to the things which he was able to look at, and these he would believe to be clearer than what was being shown to him".
Socrates continues: "Suppose... that someone should drag him... by force, up the rough ascent, the steep way up, and never stop until he could drag him out into the light of the sun". The prisoner would be angry and in pain, and this would only worsen when the radiant light of the sun overwhelms his eyes and blinds him.
"Slowly, his eyes adjust to the light of the sun. First he can see only shadows. Gradually he can see the reflections of people and things in water and then later see the people and things themselves. Eventually, he is able to look at the stars and moon at night until finally he can look upon the sun itself (516a)". Only after he can look straight at the sun "is he able to reason about it" and what it is (516b). (See also Plato's analogy of the Sun, which occurs near the end of The Republic, Book VI.)
Socrates continues, saying that the free prisoner would think that the world outside the cave was superior to the world he experienced in the cave and attempt to share this with the prisoners remaining in the cave attempting to bring them onto the journey he had just endured; "he would bless himself for the change, and pity [the other prisoners]" and would want to bring his fellow cave dwellers out of the cave and into the sunlight (516c).
The returning prisoner, whose eyes have become accustomed to the sunlight, would be blind when he re-entered the cave, just as he was when he was first exposed to the sun (516e). The prisoners who remained, according to the dialogue, would infer from the returning man's blindness that the journey out of the cave had harmed him and that they should not undertake a similar journey. Socrates concludes that the prisoners, if they were able, would therefore reach out and kill anyone who attempted to drag them out of the cave (517a).
The allegory is related to Plato's theory of Forms, according to which the "Forms" (or "Ideas"), and not the material world known to us through sensation, possess the highest and most fundamental kind of reality. Knowledge of the Forms constitutes real knowledge or what Socrates considers "the Good". Socrates informs Glaucon that the most excellent people must follow the highest of all studies, which is to behold the Good. Those who have ascended to this highest level, however, must not remain there but must return to the cave and dwell with the prisoners, sharing in their labors and honors.
Plato's Phaedo contains similar imagery to that of the allegory of the cave; a philosopher recognizes that before philosophy, his soul was "a veritable prisoner fast bound within his body... and that instead of investigating reality of itself and in itself is compelled to peer through the bars of a prison".
Scholars debate the possible interpretations of the allegory of the cave, either looking at it from an epistemological standpoint—one based on the study of how Plato believes we come to know things—or through a political (politeia) lens. Much of the scholarship on the allegory falls between these two perspectives, with some completely independent of either. The epistemological view and the political view, prominently represented by Richard Lewis Nettleship and A. S. Ferguson, respectively, tend to be discussed most frequently.
Nettleship interprets the allegory of the cave as representative of our innate intellectual incapacity, in order to contrast our lesser understanding with that of the philosopher, as well as an allegory about people who are unable or unwilling to seek truth and wisdom. Ferguson, on the other hand, bases his interpretation of the allegory on the claim that the cave is an allegory of human nature and that it symbolizes the opposition between the philosopher and the corruption of the prevailing political condition.
Cleavages have emerged within these respective camps of thought, however. Much of the modern scholarly debate surrounding the allegory has emerged from Martin Heidegger's exploration of the allegory, and philosophy as a whole, through the lens of human freedom in his book The Essence of Human Freedom: An Introduction to Philosophy and The Essence of Truth: On Plato's Cave Allegory and Theaetetus. In response, Hannah Arendt, an advocate of the political interpretation of the allegory, suggests that through the allegory, Plato "wanted to apply his own theory of ideas to politics". Conversely, Heidegger argues that the essence of truth is a way of being and not an object. Arendt criticised Heidegger's interpretation of the allegory, writing that "Heidegger ... is off base in using the cave simile to interpret and 'criticize' Plato's theory of ideas".
Various scholars also debate the possibility of a connection between the work in the allegory and the cave and the work done by Plato considering the analogy of the divided line and the analogy of the Sun. The divided line is a theory presented to us in Plato's work the Republic. This is displayed through a dialogue given between Socrates and Glaucon in which they explore the possibility of a visible and intelligible world, with the visible world consisting of items such as shadows and reflections (displayed as AB) then elevating to the physical item itself (displayed as BC) while the intelligible world consists of mathematical reasoning (displayed by CD) and philosophical understanding (displayed by DE).
Many see this as an explanation for the way in which the prisoner in the allegory of the cave goes through the journey, first in the visible world with shadows such as those on the wall, then the realization of the physical with the understanding of concepts such as the tree being separate from its shadow. It enters the intelligible world as the prisoner looks at the sun.
The Analogy of the Sun refers to the moment in book six in which Socrates, after being urged by Glaucon to define goodness, proposes instead an analogy through a "child of goodness". Socrates reveals this "child of goodness" to be the Sun, proposing that just as the Sun illuminates, bestowing the ability to see and be seen by the eye with its light, so the idea of goodness illumines the intelligible with truth, leading some scholars to believe this forms a connection of the Sun and the intelligible world within the realm of the allegory of the cave.
The themes and imagery of Plato's cave has influenced civil thought and culture. For instance:
The following is a list of supplementary scholarly literature on the allegory of the cave that includes articles from epistemological, political, alternative, and independent viewpoints on the allegory: