Many appreciate Richard P. Feynman’s contributions to twentieth-century physics, but few realize how engaged he was with the world around him—how deeply and thoughtfully he considered the religious, political, and social issues of his day. In this collection of lectures that Richard Feynman originally gave in 1963, unpublished during his lifetime, the Nobel Prize–winning physicist discusses several mega questions of science. What is the nature of the tension between science and religious faith? Why does uncertainty play such a crucial role in the scientific imagination? Is this really a scientific age? What explains our universal fascination with flying saucers, faith healing, and telepathy?

Marked by Feynman’s characteristic combination of rationality and humor, these lectures provide an intimate glimpse at the man behind the legend. At the start of his final lecture he says, “I dedicate this lecture to showing what ridiculous conclusions and rare statements such a man as myself can make.” Rare, perhaps, and irreverent, sure. But ridiculous? Not even close.

This is quintessential Feynman—reflective, amusing, and ever enlightening.