Full Idea
Socrates' great point of agreement with the sophists is his acceptance of the thesis that areté is teachable. But paradoxically he denies that there are teachers.
Clarification
'Areté' is excellence or virtue
Gist of Idea
Socrates agrees that virtue is teachable, but then denies that there are teachers
Source
report of Socrates (reports of career [c.420 BCE]) by Alasdair MacIntyre - A Short History of Ethics Ch.3
Book Reference
MacIntyre,Alasdair: 'A Short History of Ethics' [Routledge 1967], p.21
A Reaction
This is part of Socrates's presentation of himself as 'not worthy'. Virtue would be teachable, if only anyone knew what it was. He's wrong. Lots of people have a pretty good idea of virtue, and could teach it. The problem is in the pupils.