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Plato: A Theory of Forms
David Macintosh explains Plato’s Theory of Forms or Ideas.
For the non-philosopher, Plato’s Theory of Forms can seem difficult to grasp. If we can place this theory into its historical and cultural context perhaps it will begin to make a little more sense.
Plato was born somewhere in 428-427 B.C., possibly in Athens, at a time when Athenian democracy was already well developed. He belonged to a wealthy and aristocratic family. Plato’s family were involved in Athenian politics, so it is likely that Plato was no stranger to politics himself. He was also the founder of the Academy in Athens, which can be regarded as the Western world’s first university, and its first school of philosophy. He died some time between 348-347 B.C.
Philosophically, Plato was influenced by a tradition of scepticism, including the scepticism of his teacher Socrates, who is also the star of Plato’s dialogues. What was obvious to many of the early Greek philosophers was that we live in a world which is not an easy source of true, ie, eternal, unchanging knowledge. The world is constantly undergoing change. The seasons reflect change. Nothing is ever permanent: buildings crumble, people, animals and trees live, and then die. Even the present is deceiving: our senses of sight, touch and taste can let us down from time to time. What looks to be water on the desert horizon is in fact a mirage. Or what I think of as sweet at one time may seem sour the next. Heraclitus, a pre-Socratic philosopher, claimed that we can never step into the same river twice.
In his Socratic dialogues Plato argues through Socrates that because the material world is changeable it is also unreliable. But Plato also believed that this is not the whole story. Behind this unreliable world of appearances is a world of permanence and reliability. Plato calls this more real (because permanent) world, the world of ‘Forms’ or ‘Ideas’ (eidos/idea in Greek). But what is a Platonic Form or Idea?
Take for example a perfect triangle, as it might be described by a mathematician. This would be a description of the Form or Idea of (a) Triangle. Plato says such Forms exist in an abstract state but independent of minds in their own realm. Considering this Idea of a perfect triangle, we might also be tempted to take pencil and paper and draw it. Our attempts will of course fall short. Plato would say that peoples’ attempts to recreate the Form will end up being a pale facsimile of the perfect Idea, just as everything in this world is an imperfect representation of its perfect Form. The Idea or Form of a triangle and the drawing we come up with is a way of comparing the perfect and imperfect. How good our drawing is will depend on our ability to recognise the Form of Triangle. Although no one has ever seen a perfect triangle, for Plato this is not a problem. If we can conceive the Idea or Form of a perfect triangle in our mind, then the Idea of Triangle must exist.
The Forms are not limited to geometry. According to Plato, for any conceivable thing or property there is a corresponding Form, a perfect example of that thing or property. The list is almost inexhaustible. Tree, House, Mountain, Man, Woman, Ship, Cloud, Horse, Dog, Table and Chair, would all be examples of putatively independently-existing abstract perfect Ideas.
Plato says that true and reliable knowledge rests only with those who can comprehend the true reality behind the world of everyday experience. In order to perceive the world of the Forms, individuals must undergo a difficult education. This is also true of Plato’s philosopher-kings, who are required to perceive the Form of Good(ness) in order to be well-informed rulers. We must be taught to recall this knowledge of the Forms, since it is already present in a person’s mind, due to their soul apparently having been in the world of the Forms before they were born. Someone wanting to do architecture, for example, would be required to recall knowledge of the Forms of Building, House, Brick, Tension, etc. The fact that this person may have absolutely no idea about building design is irrelevant. On this basis, if you can’t recall the necessary knowledge then you’re obviously not suited to be an architect, or a king. Not everyone is suited to be king in the same way as not everyone is suited to mathematics. Conversely, a very high standard in a particular trade suggests knowledge of its Forms. The majority of people cannot be educated about the nature of the Forms because the Forms cannot be discovered through education, only recalled.
To explain our relationship to the world of the Forms, in the Republic Plato uses the analogy of people who spend their whole lives living in a cave [see Allegory of the Cave]. All they ever see are shadows on the walls created by their campfire. Compared with the reality of the world of the Forms, real physical objects and events are analogous to being only shadows. Plato also takes the opportunity to use the cave analogy as a political statement. Only the people who have the ability to step out into the sunlight and see (recall) the true reality (the Forms) should rule. Clearly Plato was not a fan of Greek democracy. No doubt his aristocratic background and the whims of Athenian politics contributed to his view, especially as the people voted to execute his mentor Socrates.
Plato leaves no doubt that only special people are fit to rule. Who are the special people who can recognise the Forms? For Plato the answer is straightforward: the ideal ruler is a philosopher-king, because only philosophers have the ability to discern the Forms. Plato goes on to say that it is only when such a person comes to power that the citizens of the state will have the opportunity to step out of the cave and see the light.
© David Macintosh 2012
David Macintosh is a professional educator in New South Wales, and a regular participant in academic and non-academic philosophy forums.
