“When I considered all this, the more closely I studied the politicians and the laws and customs of the day, and the older I grew, the more difficult it seemed to me to govern rightly. Nothing could be done without trustworthy friends and supporters; and these were not easy to come by in an age which had abandoned its traditional moral code but found it impossibly difficult to create a new one. At the same time law and morality were deteriorating at an alarming rate, with the result that though I had been full of eagerness for a political career, the sight of all this chaos made me giddy, and though I never stopped thinking how things might be improved and the constitution reformed, I postponed action, waiting for a favourable opportunity. Finally I came to the conclusion that all existing states were badly governed, and that their constitutions were incapable of reform without drastic treatment. I was forced, in fact, to the belief that the only hope of finding justice for society or for the individual lay in true philosophy, and that mankind will have no respite from trouble until either real philosophers gain political power or politicians become by some miracle true philosophers”.
Plato is highly critical of the types of Greek constitution which he had experienced in his political life: Timarchy, Oligarchy, Democracy, and Tyranny. Many find surprising his fierce attack on Democracy, but Plato is drawing on his own experiences at Athens. The population of Athens when Plato was born was perhaps 200-300.000, including men, women, and slaves. In a democracy the vote was confined to the adult male citizen population. At Athens slaves may have numbered some 60-80,000, and there were perhaps 35-40,000 “metics”, that is, residents who because they had been born elsewhere did not qualify for citizenship. The total voting population was about 35-45,000. But within this body of voting citizens popular control was complete; for the Greeks never invented representative government (one Member of Parliament representing many citizens and speaking on their behalf), and the sovereign body at Athens was the Assembly, a mass meeting of all adult male citizens. Of course not all citizens bothered to attend regularly, but in theory all could always attend. Such a complete system of popular control has never been known before or since. And it is important to remember that this, and not any form of modern representative government, is the background to Plato’s comments on democracy. It involved, said Thucydides, “committing the conduct of state affairs to the whims of the multitude”. We shall examine Plato’s criticisms of Athenian democracy, and we can then ask whether modern democracy escapes his sustained criticism.
The long section on knowledge and the philosopher in books V-VII of the Republic is undoubtedly the most famous passage in Plato’s work. The passage fits into the context of the whole Republic in the following way. Socrates, the main character in the dialogue, has been discussing with two friends, Glaucon and Adeimantus, what justice is, in both individual and state. Socrates argues that a state would be governed in a just way if it were ruled by a special type of person whom he calls “Guardians” – people who are intelligent, and who have also good qualities of character. He bases his claim that a state would be just if Guardians ruled it on the claim that only they have the ability to reason for the good of the whole polis, rather than for their own selfish concerns or the interests of a class. Now since Plato’s time many political thinkers have had similar thoughts; but hardly anybody has gone on to take the surprising step which Plato does in Book V – that is, to claim that the ideal rulers would not just be intelligent and disinterested, but would be “philosophers”. Plato is quite aware that this is, to most people, a highly peculiar claim to make, and this is doubtless why when he defends it in books V-VII he writes in the way that he does – in a very urgent and vivid style, quite unlike that of any modern philosophy textbook or article.
The account has three parts. Firstly (474c-484a), Plato claims that it is philosophers, and not the rest of us, who have knowledge. Then (484a-502c) he shows why philosophers are not valued in society as it is. Lastly (502c-521b) he gives us three pictures, generally known as Sun, Line, and Cave, which give us some idea of what the knowledge is like which the philosopher has.
In these passages Plato has much to say about knowledge and the objects of knowledge, quite independently of the ideal state. We shall see this section in detail and we shall discuss the main views as they arise.
PLATO: Republic V-VII
Socrates has been describing the “ideal” state in great detail. Glaucon presses him now to prove that such a State can actually come about. Socrates’ reply: “…There will be no end to the troubles of States, or of humanity itself, till philosophers become kings in this world, or till those we now call kings and rulers really and truly become philosophers”. Glaucon is astonished and asks Socrates to explain.
Definition of the Philosopher.
