I like your answer to the effect that (I hope I understand you correctly) what makes the final definition of the sophist imperfect is its failure to exclude Socrates the philosopher. Well, I always thought that the definiens (including 'eiro[-]nikon') refers to someone who pretends to know what he/she isn't sure about, and that this feature is foreign to Socrates. Let me think more. Could you give me the reference again? Thanks a lot!