1. Why does Glaucon mention the myth of the Ring of Gyges? What intuition of ours is he trying to jog?
In Book II, Glaucon tries to reinforce the challenge to justice that Socrates must meet in the remainder of the book. He argues that justice is the sort of good that is only desired for its consequences, not for its own sake. Justice, he claims, is a necessary evil that human beings endure out of fear and weakness. Because we can all suffer from one another’s injustices, he explains, we agree, as a society, to behave justly and thus avoid greater harm. Given the chance to escape reprisals, though, any human being would choose to be unjust rather than just.
In order to illustrate this point, Glaucon appeals to the Ring of Gyges. According to mythology, this ring has the special power to make its possessor invisible. Glaucon’s intention in invoking this magical entity is to argue that even the most just man only behaves as he does because of fear of reprisal. If such a man were able to behave unjustly with impunity—as he could if he were invisible—then he would do so.
Glaucon himself does not believe that justice is a necessary evil; he thinks that it is the highest form of good, the sort that is desired both for its own sake and for its consequences. His wish is that Socrates provide a compelling argument to this effect.
Why does Plato go to such lengths to prove that there are three distinct parts to the human soul? Explain both why he needs three aspects to the soul, and also why these aspects need to be distinct and independent from one another.
Plato applies the word ‘justice’ to both societies and individuals, and his overall strategy in The Republic is to first explicate the primary notion of political justice, and then to derive an analogous concept of individual justice. Plato defines political justice as being inherently structural. A society consists of three main classes of people—the producers, the auxiliaries, and the guardians; the just society consists in the right and fixed relationships between these three classes. Each of these groups must do the job appropriate to it, and only that job, and each must be in the right position of power and influence in relation to the others.
In Book IV, Plato demonstrates that these three classes of society have analogs in the soul of every individual. The soul is a tripartite entity. The just individual can be defined in analogy with the just society; the three parts of his soul are fixed in the requisite relationships of power and influence.
That is why Plato needs to show that there are three parts of the soul, but we can still ask why it is important for Plato to demonstrate that the three types of desire present in every individual correspond to three independent sources of desire.
This distinction of parts allows the three types of desire to be exerted simultaneously and to coexist with each other in both conflict and harmony. Political justice is a structural property, consisting in the realization of required relationships between three classes. The relationships constituting political harmony are fixed and static in the same sense as are the mathematical ratios constituting musical harmony. So in the just individual as well, though desires come and go, the relationship between the different sets of desires remains fixed and permanent.
3. Why does Plato banish the poets from his city?
After defining justice and proving its worth, Socrates turns his critical eye toward the poets. In a shocking move, he banishes nearly all poetry from his city (the only exceptions he makes are for hymns to gods and eulogies for famous men). Plato regrets this edict, feeling that it is an aesthetic sacrifice, but one necessitated by the greater good of the city; the poets, he feels, are too dangerous. He lays out three distinct, though related reasons for his harsh judgement.
His first gripe with the poets is that they deal in the least real things. Their wares are images, shadows, reflections. The objects of their art are, as Socrates puts it, far removed from “what is.” By “what is,” we understand the Forms—the unchanging, absolutes of the intelligible realm. The imperfect mutable copies of the Forms, sensible particulars such as trees, chairs, tables, flowers, are once removed from this most real realm. But the products of poetry are nothing but copies of these once-removed objects. Worse, since only the Forms can be objects of knowledge, the poets know nothing, though they are widely believed to have vast stores of knowledge.
In addition, poets make a practice of imitating the worst aspects of souls. They do not imitate the rational part, since this aspect is both hard to imitate and hard to understand. Instead, they imitate the appetitive part of the soul, and attempt primarily to gratify the appetites with laughter and cheap thrills.
Worst of all, poetry corrupts the soul, strengthening the appetitive part and weakening the rational. It encourages us to indulge in emotions like pity, amusement at base jokes, sympathy with sexual lusts. Because we feel these emotions vicariously through fictional characters, and not ourselves, we believe that we are safe. However, we do not realize that once we begin to allow these sorts of emotion reign they gain power and flourish. Soon we are feeling pity for ourselves, amusement at base events in our own life, and our own sexual lusts. Our appetitive part begins to gain control of the rational, and we are made unjust.
Suggested Essay Topics
1. Thrasymachus declares that justice is nothing but “the advantage of the stronger.” What do you think he means? Make sure your interpretation of the statement explains how it serves as the challenge which The Republic sets out to meet.
2. Why does Plato think that the guardians should share all of their goods in common? Is this the same reason that he thinks they should share spouses and children in common, or is there a different reason for this?
3. According to Plato, what makes the philosopher-king the best possible ruler? Do you agree with his analysis?
4. What is the allegory of the cave meant to illustrate? Explain how it does so. What primary conclusion are we meant to draw from this extended analogy?
5. Plato’s just city goes through three stages of development: trace these stages and explain why each is necessary. In which of these three stages does justice reside? Why?
6. What is Plato’s opinion of erotic love? Of the five character types that he describes in detail, with whom is erotic desire most closely associated? Relate this to his discussion of sexual activity in Book III.
7. Why do you think Plato ends The Republic by invoking the myth of Er?