Science writer and bio-philosopher Jeremy Sherman, Ph.D., M.P.P. puts doubt in perspective, demonstrating with wit and clarity how the handful of difficult choices that gnaw at you have gnawed adaptively and productively at organisms since the origin of life itself. An uplifting journey through the meaning of life science filled with insights for making better decisions and feeling better about the decisions you make; a broad and encompassing sweep--disarming, playful, and yet profound, this is a groundbreaking synthesis of biology, philosophy, and practical decision theory speaking directly to your everyday gut experience, doubting, betting, and sticking to your beliefs in our wiggly world.