An important concept to bear in mind when considering Plato's metaphysical dualism is his "theory of Forms". According to this view, each thing that exists on earth (the realm of Becoming [horeton]) - or even as an object of language - has a corresponding "Form" (Eidos) or perfect idea in ‘the realm of Being’ (noeton). So, in the example used by Plato, a simple thing such as a bed would be linked to the perfect idea of a bed that exists independently (which all other beds share). The same thing would also apply to such things as colours, moral values or types of animal. For instance, the thing that all the different shades of red have in common is that they all correspond in some way to the Form, or perfect idea, of "red". Another point worth considering is that due to the fact that everything in the ‘realm of Becoming’ is in constant flux it can not be perfect; this realm is based on beliefs (pistis) and opinions which in turn help to create an illusionary world (eikasia).
For Plato, the soul - or mind - obtained knowledge through recollection of Forms. By doing this the soul was simply returning to the state of knowledge which it had before birth. The Forms that Plato describes are invisible, divine, eternal, space-less, immutable, universal and perfect. Plato’s Forms are not mental entities, nor even mind-dependent. They are independently existing entities whose existence and nature are graspable only by the mind, even though they do not depend on being so grasped in order to exist.
Plato believed that the Forms were interconnected and arranged in a hierarchy. The most important Form is the Form of the Good. All Forms are aspects of Goodness. E.g. Justice is an aspect of Goodness. Plato said that the Form of the Good is “the greatest thing we have to learn”. Knowledge of the Good is an end in itself and gives meaning and purpose to life. One needs to note that the Form of the Good is not necessarily one in the moral sense as the Form of the Good gives perfection to all things.
In the Analogy of the Cave Plato puts into symbolic form this view of the human condition in relation to reality as a whole, and his dualistic ideas concerning the two worlds, that of ‘being’ and that of ‘becoming’.
There are prisoners living in a cave under the surface of the earth. All along the cave, these prisoners have been chained by their legs and necks so they can only see in front of themselves, they haven’t been able to turn their heads or look to either side since childhood. There is a fire burning behind them and between the fire and the prisoners there is a wall. Behind the wall puppeteers are carrying all sorts of statues and figures of animals, which appear above the wall. All the prisoners can see are the shadows that the blazing fire creates and which are reflected exactly in front of them on the wall of the cave. One day one of the prisoners is permitted to leave the cave; he turns to face the fire and is momentarily blinded. Once his eyes become accustomed he exits the cave (the ascent to the outside world is a painful procedure) where he is overwhelmed by the light from the Sun. He becomes aware that until that moment everything he knew, or that he thought that he knew, was mistaken and disfigured, and all of the shadows were reflections of a complex reality. The prisoner tries hard to return to the cave, in order to share the new reality with the other prisoners. The returning prisoner cannot accept the shadows as the true behaviour of the system and from the other side the prisoners couldn't realize the new reality, the new domain of existence, because the images of the cave remain the only familiar perception of the reality. The prisoners consider the new world as dangerous and the returning prisoner as suspect.
The above analogy is used as a metaphor to symbolise a number of Plato’s theories. The cave and the outside world represent the two worlds. The cave is ‘the realm of Becoming’ in which we are imprisoned by our need for empirical knowledge and short sightedness. The outside world represents ‘the realm of Being’ where the Forms reside. However the journey between the two worlds is difficult and painful but ultimately rewarding and true knowledge is gained. The puppeteers are the people in power who help to shield our eyes and the freed prisoner is a philosopher, and in this case Socrates himself. The shadows projected on the wall are similar to the illusions we see of the perfect Form. They are known as ‘particulars’. The particulars of Plato are copies or imperfect representations of the universal Forms. He also poetically compares the Form of the Good to the sun. Just as the sun emanates light, so the Form of the Good eminates truth. And just as we are able to see the world with our eyes using the light of the sun, so we can make sense of the world with our rational minds only through the assistance of truth, derived from the Form of the Good. But the Form of the Good has neither personality nor the power of creating. According to Plato, Demiurge is the divine maker which formed the heavens and the earth by successive infusions of souls. Demiurge, however, cannot be identified with God, for if he is superior to matter, he is inferior to ideas, which provide the model he uses to arrange matter and transform Chaos in the visible world.
A last point about the Forms. They are what gives us knowledge, but they are also what gives things their reality. The sun casts light upon the earth allowing us to see what is there, and it also supplies the energy through which things grow and prosper. So the Form of the Good gives to the sensible world the reality it has. Later philosophers, in the early days of Christianity, were to adapt this image of the sun into a thought of God as the source of all reality and knowledge.
b) Plato had a theory of Forms, though clear grounds for this claim are scarce in Plato's writings. Nowhere does Plato lay out a complete theory. Elements appear briefly in various dialogues, and with some inconsistency. This has given rise to a number of criticisms concerning his theory.
