A "clear, accessbile" investigation into the philosophical and scientific foundations of human life, from one of the world's leading neuroscientists (San Francisco Chronicle).

Joy, sorrow, jealousy, and awe—these and other feelings are the stuff of our daily lives. In the seventeenth century, the philosopher Spinoza devoted much of his life's work examining how these emotions supported human survival, yet hundreds of years later the biological roots of what we feel remain a mystery.