Malcolm Gladwell in The New Yorker:
In “Why?” (Princeton; $24.95), the Columbia University scholar Charles Tilly sets out to make sense of our reasons for giving reasons. In the tradition of the legendary sociologist Erving Goffman, Tilly seeks to decode the structure of everyday social interaction, and the result is a book that forces readers to reëxamine everything from the way they talk to their children to the way they argue about politics.
In Tilly’s view, we rely on four general categories of reasons. The first is what he calls conventions—conventionally accepted explanations.
More here.