There are two modes of swearing: oaths and obscenities. Both reflect deep cultural values, signaling what's sacred and what's taboo. Mohr's history of swearing looks back to ancient Rome, considering how "swear" came by its dual meanings, examining both the psychological and physiological effects of swearing, and pondering whether we swear more now than people did in the past.This event was recorded on at Politics & Prose Bookstore in Washington, DC, on June 4, 2013.