Human thought is an amazing thing. It has given us not only science, literature, and morality, but also superstition, slavery, and war. Thought has the power to uncover the deepest mysteries of the universe. Or to create new realities – social realities. But what makes human thought so powerful? John and Ken put this question and more to renowned cognitive scientist Steven Pinker, author of the best-selling The Language Instinct: How the Mind Creates Language and The Stuff of Thought: Language as a Window into Human Nature.