[Chinua Achebe's four novels] are all set in Nigeria. Read as a tetralogy, they reveal a theme of tragedy together with intense moral concern. The tragedy and moral concern are not just for the fictional characters in the novels, nor are they just for the people of Nigeria, who experience extreme changes in their lives as a result of colonialism and internal strife. Rather, these novels, as they focus upon tragedy and morality, transcend their setting. By being extremely provincial, Achebe projects a picture of human experience with universal applicability. His art entertains, but it entertains in order to instruct, and it instructs about the nature of tragedy and about workable morality in fiction and in life. Of course, a great deal of fiction written in English is roughly analogous in intent and function; but Achebe's novels reflect the Ibo tradition of non-separation of art from other aspects...