After the failure of the Pre-Socratics, and the effects of this failure, namely Sophism, the problem of epistemology became the primary concern of Plato. If the Pre-Socratics failed to make sense of a material reality, then the problem must be that reality is not corporeal/material; or at least there is a non-corporeal world. Dr. Clark describes the task Plato had before him:
“the problem of epistemology is now defined. The search for a knowledge that can give a rational account of itself, that understands the nature of its objects and their causes.”
Plato’s philosophy is mostly known by the objects of knowledge, the Ideas. Plato argues that these objects must be non-corporeal. The clearest argument he gives is the cube argument. Let’s say you have two dice and one wooden block. If the Idea Cube was one physical object, say one of the dice, the other dice and the block could not be Cube because they are not that one dice. If Cube was the sum total of all cubes no individual cube could be Cube because each individual is not the sum total or aggregate of them all. If all dice, blocks and other cube shaped objects were destroyed, the Idea Cube would still remain. Therefore, Cube is not corporeal. Cube must be a single, eternal, unchangeable, object of thought, above the realm of the senses, in the world of Ideas.
These Ideas are then the real essences and the objects of knowledge. There is an important point to understand why the Ideas are superior to sense objects. Admittedly, sense objects constantly change (Heraclitian flux) and objects of knowledge must be stable. If you want the words you use to mean the same thing before and after you speak a sentence, sense objects simply will not do. Thus, the eternal and unchangeable Ideas of Plato.
Plato’s Cave Allegory
To describe the relationship of the lower visible world we live in to sensation and the Ideas, Plato constructed his famous cave allegory. Plato describes human kind like a number of people in a cave, facing the back of a cave with their necks chained so they cannot turn around. Behind them is a roadway, and behind the roadway is a fire. When a person walks down the roadway and passes by the cave the person’s figure casts a shadow on the back wall. This shadow is all the shackled people see of the person. In the same way, when we observe the visible world we live in, we observe a half reality; a shadow of that which is real. The true reality is the world of Ideas, or in the allegory, the persons walking by. When we have a sensation of that shadowy reality, we are reminded of what we know already, but in an incomplete sense.
The world of Ideas is itself the supreme Being and a living mind. The Ideas that compose this world are an ordered system with the Idea of the Good as the supreme principle. It is through the Good that all the subordinate concepts are to be understood and only in relation to the Good. Therefore, we understand Justice and become just for the purpose of the Good, not for Justice in itself. In this sense the Platonic system is teleological in contrast with Democritus’ system which was mechanical.
The Chain of Being
As was stated earlier the world of Ideas is the supreme Being. Below this world there is the Demiurge. The Demiurge is god, an independent and eternal Being, the maker of heaven and earth. Below the Demiurge is chaotic Space and Matter, also independent but Space is non-Being. Good and evil is discerned by how much Being something has. The more Being the better, the less Being the worse. The same goes for false and true propositions. Plato would say that,
“the true opinion is the real opinion, and the false opinion is its contrary; the real opinion grasps the object, but the false opinion apparently grasps nothing. In other words, it is no opinion at all, or, conversely, all opinions are true.”
Plato classed all things as either “Being” or “Becoming”; that which is (Being) is the subject of rational statements, discussions and truths. That which is becoming is the realm of opinion and science. Plato would be an Operationalist in his philosophy of science. That which is becoming is always changing and can never be an object of knowledge. Therefore, if certain scientific procedures seem to invent things and help people, fine and good but these procedures are never true. As a matter of fact the procedure is actually false the moment after the concept is grasped, even though it may work.
The Demiurge and the Cosmos
The Demiurge, wanting to metaphysically raise Space/Matter fashions a world-soul and through it produces the visible world as we know it in the lower realm. This was done in an attempt to organize chaos and from chaos create beauty. The material world is metaphorically described as a body and the upper world the mind.
Thus, Plato’s Timaeus describes the creation of the physical universe consisting of the concentric spheres, the World Soul surfacing the whole:
[34a] “Such was the whole plan of the eternal God about the god that was to be, to whom for this reason he gave a body, smooth and even, having a surface in every direction equidistant from the centre, a body entire and perfect, and formed out of perfect bodies. And in the centre he put the soul, which he diffused throughout the body, making it also to be the exterior environment of it; and he made the universe a circle moving in a circle, one and solitary, yet by reason of its excellence able to converse with itself, and needing no other friendship or acquaintance. Having these purposes in view he created the world a blessed god.
