I had the privilege of hearing Robert "r0ml" Lefkowitz deliver both part I (the thesis) and part II (the antithesis) of his Semasiology of Open Source talk in person at the Open Source Convention.
This year, I wasn't able to attend OSCON because I was on vacation, so I was sorry to learn that he'd finished the series with part III (the synthesis), it was a big disappointment. (N.b., the threefold manner of presentation is called a Hegelian dialectic, so having done the "synthesis", r0ml is done with this topic.) Fortunately, IT Conversations has the third part of talk and I was able to listen to it last week on the way home from USU.
I'm sure r0ml's style of presentation isn't for everyone, but I sure enjoy it. He's funny, engaging, and interesting. His literary asides alone are worth the time.
r0ml's presentation ranges from a discussion of Terry Winograd's Understanding Computers and Cognition, a book I haven't read since I was in grad school (when it was new), to labor relations. What does any of this have to do with Open Source? r0ml ties it all together. I loved this talk.