Barbara reappears with her father and introduces him as a Secularist. Startled, Undershaft corrects her and says that being a millionaire is his faith. When Shirley declares that he is proud to not be one, Undershaft replies gravely that poverty is nothing of which he should be proud. Barbara asks Shirley to lend a hand in the shelter. He notes bitterly that he must as he is in their debt; Barbara retorts that he must "for the love of them."
Under Undershaft's watch, Barbara continues her assault on Bill. He must join them and "brave manhood on earth and eternal glory in heaven." Just as Bill is about to break down, a drum is heard in the shelter, and Cusins enters. Bill resolves to go to Canningtown and give Mog a good beating and departs.
Barbara returns to her work, leaving Cusins to explain the shelter to her father. Presenting himself as a "collector of religions," Cusins asks into Undershaft's faith. Undershaft believes that two things are necessary to salvation: Money and Gunpowder. Love, truth, mercy, honor, justice, and onward are the graces of a "rich, strong, and safe life." Cusins warns that Barbara cannot endure his dogma.
Undershaft replies that Barbara will soon discover that Cusins himself carries a hollow drum in his own beliefs. Cusins protests his faith and the Army makes men and women out of wasters and worms. It has revealed the "true worship of Dionysus" to the Greek scholar, sending him into the street "drumming dithyrambs." Cusins plays a flourish on the drum. From his own translation of Euripides's The Bacchae, he states that he who knows that "to live is happy" has "found his heaven." Before the Eternal, "Barbara" or "Loveliness" will be loved forever. Undershaft asks if Cusins considers himself a good match for his daughter. With polite obstinacy, Cusins responds that while he fears marriage intensely, he always gets what he feels he must have. He will not stick to the conversion of the Army to Dionysus, as the pathfinder of salvation matters little to him. Undershaft and Cusins shake hands.
Undershaft then talk about how the two of them must win Barbara. Both know that Barbara's power comes not from any doctrine but her own "inspiration." Undershaft intends to give her the business so she can preach his gospel. Cusins remarks that he is mad—a "Father Colossus—Mammoth Millionaire." Reeling with excitement, Undershaft declares Cusins and Barbara mad as well. The millionaire, poet, and savior have no truck with the common mob.
When Cusins protests that he and his fiancée love the people, Undershaft scoffs at their romanticism. Let the poor pretend their poverty is a blessing. Only people who stand above them such as they can help their children rise to their level. Cusins is certain that Undershaft cannot win Barbara. Undershaft replies that he should not underestimate the power of his wealth; thus he will buy the Army. Indeed, the Army serves his interests, keeping the workers sober, domesticated, focused on heaven rather than unions and socialism, and onward. Cusins is overwhelmed.
The exchange between Cusins and Undershaft begins the full elaboration of what Shaw dubs in the play's preface the "gospel of Saint Andrew" and Cusins's conversion to this dogma. As Shaw observes with dismay in the preface, many critics have tended to identify too readily these discussions as having Nietzsche's ideas in their subject matter. We should note that the apparent similarities between, for example, Nietzsche's superman and Undershaft's mad one or the Dionysian and Cusins's worship of Dionysus not self-evident and that any discussion of the two authors demands the careful examination of both bodies of work.
In the men's tête-à-tête, Undershaft poses the existence of great, mad figures who stand above the herd, such as the millionaire, poet, and savior, or himself, Cusins, and Barbara. Only these inspired madmen determine the course of the world, controlling life and death itself.
Declaring his fatherly love, Undershaft claims alliance with Cusins and insists that they must win Barbara. She is his heir, the daughter who would carry forth the Undershaft's gospel in his wake. As we will see, however, it is the father's coeval, Cusins, who will ultimately become Undershaft's true heir, becoming the foundling who assumes the company name and, unlike the earnest Barbara, is "in" on all of the calculating father's machinations. Note how Barbara figures as a jointly owned commodity of sorts that binds the two men together. Cusins casts her as a possession he must have. Later, Undershaft will twin her with his ducats.
For Undershaft, none of the trio needs to work under the sign of Salvation Army. He knows that Barbara's greatness does not come from some doctrine, whether the Army's or otherwise, but from her inspiration. The army is only her instrument.
Undershaft also knows that Cusins—self-described as a "collector of religions"—does not believe in the Army either but uses it the drum for his poetry, as a means of bringing ecstasy to the masses. Cusins is a worshipper of Dionysus, the Greek god of wine and deity of excess, annihilation, and ecstasy. Through the Army, he would bring Dionysus's poetry into the street, where it serves as a "pathfinder of salvation." As a student of Euripides, the most famous democrats of the Greek tragedians, Cusins ostensibly does this work for the love for the people. Part of the perversity of the play's conclusion will lie in Cusins's reconciliation of this love with his decision to join the Undershaft firm.
In contrast, Undershaft has no love for the people themselves. He does cling, however, to the redemption of society. As he scandalously declares, in the gospel of the millionaire, this redemption is contingent on Money and Gunpowder. All social goods are contingent on the "rich, strong, and safe" life only a millionaire can provide. Undershaft will reveal the extent of the millionaire's power in purchasing the Army in the following scene and thus robbing Barbara of Bill's soul. Indeed, as he tells Cusins, the Army already serves his interests, colluding in the domestication of the masses that keeps him in power.
With Undershaft's gospel in mind, the name of his partner, Lazarus, comes to refer ironically to the biblical parable of the rich and poor. Lazarus (Luke XVI) is the virtuous beggar who lies suffering and neglected at a rich man's gate. Upon both their deaths, the rich man, parching in hell, pleads in vain that Lazarus, now happy in heaven, be permitted to give him a cooling drink. This parable would console the poor in their immediate suffering. While they may suffer in this world at the hands of the wealthy, the tables will be turned in the afterlife. The poor are virtuous and the rich decidedly wicked. Within the gospel of the millionaire, poverty is no virtue. Moreover, the inspired millionaire figures as savior rather than sinner. Again, only the millionaire can rescue men from their wretchedness and redeem their lives.