If philosophers must be rulers then we need to know precisely what a philosopher is. Plato gives us at least a dozen definitions: “A philosopher’s passion is for wisdom of every kind without distinction… The man who is ready to taste every branch of learning, is glad to learn and never satisfied… Those who love to see the truth…. The philosopher is very much awake, being the man who believes in beauty itself and can see both it and the particular things which share in it… Philosophers have eyes for the eternal, unchanging things, who have knowledge and not opinion… Philosophers are lovers of wisdom… Philosophers have the capacity to grasp the eternal and immutable” etc.
Plato distinguishes philosophers from “sight-lovers”: sight-lovers are those “who love looking and listening and are delighted by beautiful sounds and colours and shapes, but their minds are incapable of seeing and delighting in the essential nature of beauty itself” The sight-lover is stuck at the level of particulars, of uncritical sense-experiences; he accumulates perceptions, facts, but does not “see” the essential nature of such particulars. He experiences many beautiful things but does not understand what beauty in itself actually is; he perceives appearances, shadows, images, but not the “reality”of things. He is “dreaming”, i.e., seeing images; the philosopher instead is “awake” because he “understands” the real essence or nature of things. Such nature or essence is to be found only in the Forms: all particular beautiful things simply partake of “beauty itself” or of the Form of Beauty which is one, simple, eternal, immutable.
All particular things partake of a Form, which contains the real nature; acts which are “just” are found to be such only because they share of the Form of Justice, etc. The Forms, from a logical point of view, are universal ideas expressed by universal or common nouns: dog, house, man, etc. From a metaphysical point of view, the Forms constitute the Real World, are “real” things deriving from the supreme Form of Good (perhaps God, according to Taylor). In other words, at the end of our earthly life in the world of “opinion”, of images, of “dreams” we shall go to the real world of the Forms, of pure knowledge, of pure intelligibility, dominated by the supreme form of the Good, the originator of all other Forms.
The philosopher has “knowledge”, the sight-lover has “opinion” or “belief”: knowledge is related to “what is”, ignorance to “what is not”, opinion or belief to “what is in between”. Knowledge is a faculty that has “what is” or reality or truth as its natural field; opinion, on the other hand, is again a faculty which has as its natural field what is in between what is and what is not, knowledge and ignorance, therefore opinion is darker than knowledge and clearer than ignorance.
What kind of things are the field of opinion, are the objects of opinion? All particular things, all things perceived through the senses. Why? Because all particular things combine within themselves “what is and what is not”: a particular beautiful thing is bound to appear ugly from some point of view; equally doubles are also halves; large or small things can appear also the opposite, etc… All particulars are “ambiguous”, belonging to the “fluctuating intermediate realm” of opinion.
If philosophers alone possess “knowledge”, if they alone are truly “awake”, seeing the real nature of all things, should they not be the ones who should be in charge of the State? “Isn’t obvious whether it’s better for a blind man or a clear-sighted one to guard and keep an eye on anything?”
Plato lists some twelve qualities of character required in the philosopher, and necessary in a good ruler:
1- The philosopher(s) have the capacity to grasp the eternal and immutable… while the non-philosophers are lost in multiplicity and change; 2- They have true knowledge of reality and clear standards of perfection in their minds; 3- They have practical experience and human excellence in all fields; 4- They love all branches of learning that reveals eternal reality; 5- He will be truthful; he will hate untruth just as he loves truth, he will yearn for the whole truth from his earliest years; 6- His pleasures will be in things purely of the mind, and physical pleasures will pass him by; 7- He will be self-controlled and not grasping about money; 8- He will have no touch of meanness or pettiness of mind; 9- He will not fear death; 10- He will be just and civilized not uncooperative and savage; 11- He must learn easily and possess a good memory; 12- He will have a mind which has grace and a sense of proportion and style.
2- The prejudice against philosophy (“philosophers are either useless or dangerous”)
Adeimantus (Plato’s elder brother) interrupts Socrates protesting that, as usual, we have been led by progressive logical little steps to conclusions which are very doubtful, i.e. that philosophers should be rulers since they are the best qualified people for the job. Adeimantus wants Socrates to explain why, instead, people think that philosophers are either 1- “very odd birds” and “thoroughly vicious” and 2- completely “useless” as members of the polis (society, city-state). To the astonishment of Adeimantus Socrates says that both charges are indeed true! He begins with the “useless” charge.
