Plato's theory of the Forms

This man "holds opinions but does not know" and his state of mind is similar to "dreaming", meaning that it entails "the confusion between a resemblance and the reality".

Opinion "corresponds something between ignorance and knowledge"

They both have distaste for the man who holds opinions "because no reasonable person would identify the infallible with the fallible".

They believe that "a man who holds an opinion grasps something...but what is not can hardly be called something - it is, properly speaking, nothing".

Thus the man with opinions "darker than knowledge but clearer than ignorance" and is "intermediate between them (ignorance and knowledge)"

In contrast, the man with true knowledge "knows what is as it is"

Finally, the true philosophers are described as "those who love to see the truth" and"those whose hearts are fixed on the true being of each thing are to be called philosophers and not lovers of opinion"

Plato argues that the only "true" knowledge comes from knowledge of the forms, shown through the divided line:

Socrates divides the world, and our understanding of it, into two main categories then divides these categories once again. 

The higher category is intelligence, or episteme which contains:

1) Noesis, the knowledge only available through the "power of the dialectics", and a world which "moves solely through forms to forms and finishes with forms"

2) Dianoia the world of mathematics and "geography and calculation" which can be still defined as this even though it deals with objects because "the real objects of their investigation being invisible except to the eye of reason"

The lower category is the visible or physical realm, defined as doxa. This contains:

3) the world of pistis which is the "originals of the images" and sensible particulars which we experience in everyday life i.e. a chair

4) eikasia which is the reflections and copies of the sensible particulars experienced in pistis, defined as "first shadows, then refelctions in water"

Crucially, the divided line represents both mental states and the objects of knowledge. Also, the simile of the divided line stands out amongst Plato's simile as it is less colourful, without vivid imagery. There are lots of questions about it, such as the significance of Plato's ratio.

One criticism is that knowledge is a special kind of belief, with strong evidence to support it. If I believe that there is a dog outside of y house, and then saw it, then I have progessed from knowledge to belief. Therefore knowledge and belief are not completely difficult faculties.

He could imply that the relationship of "shadows, then reflections in the water" to the actual objects is mirrored in the relationship between Forms and numbers. This does not seem to be evidenced, and Plato could respond saying that the shadow depends on something else, just as the numbers depend on te Forms.

The divided line emphaises Plato's devotion to rationalism.

Plato asks Glaucno to imagine a scenario in which men are held captive in a cave, and they:

"They can only look straight ahead of them and cannot turn their heads"

"They would believe that the shadows of the objects we mentioned were the whole truth"

Once they leave the cave, they are "cured of their delusions"

However, once the man sees light "he would be too dazzled to see properly the ojects of which he used to see the shadows"

He assumes that the outside world was "empty nonsense"

The light of the fire would "hurt his eyes"

He sees the shadows as something "really clearer than the things being shown to him"

Plato summarises that "the process would be a painful one"

Once his eyes readjust the man can "look directly at the sun itself and gaze at it without using reclections in water or any other medium"

There was "honour and glory to be won among the prisoners and prizes for keensightedness"

The relieved prisoner would prefer "anything else in the world than hold the opinions and live the life that they do"

When he re-enters the cave again he is "blinded by the darkness"

When he tries to lead them outside "they would kill him if they could lay hands on him"

"the realm of sight corresponds to the prison and the light of the fire in the prison to the power of the sun"

"anyone else who is going to act rationally in either public or private life must have sight of it"

The man is confused about whether he has come from a clearer world and is confused by the unaccustomed darkness, or whether it is dazzled by the stronger light of the clearer world to which it has escaped from it's previous ignorance."

The simile of the sun has four purposes.

1. The Form of the Good helps us see and understand the "truth" of the world we live in, enabling you to: "see clearly, and obviously  have vision" whereas without it people "see dimly and appear to be almost blind, as if they had no clear vision"

2. Both the Form of the Good and the sun create life and knowledge by starting the "the process of generation, growth and nourishment".

3. The sun is transcendent from our world, just as the form of the good is. It is "superior in dignity and power" and the sun is still "beyond it, superior to it in dignity and power" because it caused the chain of existence.

4. Both the sun and hte form of the good are visible in itself, sperate from the cycle, and can be understood as "it is also knowable" and is "of their being and reality"  whilst "it is also seperate".

The Simile of the cave seems quite hard to match up with the simile of the divided line. This is because the state of "illusion" does not appear to be what we are normally trapped in, and Plato threatens to furhter limit our understanding of the world.

However, a modern response is to see eikasia as us trusting the words of others and not finding out the truth ourselves. A modern revival would liken eikasia to trusting the hysterical media.

Plato's similees are undeniably hard to decipher. A simile never states the reality, because in Plato's opinin, this reality cannot be fully understood. Plato's analogies are not always incredibly convincing, but this is partly because he is trying to explain, rather than justify his understanding of analogy. 

Plato's ideas have been praised as we talk about ideas like "justice" as if there is a reality out there. Furthermore, Plato's ideas offer an opportunity to have true knowledge, which would be useful.

However, Plato has been criticised for deriving his epistemology from his ontology, he assumed his idea of reality and then decided what his theory of knowledge. Descartes was one of the first to reject his ontology and create his epistemology first, an action which has often been praised

1. They are independent from particulars, Glaucon mocks them as "miraculously transcendent" but Socrates defines the form of the good as "beyond it (the world) and superior to iit in dignity and power"

2. The forms are perfect, there is a distinction between "participating in" and "being" beauty, because they al stem from the Form of the Good which is so perfect it created out sun, and is always described as "good" 

3. They are "eternal unchanging things" which exist in a world "unaffected by the vissitudes of change and decay"

4. They are all simple "each of them is seperate"

Plato's ideas have been criticised as they are elitist, but Plato would respond saying that does not mean that his forms do not exist.

Plato's forms could be too transcendent from our world, Aristotle created forms which existed in the world.

Plato's ideas would limit our scientific progress, as we could only develop knowledge through the Forms and dialectics.

Aristotle's third man argument also criticises his claim.