Selected by the series producer, Jim Frank.
The artist Grayson Perry discusses art and revolution.
Art can bring the dead back to life, argues the late novelist Hilary Mantel.
Atul Gawande calls for a radical rethink of medical systems to transform healthcare.
Eliza Manningham-Buller reflects on 9/11 in the first of her Reith Lectures 2011.
Prof Michael Sandel considers the expansion and moral limits of markets.
Philosopher Kwame Anthony Appiah argues for a world free of racial fixations.
Professor Tom Kirkwood explores the connections between sex and death.
Margaret MacMillan explores our complex relationship with the people who go to war.
Musician and conductor Daniel Barenboim examines the physical phenomenon of sound.
Professor Ramachandran examines how we 'see' and become conscious of our surroundings.