'If you really want to understand human nature, you must observe people as they are before they are corrupted by language and culture, by MTV and Hebrew school. You must look at babies.' So contends psychologist Paul Bloom in this fascinating account of how we learn to make sense of reality. All humans see the world in two fundamentally different ways: Even babies have a rich understanding of both the physical and social worlds. They expect objects to obey principles of physics, and they're startled when things disappear or defy gravity. Yet they can also read emotions and respond with anger, sympathy, and joy. In Descartes' Baby, Bloom draws on a wealth of scientific discoveries to show how these two ways of knowing give rise to such uniquely human traits as humor, disgust, religion, art and morality. The myriad ways that our dualist perspectives, born in infancy, undergo development throughout our lives and profoundly influence out thoughts, feelings, and actions is the subject of this richly rewarding book.