One of the critical themes that Twain explores is the role of wealth in modern society. When stripped of their external conditions, nothing really differentiates Tom and Edward. For all practical purposes, they are the same. However, when it comes to external reality, they are fundamentally different. Born on the same day, and looking exactly alike, there is no difference between them. However, when viewed by society, they are perceived as fundamentally different. Tom is a street urchin, unwanted and deemed without value and Edward is the coveted and protected prince. Their role reversal is indicative of how wealth and external conditions determine individual worth in the modern setting. In switching roles, Twain is making a statement about how human beings are defined by wealth and external reality in the modern setting.
Another theme that is evident in the novel is how human beings can take action. When Edward is placed in Offal Court and struggles in the "foul little pocket," he never quits insisting on his royal heritage. Edward never capitulates and never stops believing that he will be able to reclaim his rightful royal place. When he does regain his throne, he uses his power to right the wrongs that he saw in his time outside of the palace. Once aware of injustice in the world, Edward acts. Edward demonstrates Twain's theme of how individuals have the capacity to take action. Even in a world where there is institutional unfairness and a sense of injustice, individuals can take action. However, small it is and however it might be received, the capacity for individuals to exercise their autonomy is present in Edward's actions. This becomes a critical theme that is evident in the novel. The will to act and the ability for action to be taken are defining elements to Edward's characterization which help to feed the theme of human action in the novel.