Physicist David Deutsch explores the theme of optimism as a force for 21st century progress. Watch the full replay here: https://youtu.be/ncJQTYc27ME RSA Spotlights - taking you straight to the heart of the event, highlighting our favourite moments and key talking points.

http://www.ted.com Legendary scientist David Deutsch puts theoretical physics on the back burner to discuss a more urgent matter: the survival of our species. The first step toward solving global warming, he says, is to admit that we have a problem.

http://www.ted.com For tens of thousands of years our ancestors understood the world through myths, and the pace of change was glacial. The rise of scientific understanding transformed the world within a few centuries. Why? Physicist David Deutsch proposes a subtle answer.

Uploaded by Christopher O'Connor on 2015-07-09.

Sam Harris and Richard Dawkins discuss Who Says Science has Nothing to Say About Morality? Taped at The Sheldonian Theatre University of Oxford April 12th 2011 by ClearStory Ltd. Registered in England and Wales: Number 7467 151 Registered Office: 3/4 Great Marlborough St, London W1V 2AR Includes Spanish closed captions.