In one of the play’s many instances of sharp social satire, Peachum comments on the irony of the relationship between criminals and the legal profession:
A Lawyer is an honest Employment, so is mine. Like me too he acts in a double Capacity, both against Rogues and for ’em; for ’tis but fitting that we should protect and encourage Cheats, since we live by them.
Looking through his Book of Accounts, in which he diligently records his finances, Peachum notes that he works in a “double Capacity.” Here, he references the two-fold nature of his occupation: first, he collects stolen items from criminals and sex workers, selling them for a profit. Second, he turns those same criminals in to the authorities, collecting the bounty on their heads. Cynically, he notes that he must "protect and encourage Cheats," since they are the source of his income, both through their criminal activity and through their bounties. Peachum, then, recognizes the situational irony of his scheme: he cooperates with the criminal justice system to punish thieves, but he's motivated only by profit and, in fact, must support those criminals until he turns them in.
Further, Peachum satirizes the legal profession, which he claims operates on a similar basis. Lawyers must prosecute criminals in court, fulfilling an essential role in the punishment of crime. And yet, at the same time, lawyers make their livelihoods through this work. Therefore, he claims that lawyers must in fact “encourage” the crime from which they profit. If there were no crime, he implies, then the lawyers would be out of work, as would Peachum himself. Peachum’s speech thus presents criminals and those who punish them as being two sides of the same coin, ultimately suggesting that they are in some way reliant upon one another.
In a short speech to Polly, Macheath hyperbolically satirizes the materialistic priorities of various classes of London society.
Is there any Power, any Force that could tear me from thee? You might sooner tear a Pension out of the Hands of a Courtier, a Fee from a Lawyer, a pretty Woman from a Looking-glass, or any Woman from Quadrille.—But to tear me from thee is impossible!
This scene is Macheath’s introduction to the stage, and his flattering, ingratiating speech proves that he has earned his reputation as a wily figure. He assures Polly that he has remained faithful to her in his absence, insisting in a hyperbole that it would be “impossible” for “any Power” or “Force” to separate him from her. He is lying—he has no intention of marrying Polly and has made similar promises to no fewer than eight other women—but at this moment it is important for him to stay in her good graces in order to gain information about her father, Peachum.
In his attempt to reassure Polly, Macheath satirizes various classes in London society, demonstrating his cynical understanding of political corruption and human vanity. He insists that he could no more tear himself away from Polly than someone could “tear a Pension out of the Hands of a Courtier,” mocking those figures in the London courts who sought funding and patronage from the wealthy. Next, he satirizes lawyers who could never be compelled to surrender a “fee,” attractive women who are attached to their “Looking-glass” or mirror, and any woman who above all else enjoys a “Quadrille” (a popular dance performed in courts). Macheath, then, indicates that these various groups of people are obsessed with materialistic concerns like money and fashion.
In conversation with Peachum’s servant and criminal apprentice, Filch, Lockit satirically alludes to a conventional figure of medieval romantic poetry and literature: the Knight Errant.
FILCH. One had need have the Constitution of a Horse to go thorough the Business.—Since the favourite Child-getter was disabled by a Mis-hap, I have pick’d up a little Money by helping the Ladies to a Pregnancy against their being call’d down to Sentence.—But if a Man cannot get an honest Livelyhood any easier way, I am sure, ’tis what I can’t undertake for another Session.
LOCKIT. Truly, if that great Man should tip off, ’twould be an irreparable Loss. The Vigor and Prowess of a Knight-Errant never sav’d half the Ladies in Distress that he hath done.—But, Boy, can’st thou tell me where thy Master is to be found?
Here, Filch and Lockit discuss the legal convention by which women could “plead their belly,” or, in other words, avoid execution if they could prove they were pregnant. Filch notes that he has in the past arranged to save various women, perhaps on behalf of Peachum, by hiring a “Child-getter” to impregnate female criminals. However, this man has since been “disabled by a Mis-hap,” likely venereal disease. In his absence, Filch himself has had to assume the duties of the former "Child-getter," a task that requires “the Constitution of a Horse.”
Lockit acknowledges the value of the former Child-Getter, whom he claims saved more “Ladies in Distress” than any “Knight-Errant.” In popular literature of the medieval period, the knight-errant was a common character type: a wandering knight who would be expected to perform brave, chivalrous acts such as defeating monsters and saving maidens from villains. Lockit’s allusion to the figure of the knight-errant is satirical: a man who is employed to impregnate women before they go to trial can hardly be thought of as conventionally chivalrous. This allusion, then, satirizes London of the early 18th century, suggesting that the “Child-Getter” is that vice-filled era’s equivalent to the brave knight.
Having spent much of the play scheming to save his own life, Macheath is surprisingly calm upon being sentenced to death. His short passage of sung verse satirizes the mores of 18th-century British society, implying that embracing death is easier than trying to make an honest living in the world.
The Charge is prepar’d;
The Lawyers are met,
The Judges all rang’d (a terrible Show!)
I go, undismay’d.—For Death is a Debt,
A Debt on demand.—So, take what I owe.
Then farewell, my Love—Dear Charmers, adieu.
Contented I die—’Tis the better for you.
Here ends all Dispute the rest of our Lives.
For this way at once I please all my Wives.
First, Macheath satirizes the criminal justice system, comparing it to an unsatisfactory theatrical performance, or a “terrible Show.” Much as actors take to the stage after memorizing their lines and rehearsing their movements, the outcome of the case is already inevitable. Rather than determining the question of guilt in a fair and unbiased manner, then, the courts have already reached their verdict in advance of the trial. Next, Macheath identifies death as just one more “Debt” that a person accrues in life. Throughout The Beggar’s Opera, characters have been forced to resort to unscrupulous and illegal means to pay off the debts that seem to be an inevitable part of life in London, so presenting death as a form of debt mockingly fits into this unfortunate societal framework.
Before his scheduled execution, Macheath gets drunk in jail and sings a short verse that bitterly satirizes the different treatment of the rich and poor by the law:
Since Laws were made for ev’ry Degree,
To curb Vice in others, as well as me,
I wonder we han’t better Company,
Upon Tyburn Tree!
But Gold from Law can take out the Sting;
And if rich Men like us were to swing,
’Twou’d thin the Land, such Numbers to string
Upon Tyburn Tree!
Macheath notes that the original intention of the law is to “curb Vice” and that the law should apply equally to “ev’ry Degree,” or every class of man, regardless of whether or not they're rich or poor. Given that the law should not make distinctions between men of different classes, Macheath notes that there should be “better Company” alongside him at the hangman’s noose. Bitterly, he notes that “Gold” can “take out the Sting” of the law—in other words, those with money are able to avoid serious punishment. Ultimately, he concludes that there would be almost nobody left in Britain if the rich were, like the poor, executed for their crimes. His short song offers a biting satire of the legal system, as well as the prevalence of crime across all classes of British society.