Protagoras by Plato

Socrates' friend Hippocrates asks Socrates to accompany him to visit Protagoras, the great sophist who has arrived in town, so that he can pay him to learn how to be a doctor. Sophists today would be like teachers of rhetoric which instead of teaching knowledge teach the appearance of knowledge, for a fee. The argument of the dialogue is whether knowledge can be taught which Protagoras defends, but by the end of the dialogue he and Socrates see, to switch positions.

Protagoras begins his argument with what I think is the most interesting part of the dialogue which is an account of the state of nature. All animals are equal to each other because they are made by the gods to be suited to their own environment. The weak have swiftness and cunning to balance their lack of physical strength. Birds have wings and beaks to provide for themselves, while camels have large humps for carrying water in the desert. Every animal has what they need to survive, nature exists in a kind of harmony. That is until man comes on the scene. Men do not have much of what they need to survive, needing clothing and fire to keep warm and weapons to ward off predators. So Prometheus stole knowledge from the Gods and gave it to man, for which he was punished. Humans have enough knowledge to provide for themselves, but this partial knowledge makes them unable to live with one other and so exist in a state of near perpetual conflict. So Zeus sent Hermes to give men a sense of shame and justice so that people could live in cities. I get the feeling that Hobbes got his state of nature directly from this passage, though without the gods.

It's from this jumping off point that Protagoras' argument that knowledge is learned comes from. Each of us is good at what we know, but since we all have enough restraint to live together, it is not by virtue of reason but feeling. To be a good citizen is to exercise that feeling wisely. Socrates argues against this by saying that nobody intentionally does wrong and that everybody acts according to what they think good. So the good is synonymous with knowledge. It is not learned it is already there and needs to be cultivated. The same argument is made in The Republic, that a doctor must know how the body works to perform his task. Likewise there must be knowledge which allows the soul which directs all tasks, knowledge which cannot be learned but honed and refined. Oddly at the end the arguments get switched around and Socrates defends the opinion that the good requires knowledge, Socratic irony. The whole story can be seen in the larger context of Platonic thought, which is the idea that knowledge is the source of the good and that knowledge is not really learned but is an act of recollection, recalling what is already known.