Plato is concerned with the difference between mere belief and true knowledge in rhetoric is because he is trying to show how rhetoric can be affected and the differences between knowledge and belief can help form or debunk the whole idea of rhetoric. In Plato’s Phaedrus, Socrates feels that rhetoric is not a skill but more of an art/ knack. By proving that rhetoric is more of a knack it gives Socrates more of a reassurance that rhetoric is based on belief because “someone who knows the truth couldn’t produce (conviction) on the basis of a systematic art,” which provides evidence that those knowledgable cannot be good rhetoricians because those who know truth are knowledgeable and cannot be unjust. With mere belief rhetoric can be presented just or unjustly because it is how one perceives it and receives the message; belief opens up endless possibilities for rhetoric. But however, if you have knowledge you have the advantage to “escape detection as one you shift from one thing to its opposite.”