Breaking off the ordinary flow of experience, the passions create a state of exception. In their suddenness and intensity, they map a personal world, fix and qualify our attention, and impel our actions. Outraged anger drives us to write laws that will later be enforced by impersonal justice. Intense grief at the death of someone in our life discloses the contours of that life to us. Wonder spurs scientific inquiry.

The strong current of Western thought that idealizes a dispassionate world has ostracized the passions as quaint, even dangerous. Intense states have come to be...