Dumb people hire smart people to surround them. Smart people hire smart people to argue with them.
This isn't exactly the quote but it's pretty close. It's from Robert Guillaume as Isaac Jaffe in Sports Night. I loved the sitcom Sport Night. It was on the in late nineties on ABC. I think it tanked because nobody was watching ABC in the late nineties! (I started watching the first season last night on DVD.)
Anyway, I like this concept a lot. I heard an interview with Dave Matthews a couple years ago where he was talking about the band and he was downplaying his role and talking about how he recruited the best musicians he could -- so that they would make him better.
Bad managers are afraid of smart, ambitious people. Bad managers take those people and stifle them wherever possible. Smart managers figure out how to make smart people shine.