Ideas are within man's soul. Man need not experience any outward events in order to know. He turns inward, making his life more spiritual and God-like, so that, free of the limitations of the senses, he approaches the spiritual source of knowledge. Each man is able to arrive at innate truths through the use of his reason. Absolute Truth .
All truths are eternal and absolute.
What is true today will always be true. Something is known as true when the proposition in the mind is logically consistent with the eternal idea. Plato believed that justice is the most important virtue. Justice can exist only in a just state. The ideal government would be ruled by the men or women who demonstrate ability and aptitude for ruling.