Full Idea
Conventional virtue was not dismissed by Aristotle, as it had been by some of the Socratic schools, nor seen as the substance of virtue, as it was by Protagoras. Instead Aristotle distinguished two levels of virtue - the conventional and the intellectual.
Gist of Idea
Aristotle said there are two levels of virtue - the conventional and the intellectual
Source
comment on Aristotle (Nicomachean Ethics [c.334 BCE]) by Richard Taylor - Virtue Ethics: an Introduction Ch.9
Book Reference
Taylor,Richard: 'Virtue Ethics: an Introduction' [Prometheus 2002], p.58
A Reaction
On balance I think Taylor is wrong about this. Aristotle is never going to concede a fully relativist view of social morality. Some things are 'just wrong', and the basis is the function of man as a political animal. Good citizenship is not conventional.