“Philosophers are useless”: the simile of the Sea-Captain.
“Suppose the following to be the state of affairs on board of a ship or ships. The captain is larger and stronger than any of the crew, but a bit deaf and short-sighted, and similarly limited in seamanship. The crew are all quarrelling with each other about how to navigate the ship, each thinking he ought to be at the helm; they have never learned the art of navigation and cannot say that anyone ever taught it them, or that they spent any time studying it, indeed they say it can’t be taught and are ready to murder anyone who says it can. They spend all their time milling around the captain and doing all they can to get him to give them the helm. If one faction is more successful than another, their rivals may kill them and throw them overboard, lay out the honest captain with drugs or drink or in some other way, take control of the ship, help themselves to what’s on board, and turn the voyage into the sort of drunken pleasure-cruise you would expect. Finally, they reserve their admiration for the man who knows how to lend a hand in controlling the captain by force or by fraud; they praise his seamanship and navigation and knowledge of the sea and condemn everyone else as useless. They have no idea that the true navigator must study the seasons of the year, the sky, the stars, the winds, and all the other subjects appropriate to his profession if he is to be really fit to control a ship; and they think that it’s quite impossible to acquire the professional skill needed for such control and that there’s no such thing as an art of navigation. With all this going on aboard aren’t the sailors on any such ship bound to regard the true navigator as a word-spinner and a star-gazer, of no use to them at all?”
Plato himself identifies for us two items of the simile: the sailors (the crew) of the ship are “the politicians who at present rule us”(democracy politicians); and the true navigators are those “whom they call useless visionaries” or word-spinners or star-gazers, i.e. the true philosophers. Other details: the ship is the polis or city-state; the captain is the democratic leader of the polis, representing the constitution of the city and obviously “larger and stronger than any of the crew” but also “a bit deaf and short-sighted and similarly limited in seamanship”: the identification is a bit tricky, because he is called “the honest captain” whom the crew try to control by all means at their disposal. One can imagine such a democratic leader to be a somewhat respectable member of the Polis by birth or by talents or by virtue of the office he represents. The stress, however, is on his lack of knowledge of “the art of navigation” and on the manipulation to which he is subjected by the various democratic factions and their leaders. The sailors “have never learned the art of navigation nor do they believe that there is such an art; their effort is to gain control of the ship and “turn the voyage into the sort of drunken pleasure cruise you would expect”.
For Plato “democracy” is an unmitigated disaster, a situation in which liberty soon is transformed in extreme freedom which does not tolerate rules and constraints and which prompts “politicians” of all kinds to experiment with their ill-thought views. Plato had first-hand experience of such “democracy”.
Things to remember: was Plato’s “democracy” equivalent to ours? (For a start it was not “representative” democracy, but the rule of all citizens gathered in the Assembly); Is political science a “craft”, an “art”, comparable to the art of navigation? Is “dealing” with people and with political issues more important than the kind of knowledge (mathematics, of the Forms) Plato wants from his philosopher ruler? What do you think of the “republic” as described by Plato? What things would you find objectionable?
“Philosophers are vicious”: the simile of the large and powerful animal.
“Suppose a man was in charge of a large and powerful animal, and made a study of his moods and wants, he would learn when to approach and handle it, when and why it was especially savage or gentle, what the different noises it made meant, and what tone of voice to use to soothe or annoy it. All this he might learn by long experience and familiarity, and then call it a science, and reduce it to a system and set up to teach it. But he would not really know which of the creature’s tastes and desires was admirable or shameful, good or bad, right or wrong; he would simply use the terms on the basis of its reactions, calling what pleased it good, what annoyed it bad. He would have no rational account to give of them, but would call the inevitable demands of the animal’s nature right and admirable, remaining quite blind to the real nature of and difference between inevitability and goodness, and quite unable to tell anyone else what it was. He would make a queer sort of teacher wouldn’t he?”
