Class: Philosophy 42, Professor Flanagan
This paper is a response to Plato’s Republic. I will discuss his use of the Divided Line and the Allegory of the Cave to repudiate psychological egoism, which is the belief that man always acts in his own self-interest. First, I will review the egoist position which Thrasymachus and Glaucon advocate in Books I and II. Second, I will recount the Divided Line and the Allegory of the Cave from Books VI and VII. Third, I will explain the connection between the stories, Plato’s view of the epistemological plight of the ordinary person, his vision of man’s epistemological and moral development, and his reason for believing that only the man who reaches the highest stage of development is truly happy. Finally, I will argue that Plato successfully defeats the egoists’ claim that man always works in his own self-interest. I will note the strength of his explanation of the existence of transcendent values and his reasons man should follow them instead of his own self-interest, and I will address the weaknesses of these views.
Thrasymachus and Glaucon argue that man is only just when it is advantageous for him; therefore, he is inherently selfish. According to Thrasymachus, a just man who obeys the laws is weakening himself because the rulers write the laws to benefit themselves, not their subjects (338c-e, 339b, 343c). The man who breaks these laws is acting in his own self-interest outsmarts his superiors and proves himself virtuous and wise (343c-d, 348b-349a). A truly brilliant man can manipulate his fellow citizens so well that he conquers the city and becomes the source of justice himself (344a-c). Glaucon says that justice is also a product of selfishness (358e-359a). Men agree to act justly so they will not destroy each other; however, if they could do whatever they wished without fear of retaliation, they would act completely unjustly (360d). Glaucon illustrates this truth through the Myth of the Lydian Shepherd. The shepherd discovers a ring which gives him the power of invisibility (359d-360a). Given total freedom of action, he seduces the queen, kills the king with her help, and takes the throne for himself (360b-c).
Plato expresses his metaphysics with the analogy of the Divided Line (509d-511e). He first cuts the line into two unequal sections; the lesser part is the physical world, and the greater part is the spiritual world. He then divides the physical world into a lesser part, Imagination, and a greater part, Belief, and the spiritual world into a lesser part, Thought, and a greater part, Understanding. Each section of the line represents a different level in the hierarchy of reality. The lowest plane of existence is the world of Imagination (509d-e). This is the world of shadows and reflections of physical objects. The world of Belief contains actual physical entities such as rocks, animals, and plants (510a). The next stage is spiritual; we cannot perceive it with the five senses, but this extrasensory dimension is more real than ours. The plane of Thought contains the ideal forms of the objects we encounter in the physical world (510c-e). Whenever I think of a chair, I imagine not a physical chair but the form of the chair. These incorporeal forms are essential for knowledge, including the sciences. Mathematicians, for example, draw physical representations of objects, but they are actually concerned with the ideal objects: the triangle, the square, the circle. Euclid’s ideal line has no width, but our senses are too limited to see it, so all drawings of the line have width.
The world of Thought gives us great freedom, but the knowledge it gives us depends on “first principles,” also known as assumptions (511a-b). For example, Euclidean geometry is based on the postulates of the point, the line, and the plane. The largest and most advanced section of the Divided Line, Understanding, treats these principles as mere hypotheses. In this level, I gain understanding of those concepts and jump from them to still higher levels of knowledge (511c-d). This realm includes abstract virtues such as love, moderation, and justice. At the very top of the line is the Form of the Good, which Plato says is so beautiful that we cannot comprehend it (507b). Plato compares it to the Sun; it is too bright for our eyes to see it, but by its light we perceive everything else in the world (507a-509c). This form illuminates all the others.
Plato’s Allegory of the Cave provides his view of man’s epistemological and moral growth. In this example, a group of men have been chained inside a cave since childhood (514a). The cave is a long tunnel which declines from the world above to the depths of the earth; these men are at the bottom. They are bound so tightly that they can only see the wall directly in front of them. Behind them is a screen like the kind used for puppet shows; behind the screen is a fire (514b). Sometimes, men walk between the screen and the fire carrying different objects (514c-515a). The captive men see the shadows of the objects on the wall and think they are the full extent of reality; they hear the conversations of the other men and think the shadows are speaking to them (515b-c).
One day, one of the men is freed from his bondage. He turns around and sees the fire; the bright light causes pain, and he feels confusion because there are objects and men in place of the shadows (515c-d). He denies the reality of these things and wishes to return to his previous existence (515e). Someone drags him out of the cave and into the outside world, nonetheless (515e-516a). The sun initially blinds him, but after his eyes adjust, he studies this new world and comes to understand its ways and the falsehood of his previous existence (516b-c). He pities his ignorant fellows below (516c-d). Eventually, he returns to the cave, despite the disorienting darkness and the abuse of his arrogant associates who think his eyesight is ruined, to free the others from their bonds and to teach them about the light (516e-517a).
In this story, the captive men represent humanity; the cave is the physical world, and the lands above are the spiritual world (517b). The man’s journey from the bottom of the cave to the outside world mirrors his journey through the sections of the Divided Line; the more he learns in the higher planes of reality, the better he understands the lower ones. The Sun represents the Form of the Good. It is good for its own sake; if it disappeared, the entire world would plunge into impenetrable darkness and die, including the men in the cave. Once man understands this form, all of existence becomes clear to him. The common man’s epistemological plight is that without the help of education and a good society, he will spend his entire life chained in his corner of the world thinking that it is all that exists. His moral and epistemological development is extremely painful; his muscles have never been used, and his eyes are accustomed to total darkness. Plato says that enlightenment must be worth the effort because the man who sees the sun never wants to leave it, and he considers his happiness in his previous life incomprehensible. He even returns to the cave despite the danger and discomfort because he feels compassion for his brothers and wants to show them the truth.
Plato successfully refutes Thrasymachus’s and Glaucon’s claim that man always works in his own self-interest by proving that transcendent values exist; they are good, and choosing them over self produces happiness. Especially strong is his substantiation of the existence of abstract concepts like justice. Whereas the egoists say justice is difficult to define because it is a subjective value which depends on the whims of mankind, Plato explains that men cannot define it because their minds are not yet advanced enough to comprehend it. Our failure to understand something does not preclude its existence. The egoist could then respond that the forms are purely theoretical and might not exist at all. Admittedly, the theory of the forms is impossible to prove; nevertheless, it provides satisfactory explanations for abstractions like mathematical thought or our innate sense of right and wrong, and egoism does not. Plato explains these phenomena, and the egoists do not; therefore, Plato has the upper hand.
Plato also provides compelling reasons for man to put justice ahead of himself. The spiritual realm is good; the philosopher loves it, and he feels so strongly that others should see it that he returns to the cave to show fellow men the way to the light. Thrasymachus could reply that man does these things because they make him happy, an egoist reason. In this case, the egoist misunderstands the nature of choice. I choose an action because I want to do it, but this does not mean it is in my self-interest. Re-entering the cave is a selfless action because man intentionally risks his own life for other people. He does it because it is the right thing to do; his own happiness is merely a side effect.
Thrasymachus and Glaucon argue that justice is a powerless concept, and man only acts in his own self-interest. Using the Divided Line and the Allegory of the Cave, Plato refutes their claims. He proves that abstract forces like justice and goodness have objective existence and intrinsic value, and man should devote himself to understanding them despite the hardships of the journey towards knowledge. Man can only achieve true happiness when he accepts something greater than himself.