Editor's note: April Alliston is a Guggenheim fellow and professor of Comparative Literature at Princeton University. She has written several books on 18th-century women's novels and is working on a book about the novel's focus on the control of women's sexuality, then and now. Susan Greenfield, associate professor of English at Fordham University, has published books and articles on the early novel; she also writes fiction. This commentary was written in association with The Op-Ed Project.
(CNN) -- There is nothing new under the sun, the saying goes, and it could not be more true than with the recycled literature of the popular "mommy porn" trilogy "Fifty Shades of Grey."
Just this week, Universal Pictures acquired the movie rights to the bodice ripper for reportedly more than $5 million as traditional publisher Knopf/Vintage promises to turn the book, which has been sold mainly as an e-book, into a paperback version with a 750,000 copy print release next month.
However hot the property appears, the plot and devices are centuries old, leading us to wonder whether the commercial success signals a breakthrough in women's sexual freedom or a new low in women's debasement.
The novel tells the story of Anastasia Steele, who finishes college by losing her virginity to billionaire Christian Grey, becoming his "submissive" in a sadomasochistic relationship. The e-book version of the trilogy has gone viral with mature women readers, even as critics have denounced the book's reactionary gender politics.
Neither extreme explains the novel's compelling relevance.
Though no literary masterpiece, "Fifty Shades" is more than parasitic fan fiction based on the recent "Twilight" vampire series.
Its abundant references to classic literature unlock a subtler commentary on enduring obstacles to women's individual freedom and rights. Whenever power relations are unequal, the novel implies, sexual consent is never black and white: It is always fifty shades of gray. Paying attention to its literary signposts shows what has changed for women in that regard and what has not.
When "Fifty Shades" begins, the heroine's favorite pastime is to curl up with a good book, not a whip. After the hero asks her to sign a contract defining her role as his submissive, she tells the reader, "[Austen's] Elizabeth Bennet would be outraged, [Bronte's] Jane Eyre too frightened and [Hardy's] Tess would succumb, just as I have."
Insistent references like this remind us that "Fifty Shades" is recycling the classic novel plot about a vulnerable young woman and a brooding older man. The hero has the lion's share of socioeconomic power; the heroine has only her magnetic strength and intelligence.
The classic plot promises that by steeling her virginity and holding out for marriage, women can achieve intellectual equality and love. Those who fail come to bad ends, but the victorious novel heroine learns the hero's secrets and gains ownership of his heart and true self. This last is exactly the fantasy that "Fifty Shades" sells.
There is nothing new either about this plot's association with pornographic whips and chains.
Alongside the genre of the novel, the 18th century saw the emergence of modern pornography, from John Cleland's "Fanny Hill," to works by the Marquis de Sade, whom Christian Grey imitates as a confessed "sadist." Gothic horror novels, which specialized in sadomasochistic innuendo and supernatural phenomena, were also sensationally popular. The whip and the vampire emerged in tandem with the marriage plot and chick lit.
Christian gives Anastasia an app for all the 18th- and 19th-century novels in the British Library, but he also presents her a $14,000 first edition of Thomas Hardy's "Tess of the D'Urbervilles." The still-disputed question Tess poses concerns whether the heroine is raped or seduced.
Though Anastasia Steele is never raped, her individual agency is equally ambiguous.
She refuses to sign Christian's contract, but she lets him spank, whip, chain and blindfold her for the remainder of the trilogy. When the debasement gets too extreme, she walks away (like Jane Eyre upon discovering Rochester's bigamy).
Yet she returns, echoing Tess: "The physical pain you inflicted was not as bad as the pain of losing you." Throughout, her self-punishing "subconscious" drives her away from Christian, while her libidinous "inner goddess" makes her dread losing him. If she doesn't submit, she will have only her books.
In exchange for her masochistic submission, Anastasia receives an infinite array of explosive orgasms and Christian's love and protection.
Sadistic Christian always uses a condom, never uses porn and always puts her pleasure first. He loves, cherishes, provides and above all uses his power to protect Anastasia -- all while gradually opening up to her, making himself psychologically vulnerable.
SPOILER ALERT: It turns out that he is a sadist because he was once victimized by older women. Lest you think women are unequal, the novel emphasizes the hero's ultimate powerlessness.
No wonder female readers are falling for this story. When the story was first popularized in the 18th century, women had virtually no individual rights. They could not vote, could rarely own property and were themselves seen as property -- so much so that if a wife had an extramarital affair, a husband could sue her lover for damages.
Though many things have changed, women remain economically disadvantaged, are far more likely to be violated than titillated by the porn industry and are publicly called "sluts" for demanding insurance coverage for birth control.
The enduring appeal of a plot like that of "Fifty Shades" suggests that even in 2012, most women cannot imagine how such inequality might disappear. Instead they clamor for the delusion that submission to men's greater power means being taken care of by them.
Of course, pornography can be seductive, and "Fifty Shades" is hot. Less enjoyable is the undercurrent about women's lack of rights.
Christian tells Anastasia, "You need to free your mind and listen to your body."
But to what extent can women enjoy free play in a country where those going by the name of "Christian" mount legislation forcing them to bear children conceived in rape? When poor young women like Christian's "crack whore" mother are denied access to birth control? By enjoying a porn of their own, women can at least indulge the fantasy that their pleasure comes first even as politicians are devising new forms of punishment.
Follow us on Twitter: @CNNOpinion
Join us at Facebook/CNNOpinion
The opinions expressed in this commentary are solely those of April Alliston and Susan Celia Greenfield.