In Book VI, Plato explains why people reproach philosophers as useless and evil. He argues that society is like a ship with a violent crew. The sailors all violently vie with one another to be captain of the ship, though all of them, but one, possess no knowledge of navigation. The one member of the crew that does possess such wisdom is considered a “star-gazer,” which is a clever use of the term. I am surprised that it translates so well into English. In other words, the most qualified individual to govern the state/ship is considered useless by his fellows because they are ignorant of the art of navigation/statesmanship. This is a useful metaphor that explains why people consider some philosophers to be useless. With regards to the philosophers considered evil, Plato simply dismisses them as pretenders.
Having established that true philosophers – i.e. virtuous people who love and seek wisdom above all else – are the people most capable of governing the direction of the State to attain happiness, Plato explains why there are no philosopher-kings. According to Plato, societies are not conducive to the growth and development of philosophers. Public opinion corrupts the majority of citizens, even those who have the capacities to become a philosopher. When family and friends recognize the unique intellectual talents of an individual, they persuade that individual to pursue an occupation that is profitable. The rare individuals who resist the societal pressures and become virtuous are saved only by the power of Providence. Society disregards these rare philosophers because they are “worthless star-gazers.” In my opinion, because it is impossible to radically alter the prevailing opinions of a society within a short period of time, one must either gradually influence the morality of a society or develop a new society from its foundations as Plato outlines in the first books of the Republic.
Granting that we will form a new State, Plato outlines the circumstances in which societies can cultivate these ideal rulers. The future kings must endure an intense physical and intellectual education, which consummates with the understanding of the Form of the Good. At this point in the narrative, Plato digresses to explain the Form of the Good, and thereby illuminate both his epistemology and his ontology.
In the Simile of the Line, Plato divides reality into two realms – the physical realm and the intelligible realm. In the physical realm, there are objects and there are images of those objects. For example, a tree is an object within the physical realm, and the reflection of that tree in a lake is an image within the physical realm. As in the physical realm, there are two orders of ideas in the intelligible realm. The lower order in the intelligible realm is composed of definitions of the Forms. For example, the definition of virtues would belong to this category. The higher order of the intelligible realm is composed of the Forms themselves – i.e. Beauty, Justice, Courage, etc.
In the physical realm, the sun holds a notable position. It shines its light on all objects, and thus enables people and other creatures to see these objects. Next, it gives existence to all things. Plants and animals could not exist without the sun. Just as in the physical realm, there is a “sun” of the intelligible realm that renders the definitions and forms intelligible; the sun of the intelligible realm is the Form of the Good.
Plato divides reality into the physical realm and the intelligible realm because he believes that the abstract concepts of physical objects and actions exist; and because abstract concepts do not exist in the physical realm, Plato concludes that they must exist in an intellectual realm. For example, the abstract concepts of a “tree” or a “dog” do not exist in the physical world, yet we use these concepts and others to categorize the world we perceive. In my opinion, I do not believe that abstract concepts exist independent of physical phenomena. Abstract concepts are derived from physical phenomena, not vice versa as Plato argues. An individual observes several different trees, abstracts particulars from those trees until only the shared qualities of the trees remain. These common qualities form the abstract idea of a “tree.”
“Say to him, that, in deeming the best votaries of philosophy to be useless to the rest of the world, he is right; but also tell him to attribute their uselessness to the fault of those who will not use them, and not to themselves. The pilot should not humbly beg the sailors to be commanded by him.”
“Will any private training enable him to stand firm against the overwhelming flood of popular opinion? or will he be carried away by the stream? Will he not have the notions of good and evil which the public in general have –he will do as they do, and as they are, such will he be?”
“When a man consorts with the many, and exhibits to them his poem or other work of art or the service which he has done the State, making them his judges when he is not obliged, the so-called necessity of Diomede will oblige him to produce whatever they praise.”
“Do not great crimes and the spirit of pure evil spring out of a fullness of nature ruined by education rather than from any inferiority, whereas weak natures are scarcely capable of any very great good or very great evil?”
“This being the class out of which come the men who are the authors of the greatest evil to States and individuals; and also of the greatest good when the tide carries them in that direction; but a small man never was the doer of any great thing either to individuals or to States.”
“The soul is like the eye: when resting upon that on which truth and being shine, the soul perceives and understands and is radiant with intelligence; but when turned towards the twilight of becoming and perishing, then she has opinion only, and goes blinking about, and is first of one opinion and then of another, and seems to have no intelligence.”
