The Pillars of Society is a four-act play written by Henrik Ibsen in 1877. The play opens in Consul Karsten Bernick's garden room, as the ladies of the town—Mrs. Bernick; Mrs. Holt and her daughter; Mrs. and Miss Rummel; Mrs. Lynge; Miss Martha Bernick and Dina Dorf—sit sewing. Also present are Rørlund and Olaf Bernick.

Aune, a shipbuilder, enters, explaining that he wishes to see the Consul. The Consul's clerk, Krap, tells Aune that he must leave; Krap also adds that Aune must stop lecturing workers about the introduction of machinery into Bernick's shipyard, the town's biggest employer. 

As the men argue, those in the garden room discuss a "moral" book schoolmaster Rørlund has been reading and contrast it to the "hollowness and rottenness" of society—specifically, the crew of an American ship, The Indian Girl, that has just moored in town. 

The company turns to the subject of trains. In the past, Bernick has managed to prevent a railroad from being placed in town, but Hilmar Tønnesen, Mrs. Bernick's cousin, reveals that the subject has resurfaced. As the group discusses morality and change, they recall when, years earlier, a group of actors came to town; the memory makes them all feel uneasy.

Mrs. Holt reveals that Mrs. Bernick's other brother, Johan, ran away to America with the acting troupe. Johan was found leaving Mrs. Dorf’s home through the attic window, and the scandal forced him to run away to America. Supposedly, Johan stole Bernicke’s mother's cashbox and took it with him. 

In his wake, Johan left disaster; Mrs. Dorf’s husband left her, and she later died. Johan’s step-sister, Lona Hessel, was spurned by Bernick, so she chose to leave for America as well. Like Johan, Lona is "a sun-spot in the Bernicks' happiness."

Mrs. Dorf’s daughter, Dina, came to live with Martha Bernick, Bernick's sister shortly thereafter. Like her mother, Dina believes herself to be "lapsed and lost.” Rørlund, however, disagrees and plans to marry her "when circumstances permit".

Bernick changes his stance on the railroad, realizing that it will not compete with his shipping business but will instead help it by supplying raw materials. Although he has resolved his worries about the railroad, his worries about The Indian Girl have not. The ship is unsafe, but its owners want it to get underway as soon as possible. Bernick knows he will make a lot of profit if he allows this but fears the consequences for the crew.

A group of Americans arrives in town—including Lona and Johan. Lona refuses to be shamed, saying she will "let in fresh air." Dina strikes up a friendship with Johan, to the discomfort of Mrs. Bernick, who resents the old scandal being stirred up just when her husband needs "unmixed good feeling" for his plans. Bernick tells Aune to have The Indian Girl ready to sail the day after tomorrow. If he doesn’t,  he will be fired.

Meanwhile, rumors swirl about Dina, who was seen in town with Johan and Lona, who are now rumored to be quite wealthy. Bernick intervenes, but his efforts backfire, revealing that he was the man seen escaping Mrs. Dorf’s house. Johan offered to cover for his brother-in-law to save his reputation; Consul Bernick agreed and began to spread rumors about Johan stealing the cashbox to worsen his reputation. Despite the betrayal, Johan agrees to keep Bernick’s secret. 

Martha tells Johan that Dina has never married because she has been waiting for him. He is surprised that she has, as she would not have known that the rumors of his misdoings were untrue; Martha explains that she...