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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.

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