But these friendships are more grievous than any enmity. For by our enemies, if we will, we are even profited; but by these we must needs be harmed, no question of it. Keep not then friends to teach thee harm; keep not friends who are enamored rather of thy table than of thy friendship. For all such persons, if thou retrench thy good living, retrench their friendship too; but they that associate with thee for virtue’s sake, remain continually, enduring every change.