Socrates agrees that most philosophers are “rogues”: before using the simile he prepares the ground by recalling the character traits of a “true” philosopher: then he claims that the character “of our ideal philosopher will occur very seldom” and even then the same noble traits can actually deteriorate and turn into vicious characteristics if the circumstances around them are not right. Feeble characters produce feeble bad actions; robust and gifted characters produce awful wickedness if the “soil” in which they find themselves is not of the right quality. Democracy conspires against the proper development of the highly gifted citizens: the Assembly becomes the place where the “noise of boos and applause” slowly moves towards corruption the highly gifted youth.
The crowd follows no standards but only what is pleasurable; the Sophists interpret the moods of the democratic crowd and teach it (for money!), hence our would-be-philosophers are really corrupted by the moods of the crowds which are the basis of the Sophists’ scientific teaching. The crowds are the real masters, the sophists the interpreters, the would-be-philosophers the victims which, because of their great talents, become extremely vicious and corrupt. Plato probably had in mind Alcibiades, an extremely talented and very promising philosopher (he used to frequent Socrates) who was swayed by the adulation of the crowds (he was also very rich, very handsome, very ambitious); but he was also thinking about his own experience and temptations to enter politics enticed by the adulation of the people.
The simile portrays the sophist (the man who studies the moods of the animal and makes it into a science), and the democratic state (the large and powerful animal). The sophist is interested only in what pleases or displeases the animal, not in what is truly good or bad; the democratic state is shown as a large and powerful animal only interested in avoiding pain and securing pleasures which it equates with “bad” and “good”. The “excessive” freedom which democracy provides results in ignorance of moral standards and of the world of the Forms and in particular of the Form of the Good.
The sophists are the “interlopers”, the second-rate philosophers who try to gain respectability by the name of philosophers but only interested in rhetoric or the art of pleasing and moving the crowd, the large animal which is democracy. Who are today’s sophists? The Media? The politicians?
3- The Philosopher Ruler not impossible
Philosophers are “useless” simply because the Polis does not value them; and some of them become corrupt and vicious by using their rare gifts in order to please popular whims and wishes. However the true philosopher should indeed rule the Polis since he has knowledge of the forms and of the Good.
Socrates is now asked if any of the existing societies can be suited to the introduction of philosopher-rulers. The answer is negative, since his own Republic does not exist yet, nor are there societies which value philosophy as it should be. In effect, Socrates claims that the study of philosophy is quite inadequate even in Athens: children of young age study it for a little while, barely touching on the abstract matters which are the basis of true philosophy, and soon after they forget it. Instead, children should be given an appropriate philosophical training comparable to their age, then this should be followed by intense physical training, and only in their mature age they should be given intense mental training which should continue well into their retirement from military and political life.
Socrates agrees that his utopian republic may never be realised, but, since there is no logical contradiction, by some divine will it could happen: maybe some philosophers may be compelled by society to take charge of their state, or perhaps some kings or their sons may become philosophers themselves and put into practice the ideals of the Republic. If this does happen then the philosophers will begin with “a clean canvas”, then they will sketch in the outline the social system they want, then they will begin to work by looking at the Forms, justice, beauty, self-discipline, etc. and also by looking at their actual situation and events, mixing and adapting accordingly.
4- The Good as ultimate object of knowledge: The simile of the Sun.
Visible World Intelligible World
The Sun The Good
Source of growth and light, Source of reality and truth
Which gives Which gives
Visibility to objects of sense Intelligibility to objects of Thought
And the power of seeing to the eye And the power of knowing to the Mind
The faculty of sight The faculty of knowledge.
To recap: philosopher-rulers are the ideal for the Polis, and a situation may arise that makes this ideal a reality. If this is the case, what kind of education should “these saviours of our society”, the philosophers, have? What are they to learn and at what age are they to learn it? The remaining parts of the book deal with this topic. The supreme knowledge which a philosopher has is the knowledge of the mother of all Forms, the Form of the Good. Plato does not describe directly the content of this supreme Form, claiming that the task is “beyond me… So please give up asking for the present what the good in itself is… But I will tell you, if you like, about something which seems to me to be a child of the good, and to resemble it very closely…” These words are followed by the Simile of the Sun. In the Republic there is no direct description of what Good in itself actually is: Taylor suggests that the Good is God; others claim that Plato was not clear about it, hence his use of the simile of the Sun; others argue that Plato revealed his views about the Good “orally” in the Academy, as he appears to suggest in some of his letters; he was possibly afraid to be misinterpreted (Good=One?). However Plato describes the “child of the Good”, or the effects that the Good has. The first thing to remember is that all other Forms are quite useless or value-less without the supreme Form of the Good: “Is there any point in having all other Forms of knowledge without that of the Good, and so lacking knowledge about what is good and valuable?” The ultimate purpose of the education of the philosopher is the possession of the Form of the Good: and since this Form is higher than all other Forms then it will be even more difficult to achieve.
