The play demonstrates the arbitrariness of values. Throughout, Peachum uses traditional moral stances, such making the characters quote the Bible, to justify exploitation and cruelty. Peachum takes biblical quotes and uses them for his own purposes, as in Act I, scene I, when he demands that Filch pay him because he will be given something in return. Peachum offers Filch a job in exchange for payment, but this job involves preying on people’s sympathies by pretending to be a beggar. Peachum is not charitable toward someone if said charity does not involve making money. But by reciting lines from the Bible, he appears as though he is helping others. Although biblical proverbs are associated with morality, it is clear that the characters are only interested in enriching themselves and not others when they quote the Bible. Peachum makes the same point about the law in Act III, scene I. Peachum proclaims his absolute devotion to obeying the law, but only because he knows that it is a useful tool for helping him exploit those weaker than him. In each of these situations, a traditional moral value (religiosity, obeying the law) is shown to be a mask for exploitation. Brecht’s point is that the foundations of society’s supposedly rigid moral values are in fact made of nothing and appear less noble beneath the surface.
Macheath’s actions present this theme from a different angle. Macheath’s middle-class aspirations embody another set of values: the belief in upward mobility and economic progress. Traditionally, these values are associated with a progression toward power and responsibility. Macheath wants to leave his life of crime, put his money into a bank, and acquire the trappings of middle-class life like quality furniture, tableware, and manners. Despite wanting to leave crime, Macheath has no intention, though, of changing his values. He steals the domestic niceties he desires, continues to visit the whorehouse even though he is married, and plans to betray his friends to make it easier to stay on the right path. By showing Macheath’s desire for economic legitimacy as completely unconnected to any change, Brecht reveals that although Macheath may plan to leave his life of crime for a safer profession, his values will remain unchanged.
In the finale to Act II, moral values are emphasized when Macheath and Jenny sing the “Second Threepenny-Final.” In the song, they sing that before moralists go preaching about personal behavior, they should make sure that everyone has food to eat. Morality is a tool of the rich and powerful to maintain their positions. For the lower-class citizens, survival has to come before morals. Brecht’s point, therefore, is not to replace one set of hollow moral values with another. Instead, he emphasizes the focus on the wellbeing of society’s poorest.
Many of the characters’ decisions create a conflict between self-interest and love. In a capitalist society in which competition rewards ruthlessness and brutality, the characters are forced to trample on each other to survive. In The Threepenny Opera, characters make decisions not based on psychology but on the need or desire for material things such as money. Every action that furthers the plot in The Threepenny Opera is based on a character pursuing self-interest. Peachum decides to bring down Macheath because losing his daughter will hurt his business, not because he fears for her life in the hands of a criminal. He does not consider Polly’s feelings for Macheath or care that she loves him; his business concerns motivate him to destroy their marriage. Jenny turns in Macheath because she needs the money, not because she hates him for abusing her. Instead of showing loyalty to his friend, Brown agrees to capture Macheath because he is afraid of Peachum’s beggars disrupting the queen’s coronation. Polly is the only character who acts out of love and not self-interest. She truly loves Macheath, so she is willing to do anything to help him. Her sweet nature turns to toughness when she must take over Macheath’s business, but her love for Macheath never diminishes even when he betrays her and tells Lucy that Polly is not his wife.
The setting of the play amidst prostitutes, beggars, and thieves emphasizes the competitiveness of the capitalist system. In The Threepenny Opera, Brecht argues that a capitalist system drives people to do anything to make money. They steal, kill, and sell their bodies, and none of these actions is out of the ordinary. These activities will arise naturally because the characters live in a system that rewards ruthless competition. For example, Macheath plans to steal the money he owes his friends so he can be successful in banking. He clearly wants to get ahead in the world and does not care who he leaves behind in the process. Jenny lets Macheath sleep with her even though he physically abused her in the past; she gives her body to Macheath in exchange for money. Another example is Peachum, who creates fake beggars that are better than the real thing to draw income from the guilty middle and upper classes. Essentially, he sells pity, and he steals from the public by allowing fake beggars to roam the streets. As an entrepreneur who sells an emotion, Peachum makes the competitiveness of the capitalist system more concrete.
The characters make decisions throughout the play that display their brutality toward one another. According to the play, in a capitalist society, exploitation is not a byproduct of the system but a natural part of it. People like Peachum who know how to use the rules of society to their advantage are rewarded for their cruelty. Macheath demonstrates this brutality that underlies society. Macheath is a vicious criminal, but rather than reprimand him or make him guilt-ridden over his crimes, Brecht puts Macheath’s criminality in context by comparing his crimes to those of banks and businesses. Those institutions do far more harm than Macheath does because they exploit the poor and workers. Macheath’s decision to pursue banking is ironic because in this industry he will be crueler and more evil than he was as a criminal. From this perspective, Macheath is not such a menace to society but just part of it like everyone else. Brecht emphasizes that if capitalism is society’s guiding principle, then even criminals should be accepted.