More than half a century ago, sociologist J. Milton Yinger remarked about religion, "There are few major subjects about which men know so little, yet feel so certain." Samuel L. Perry says that Yinger had it right. Americans—and Westerners more generally—neglect the scientific study of religion, and we do so at our peril. In , Perry argues that we need the scientific study of religion—the rational, data-driven analysis of religious life-now more than ever. Contrary to the fears of many religious Americans, the scientific study of religion only threatens falsehoods, promulgated often to the benefit of charlatans and demagogues. And contrary to the silent hopes of many secular academics, religion doesn't go away when you ignore it. Instead, interest groups fill the void to shape the public's understanding of religious reality: sometimes well, usually poorly. Perry makes the case that, as people in the West self-sort into partisan tribes, all of us—religious and irreligious alike—need the scientific study of religion. This book presents a practical roadmap for ensuring that its insights are widely available, accessible, and impactful.