In the opening passage of Plato’s Gorgias Socrates declares his intention of learning from Gorgias himself ‘what the power of the man’s craft is, and what it is that he advertises and teaches’.1 orgias, for his part, is only too willing to tell him; he teaches, Gorgias says, the craft of speech, speech in particular about ethical matters-‘the things which are just and unjust’2 in the wide Greek sense of those terms. He concedes, when pressed, that he does not teach such bodies as juries about these matters, but merely persuades them that what he says is true. However, he also claims that as far as his own pupils are concerned, what he has to offer in exchange for their fees is knowledge-and not mere convictionabout ‘the just and the unjust, the fine and the shameful, and the good and the bad’;3 it is not the case that he makes them only appear to know about such things as these.4