It used to be a commonplace that the discipline of philosophy was deeply concerned with questions about the human condition. Philosophers thought about human beings and how their minds worked. They took an interest in reason and passion, culture and innate ideas, the origins of people’s moral and religious beliefs. On this traditional conception, it wasn’t particularly important to keep philosophy clearly distinct from psychology, history, or political science. Philosophers were concerned, in a very general way, with questions about how..