Knowledge is a representation of Reality, or Nature, constructed by human beings so that, as individuals and groups (from families to civilizations), humans can act effectively (that is, can stay alive and prosper). But what, exactly IS knowledge? Here’s an excerpt from Plato’s Republic—the allegory of the cave.
Plato, Book VII, The Republic. Benjamin Jowett translation (Vintage, 1991), pp. 253-261.
What I think he means.
The Republic is a conversation between Socrates and several young men. The form of the dialogue is called elenchus, or disputation.
1. Socrates asks questions, such as “What is [the definition of, or your definition of] justice?” Or “What should be the qualities of a good ruler?”
2. His students or other persons answer.
3. Socrates then makes deductions from the answers. For instance, “You say that justice is whatever is in the interests of the stronger. But sometimes, the stronger are wrong in what they think are their best interests, and so their definition of justice would be counterproductive for them. How can ‘justice’ be that which has adverse consequences?”
4. This challenges the other persons to think about their beliefs and perhaps to change them until they are logical; that is, beliefs flow from valid reasoning (not speculation, the opinions of important persons, or the opinions of the mob).
This form of conversation is today called “Socratic instruction.”
This portion of dialogue shows that teaching---what Socrates is doing---is NOT about fun and clever activities. Teaching is about helping students to examine the world, and their own beliefs, using inductive reasoning (“What generalization can I make from these examples?”) and deductive reasoning (“What are the consequences of USING my generalizations?”) to go beyond ever-changing experience and arrive at enduring Truth.
Why? Because by approaching Truth, we approach the Divine.
And, only persons who use reason to approach Truth should be in the position of rulers and teachers.
And, an ignorant and irrational mob (democracy) will invariably do things that are suicidal. Sure enough, the Athenian democracy not only voted to put Socrates to death (for teaching young men to think in ways that challenged common beliefs) but voted to go to war with Sparta---a real dumb idea.
[Socrates] And now, I said, let me show in a figure how far our nature is enlightened or unenlightened: --Behold! human beings living in a underground cave, which has a mouth open towards the light and reaching all along the cave; here they have been from their childhood, and have their legs and necks chained so that 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.
[Glaucon] I see.
[Socrates] And do you see, I said, 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, others silent.
[Glaucon] You have shown me a strange image, and they are strange prisoners.
[Socrates] Like ourselves, I replied; and they see only their own shadows, or the shadows of one another, which the fire throws on the opposite wall of the cave?
[Glaucon] True, he said; how could they see anything but the shadows if they were never allowed to move their heads?
[Socrates] And of the objects which are being carried in like manner they would only see the shadows?
[Glaucon] Yes, he said.
[Socrates] And if they were able to converse with one another, would they not suppose that they were naming what was actually before them?
[Glaucon] Very true.
[Socrates] 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 which they heard came from the passing shadow?
[Glaucon] No question, he replied.
[Socrates] To them, I said, the truth would be literally nothing but the shadows of the images.
[Glaucon] That is certain.
[Socrates] And now look again, and see what will naturally follow if the prisoners are released and disabused of their error. 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, when he is approaching nearer to being and his eye is turned towards more real existence, he has a clearer vision, -what will be his reply? And you may further imagine that his instructor is pointing to the objects as they pass and requiring him to name them, -will he not be perplexed? Will he not fancy that the shadows which he formerly saw are truer than the objects which are now shown to him?
[Glaucon] Far truer.
[Socrates] And if he is compelled to look straight at the light, will he not have a pain in his eyes which will make him turn away to take and take in the objects of vision which he can see, and which he will conceive to be in reality clearer than the things which are now being shown to him?
[Glaucon] True, he now.
[Socrates] And suppose once more, that he is reluctantly dragged up a steep and rugged ascent, and held fast until he 's forced into the presence of the sun himself, is he not likely to be pained and irritated? When he approaches the light his eyes will be dazzled, and he will not be able to see anything at all of what are now called realities.
[Glaucon] Not all in a moment, he said.
[Socrates] He will require to 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?
[Socrates] Last of he will be able to see the sun, and not mere reflections of him in the water, but he will see him in his own proper place, and not in another; and he will contemplate him as he is.
[Socrates] He will then proceed to argue that this is he who gives the season and the years, and is the guardian of all that is in the visible world, and in a certain way the cause of all things which he and his fellows have been accustomed to behold?
[Glaucon] Clearly, he said, he would first see the sun and then reason about him. ….
[Socrates] This entire allegory, I said, you may now append, dear Glaucon, to the previous argument; 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 according to my poor belief, which, at your desire, I have expressed whether rightly or wrongly God knows. But, whether true or false, 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 of 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.
[Glaucon] I agree, he said, as far as I am able to understand you….
[Socrates] Whereas, our argument shows that the power and capacity of learning exists in the soul already; and that just as the eye was unable to turn from darkness to light without the whole body, so too the instrument of knowledge can only by the movement of the whole soul be turned from the world of becoming into that of being, and learn by degrees to endure the sight of being, and of the brightest and best of being, or in other words, of the good.
[Glaucon] Very true.
This is the condition of ordinary humans. We live in a world of shadows projected onto a wall by puppeteers; e.g., teachers and political figures who: (1) are ignorant; (2) are trying to keep ordinary humans ignorant and believing falsehoods.
It is as if humans were chained to a wall and could not look around to SEE how they are being stupidified by shadows, which they TAKE to be reality.
In other words, humans don’t know the rules of valid reasoning, and so they can’t criticize and debunk what they are told and what they have come to believe.
I think the light is the reality of enduring Truth---the IDEAS of justice, love, beauty, manhood, womanhood, duty, morality, courage, time, space, mathematics. The light-TRUTH-is outside the cave, and can be approached only by crawling up and out--becoming educated in logical thinking.
However, ordinary persons are comfortable in their ignorance---especially if living is easy for them. Illogical farmers starve to death. But if someone else grows the food you eat, you can remain an idiot.
These are the stages of education: growing accustomed to using logic, seeing things more clearly, and finally achieving knowledge of what is behind mere APPEARANCE in everyday life---namely,
Therefore, anything we believe about the everyday world is an illusion. Just as any objects and relationships you “see” in a kaleidoscope are an illusion---not really there.
The “power and capacity of the soul” is logic.
2. The world of eternal Ideas—the world of being---concepts (e.g., Justice, Beauty), rules or Laws (cause and effect, of how some class are part of larger classes); and routines (e.g., valid explanations—sequences of rules).
Notice how Socrates says that moving from the everyday world of illusion and ignorance to the world of enduring truths is NOT a mere addition to the person. A person who bases beliefs and actions on Reason (rather than opinion) has changed his whole orientation to Reality.
Our sense organs (eyes, ears, nose, skin) take in only a tiny amount of Reality. Humans have a learning mechanism---brain, limbs, plus senses (Engelmann and Carnine. 1991. Theory of instruction. ADI Press)----that transforms the tiny amount that our sense organs take in [sensations: color, sound, touch] into a representation of Reality or Nature. We call these representations “knowledge.”