History

Plato's Allegory of the Cave: Part II

Written by Dr. Jason Rheins on March 16, 2022

In the previous post, we looked at the basic scenario posed by the allegory of the cave: prisoners are forever chained inside of a dim, fire-lit cave and can only see the shadows cast by idols or puppets that are carried about behind them.

The result of a life without access to any other kind of experience than the shadows on the wall they are forced to face or the echoes of voices bouncing off that same wall is that these prisoners take these shadows to be true and primary realities, or, as Socrates puts it: “[I]n every way such prisoners would deem reality to be nothing else than the shadows of the artificial objects (515c).”

We also discussed why Socrates claims that the prisoners are very much like us. For Plato, physical objects disclosed by our senses are "becomings", ephemeral and imperfect imitations of the real, intelligible *beings*, i.e. the so-called "Forms" or "Ideas". Furthermore, if the sensible world is a shadow or imitation of the Forms, then the stories, pictures, and speeches that depict the sensible world are the shadows of imitations just like the images on the prisoners' cave wall.

So, Plato has made the incredibly provocative suggestion that nearly all of humankind is completely unaware of what is fully real, and is ignorant to the point of metaphysical delusion. In this post, we will look at the next part of the allegory and examine what Plato thinks will happen if and when someone begins to "leave the cave" and become aware of what is really real. This introduces us to two further aspects of Plato’s thoughts regarding education. In particular, we will see 1. the impediments to enlightenment he attributes to prior ignorance and illusion and 2. the role of mathematics in training would-be philosophers during their ascent to transcendent truth.

Republic VII.515c-e

“Consider, then, what would be the manner of the release and healing from these bonds and this folly if in the course of nature something of this sort should happen to them: When one was freed from his fetters and compelled to stand up suddenly and turn his head around and walk and to lift up his eyes to the light, and in doing all this felt pain and, because of the dazzle and glitter of the light, was unable to discern the objects whose shadows he formerly saw, what do you suppose would be his answer if someone told him that what he had seen before was all a cheat and an illusion, but that now, being nearer to reality and turned toward more real things, he saw more truly? And if also one should point out to him each of the passing objects and constrain him by questions to say what it is, do you not think that he would be at a loss and that he would regard what he formerly saw as more real than the things now pointed out to him?” “Far more real,” he said. “And if he were compelled to look at the light itself, would not that pain his eyes, and would he not turn away and flee to those things which he is able to discern and regard them as in very deed more clear and exact than the objects pointed out?” “It is so,” he said.

“And if,” said I, “someone should drag him thence by force up the ascent which is rough and steep, and not let him go before he had drawn him out into the light of the sun, do you not think that he would find it painful to be so haled along, and would chafe at it, and when he came out into the light, that his eyes would be filled with its beams so that he would not be able to see even one of the things that we call real?” “Why, no, not immediately,” he said."

Things do not change, at least at first, if the light we consider is the true light of the Sun and the objects are the real things outside the cave. Socrates' question suggests that a prisoner might have to be dragged forcibly up and out of the cave and into the daylight. The path from the imprisonment of ignorance to knowledge is a long and steep one. For another thing, the prisoner's eyes are still weak, the light above is even brighter and more painful, and its objects are even harder to see and harder still to believe.

Seeing real things outside of the cave and in the light of the Sun corresponds in Plato's own metaphysics and epistemology to grasping the Forms with an intellectual understanding. At first, before one is used to reasoning about intelligible beings, one cannot grasp even a single Form. One might be able to recognize beautiful faces, beautiful skies, and beautiful songs, but one would have no comprehension of Beauty itself, nor would one be ready to believe or understand that Beauty itself is far more real than the many so-called beautiful things available to the senses. In general, Plato suggests that a soul needs to become strong enough— sufficiently oriented towards intellect and away from the senses—to be ready to actually achieve any true knowledge.

Republic VII.516a-c

“Then there would be need of habituation, I take it, to enable him to see the things higher up. And at first he would most easily discern the shadows and, after that, the likenesses or reflections in water of men and other things, and later, the things themselves, and from these he would go on to contemplate the appearances in the heavens and heaven itself, more easily by night, looking at the light of the stars and the moon, than by day the sun and the sun's light.” “Of course.” “And so, finally, I suppose, he would be able to look upon the sun itself and see its true nature, not by reflections in water or phantasms of it in an alien setting, but in and by itself in its own place.” “Necessarily,” he said. “And at this point he would infer and conclude that this it is that provides the seasons and the courses of the year and presides over all things in the visible region, and is in some sort the cause of all these things that they had seen.” “Obviously,” he said, “that would be the next step.”

Here, Socrates continues the allegory by describing the process of habituation by which a former prisoner could gradually come to see and understand the things of the upper world. The light of the Sun would be too bright to look upon directly, and even objects in that light would be hard to see. So, at first, the former prisoner would grow used to looking at the reflections in water and shadows of the things in the upper world. The shadows and images of the real things in the sun-lit world correspond to the study of mathematics in the divided line at the end of book VI.

