Explaining Plato’s Theory Plato’s theory of ideas was based on the concept that all knowledge was innate and was achieved by way of recollection. He thus stated that “a man must have intelligence of universals, and be able to proceed from the many particulars of sense to one conception of reason,” (417) explaining that through the sense of the universals, one could grasp the Ideas that served as the ultimate reality. These Ideas were discernible, according to Plato, because they were basically written on the soul and they were recalled by the intellect. Plato described the process in this manner: “this is the recollection of those things which our soul once saw while following God—when regardless of that which we now call being she raised her head up towards the true being” (417-418). Plato’s theory that Ideas serve as the ultimate reality stems from the concept of God being the ultimate reality, or as Plato has Socrates say: God is “the true being,” as described in Phaedrus.

According to this argument, God is the truth and the soul before it is sent into the body passes before God/Truth, from which it obtains the Ideas that are imprinted on the soul and that man recollects as he grows on Earth: God is thus the ultimate Reality and the Ideas that are one with God go into the souls of men, which then “pass into the human form” (417). Plato’s...

This is his a priori argument: man is able to know Truth because the soul was exposed to Truth or came from Truth/God before it went into the man. God/Truth is the cause of all knowledge as all Ideas come from Him, essentially—and thus God is the a priori idea.
The knowledge that man recollects is thus there in the soul a priori and only is waiting for man to remember or recall it. Man recalls it by way of an experience: for example, he is learning mathematics and is told that 1+1= 2 and he assents to this because he recalls that this is so, implicitly—not explicitly; but all the same, the affirmation is there, inherent in his being. This is how Plato’s theory if ideas can be called as a representation of a priori ideas.

Critique

However, a priori ideas proceed from the general to the particular and are deduced rather than obtained by way of inductive reasoning. Plato often starts with a question in mind and gradually works his way to a theory—which is the opposite of beginning with a priori ideas—i.e., starting with a theory and working towards a conclusion. Plato is like the investigator who has a bit of information and wants to ask more questions to arrive at a bigger picture.

The Allegory of the Cave is a perfect example…