This has been around for a long time, but well worth revisiting if you haven't seen it for a while. And if you HAVEN'T seen it, well ... it's an absolute MUST! You gotta LOVE this guy!
[Hat tip to P.M. via Fr. Z.]
"What is the first business of philosophy? To part with self-conceit. ...It is impossible for anyone to begin to learn what he thinks he already knows." -- Epictetus (c. 100 A.D.)