Dan Dennett: Can we know our own minds?

Bill Gates: How I'm trying to change the world now - Bill Gates hopes to solve some of the world's biggest problems using a new kind of philanthropy. In a passionate and, yes, he asks us to consider two big questions and how we might answer them.

TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world's leading thinkers and doers are invited to give the talk of their lives in 18 minutes -- including speakers such as Jill Bolte Taylor, Sir Ken Robinson, Hans Rosling, Al Gore and Arthur Benjamin. T

ED stands for Technology, Entertainment, and Design, and TEDTalks cover these topics as well as science, business, politics and the arts.