Dennett takes on The Purpose-Driven Life, disputing its claim that, to be moral, one must deny evolution.

His new book, Denialism, asks why we have increasingly begun to fear scientific advances instead of embracing them.

Sam Harris argues that science can — and should — be an authority on moral issues.

Louise Leakey asks, “Who are we?” The question takes her to the Rift Valley in Eastern Africa, where she digs for the evolutionary origins of humankind — and suggests a stunning new vision of our competing ancestors.

Michael Shermer says the human tendency to believe strange things boils down to two of the brain’s most basic, hard-wired survival skills.