The act begins with Sir Robert and Lord Goring in the Chiltern house discussing how to manage the crisis put in action the preceding night. Goring appears somewhat unsettled by Chiltern's moral failure and urges him to tell his wife the truth about his past as soon as possible. Robert, who kept the secret to maintain his wife's idealistic view of him, is concerned she will never forgive his impurity. Lord Goring, in a serious and weighted tone in stark contrast to the preceding act, still urges him to be honest and promises to talk with Lady Chiltern about the negative influence of expecting and accepting only perfection.
Chiltern tells Lord Goring about his history with Baron Arnheim and the circumstances of his ill-gotten fortune. Despite his name and family, Chiltern was poor while under the Baron's mentorship. As an impressionable young man, he took the Baron's advice about the importance of wealth and money to heart, and therefore took advantage of an opportunity to ensure his financial stability. Sir Robert vehemently says that his decision to sell government secrets to the Baron was an act of courage and not weakness. He also admits that he has not felt regret for it. Lord Goring expresses sorrow for his friend, but Sir Robert talks about how he paid his debt with his guilt, and by giving to charity. After hearing about Chiltern's past, Lord Goring responds with potential actions to take to quell the coming storm, and concludes he must fight against Mrs. Cheveley's blackmail. Chiltern aggress, but recoils at the thought of telling Lady Chiltern, saying that it would kill her love for him. At this point, Goring reveals that he and Mrs. Cheveley were once engaged. Sir Robert decides to write a letter to Vienna to investigate Mrs. Cheveley's life and dig out any scandals that might weaken her power against him. Goring reluctantly concedes this plan, but also explains that he believes Mrs. Cheveley would revel in a scandal rather than run from it.
Lady Chiltern then arrives from the Woman's Liberal Association, and asks Lord Goring to stay for tea. Lord Goring engages in a light banter with her about her bonnet. She leaves briefly, in which time Sir Robert gratefully thanks Lord Goring, but Lord Goring says he has not done anything for him yet. Sir Robert tells him that at the very least he has allowed him to tell the truth. When his wife returns he escapes by giving the excuse that he has letters to write.
Lord Goring and Lady Chiltern have an interesting conversation where Lord Goring becomes serious and talks with Lady Chiltern about the situation with Mrs. Cheveley. Lady Chiltern only knows that she tried to persuade Sir Robert to support her financial scheme, and she firmly believes it would be a stain on his character. Lord Goring discusses a hypothetical situation to test Lady Chiltern's understanding of her husband's true situation, but she cannot imagine him doing such a foolish thing. Lord Goring tells her that her views on life are quite hard and unforgiving of people's natural tendency to make mistakes. He explains that love is the only thing that can explain the world. Lady Chiltern asks Lord Goring if he is a pessimist, and he tells her that life must be lived with charity, and only through charity can life be understood. Finally, with intense seriousness of which Lady Chiltern takes note, he offers her help whenever she needs it.
Mabel arrives and proclaims that seriousness does not suit Lord Goring. He tells her that he must be leaving, which causes her to comment on his bad manners. They exchange light banter for several more minutes before Lord Goring finally leaves. Mabel asks Lady Chiltern to speak to Tommy Trafford for her, because he constantly proposes to her in awkward situations. Lady Chiltern responds by saying Tommy has a bright future, while Mabel claims she will never marry anyone with a bright future.
Lady Markby and Mrs. Cheveley arrive. Mabel starts to leave, but speaks with the two guests first. Lady Markby tells her that she is becoming very modern, which can be dangerous in that one might suddenly become out of date. Mabel leaves and Lady Markby tells Lady Chiltern they have come to find Mrs. Cheveley's diamond brooch, which she lost. As they wait for the Mason, Lady Markby comments that London has become over populated. The Mason arrives explaining that no bracelet has turned up overnight. The ladies wait for tea. Lady Markby makes a derogatory comment about the Higher Education of Women, and Lady Chiltern proclaims that she and her husband are great champions of women's rights.
They continue to discuss the education of men, their husbands, and the modern woman. Lady Markby declines tea and goes out for a short visit to a nearby friend. She leaves Lady Chiltern and Mrs. Cheveley together. Mrs. Cheveley comments that Lady Markby talks more but says less than anyone she has ever met. Lady Chiltern remains standing and coldly tells her that had she recognized Mrs. Cheveley from their schooldays she would never have invited her to her party the previous night. Mrs. Cheveley appears amused and notes Lady Chiltern has not changed. Mrs. Cheveley discovers that Lady Chiltern made Sir Robert write a letter revoking his promise to support her financial scheme and demands Sir Robert reverse his decision. Sir Robert enters the room, and Mrs. Cheveley angrily tells Lady Chiltern that Sir Robert is fraudulent and dishonest and sold a cabinet secret to a stockbroker to gain his fortune. Lady Chiltern asks Sir Robert if the story is true, and he orders Mrs. Cheveley from his house.
Lady Chiltern begs her husband to deny these accusations, but he does not, and moves towards her to console her. She warns him off, and cries out that he lied to the whole world but will not lie to her. She thrusts him off her, and in dismay wonders why she made him her ideal in life and worshipped him. Sir Robert passionately proclaims that this was her mistake, and one that all women make. He wonders aloud why all women cannot love men with all their faults. Why do they place their men on pedestals? In contrast, he says, men love women with their imperfections, and it is in all their imperfection that men need love. He tells his wife she has made a false idol of him, and he was not strong enough to show her his imperfections. Now, in losing her love she has ruined his life.
