Civility
The Lapham and Corey family are families of near or equivalent wealth. Even so, the Coreys identify themselves as a different type of family and hold themselves in higher esteem than the Laphams because of one thing—their civility. However, for a novel that centers on civility, decorum, and the right way for civilized people to act in society, there is a large amount of uncivil behavior on the Coreys' part.
For example, the Coreys pride themselves on being civilized individuals, yet they constantly criticize and belittle the Laphams for not consuming the right media, spending their money well, or being part of any fashionable clubs. This criticism of another’s lifestyle is itself rather uncivil. This behavior occurs time and again throughout the novel, most notably when Anna, Bromfield, and their daughters plan a dinner party in order to dissuade Tom from his fixation on the Laphams.
This in itself also leads Silas to make a desperate attempt at civility. Before the Corey dinner party, he reads many etiquette books on what to wear to such an occasion. Despite trying extremely hard to be civilized in appearance and manner, such as by not refusing any food or drink, Silas ends up being extremely uncivilized, getting louder and more intoxicated as the night continues.
Thus, while many characters in The Rise of Silas Lapham make claims to civility, very few manage to convincingly behave in a civilized and honest manner.
Money
This particular irony also focuses on the differences between the Laphams and Coreys. Again, the Laphams and the Coreys seem to possess a similar amount of wealth, which might lead one to think that they would belong to the same social class. However, this novel, as a comedy of manners set in Gilded Age America, is very conscious of the stark and ironic divide between new and old money. While the money earned by the Laphams comes honestly, from belief and effort invested in a business venture, the Coreys' money is earned through colonial exploitation and then mooched off for generations. Ironically, however, the money that the Coreys count on is perceived widely to be more honest and worthwhile than the fortune that Silas earns for himself.
Howells portrays this attitude towards old money as ironic not only in the dialogue of Bromfield Corey (who seems to unwittingly make his own life seem pathetic when he relishes in the fact that he has never had to work for a living), but also in the fact that so much of what is substantively the same between the Laphams and Coreys is put down by the latter party on account of the Lapahams' new money. One such example is the Laphams' cottage in Nantaket, which is seen as unfashionable when compared to the Coreys' vacation home in Bar Harbor. Ironically, to have money is not seen as enough of an equalizer in Gilded Age Boston society; one also needs to have the right background and know the right objects to spend it on.
The Beacon Street Fire
Just as Silas' acceleration towards bankruptcy begins, he thinks of selling the house on Beacon Street that he is building, even though he treasures it a great deal. When he cannot bring himself to do this, however, he tests a chimney in the house and enjoys it, but later, the house burns down. While this in itself is ironic, a greater irony is what happens in the aftermath of the fire. When Silas reports back to Persis that their new home has burned down, she worries that people will think that Silas burned it down on purpose to claim the insurance money and stave off bankruptcy. However, the insurance that Silas had on the property ran out just a week before, so he will recoup none of the money lost in the house fire. This irony is almost comic rather than situational or dramatic, and it is one of the final nails in the coffin of Silas' impending bankruptcy.
Tom Corey's Romantic Choices
Tom Corey is the son of Bromfield, an ambitiously rich father, and Anna, a snobbish and judgmental mother. It is therefore expected that Tom is as driven by money and public opinion as they are, and when it comes time for him to choose a wife, almost all assume that he will opt for an aesthetically pleasing young woman like Irene Lapham. Instead, Tom chooses the thoughtful, intelligent, and more aesthetically dull Penelope Lapham. There is irony in the difference between social expectations and Tom’s choices, which shock not just the Laphams but also his own family members.
However, there is also an additional irony to Tom's choices in courtship. Howells first introduces Tom as an intuitive, clever, and independent young man. Even so, he is oblivious to how Irene reacts to him throughout the novel, and he is also oblivious to the picture of their relationship that others imagined and took action towards. While Tom is, for example, able to notice that Irene is nervous and playing with wood shavings, he is unable to notice that she has feelings for him and focuses blindly on Penelope, the object of his affection.
Silas' "Rise"
That Howells titled his novel The Rise of Silas Lapham is itself a huge irony. Silas’ rise to money and power occurs before the start of the novel, when we are introduced to him bragging to Bartley Hubbard about his success. What the novel attests to then, is not so much Silas' rise but rather the circumstances that precipitate his fall from wealth and status. These include his and his family's misreading of the Tom Corey situation, his loaning of additional money to Mr. Rogers, and his ongoing support of Zerilla Dewey and her mother. At the same time, however, while the novel serves as a testament to Silas' financial ruination, it also serves as a chronicle of a kind of spiritual rise, from the lows of dubious business to the highs he reaches after going bust and returning to his country home. Ironically, it is the very fall from riches that facilitates his eventual spiritual rebirth and rise.