There was a discussion involving ‘the young Socrates’ and the two Eleatics, Zeno and his teacher Parmenides. The Eleatics argued for monism, the view that reality is one: a permanent and unchanging unity. In their view, pluralism, the view that there are many real things, was false. Socrates offered the Theory of Forms as an alternative to Eleatic monism. It was put forward as a variety of pluralism that did not give rise to the absurdities that the Eleatics found in pluralistic theories. Parmenides and Zeno replied by attacking the Theory of Forms, to show it leads to puzzling consequences of its own.
The first objection to the Theory of Forms is that of the extent of the World of Forms or generality. It was asked, what things are there Forms for? Was there Forms for moral and aesthetic ideals (justness, beauty, goodness), natural kinds (human beings), natural stuffs (fire, water) and ‘undignified’ things such as hair, mud and dirt. (Socrates denied Forms for these things; this is obviously a conflict between the role of Forms as [morally or aesthetically pleasing] paradigms and their role as universals). Forms therefore degenerate into something which has little meaning or use. If there are too many Forms it can make the truth inaccessible. If there are Forms for everything then there must be a Form for evil and other sources of suffering such as disease. This then poses the question; why would the Form of the Good create these things? Plato himself was ambiguous to whether or not there was a Form for absolutely everything. This leads to the next objection, that of the nature of participation.
The nature of participation or inconsistency of characteristics, talks about the extent of involvement. The question asked is, is the whole Form, or only a part of it, in each participant? If it is the whole Form, then each Form will be ‘separate from itself’ if it is in many things. However if it is only part of a Form, then the Form is divisible, and therefore no longer a unity. The conclusion of this dilemma seems to be that Forms will either be divisible or not shareable. But Forms have to be shareable, that is the whole point of having the theory. So the consequence of making Forms divisible is usually persued. I shall give an example. A triangle must be either isosceles or scalene. Therefore the Form of a triangle must be either isosceles or scalene. Since not all triangles are isosceles, the Form of the triangle cannot be isosceles. However not all triangles are scalene, so the Forma cannot be scalene either. The Form of the triangle has to be either isosceles or scalene, but it cannot be isosceles and it cannot be scalene either. But this is impossible, so the theory cannot be true as stated. This on the other hand leads to some puzzling consequences if Forms are divisible. The parts of Largeness are small (with respect to Largeness) but still make the things they are in large. (This conflicts with one of Plato’s requirements: what makes something F must itself be F.) A further puzzle is a part of Equality which is ‘less than equality itself’ nevertheless makes what it is in equal. And furthermore the parts of smallness are smaller than Smallness itself! And addition of such a part to something makes that thing smaller than it was before the addition of that small part!
The last objection made to the Theory of Forms was the Third Man Argument (TMA) or an infinite regress argument. The regress is epistemologically vicious. The Theory of Forms is a theory of faith (the mental state that is common to both knowledge and belief). Believing involves consulting Forms: to believe that x is F is to consult the Form F-ness and to see x as being sufficiently like F-ness to qualify to predicate F. The TMA is designed to reduce to absurdity the claim that it is the consultation of Forms which enables us to believe. It does this by showing that if that were the case, we would have to perform an infinite number of such consultations to construct just one belief.
The Third Man Argument: several individuals are men. Therefore, there is a Form of a Man in which they all participate. The Form of Man is a man (indeed, the Perfect Man). All individual men plus the Form of Man taken together are all men. So there is a single Form in which they all participate. This new Form cannot be the Form of Man, for then it would have to participate in itself which is impossible, so this has to be a Third Man (besides the singular men and their Form). But we can repeat the same reasoning for this Third Man as well, so there would have to be a Fourth, a Fifth, Sixth, etc. to infinity. So for a set of individuals there would have to be an infinity of Forms. But the Theory also states that there is only a single Form for any set of individuals. So the theory is inconsistent, consequently it cannot be true.
The Forms in the end are only a theory. It was argued by Aristotle and other empiricists that the Forms cannot be verified by the senses. This means Plato needs to prove that the Forms are more than just ideas in his head, that they actually exist independently from his mind; he needs to provide some logical proof. Creating a concept and showing that there really is something to which the concept refers are two different processes. Plato’s theory only tells us what the Forms would be like if they existed. He could not establish whether the Forms do in fact exist. Plato’s conclusion depends on whether we accept his concepts and arguments as analytically true or correct. Plato seems to take the existence of the Forms for granted, more as a matter of faith rather than reason and logical argument. The Forms are not as self-evident as Plato presumes.
