She was right about the warning, wrong about the outcome. As she foretold, pornography did breach the dike that separated a marginal, adult, private pursuit from the mainstream public arena. The whole world, post-Internet, did become pornographized. Young men and women are indeed being taught what sex is, how it looks, what its etiquette and expectations are, by pornographic training—and this is having a huge effect on how they interact.

But the effect is not making men into raving beasts. On the contrary: The onslaught of porn is responsible for deadening male libido in relation to real women, and leading men to see fewer and fewer women as “porn-worthy.” Far from having to fend off porn-crazed young men, young women are worrying that as mere flesh and blood, they can scarcely get, let alone hold, their attention.

Here is what young women tell me on college campuses when the subject comes up: They can’t compete, and they know it. For how can a real woman—with pores and her own breasts and even sexual needs of her own (let alone with speech that goes beyond “More, more, you big stud!”)—possibly compete with a cybervision of perfection, downloadable and extinguishable at will, who comes, so to speak, utterly submissive and tailored to the consumer’s least specification?

For most of human history, erotic images have been reflections of, or celebrations of, or substitutes for, real naked women. For the first time in human history, the images’ power and allure have supplanted that of real naked women. Today, real naked women are just bad porn.

For two decades, I have watched young women experience the continual “mission creep” of how pornography—and now Internet pornography—has lowered their sense of their own sexual value and their actual sexual value. When I came of age in the seventies, it was still pretty cool to be able to offer a young man the actual presence of a naked, willing young woman. There were more young men who wanted to be with naked women than there were naked women on the market. If there was nothing actively alarming about you, you could get a pretty enthusiastic response by just showing up. Your boyfriend may have seen Playboy, but hey, you could move, you were warm, you were real. Thirty years ago, simple lovemaking was considered erotic in the pornography that entered mainstream consciousness: When Behind the Green Door first opened, clumsy, earnest, missionary-position intercourse was still considered to be a huge turn-on.

Well, I am 40, and mine is the last female generation to experience that sense of sexual confidence and security in what we had to offer. Our younger sisters had to compete with video porn in the eighties and nineties, when intercourse was not hot enough. Now you have to offer—or flirtatiously suggest—the lesbian scene, the ejaculate-in-the-face scene. Being naked is not enough; you have to be buff, be tan with no tan lines, have the surgically hoisted breasts and the Brazilian bikini wax—just like porn stars. (In my gym, the 40-year-old women have adult pubic hair; the twentysomethings have all been trimmed and styled.) Pornography is addictive; the baseline gets ratcheted up. By the new millennium, a vagina—which, by the way, used to have a pretty high “exchange value,” as Marxist economists would say—wasn’t enough; it barely registered on the thrill scale. All mainstream porn—and certainly the Internet—made routine use of all available female orifices.

The porn loop is de rigueur, no longer outside the pale; starlets in tabloids boast of learning to strip from professionals; the “cool girls” go with guys to the strip clubs, and even ask for lap dances; college girls are expected to tease guys at keg parties with lesbian kisses à la Britney and Madonna.

But does all this sexual imagery in the air mean that sex has been liberated—or is it the case that the relationship between the multi-billion-dollar porn industry, compulsiveness, and sexual appetite has become like the relationship between agribusiness, processed foods, supersize portions, and obesity? If your appetite is stimulated and fed by poor-quality material, it takes more junk to fill you up. People are not closer because of porn but further apart; people are not more turned on in their daily lives but less so.

The young women who talk to me on campuses about the effect of pornography on their intimate lives speak of feeling that they can never measure up, that they can never ask for what they want; and that if they do not offer what porn offers, they cannot expect to hold a guy. The young men talk about what it is like to grow up learning about sex from porn, and how it is not helpful to them in trying to figure out how to be with a real woman. Mostly, when I ask about loneliness, a deep, sad silence descends on audiences of young men and young women alike. They know they are lonely together, even when conjoined, and that this imagery is a big part of that loneliness. What they don’t know is how to get out, how to find each other again erotically, face-to-face.

So Dworkin was right that pornography is compulsive, but she was wrong in thinking it would make men more rapacious. A whole generation of men are less able to connect erotically to women—and ultimately less libidinous.

The reason to turn off the porn might become, to thoughtful people, not a moral one but, in a way, a physical- and emotional-health one; you might want to rethink your constant access to porn in the same way that, if you want to be an athlete, you rethink your smoking. The evidence is in: Greater supply of the stimulant equals diminished capacity.

After all, pornography works in the most basic of ways on the brain: It is Pavlovian. An orgasm is one of the biggest reinforcers imaginable. If you associate orgasm with your wife, a kiss, a scent, a body, that is what, over time, will turn you on; if you open your focus to an endless stream of ever-more-transgressive images of cybersex slaves, that is what it will take to turn you on. The ubiquity of sexual images does not free eros but dilutes it.

Other cultures know this. I am not advocating a return to the days of hiding female sexuality, but I am noting that the power and charge of sex are maintained when there is some sacredness to it, when it is not on tap all the time. In many more traditional cultures, it is not prudery that leads them to discourage men from looking at pornography. It is, rather, because these cultures understand male sexuality and what it takes to keep men and women turned on to one another over time—to help men, in particular, to, as the Old Testament puts it, “rejoice with the wife of thy youth; let her breasts satisfy thee at all times.” These cultures urge men not to look at porn because they know that a powerful erotic bond between parents is a key element of a strong family.

And feminists have misunderstood many of these prohibitions.

I will never forget a visit I made to Ilana, an old friend who had become an Orthodox Jew in Jerusalem. When I saw her again, she had abandoned her jeans and T-shirts for long skirts and a head scarf. I could not get over it. Ilana has waist-length, wild and curly golden-blonde hair. “Can’t I even see your hair?” I asked, trying to find my old friend in there. “No,” she demurred quietly. “Only my husband,” she said with a calm sexual confidence, “ever gets to see my hair.”

When she showed me her little house in a settlement on a hill, and I saw the bedroom, draped in Middle Eastern embroideries, that she shares only with her husband—the kids are not allowed—the sexual intensity in the air was archaic, overwhelming. It was private. It was a feeling of erotic intensity deeper than any I have ever picked up between secular couples in the liberated West. And I thought: Our husbands see naked women all day—in Times Square if not on the Net. Her husband never even sees another woman’s hair.

She must feel, I thought, so hot.

Compare that steaminess with a conversation I had at Northwestern, after I had talked about the effect of porn on relationships. “Why have sex right away?” a boy with tousled hair and Bambi eyes was explaining. “Things are always a little tense and uncomfortable when you just start seeing someone,” he said. “I prefer to have sex right away just to get it over with. You know it’s going to happen anyway, and it gets rid of the tension.”

“Isn’t the tension kind of fun?” I asked. “Doesn’t that also get rid of the mystery?”

“Mystery?” He looked at me blankly. And then, without hesitating, he replied: “I don’t know what you’re talking about. Sex has no mystery.”