Plato’s definition of Rhetoric in Gorgias

Just as ours is, Plato’s definition of Rhetoric is always changing. In Gorgias, he interrogates Gorgias on his definition of Rhetoric. As we see on page 143, Socrates’ definition of Rhetoric is that it is “artificer of persuasion” (143). He also says that rhetoric is the art of persuasion in courts and other assemblies, as I was just now saying, and about the just and unjust” (143).

Why is Plato concerned about the difference between mere belief and true knowledge, particularly concerning the issues of justice? how does this affect his view of rhetoric:?

Plato is concerned with the difference between belief and knowledge because Plato thinks that belief can be an illusion. Sort of like how pleasures can create the illusion of goodness, but only true goodness can come from knowledge. This is related to Plato’s famous cave allegory, in which we see prisoners who have only seen false images in the form of shadows (beliefs) for their whole lives. When one prisoner escapes the cave and sees the objects in the real world, he understands what they actually are. He then has knowledge rather than the belief in things. I think Plato would think that this is especially important in the issue of justice because to have true knowledge about justice is to live your life the right way. This affects his definition of rhetoric because, as he says on page 143, “[rhetoric] creates belief about the just and unjust” (143). I take this as saying that rhetoric creates mere belief about justice, but not knowledge. So he views rhetoric negatively and claims that it can only give one a false understanding of justice and not the truth.