This book is an entry into the fierce current debate among psycholinguists, neuroscientists, and evolutionary theorists about the nature and origins of human language. A prominent neuroscientist here takes up the Darwinian case, using data seldom considered by psycholinguists and neurolinguists to argue that human language--though more sophisticated than all other forms of animal communication--is not a qualitatively different ability from all forms of animal communication, does not require a quantum evolutionary leap to explain it, and is not unified in a single "language instinct." Using clinical evidence from speech-impaired patients, functional neuroimaging, and evolutionary biology to make his case, Philip Lieberman contends that human language is not a single separate module but a functional neurological system made up of many separate abilities. Language remains as it began, Lieberman argues: a device for coping with the world. But in a blow to human narcissism, he makes the case that this most remarkable human ability is a by-product of our remote reptilian ancestors' abilities to dodge hazards, seize opportunities, and live to see another day.