Protagoras by Plato is a dialogue by Plato. The traditional subtitle (which may or may not be Plato's) is "or the Sophists". The main argument is between Socrates and the elderly Protagoras, a celebrated sophist and philosopher.
The discussion takes place at the home of Callias, who is host to Protagoras while he is in town, and concerns the nature of sophists, the unity and the teachability of virtue. A total of twenty-one people are named as present.
The dialogue begins with an unnamed friend of Socrates asking him how his pursuit of the young Alcibiades, just now reputed to be growing his first beard, is proceeding. Socrates explains that while he has just been in the company of Alcibiades, his mind is now on more interesting matters. He says that the Sophist Protagoras, the wisest man alive (309c–d), is in town.
Socrates relates the story of how his young friend, Hippocrates, son of Apollodorus, came knocking on his door before daybreak and roused him out of bed. Hippocrates was in a big hurry to be present when Protagoras held court, as he was expected to do, at the home of Callias, and wanted Socrates to introduce him as a potential student to the old Sophist, as Protagoras had a great reputation as a teacher.
