The essay is quintessential pg: some things that are not his specialty he gets wrong but clear and full of great insight. It should be required reading.
When pg talks about his naive decision in high school to major in philosophy he says: "I thought studying philosophy would be a shortcut straight to wisdom." I believe this is the central fallacy that people have about the discipline that turns them off quickly once they realize that it's not a royal path to wisdom but a broad and technical discussion on what qualities such a path would have.
http://paulgraham.com/philosophy.html
It matches my experience of getting a B.A. from a SLAC quite closely, and I regularly share it with non-techies.