Plato deals with two common answers to the question, What is Good? Some say that “pleasure is the good” while the more sophisticated think it is knowledge. That the Good cannot be “pleasure” is shown by the fact that there are “bad pleasures”; the Good cannot be simply “knowledge” since it is quite impossible to define what knowledge is in itself without reference to Good, showing that knowledge and Good are connected but not identical.
The simile of the Sun is explained clearly by Socrates himself. The Sun stands for the Form of the Good. The Sun is the source of light and growth: the Good is the source of truth and reality. The Sun gives visibility to the world around us (objects of sight, the particulars) and gives the eye the power of seeing, enables the faculty of sight: the Good gives intelligibility to objects of thought (e.g. the Forms) and the power of knowing to the mind, enables the faculty of knowledge.
Notice: the Sun is not identical with sight nor with light; the Good is not identical with knowledge (the Forms) nor with intelligibility and truth. Knowledge and truth are the child of the Good but not the Good itself, which remains unexplained.
“What gives the objects of knowledge their truth and the knower’s mind the power of knowing is the Form of the Good. It is the cause of knowledge and truth…yet itself is even more splendid than knowledge and truth”
“The Good therefore may be said to be the source not only of the intelligibility of the objects of knowledge, but also of their being and reality; yet it is not itself that reality, but is beyond it, and superior to it in dignity and power”.
The simile of the Sun had made it clear that there are two powers, one of them supreme in the intelligible order or region (the Form of the Good), the other in the visible region (the Sun). So there are two orders, two worlds, the visible and the intelligible. The education of the philosopher must move progressively, from the lowest mental state illusion to belief to reason to intelligence. The mental state “intelligence” or “dialectic” is the most valuable and the highest, with the contemplation of the Forms and of the Form of the Good. Illusion and belief belong to the visible realm, the world of the senses; reason and dialectic belong to the intelligible world (the real world of the Forms). The visible world is an “image” of the intelligible world (the original); within the visible world physical objects (trees, stars, etc) are the original of the images (reflections, shadows, etc) ; within the intelligible world mathematical diagrams and postulates are “images” of the originals the pure Forms at their most abstract
The Line is divided firstly in two unequal parts, to indicate the two worlds, the intelligible and visible; the visible, the world of “opinion”, being a copy, an “image” of the original, the world of knowledge.
Each of the two unequal parts is in turn divided in two unequal parts in the same ratio as above; the intelligible world is divided into mathematical thinking (reason), the “copy”, and dialectic or intelligence, the “original” and the highest of mental states or thinking, proper of philosophers.
The visible world is the world of “opinion”, of belief, the world of the “sight-lover”, the world of shadows of things (illusions) or of particular objects: this is the world “of the cave”, the world of shadows on the wall, and the world of the real particulars parading before the fire. If one moves from the world of simple perception to the world of thought then he first begins with mathematical reasoning: at this stage one is already in the “real” world, the world of those who are “awake”, but his thinking is still not pure, his mathematical reasoning will use diagrams of figures, will begin with assumptions which are taken for granted. The highest form of thinking is Dialectic, or contemplation of the Forms in their most pure and abstract state, thinking which has been trained to question ruthlessly all assumptions, crystal-clear thinking without any help from diagrams. This highest form of thinking can be reached only after extensive training and studying, it is the thinking proper of philosophers. The would-be-philosopher, therefore, must be trained to move up from the world of illusion to the world of belief; from the world of belief to mathematical-geometrical thinking of objects and finally to the world of pure Forms and of the Form of the Good.
