Plato’s Republic

In Plato's Republic, Socrates goes to great lengths to explain and differentiate between the ideas of opinion and knowledge. Throughout society, most common men are lovers of sights and sounds. "Lovers of sights and sounds like beautiful sounds, colors, shapes, and everything fashioned out of them, but their thought is unable to see and embrace the nature of the beautiful itself (Republic 476b)." The few who do recognize the beautiful itself are followers of the sight of truth, the philosophers.

Knowledge is based on what is, or truths. The only established truths are the forms. The forms represent true, eternal, unchanging, or facts. Knowledge stems from the idea of forms. One who has knowledge must understand the forms. Only a philosopher has this understanding, and therefore only a philosopher has knowledge.

Contrary to knowledge, ignorance is based on what is not, or untruths. Opinion represents all that remains, therefore opinion is both what is and what is not. The opinion represents all truths other than the eternal unchanging forms. Those who love merely sights and sounds cannot obtain knowledge, for they do not recognize the forms in the sights they see, but only the sights themselves. These lovers of sights and sounds instead have opinions.