Oliver's relationship to duty goes back to his grandfather Nathaniel Alden who seems to only do things out of a sense of duty. It is stated in the opening scene "If he Alden went out at all it was to perform some duty, such as to ascertain the state of his financial affairs." Peter is more inclined to be a free spirit and involve himself with pleasurable things. This gets him into trouble with his older sibling and is the catalyst for Peter's adventures around the world. It is also important to note how Nathaniel feels about interacting with others. He sees this as nothing more than mere gossip, and the pleasantries of conversation are nothing more than staged mechanical mannerisms. We see this when both Peter and Nathaniel attend one of the Unitarian Church services. When Nathaniel is interacting with the others, you get the distinct feeling that he only does so out of duty.