Robert N. Proctor

How many cigarettes are sold each year, worldwide? Believe it or not, six trillion. Our guest, who calls the cigarette "the deadliest artifact in the history of human civilization," was the first-ever historian, several years ago, to testify in court against Big Tobacco. On this installment of our show, we speak by phone with Robert N. Proctor, Professor of the History of Science at Stanford University.