"I want you to go on to picture the enlightenment or ignorance of our human condition somewhat as follows. Imagine an underground chamber like a cave, with a long entrance open to the daylight and as wide as the cave. In this chamber are men who have been prisoners there since they were children, their legs and necks being so fastened that they can only look straight ahead of them and cannot turn their heads. Some way off, behind and higher up, a fire is burning, and between the fire and the prisoners and above them runs a road, in front of which a curtain-wall has been built, like the screen at puppet shows between the operators and their audience, above which they show their puppets."

"I see."

"Imagine further that there are men carrying all sorts of gear along behind the curtain-wall, projecting above it an including figures of men and animals made of wood and stone and all sorts of other materials, and that some of these men, as you would expect, are talking and some not."

"An odd picture and an odd sort of prisoner."

"They are drawn from life," I replied. "For, tell me, do you think our prisoners could see anything of themselves or their fellows except the shadows thrown by the fire on the wall of the cave opposite them?"

"How could they see anything else if they were prevented from moving their heads all their lives?"

"And would they see anything more of the objects carried along the road?"

"Of course not."

"Then if they were able to talk to each other, would they not assume that the shadows they saw were the real things?"

"Inevitably."

"And if the wall of their prison opposite them reflected sound, don't you think that they would suppose, whenever one of the passers-by on the road spoke, that the voice belonged to the shadow passing before them?"

"They would be bound to think so."

"And so in every way they would believe that the shadows of the objects we mentioned were the whole truth."

"Yes, inevitably."

"Then think what would naturally happen to them if they were released from their bonds and cured of their delusions. Suppose one of them were let loose, and suddenly compelled to stand up and turn his head and look and walk towards the fire; all these actions would be painful and he would be too dazzled to see properly the objects of which he used to see the shadows. What do you think he would say if he was told that what he used to see was so much empty nonsense and that he was now nearer reality and seeing more correctly, because he was turned towards objects that were more real, and if on top of that he were compelled to say what each of the passing objects was when it was pointed out to him? Don't you think he would be at a loss, and think that what he used to see was far truer than the objects now being pointed out to him?"

"Yes, far truer."

"And if he were made to look directly at the light of the fire, it would hurt his eyes and he would turn back and retreat to the things which he could see properly, which he would think really clever than the things being shown him."

"Yes."

"And if," I went on, "he were forcibly dragged up the steep and rugged ascent and not let go till he had been dragged out into the sunlight, the process would be a painful one, to which he would much object, and when he emerged into the light his eyes would be so dazzled by the glare of it that he wouldn't be able to see a single one of the things he was now told were real."

"Certainly not at first," he agreed.

"Because, of course, he would need to grow accustomed to the light before he could see things in the upper world outside the cave. First he would find it easier to look at shadows, next at the reflections of men and other objects in water, and later on at the objects themselves. After that he would find it easier to observe the heavenly bodies and the sky itself at night, and to look at the light of the moon and stars rather than at the sun and its light by day."

"Of course."

"The thing he would be able to do last would be to look directly at the sun itself, and gaze at it without using reflections in water or any other medium, but as it is in itself."

"That must come last."

"Later on he would come to the conclusion that it is the sun that produces the changing seasons and years and controls everything in the visible world, and is in a sense responsible for everything that he and his fellow-prisoners used to see."

"That is the conclusion which he would obviously reach."

"And when he thought of his first home and what passed for wisdom there, and of his fellow-prisoners, don't you think he would congratulate himself on his good fortune and be sorry for them?"

"Very much so."

"There was probably a certain amount of honor and glory to be won among the prisoners, and prizes for keen-sightedness for those best able to remember the order of sequence among the passing shadows and so be best able to divine their future appearances. Will our released prisoner hanker after those prizes or envy this power or honor? Won't he be more likely to feel, as Homer says, that he would far rather be 'a serf in the house of some landless man,' or indeed anything else in the world, than hold the opinions and live the life that they do?"

"Yes," he replied, "he would prefer anything to a life like theirs."

"Then what do you think would happen," I asked, "if he went back to his old seat in the cave? Wouldn't his eyes be blinded by the darkness, because he had come in suddenly out of the sunlight?"

"Certainly."

"And if he had to discriminate between the shadows, in competition with the other prisoners, while he was still blinded and before his eyes got used to the darkness--a process that would take some time--wouldn't he be likely to make a fool of himself? And they would say that his visit to the upper world had ruined his sight, and that the ascent was not worth even attempting. And if anyone tried to release them and lead them up, they would kill him if they could lay hands on him."

"They certainly would."

"Now, my dear Glaucon," I went on . . . "The realm revealed by sight corresponds to the prison, and the light of the fire in the prison to the power of the sun. And you won't go wrong if you connect the ascent into the upper world and the sight of the objects there with the upward progress of the mind into the intelligible regions. That at any rate is my interpretation, which is what you are anxious to hear; the truth of the matter is, after all, known only to god. But in my opinion, for what it is worth, the final thing to be perceived in the intelligible region, and perceived only with difficulty, is the form of the good; once seen, it is inferred to be responsible for whatever is right and valuable in anything, producing in the visible region light and the source of light, and being in the intelligible region itself [the] controlling source of truth and intelligence. And anyone who is going to act rationally either in public or in private life must have sight of it."

"I agree," he said, "so far as I am able to understand you."

"Then you will perhaps also agree with me that it won't be surprising if those who get so far are unwilling to involve themselves in human affairs, and if their minds long to remain in the realm above. . . ."