Now God did not make the soul after the body, although we are speaking of them in this order; for having brought them together he would never have allowed that the elder should be ruled by the younger; but this is a random manner of speaking which we have, because somehow we ourselves too are very much under the dominion of chance. Whereas he made the soul in origin and excellence prior to and older than the body, to be the ruler and mistress, of whom the body was to be the subject. And he made her out of the following elements and on this wise: Out of the indivisible and unchangeable, and also out of that which is divisible and has to do with material bodies, he compounded a third and intermediate kind of essence, partaking of the nature of the same and of the other, and this compound he placed accordingly in a mean between the indivisible, and the divisible and material. He took the three elements of the same, the other, and the essence, and mingled them into one form, compressing by force the reluctant and unsociable nature of the other into the same. When he had mingled them with the essence and out of three made one, he again divided this whole into as many portions as was fitting, each portion being a compound of the same, the other, and the essence. And he proceeded to divide after this manner:-First of all, he took away one part of the whole , and then he separated a second part which was double the first , and then he took away a third part which was half as much again as the second and three times as much as the first , and then he took a fourth part which was twice as much as the second , and a fifth part which was three times the third , and a sixth part which was eight times the first , and a seventh part which was twenty-seven times the first . After this he filled up the double intervals [i.e. between 1, 2, 4, 8] and the triple [i.e. between 1, 3, 9, 27] cutting off yet other portions from the mixture and placing them in the intervals, so that in each interval there were two kinds of means, the one exceeding and exceeded by equal parts of its extremes [as for example 1, 4/3, 2, in which the mean 4/3 is one-third of 1 more than 1, and one-third of 2 less than 2], the other being that kind of mean which exceeds and is exceeded by an equal number. Where there were intervals of 3/2 and of 4/3 and of 9/8, made by the connecting terms in the former intervals, he filled up all the intervals of 4/3 with the interval of 9/8, leaving a fraction over; and the interval which this fraction expressed was in the ratio of 256 to 243. And thus the whole mixture out of which he cut these portions was all exhausted by him. This entire compound he divided lengthways into two parts, which he joined to one another at the centre like the letter X, and bent them into a circular form, connecting them with themselves and each other at the point opposite to their original meeting-point; and, comprehending them in a uniform revolution upon the same axis, he made the one the outer and the other the inner circle. Now the motion of the outer circle he called the motion of the same, and the motion of the inner circle the motion of the other or diverse. The motion of the same he carried round by the side to the right, and the motion of the diverse diagonally to the left. And he gave dominion to the motion of the same and like, for that he left single and undivided; but the inner motion he divided in six places and made seven unequal circles having their intervals in ratios of two-and three, three of each, and bade the orbits proceed in a direction opposite to one another; and three [Sun, Mercury, Venus] he made to move with equal swiftness, and the remaining four [Moon, Saturn, Mars, Jupiter] to move with unequal swiftness to the three and to one another, but in due proportion.
Now when the Creator had framed the soul according to his will, he formed within her the corporeal universe, and brought the two together, and united them centre to centre. The soul, interfused everywhere from the centre to the circumference of heaven, of which also she is the external envelopment, herself turning in herself, began a divine beginning of never ceasing and rational life enduring throughout all time. The body of heaven is visible, but the soul is invisible, and partakes of reason and harmony, and being made by the best of intellectual and everlasting natures, is the best of things created.”
The above image is what is shown to traditionally depict Plato’s view of the Universe but let the reader understand that these circular lines are meant to depict concentric spheres.
The Demiurge bases his construction on the pattern of the world of Ideas and imposes this pattern on space and matter (Though Plato was not a mechanist and a materialist he used “space” and “matter” univocally with the materialists). This visible world though is recalcitrant and cannot be perfected, and therefore, the Ideas: Justice, Beauty, Equality etc. cannot be perfectly exemplified here. This demands Plato’s concept of participation. The Idea Cube is not hypostatized in the dice, but the dice participates in the Idea Cube. Due to the recalcitrant nature of Space the cosmos is in a never ending process of fashioning.
“World follows world, reincarnation follows reincarnation, as day follows night, forever.”
It should be noted that the Demiurge is not creating out of nothing as the Hebrew tradition teaches, but the Demiurge makes the cosmos from the chaotic space.
The World Within
Plato rejected the notion that sensation is the beginning of knowledge. He posited the concept of the pre-existence of the soul. In order to understand class concepts upon being introduced to them, man’s soul must have existed before his birth in the world of Ideas and had contact with them. As young children, we understand when someone is violating the Idea Justice before anyone explains it to us. This is innate in man as he comes into consciousness. Through multiple reincarnations, man re-learns what he already knows. Man is inherently omniscient yet with each new life he needs to be reminded of what he knows. Sensation is the occasion upon which recollection is made. Plato would not say that sensation is knowledge, but he would say sensation is the stimulant to knowledge. Maybe, a better word would be the “second cause” or “occasion” to knowledge. Plato shows the difficulty inherent in learning without already knowing:
“A man cannot inquire about what he knows, because he knows it…nor again can he inquire about what he does not know, since he does not know about what he is to inquire.” (Meno, 80d,e, Loeb Classical Library)
“a very brilliant man will be able to understand that there is a genus for each thing and an absolute reality per se…But if anyone denies the existence of Ideas of things, because of the objections above and similar ones, and refuses to posit a Form for each individual thing, he will not know how to conduct his thought, for he has denied that an Idea of each reality is always the same, and thus he completely destroys the possibility of argumentation.”
Here he proves the necessity for at least some form of apriori structures.
Due to the epistemology and metaphysics of Plato his concept of piety emphasizes a departure from sensation and an emphasis on knowledge. Plato taught that pleasure, through sensation, melds the soul to the body and the body is a tomb, thus continuing the Pythagorean Tradition. The task before the pious man is therefore a detachment from sensation and an intellectual preparation to commune with the Ideas after death.
In conclusion, I believe in no such thing as an upper world of Ideas, a world soul, or a soul in general. Man is a physical holistic being. There is no soul. The way I account for man’s knowledge is explained in the modern science of DNA. The creator, a concrete entity above the dome of the flat earth, when he created man, included a language program in his DNA that he did not include in the other creatures, pace Chomsky’s Universal Language.
 Gordon Clark, Ancient Philosophy (The Trinity Foundation, 1997), 90
 Ibid., 126
 Ibid., 278
 Ibid., 103
 Gordon H. Clark, Thales to Dewey (Unicoi, Tennesse.: The Trinity Foundation, 1957, Fourth edition 2000), 81