Even geniuses change their minds sometimes. Edge (www.edge.org), the influential online intellectual salon, recently asked 150 high-powered thinkers to discuss their most telling missteps and reconsiderations: What have you changed your mind about? The answers are brilliant, eye-opening, fascinating, sometimes shocking, and certain to kick-start countless passionate debates. Steven Pinker on the future of human evolution • Richard Dawkins on the mysteries of courtship • SAM HARRIS on the indifference of Mother Nature • Nassim Nicholas Taleb on the irrelevance of probability • Chris Anderson on the reality of global warming • Alan Alda on the existence of God • Ray Kurzweil on the possibility of extraterrestrial life • Brian Eno on what it means to be a "revolutionary" • Helen Fisher on love, fidelity, and the viability of marriage • Irene Pepperberg on learning from parrots . . . and many others.