Lord Goring and Robert Chiltern agree that men do corrupt things everyday, but Lord Goring points out that is the reason why they are all so eager to expose one another, because it takes attention away from their own dishonesty. Sir Robert explains how his access to private information was nothing new, and that all modern fortunes are built on such information. Wilde understood the power of information from contemporary events, and throughout the plot, information (the letters), rather than money, is the source of power.
Once again Sir Robert references the idea of modernity, and how in this new age information leads to wealth and power. He tells Lord Goring about Baron Arnheim's formula for success in the modern day: wealth, which leads to domination. Ironically, Lord Goring who is the picture of a Victorian dandy and revels in the superficial aspects of life, disagrees with this theory. Wilde criticizes this philosophy throughout the play by effectively making wealth useless. Sir Robert cannot buy his way out of his predicament and Mrs. Cheveley laughs at the fact that he would even try. In the realm of the play, money has little power.
Sir Robert's primary concern is detection. He fears his wife will hate him and his career will be ruined. With frustration he asks Lord Goring whether a foolish mistake made in his youth should cost him so much. His corruption does not cause him any real sense of guilt or regret, and he justifies it by pointing out others who have done the same. He thanks Lord Goring for enabling him to tell the truth, but in reality he only tells it because he knows Lord Goring will not judge him for it. Thus, he is willing to face the truth only when there are no consequences attached. Sir Robert's words connect with Wilde's disdain for the lack of morality in contemporary society, especially the loose moral principles of politicians. One of the main themes of the play is society's moral corruption. Wilde criticizes the way characters gravitate towards material possessions, such as wealth, rather than cherishing the importance of kindness and love. Even Lady Chiltern, for all her moral sermons, is hypocritical, for she values Sir Robert's social status.
When Lady Chiltern enters the scene, and tells the two men she has been at a meeting for the Women's Liberal Association, Lord Goring mocks her and asks if they discussed bonnets. The question of a woman's role in society and marriage constantly arises, and Lord Goring clearly sees women's work as rather trivial. This scene engages with the topic of what a woman's proper role is within society and marriage, as does the discussion between Lady Markby, Lady Chiltern, and Mrs. Cheveley, when Lady Markby argues that the House of Commons is the worst thing to happen to marriage since the higher education of women. As a member of the more conservative part of London society, Lady Markby does not believe in the advancement of women, while Lady Chiltern, as a member of the Women's Liberal Association, clearly does. The differences between these two women, and Lady Chiltern's constant defense of women's rights and liberal values demonstrates that this new, modern perspective of a more independent woman was just beginning to gain strength in the Victorian era.
Lord Goring becomes quite serious in his conversation with Lady Chiltern, which is a contrast from his lighthearted behavior at the party the night before. After acting as a confidant and advisor to her husband, he acts as a teacher to Lady Chiltern, telling her that her views on life are rather harsh and she must understand that all people are flawed. Lady Chiltern says that she loves her husband, but really she adores the version of him that she has created - the Sir Robert who exemplifies the best of English life. If he must be perfect, how sincere can her love be? Lord Goring tells Lady Chiltern that it is love, and not German philosophy, that truly explains the world, and that one must live life with charity towards others. His speech ties together several themes that continually arise throughout the play, specifically that love and forgiveness must guide one through life. With this statement, the readers begin to see that the truth will come out and forgiveness will be necessary for the Chiltern marriage to survive.
Mabel's complaints about Tommy Trafford, who insistently and secretly proposes to her, provide a comic interlude, but also again discuss the notion of marriage. Mabel complains that she wouldn't find the whole process so frustrating if his statements had any kind of effect on the public. Apparently, it is not his proposals that bother her so much, but the way in which he proposes. She wishes his feelings were in the public domain, and believes only then they would be worth responding to. Mabel wants public intrusion in her life, while such public intrusion threatens to ruin Sir Robert's public career and his marriage.
The definition of love and marriage is at the heart of the action here. The lighthearted conversation of the first act is replaced by a more serious tone that analyzes and discusses the morality of human beings and why and how people should love each other. Lord Goring, who often carries the voice and opinions of the author, mocks Lady Chiltern's expectations of moral perfection. Lord Goring finds it a shame that Lady Chiltern cannot accept her husband, faults and all. This analysis of love supports the social values and gender inequality of the Victorian era. Sir Robert Chiltern argues that a man's love allows for faults and errors, while a woman's love is unforgiving and demanding of unattainable perfection. Although this analysis of love presents the image of the unyielding woman, the play will actually conclude with Lady Chiltern forgiving and supporting her husband. Thus, the play depicts the woman's role of a caregiver and supporter of her male counterparts, a classic Victorian perspective.
The climax of this act is Lady Chiltern's discovery of her husband's moral faults. She is shocked and sees a new person in her husband's skin, claiming, "what a mask you have been wearing all these years!" The images presented by all the party guests and the hosts the night prior are the pieces of themselves people want the public to see. With the revelation of Sir Robert's fallibility, this false image of perfection and the socially acceptable image are torn down. Now, the reader is left to wonder if Lady Chiltern will manage to overcome the reality of a husband who is imperfect. She must determine what true love means, and how to define an ideal marriage.