Plato's Protagoras
These notes rely to a great extent on Terry Penner's 'Socrates' Response to Protagoras in The Cambridge History of Greek and Roman Political Thought.

The dialogue breaks down into the following sections:

• 309-319: Introductory exchange: what is the nature of Protagoras' knowledge?
• 320-328: Protagoras' "Great Speech": everyone teaches
  
• 328-334: Arguments about the virtues and Virtue
• 334-338: Skirmishing: Socrates wants short answers
• 338-348: Simonides poem interpretation
• It's hard to become virtuous
• The only way to become worse is to become less knowledgeable
• No one errs willingly.
• 348-349: Socrates explains that since Protagoras knows what virtue is, Socrates will gladly learn from him.
• 349-360: Protagoras argues that courage is not the same as wisdom. Socrates argues that it is.
• 360-362: Socrates holds that virtue is knowledge but is not teachable. Protagoras holds that it is not knowledge, but is teachable. That's absurd.