Friendship with the upright, with the truthful and with the well informed is beneficial. Friendship with those who flatter, with those who are meek and who compromise with principles, and with those who talk cleverly is harmful.
It is clear, then, that wisdom is knowledge having to do with certain principles and causes. But now, since it is this knowledge that we are seeking, we must consider the following point: of what kind of principles and of what kind of causes is wisdom the knowledge?