Call me Ishmael, Moby-Dick begins, in one of the most recognizable opening lines in Western literature. The name has come to symbolize orphans, exiles, and social outcasts - in the opening paragraph of Moby-Dick, Ishmael tells the reader that he has turned to the sea out of a feeling of alienation from human society. Ishmael soon learns that Ahab has one purpose on this voyage: to seek out a specific whale-Moby Dick, a ferocious, enigmatic white sperm whale. In a previous encounter, the whale destroyed Ahab's boat and bit off his leg, which now drives Ahab to take revenge.