But for literarily inclined members of my generation, the key text on sentimental education was Jeffrey Eugenides’s 2011 novel “The Marriage Plot.” Madeleine, the book’s 22-year-old heroine, meets her boyfriend, Leonard, in a semiotics seminar at Brown. Alert readers know this is not a good sign. The book is set in the 1980s; poststructuralism is all the rage. Naturally, the seminar’s syllabus is heavy on French theory — Derrida, Barthes — that “deconstructed the very notion of love.”

At the same time, Madeleine is writing an honors thesis under the tutelage of a professor who believes the novel reached its apogee in the 19th century, in the “marriage plot” fiction of Austen, Eliot and James, and has been in decline ever since, thanks to no-fault divorce, women’s lib and prenups — all symptoms of marriage’s demise as a meaningful institution.

Thus, as Madeleine embarks on a relationship with Leonard, she is on very shaky phenomenological ground. The narrative scripts and plotlines that have governed romance for centuries are under attack, and with nothing in the wings to replace them, a sense of impending crisis prevails. “The thing about desire is that there is no there there,” the semiotics professor solemnly opines.

As Madeleine and Leonard’s relationship develops, gathering substance and complication along with an erotic charge, Madeleine’s thoughts inevitably turn to the 19th-century fiction she knows so well: “There were all kinds of outmoded, novelistic words to describe how she was feeling, words like aflutter.” She’s smart enough not to say any of them aloud.

When, in a moment of physical abandon, she impulsively tells Leonard that she loves him, he responds by handing her a copy of Barthes’s “A Lover’s Discourse” open to a passage headed “I Love You.” Madeleine is ecstatic, but Leonard silently motions her to keep reading: “The figure refers not to the declaration of love, to the avowal, but to the repeated utterance of the love cry. …. Once the first avowal has been made, ‘I love you’ has no meaning whatsoever.”

The crisis is in full throes.

The question Eugenides set for himself with “The Marriage Plot” was not just academic — can the novel survive the death of the marriage plot? — but existential: Can love survive the death of the novel?

The answer he works out in his book is clever; there is a marriage and lots of love, but the marriage seems unlikely to last, and Eugenides seems determined to grant his characters freedom to construct their futures outside its constraints. Yet his ending is also ambiguous enough that it may leave some readers unsatisfied. (In this way, it is not so different from “The Portrait of a Lady,” whose conclusion famously leaves open the question of what Isabel, now apprised of her husband’s despicable behavior and bound for his home in Rome, will do once she gets there.)