Plato is concerned with the distinction between mere belief and true knowledge because it is a critical presupposition which often gets over looked. For a man can believe that the sun orbits around the earth; he can believe it with his entire heart. In addition, the majority of the populace can believe this same statement. Nonetheless, no amount of belief can change the reality of the earth orbiting the sun. It is “true knowledge” and a legitimate fact. Plato is concerned, and rightly so, that the Sophists are manipulating peoples beliefs with rhetoric, largely discrediting or minimizing the facts.