Notice: the line is continuous and progressive, without dramatic moments; it is not easy to align the details of the line with the details of the Cave; in the Cave there is real drama and huge difficulties in passing from one stage to the next: the prisoners are chained, they need somebody to free them, they must go through a difficult “conversion”, looking at the fire and being blinded, etc…. There is no perfect correspondence in the details, even if scholars try hard to harmonise the three similes.
6- The simile of the Cave.
“Next, then, I said, take the following parable of education and ignorance as a picture of the condition of our nature. Imagine mankind as dwelling in an underground cave with a long entrance open to the light across the whole width of the cave; in this they have been from childhood, with necks and legs fettered, so they have to stay where they are. They cannot move their heads round because of the fetters, and they can only look forward, but light comes to them from fire burning behind them higher up at a distance. Between the fire and the prisoners is a road above their level, and along it imagine a low wall has been built, as puppet showmen have screens in front of their people over which they work their puppets”.
“I see”, he said.
“See, then, bearers carrying along this wall all sorts of articles which they hold projecting above the wall, statues of men and other living things, made of stone, or wood, and all kinds of stuff, some of the bearers speaking and some silent, as you might expect.”
“What a remarkable image”, he said, “and what remarkable prisoners!”
“Just like ourselves”, I said.
“For, first of all, tell me this: what do you think such people would have seen of themselves and each other except their shadows, which the fire casts on the opposite wall of the cave?”
“I don’t see how they could see anything else”, said he, “if they were compelled to keep their head unmoving all their lives!”
“Very well, what of the things being carried along? Would not this be the same?”
“Of course it would”.
“Suppose the prisoners were able to talk together, don’t you think that when they named the shadows which they saw passing they would believe they were naming things?”
“Then if their prison had an echo from the opposite wall, whenever one of the passing bearers uttered a sound, would they not suppose that the passing shadow must be making the sound? Don’t you think so?”
“Indeed I do”, he said.
“If so, such persons would certainly believe that there were no realities except those shadows of hand made things”.
“So it must be”, said he.
“Now consider, said I, what their release would be like, and their cure from these fetters and their folly; let us imagine whether it might naturally be something like this. One might be released, and compelled suddenly to stand up and turn his neck round, and to walk and look towards the fire light, all this would hurt him, and he would be too much dazzled to see distinctly those things those shadows he had seen before. What do you think he would say, if someone told him that what he saw before was foolery, but now he saw more rightly, being a bit nearer reality and turned towards what was a little more real? What if he were shown each of the passing things, and compelled by questions to answer what each one was? Don’t you think he would be puzzled, and believe what he saw before was more true than what was shown to him now?”
“Far more”, he said.
“Then suppose he were compelled to look towards the real light, it would hurt his eyes, and he would escape by turning them 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.”
“Just so”, said he.
“Suppose, now, that someone should drag him thence by force, up the rugged ascent, the steep way up, and never stop until he could drag him out into the light of the sun, would he not be distressed and furious at being dragged; and when he came into the light, the brilliance would fill his eyes and he would not be able to see even one of the things now called real?”
“That he would not”, said he, “all of a sudden”.
“He would have to get used to it, surely, I think, if he is to see the things above. First he would most easily look at shadows, after that images of mankind and the rest in water, lastly the things themselves. After this he would find it easier to survey by night the heavens themselves and all that is in them, gazing at the light of the stars and moon, rather than by day the sun and the sun’s light.”
“Last of all I suppose, the sun; he could look on the sun itself by itself in its own place, and see what it is like, not reflections of it in water or as it appears in some alien setting.”
“Necessarily”, said he.
“And only after all this he might reason about it, how this is he who provides seasons and years, and is set over all there is in the visible region, and he is in a manner the cause of all things which they saw”.
“Yes, it is clear”, said he, “that after all that, he would come to this last”.
“Very good. Let him be reminded of his first habitation, and what was wisdom in that place, and of his fellow prisoners there; don’t you think he would bless himself for the change, and pity them?”
“Very much so”.
“Then what do you think would happen”, I asked, “if he went back to sit in 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?”
“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”.
