her new, must-read book, is "the great agnostic: robert ingersoll and american freethought." susan jacoby, welcome back. >> i'm very happy to be back here today. >> robert ingersoll, once our most famous orator, a towering public intellectual between the end of the civil war and the beginning of the 20th century. what drew you to him? >> it's hard to exaggerate how famous he was in the last two decades of the 19th century. lecturing was then the chief form of mass entertainment, even though newspapers were read and widely circulated. there was no tv. there were no movies. lecturing is what people went to to be entertained as well as informed. and like everybody of his generation, his dates are 1833 to 1899. he was in the civil war. he joined the republican party during the civil war because he was an abolitionist. but after the civil war, something happens to him. he starts speaking out on behalf of separation of church and state, against what religion was silent about, about slavery for so long, and what religion was still silent about, about what needed to be done to provid