The influence that Plato, the Greek philosopher born in 427 BC in Athens, has had throughout the history of philosophy has been monumental. Among other things, Plato is known for his exploration of the fundamental problems of natural science, political theory, metaphysics, theology and theory of knowledge; many of his ideas becoming permanent elements in Western thought. The basis of Platos philosophy is his theory of Ideas, or doctrine of Forms. While the notion of Forms is essential to Platos philosophy, over years of philosophical study, it has been difficult to understand what these Forms are supposed to be, and the purpose of their existence. When examining Platos forms and evaluating the theory, some conclusions have proved to be unclear and unanswered. However, the doctrine of Forms is essential to Platos philosophy.
Plato came to his view of the Forms based on two premises: first, that knowledge cannot come through the senses; and second, we do nevertheless manage to know things in mathematics, for instance. Plato believed in two worlds; the empirical realm of concrete, familiar objects known through sensory experience, and the rational realm of perfect and eternal Forms. According to Plato, the empirical realm is not real, as sensory objects are not completely real. Beliefs derived from experience of such objects are therefore vague and unreliable, whereas principles of mathematics and philosophy, discovered by inner, rationalistic meditation on the Forms, constitute the only real knowledge. Such familiar, concrete things as trees, human bodies and animals, which can be known through the senses, are merely shadowy, imperfect copies of their Forms. For every sense object in the empirical world, there is a corresponding perfect Form. These Forms are nonphysical, permanent, eternal, and invisible. How then, you may ask, can one ever know of the Forms if they cannot be known by sense perception? Plato answers this question by stating that the Forms are known in thought. They are the objects of thought, therefore, whenever you are thinking, you are thinking of Forms. An important point to note about the Forms is the idea of permanence. The Forms are forever unchanging. An important standard of Platos theory of knowledge was that all genuine objects of knowledge be described without contradiction. Therefore, because all objects perceived by sense undergo change, an assertion can be made that such objects at one time will not be true at a later time. Because what is fully real must, for Plato, be fixed, permanent, and unchanging, he identified the real with the ideal realm of being as opposed to the empirical world of becoming.
This all leads to Platos inevitable rejection of empiricism. The true definition of empiricism is, the view that holds sense perception to be the sole source of human knowledge (Jones, 369). It is obvious that this view is highly contradictive with Platos theory of Forms. He thought that propositions derived from sensory experience have, at most, a degree of probability; they are not certain. Pure knowledge may only be derived from certain, permanent facts. The argument is really that not only do the things we perceive change, but so do the circumstances in which we perceive them. Take this example, for instance. If I were to hold a cup of hot coffee in my left hand and a cold beer in my right, and then place both hands into a tub of lukewarm water, that same tub of water would feel cold to the left hand, and warm to the right hand. Moreover, things must often seem different to me than they do to anyone else, for the circumstances of others are rarely the same as mine. We are also liable to experience illusions, states of dreaming and hallucination, and our initial judgments are also often influenced by our expectations and biases. As a result of these circumstances, Plato supposes that we can never gain knowledge through our senses. Empiricism is rejected in Platos philosophy, contradicting with his theory of Forms to a large degree.
Plato conceived the Forms as arranged hierarchically. A dividing line splits the rational realm into C and D. The division of C represents the lower Forms, and D represents the higher Forms, including the Form of the Good. The Form of the Good is the supreme Form, the highest in the hierarchy, and includes all other forms within it. Everything depends on this Form, and the Form itself depends on nothing. If we could know this Form, we would illuminate and readjust our knowledge. Truth, beauty, and justice coincide in the Form of the Good, and it is something that answers all ultimate questionings. In Platos Republic, the sun in the Allegory of the Cave represents the Form of the Good. Plato sums up his views in an image of ignorant humanity, trapped in the depths of a cave and not even aware of its own limited perspective. They mistake shadows on the walls of the cave as true reality, when in fact reality lies in the world outside of the cave, the world of Forms. The rare individual escapes the limitations of that cave and, through a long intellectual journey, discovers a higher realm, a true reality, the sunlight on the other side of the cave. The sunlight is discovered with a final, almost mystical awareness of Goodness as the origin of everything that exists. Such a person is then the best equipped to govern in society, having a knowledge of what is ultimately most worthwhile in life and not just a knowledge of techniques; but that person will frequently be misunderstood by those ordinary folks back in the cave who haven’t shared in the intellectual insight. Ideally, it is the philosopher who is able to penetrate the world outside the cave of ignorance and achieve the true reality of the world of Forms.
Philosophers have criticized Platos theory of Forms for centuries. Two main criticisms are frequently equated with Platos Forms. The first criticism commonly expressed deals with which things in this world have a Form. Plato believes that for all physical things, a heavenly, perfect Form exists. It appears to be forgotten that not all material objects on earth are pleasant. Therefore, how can this world of Forms be heavenly when disgusting and rather vulgar physical things are present as well? Take vomit, for example. In his divine world of Forms, is there a perfect, eternal and unchanging Form for vomit? The notion seems to contradict with the glorious picture Plato presents of this perfect world of Forms. The argument is then, Plato must have to agree that all material objects, good or evil, have a Form. However it seems unlikely that Plato would allow for such distastefulness in his rational realm. But if he were to disagree, the theory would then be of no value who and what would determine which specific physical objects had Forms? The second criticism most famous to philosophers throughout history is the problem with too many Forms. If all things have a Form, and there is always something further and higher, then wouldnt there then be Forms for Forms? According to the theory, the cycle would be endless. The problem is that Plato can’t stop at just one Form for each type of thing. An infinite number of Forms is a ridiculous notion. If we deny that there are an infinite number of Forms for each thing, which Plato surely would, then how would it be proven that there is even one Form for each type of thing?