Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
Ironic, Nostalgic
The Age of Innocence has a love-hate relationship with its setting, 1870s New York. The narrative is frequently ironic, particularly when it comes to the characters and their prejudices. It tends to be super sarcastic about the more obviously hypocritical characters, such as Lawrence Lefferts, who is up on his high horse about chastity and family values most when he's trying to conceal an affair.
It also has an ironic take on the most self-important characters. Here's an example of the van der Luydens' understanding of their center-of-the-universe-ness:
"It had been represented to them that the disarray into which society had been thrown by this deplorable affair made their presence in town more necessary than ever. It was one of the occasions when, as Mrs. Archer put it, they "owed it to society" to show themselves at the Opera, and even to open their own doors." (32.2)
Check out those adjectives: deplorable, necessary. Check out those scary verbs: thrown, made, owed. Golly gee. This sounds like maybe police intervention is necessary. Or FEMA. Was it a flood? An arson? A homicide?
Oh. It's one man's financial woes? Seriously? And this is the kind of uber-dramatic response that is warranted?
The gulf between the (fairly minor) society events in The Age of Innocence and the pompous language used to describe them are what makes the tone so absolutlely ironic. This ironic tone lets us know just how self-important and insular the world of New York society was. Any society that believes that a couple of old people showing up at the opera will heal all wounds is, to put it lightly, pretty deluded.
And yet, The Age of Innocence can also wax nostalgic about the past. This is particularly evident when the novel wants to highlight the past as a time when people were honest and decent (despite the Lawrence Lefferts of the world); a time when New York City was still relatively undeveloped, and a certain kind of civic pride existed in society. Hints of this nostalgia pop up when the novel describes Central Park as a place where people took pleasant strolls to escape from urban life.
Old-fashioned NewYork dined at seven, and the habit of after-dinner calls, though derided in Archer's set, still generally prevailed. As the young man strolled up Fifth Avenue from Waverley Place, the long thorough fare was deserted but for a group of carriages standing before the Reggie Chiverses' (where there was a dinner for the Duke), and the occasional figure of an elderly gentleman in heavy overcoat and muffler ascending a brownstone doorstep and disappearing into a gas-lit hall. (12.1)
These strolls and after-dinner calls and carriages all sound so pleasant, don't they? Descriptions like this lull you into a false sense of nostalgic security… until the next of Wharton's ironic barbs gets you again.