William James once defined philosophy as "the unusually stubborn attempt to think clearly." But for many people philosophy seems more like the attempt to think in the most stubbornly unusual way possible. The Deepest Human Life: An Introduction to Philosophy for Everyone is my attempt to bring philosophy down from its cloudy theorizing and put it back on the earth where it belongs, among wrestlers and chiropractors, preschool music teachers and undertakers, soldiers and moms, chefs and divorcees—you and me, in fact. It relates the stories and ideas of great philosophers (Socrates, Epicurus, Epictetus, al-Ghazali, Descartes, Kant, and others) to the lives of those struggling to live better. William James—my hero, who saw his essential work as "popular philosophy"—also said, "The deepest human life is everywhere."