Mr. Pinker's new book had infuriated linguistic conservatives--among whom, count WFB--but in this relaxed conversation, host and guest agree as much as they disagree. SP: "All innovations, all words have to come from somewhere. Someone has to be the first person to use a word. They weren't handed down by a committee. And that means that all words at some point must have been slang, and words like 'mob,' 'bully,' 'sham,' 'jazz,' all were decried as horrible violence against the language.... If I was to say, 'It's been groovy rapping with you,' I would be embarrassing myself. And so in any judged, precise use of language, you have to develop an ear for what is likely to be durable and what is likely to be ephemeral."