Brief explanation of the simile:
Pictures on the wall: world of images, of conjectures, of uncritical thinking, second-hand opinions;
Chains: uncritical acceptance of culture, society’s pressure to accept images and appearances;
Dramatic release: with the help of philosopher, total and painful conversion to real understanding;
The fire: realisation that there is more to particulars than appearances; critical understanding
The steep and rugged ascent: the long and difficult process of education, leaving behind opinions..
The shadows in the real world: mathematical-geometrical reasoning
The real things in the real world: the Forms arrived at through Dialectics;
The Sun in the real world: the Form of the Good;
Going back into the Cave: the philosopher must return to instruct and set free the prisoners even if he does not want it, even if he may well risk ridicule and perhaps death. The philosopher must serve the community, his training must benefit the community.
Plato himself gives an interpretation of the simile of the Cave: “Now, my dear Glaucon this simile of the Cave must be connected throughout with what preceded it (the similes of the Sun and the Line). The realm revealed by sight (the visible world) corresponds to the prison (the cave), and the light of the fire in the prison (the cave) to the power of the Sun. And you won’t go wrong if you connect the ascent into the upper world and the sights of the objects there with the upward progress of the mind into the intelligible region… In my opinion, 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 controlling source of truth and intelligence”.
Plato’s fundamental discovery was that the “senses”, the world of “perception” cannot give us knowledge, but simply opinion. Everything in the world of the senses is in a constant flux, is changing all the time, things are never fixed, immutable, necessary, and our sensations of things are always different, varied, contingent. How can you know a thing when that thing is constantly changing? How can you fix in a permanent definition
something that by its own nature is not permanent? It is for this reason that Plato rejected the view that knowledge can be acquired by the senses, by perception of things through the senses.
In the Theaetetus, Plato argues that there is a continuous battle going on between those who take as true the instinctive belief that the senses give knowledge and those who argue that knowledge can only be given by the eternal, unchanging, immutable Forms. He calls this the battle of the Giants and of the Gods: the former holding that sense perception gives knowledge of what is, the latter holding that true existence, true reality, is in the incorporeal Forms which are objects of the mind.
If we rely on sense perception, we remain like the prisoners in the cave and are aware only of shadows; we take these to be reality. But if we use our understanding and aspire to the light then the fetters of sense perception may be broken. At first we shall feel puzzled and afraid, but once we have become used to the light we shall appreciate that we have knowledge which was not available in the cave.
But, if the eternal world of the Forms or Ideas cannot be given by the senses, how can we ever be able to possess it? Plato explains that by thought, we are able to “remember” that world of Forms which the soul inhabited before its earthly life began. Plato held that the immaterial soul was independent of and also superior to the material body. He said that the soul belonged to the changeless and external world of the Forms, not to the changing, impermanent and shadowy world of sense perception. After death we might go back to the world of Forms, though it might return from thence to this material world again. But each time it returned within a body it was as though it had been once more imprisoned. It longed for release in order to return to the world of the Forms.
Material objects and our sense perception of them are not disregarded by Plato, since it is from them, the shadows, that we might begin our ascent to the Forms. The particular horse we experience is a shadow of the real, perfect, unchanging Form of the horse: by perceiving the earthly horse we might “remember” the Form of the horse, and by thought that Form might become clearer and more splendid in our mind.
For Rosmini, Plato’s mistake was to say that the Forms of all things must be innate. We possess them all from birth, having seen them in the other world before our birth. This was his solution to the fact that we have many universal ideas, in a confused way: the idea of chair, dog, horse, tree, star, etc. We have the universal idea of horse, and we apply the idea to a variety of creatures we call equally horse. The idea is therefore in us, experience simply brings it out of us into the open, although in a confused way; I said “brings it out of us” because experience cannot create it for us, being experience always particular and the idea always universal. How can the particular give us the universal? Plato, therefore, was aware of the problem of the origin of ideas; his solution was to say that all ideas are innate, and knowledge is to “remember”. For Rosmini, there is only one innate idea, the idea of being: this idea is to be found in all ideas, is the mother of all ideas; all ideas can be derived from it, some simply by reasoning over the idea of being, others with the help of sense experience.