Men are four:
He who knows not and knows not he knows not, he is a fool—shun him;
He who knows not and knows he knows not, he is simple—teach him;
He who knows and knows not he knows, he is asleep—wake him;
He who knows and knows he knows, he is wise—follow him!
Lady Burton—Life of Sir Richard Burton. Given as an Arabian Proverb.
I would say that there are four types of people. There are teachers, students, peers (those who teach and learn from each other), and fools (those that know not that they know not.)
The four types of people:
The peer. Peers will learn from and teach each other.
The teacher. He will recognize students that want to learn and can learn. He will teach with sound data and sources. He will use good logic, extrapolate well and stamp out false sources and logical fallacies.
The student. He will listen, question wisely, and learn. He will be polite and respectful. He will exchange for his training. He knows there is something to learn. He is wise enough to know that he can learn and doesn’t know everything.
The fool. He will be disruptive and disrespectful. He will rationalize, use false logic and use fallacies. He will use poor sources of information. He will neither learn or teach. He may think he knows it all already.