Steven Pinker's research at Harvard is into language and cognition. His new book The Sense of Style: The Thinking Person's Guide to Writing in the 21st Century explores the links between syntax and ideas. Will Self experiments with language and literary form. Will Self's new book Shark links an incident in World War II with an American resident in a therapeutic community in London overseen by psychiatrist Zack Busner. They join Matthew Sweet for a Free Thinking programme about language.