MODERN READERS will naturally wonder how Marcus was able to accomplish this feat, how he was able to overcome his disgust for his fellow humans and work on their behalf. Part of the reason we marvel at Marcus’s accomplishment is that we have a different notion of duty than he did. What motivates most of us to do our duty is the fear that we will be punished—perhaps by God, our government, or our employer—if we don’t. What motivated Marcus to do his duty, though, was not fear of punishment but the prospect of a reward.