The divided line represents various levels of cognition and reality. The line is divided into a 1/3 and a 2/3 segment. One of these corresponds to sensible becoming(s), about which we only have opinions (doxa), and the other corresponds to intelligible being(s), about which we can have knowledge(nous, epistēmē). Then, these two sections are each subdivided in the same proportion, so that the 1/3 segment is now 1/9 and 2/9, and the 2/3 section is now 2/9 and 4/9.[1] Opinion concerning sensible becoming is subdivided into belief (pistis) about bodies (i.e. visible, tangible things) and imagining (eikasia) about the images, shadows, reflections, and other likenesses of bodies. Knowledge of being is subdivided into understanding (noēsis) of the Forms and thought (dianoia) based on intelligible hypotheses (which knowledge of the Forms renders non-hypothetical). As shadows or reflections are to the bodies that cast them, so hypotheses are to the knowledge of the Forms. Moreover, this level of "thought" (dianoia) corresponds in Plato's mind to mathematics, at least for mathematicians who do not know about the Forms themselves.

Following the analogy, the objects carried before the fire are like bodies and their shadows are mere images. The light of the fire inside the cave is like opinion, while seeing in the sunlight is like knowledge. The real objects in the upper world are the Forms, so learning from their reflections and shadows is like studying mathematics. In fact, Socrates will go on to describe how years of training in the mathematical sciences is the only way to prepare future guardians for grasping the Forms and mastering the ultimate science of reality, dialectic.

[Republic VII.516c-517a is discussed in the next part of this series.]

Republic VII.517a-c

“This image then, dear Glaucon, we must apply as a whole to all that has been said, likening the region revealed through sight to the habitation of the prison, and the light of the fire in it to the power of the sun. And if you assume that the ascent and the contemplation of the things above is the soul's ascension to the intelligible region, you will not miss my surmise, since that is what you desire to hear. But God knows whether it is true. But, at any rate, my dream as it appears to me is that in the region of the known the last thing to be seen and hardly seen is the idea of good, and that when seen it must needs point us to the conclusion that this is indeed the cause for all things of all that is right and beautiful, giving birth in the visible world to light, and the author of light and itself in the intelligible world being the authentic source of truth and reason, and that anyone who is to act wisely in private or public must have caught sight of this.” “I concur,” he said, “so far as I am able.”

In the Sun analogy in book VI, Socrates makes clear that what the Sun is to vision and the visible world, the Good is to understanding and the intelligible world. Vision is not the same thing as light, but light makes vision possible, and the thing most visible but hardest to see, the Sun, is itself the greatest source of light as well as the preserver and ruler of the whole sensible world. Likewise, knowledge and intellectual light, as it were, are not the same, but the intellectual light of the Form of the Good renders all the Forms intelligible to the soul. Like the Sun and the eye of the body, only the strongest eye of the soul can fully look upon the Form of the Good. In other words, only a fully enlightened philosopher is fully capable of grasping the ultimate Being. However, once a philosopher has grasped the form of the good, she is able to see how everything else is related to it and depends upon it. It is for this reason that Plato thinks philosophers are uniquely qualified to rule: they alone truly grasp what is Good and only they see how all other things relate to the good or not. Therefore, they have real insight into truth and value that Plato thinks no other human beings have.

This part of the allegory of the cave shows Plato’s profound insight and his profound epistemic elitism and anti-empirical rationalism. Plato’s allegory emphasizes a profound challenge with respect to education and enlightenment. There are real “epistemic sinkholes”; some the results of mere ignorance and others deliberate misinformation, in which not only is the truth unknown but apt to be resisted as unreal and contrary to familiar misconceptions. In other words, while ignorance fundamentally is a lack of knowledge, in its fullness in an adult community it is not just an absence, but also the presence of misconceptions, distractions, and distortions that impede communication of the truth.

Furthermore, Plato thinks that education is transformative. It not only introduces the learner to more things that are like what she already knew, but to wholly new possibilities that were not even conceivable in her state of ignorance. Unfortunately, Plato understands the world of the senses and the so-called “knowledge” we have about it to be at best a mere shadow of knowledge and at worst an illusion and distraction. Only a tiny number of intellectual elites, he thinks, actually have any idea of what is real and what is really important. The political consequences of this in his ideal state are staggering levels of paternalism and control.


1. It is unclear whether knowledge is the larger section (2/3) and understanding the smallest sub-section (1/9) or the reverse (knowledge = 2/3, understanding = 4/9). It has been much debated by students of Plato since antiquity.

Dr. Jason Rheins

Dr. Jason G. Rheins is a scholar of ancient Greek and Roman philosophy. In 2003 he received his BA with honors in Philosophy and Classical Studies from Stanford University. In 2010 he earned his PhD in Philosophy from the University of Pennsylvania. He has taught or held professorships at the University of Pennsylvania, Swarthmore College, UNC Chapel Hill, St. John’s University, and Loyola University Chicago. He has published articles and book chapters on the history of philosophy, the philosophy of science, and metaphysics. He is currently completing a monograph on Plato’s theology.

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