What is the major theme?

This book begins and ends with remorse, Erasmus' remorse. He regrets his feelings of irritation towards his father, because he does not realize how soon his father would die. At the end of the story, Erasmus regrets allowing Paris, the cousin he has so strongly detested, to die, because he realizes how wrong he has been about the man. Throughout the story various characters feel remorse, Paris for the death of his wife and for his pride, Calley for deserting Deakin, Sullivan for playing in the tavern and protecting his friend.