--Plato, The Republic, Book VII, 514-517d

Timaeus. We must . . . first make this distinction: what is that which is always real and has no becoming, and what is that which is always becoming and is never real? That which is apprehensible by thought with a rational account is the thing that is always unchangeably real; whereas that which is the object of belief together with unreasoning sensation is the thing that becomes and passes away, but never has real being. Again, all that becomes must needs become by the agency of some cause; for without a cause nothing can come to be. Now whenever the maker of anything looks to that which is always unchanging and uses a model of that description in fashioning the form and quality of his work, all that he thus accomplishes must be good. If he looks to something that has come to be and uses a generated model, it will not be good.

So concerning the whole Heaven [cosmos] or World--let us call it by whatsoever name may be most acceptable to it--we must ask the question which, it is agreed, must be asked at the outset of inquiry concerning anything: Has it always been, without any source of becoming; or has it come to be, starting from some beginning? It has come to be; for it can be seen and touched and it has body, and all such things are sensible; and, as we saw, sensible things that are to be apprehended by belief together with sensation are things that become and can be generated. But again, that which becomes, we say, must necessarily become by the agency of some cause. The maker and father of this universe it is a hard task to find, and having found him it would be impossible to declare him to all mankind. Be that as it may, we must go back to this question about the world: After which of the two models did its builder frame it--after that which is always in the same unchanging state, or after that which has come to be? Now if this world is good and its maker is good, clearly he looked to the eternal; on the contrary supposition (which cannot be spoken without blasphemy), to that which has come to be. Everyone, then, must see that he looked to the eternal; for the world is the best of things that have become, and he is the best of causes. Having come to be, then, in this way, the world has been fashioned on the model of that which is comprehensible by rational discourse and understanding and is always in the same state.

Again, these things being so, our world must necessarily be a likeness of something. Now in every matter it is of great moment to start at the right point in accordance with the nature of the subject. Concerning a likeness, then, and its model, we must make this distinction: an account is of the same order as the things which it sets forth--an account of that which is abiding and stable and discoverable by the aid of reason will itself be abiding and unchangeable . . . while an account of what is made in the image of that other, but is only a likeness, will itself be but likely, standing to accounts of the former kind in a proportion: as reality it to becoming, so is truth to belief.

. . .

Let us, then, state for what reason becoming and this universe were framed by him who framed them. He was good; and in the good no jealousy in any matter can ever arise. So, being without jealousy, he desired that all things should come as near as possible to being like himself. That this is the supremely valid principle of becoming and of the order of the world, we shall most surely be right to accept from men of understanding. Desiring, then, that all things should be good and, so far as he might be, nothing imperfect, the god took over all that is visible--not at rest, but in discordant and unordered motion--and brought it from disorder into order, since he judged that order was in every way the better.

Now it was not, nor can it ever be, permitted that the work of the supremely good should be anything but that which is best. Taking thought, therefore, he found that, among things that are are by nature visible, no work that is without intelligence will ever be better than one that has intelligence, when each is taken as a whole, and moreover that intelligence cannot be present in anything apart from soul. In virtue of this reasoning, when he framed the universe, he fashioned reason within soul and soul within body, to the end that the work he accomplished might be by nature as excellent and perfect as possible. This, then, is how we must say, according to the likely account, that this world came to be, by the god's providence, in very truth a living creature with soul and reason.

This being premised, we have now to state what follows next: What was the living creature in whose likeness he framed the world? We must not suppose that it was any creature that ranks only as a species; for no copy of that which is incomplete can ever be good. Let us rather say that the world is like, above all things, to that Living Creature of which all other living creatures, severally and in their families, are parts. For that embraces and contains within itself all the intelligible living creatures, just as this world contains ourselves and all other creatures that have been formed as things visible. For the god, wishing to make this world most nearly like that intelligible thing which is best and in every way complete, fashioned it as a single visible living creature, containing within itself all living things whose nature is of the same order.

. . .

And for shape he gave it that which is fitting and akin to its nature. For the living creature that was to embrace all living creatures within itself, the fitting shape would be the figure that comprehends in itself all the figures there are; accordingly, he turned its shape rounded and spherical, equidistant every way from center to extremity--a figure the most perfect and uniform of all; for he judged uniformity to be immeasurably better than its opposite. And all round on the outside he made it perfectly smooth, for several reasons. It had no need of eyes, for nothing visible was left outside; nor of hearing, for there was nothing outside to be heard. There was no surrounding air to require breathing, nor yet was it in need of any organ by which to receive food into itself or to discharge it again when drained of its juices. For nothing went out or came into it from anywhere, since there was nothing; it was designed to feed itself on its own waste and to act and be acted upon entirely by itself and within itself; because its framer thought that it would be better self-sufficient, rather than dependent upon anything else.

It had no need of hands to grasp with or to defend itself, nor yet of feet or anything that would serve to stand upon; so he saw no need to attach to it these limbs to no purpose. . . .

All this, then, was the plan of the god who is forever for the god who was sometime to be. According to this plan he made it smooth and uniform, everywhere equidistant from its center, a body whole and complete, with complete bodies for its parts. And in the center he set a soul and caused it to extend throughout the whole and further wrapped its body round with soul on the outside; and so he established one world alone, round and revolving in a circle, solitary but able by reason of its excellence to bear itself company, needing no other acquaintance or friend but sufficient to itself. On all these accounts the world which he brought into being was a blessed god.

Now this soul, though it comes later in the account we are now attempting, was not made by the god younger than the body; for when he joined them together, he would not have suffered the elder to be ruled by the younger. . . . [B]ut the god made soul prior to body and more venerable in birth and excellence, to be the body's mistress and governor.

--Plato, Timaeus, 28-29c, 29e-30d, 33b-34c