Book VII contains the most famous metaphor of philosophy – the Allegory of the Cave. Plato asks the reader to imagine a group of prisoners chained since birth in the bottom of a cave. The prisoners can only see the wall in front of them. They cannot turn to either side. Behind the prisoners, puppeteers move statues in front of a fire so that the shadows of the statues are cast onto the wall in front of the prisoners. The prisoners speak of these shadows as we speak of our world. They call the shadows ‘horses’, ‘dogs’, ‘men’, etc.
Suppose a prisoner breaks free from his chains and turns around. His eyes, unaccustomed to the light of the fire, are not able to discern the statues. But after a period of time, his eyes adjust to the light, and he sees that the statues and the fire are more real than the shadows. The existence of the shadows depends upon the existence of the statues, not vice versa.
Suppose the prisoner ascends from the cave into the upper world. Once again, his eyes being unaccustomed to the light of the sun, he is incapable of looking upon the objects of the world. But by gradations he looks first upon shadows, then reflections in water, then the objects themselves, and finally the sun itself. He concludes that the sun is the reason why he can see the objects of the world, and also concludes that the sun is the source of all existence.
The Allegory of the Cave is a more elaborate and beautiful metaphor than the Simile of the Line, but the subject matter is the same. Plato uses both metaphors to illustrate his conception of reality and the different stages of knowledge.
I always had difficulty distinguishing between the types of knowledge of the intelligible realm. The following example clarified my confusion. A man who gives a definition of Courage, or explains that some particular set of notes produce harmony has knowledge of the concepts of Courage and music. But the man who can explain why the definition of Courage is “Good”, or why a particular set of notes produces harmony has reached the ultimate level of understanding. One must have a grasp of the Form of the Good, and be capable of relating his knowledge of anything to the Form of the Good, which means one must be capable of providing the answer to: Why?
In order to attain the knowledge of the Form of the Good, one must study mathematics and dialectics. Mathematics directs the mind toward abstract truths, not objects of the physical realm, because numbers exist in the intelligible realm, not the physical realm. Studying mathematics prepares the student for dialectics. A student can only attain the knowledge of the Form of the Good through the study of dialects because the student can only arrive at absolute truth through the use of reason alone. Thus, Plato rejects the assertion that one can acquire knowledge through observation. According to Plato, one can only attain truth through the use of pure reason. This directly contradicts the scientific method, which relies primarily on observation.
In my opinion, I believe that Plato meant to argue that the ultimate truth – i.e. the knowledge of the Form of the Good, or knowledge of God, or the Theory of Everything – is impossible to attain by observation. I agree with Plato under these circumstances. I disagree with him if he meant that no truths can be attained from observation. For example, suppose I form the hypothesis that all swans are white because I have only seen white swans. When I observe a black swan, I discover a truth through observation – i.e. not all swans are white. However, Plato may state that the swans that I observe are like the shadows and statues in the Allegory of the Cave; and thus any conclusion I make about the shadows and statues are essentially meaningless because the shadows and statues are not real. They exist in the realm of becoming, not being.
“What if there had been a circumcision of such natures in the days of their youth; and they had been severed from those sensual pleasures, such as eating and drinking, which, like leaden weights, were attached to them at their birth, and which drag them down and turn the vision of their souls upon the things that are below?
“The true use of math is simply to draw the soul toward being.”
“We must endeavor to persuade those who are to be the principal men of our State to go and learn arithmetic, not as amateurs, but they must carry on the study until they see the nature of numbers with the mind only; nor again, like merchants or retail-traders, with a view to buying or selling, but for the sake of the soul herself; and because this will be the easiest way for her to pass from becoming to truth and being.”
“Those who have a natural talent for calculation are generally quick at every other kind of knowledge; and even the dull if they have had an arithmetical training, although they may derive no other advantage from it, always become much quicker than they would otherwise have been.”
“With dialectic, when a person starts on the discovery of the absolute by the light of reason only, and without any assistance of sense, and perseveres until by pure intelligence he arrives at the perception of the absolute good, he at last finds himself at the end of the intellectual world, as in the case of sight at the end of the visible.”
“There are four divisions; two for intellect and two for opinion, and to call the first division science, the second understanding, the third belief, and the fourth perception of shadows, opinion being concerned with becoming, and intellect with being.”