At TEDGlobal 2010, author Matt Ridley shows how, throughout history, the engine of human progress has been the meeting and mating of ideas to make new ideas. It's not important how clever individuals are, he says; what really matters is how smart the collective brain is.
When extrapolated a bit, this thesis is one of the best arguments for why Twitter and other methods of social media are so useful. There really is a great idea at the core of this presentation.