1. Moby-Dick features several characters who seem insane. How does insanity relate to this story? How do these characters contrast with one another?

One definition of insanity is "doing the same thing over and over again" and expecting a different outcome.  Obviously Captain Ahab has this problem, because he keeps hunting for Moby Dick and expects to triumph over him if he can only find him.  His obsession then affects other characters; for a moment, they believe in Ahab's vision when they see St. Elmo's Fire.  Yet, they cannot keep a straight mind in the face of his insanity.  Ultimately, Pip, the cabin boy goes insane and Queequeg appears to go insane as he prepares for his death in his own pagan rituals.