"For if anyone can make that clear to him, he'll renounce his error of his own accord, but if you fail to show him, don’t be surprised if he persists in it" (v. 5, p. 140)
"Make the ruling centre aware of a contradiction, and it will renounce it; but if you fail to make it clear, blame yourself rather than the person whom you’re unable to convince." (v. 7, p. 141)
In summary, we must assume people are rational and want to do what is right. We must also assume that once a person is taught correctly, they will act correctly. Furthermore, if we attempt to correct others, we must not become shocked if they don't immediately change. Do your best to teach and correct others, but don't fault yourself if you're unable to change their mind.
Marcus Aurelius prodded himself to always be in the mindset of, not blame, but of helping and teaching others in Book 6.27 and again in Book 5.28.