Feynman has hit on a great way of dealing with philosophy. with humor and an appreciation of the diverse ways of thinking about philosophical matters.
i like it.

his last statement:
"You haven't thought deeply enough; first let me define the world for you."
Well, I'm going to investigate it without defining it! "
is interesting. it reminds me of a situation i had to deal with when studying calculus 1 and then calculus 2. each course was taught by a different professor. the first course we were lead "by hand" the whole way through, proving everything each step of the way. we learned differentiation and integration thoroughly.
then comes the second course. a different professor, this guy doesn't prove anything or if he does he certainly doesn't consider it of much import. so there it's proved now lets move on to the real goal. he throws complex theorems at us one after another and in effect says now use them. he uses one "short cut" after another effectively cutting through all the "bull" of understanding or proofs with an almost irreverent single mindedness of getting results.
i don't argue against the methods of either one of those professors. each had his merits, lessons in reasoning were learned from both.

regards tim