Martin Amis wonders if pornography is ruining your life.

The excellent thing about having a small penis—a real “cashew,” as the tabloid journalist Clint Smoker puts it in Martin Amis’ new novel Yellow Dog—is “the likelihood of anal bliss, increased access to the tradesmen’s entrance being something the smaller bloke could legitimately expect.” Clint discovers this at the San Sebastiano Academy for Men of Compact Intromission. That’s where he retreats after neither the erection drug Potentium nor a treatment called “His Voluminousness” nor a toolshed’s worth of penile-growth gadgetry succeeds in solving Clint’s problem: that he is a “crap fuck”—at least if the unanimous opinion of the women he has dated is anything to go by.

Over the course of a decade that began in the mid-1980s, Amis wrote four of the best novels any writer of his age has churned out: Money (1984), London Fields (1990), Time’s Arrow (1991), and The Information (1995). Since then, he has been productive as a memoirist and nonfiction writer, but his only novel, Night Train (1997), was short and bad. Yellow Dog is a hard book to judge. On one hand, it is a convincing return to those big, bravura novels, with their black humor, intellectual complexity and Nabokovian wordplay, that he wrote in the Thatcher-Major years. But it is also—in the ethically deadpan way it constructs a world of pornography, incest, sexual violence, and child abuse—thoroughly repellent.

Yellow Dog is an achievement in its obscenity alone. It has four major subplots. Clint’s is the closest to what we can call, for the nonce, traditional sexual morality. Among the others:

1. The minor writer Alexander “Xan” Meo gets clubbed on the head in a cocktail bar and passes through a period of “post-traumatic satyriasis,” embarking on a bender of cruelty and nightmarish sexual fantasy.

2. Henry IX, the current king of England, is being blackmailed by gangsters who have used a secret camera to make a porn video of the crown princess Victoria. (Victoria, incidentally, is mulling a conversion to Islam.)

3. Karla White, a California porn star and victim of child abuse, hopes to avenge the damage done to her by ruining the life of another in turn—Xan, whom she assumes to be her first cousin once removed.

These plot lines are all set rolling by the same tragic flaw: the unsustainability of sexual equilibrium for your average male. Some of these men have more than the “right” level of virility, wrecking the order of the world. (The sinister English gangster Joseph Andrews says, “If I did have a regrettable habit, back then, it was that: giving me mates’ wives one.”) The others, more commonly, founder in impotence and onanism—like Clint himself, who is the book’s evangelist of masturbation. He is a maniac for pornography, too, writing movie reviews with passages like: “and have your bogroll handy for when gueststar Dork Bogarde pumps his lovepiss over the heaving norks of our very own Donna Strange.” What else is there to life?

It is Amis’ point that with the digital proliferation (and the widening cultural acceptance) of pornography, sexual equilibrium has become even more elusive. Pornography’s hidden viciousness is that it wreaks its worst damage on those who follow that most noble of precepts: “Know thyself.” Occasionally in Yellow Dog, sexual self-knowledge arrives as a form of unearned Augustinian grace, as it does for Henry IX, whose wretched sex life is so bad that it is unaffected when his wife suffers a riding accident that leaves her on life support. This opens up a position for his Chinese mistress He Zizhen, whose erotic ministrations turn “his collateral heart (so torpid, so workshy, so decidedly valetudinarian)” into “a length of towel rack.”

But those who reach this knowledge through porn are less lucky. The king’s assistant, Brendan “Bugger” Urquhart-Gordon, assumes he’s asexual until he watches a movie in which an actress tricked up to look like the pubescent princess is violated (“Brendan attended to the ordeal of his own arousal. You’d better hope that this doesn’t happen, he thought, when you’re watching the one about the oversexed undertaker, the coprophagic pigfarmer, the ladykilling ladykiller …”). Since much modern porno involves recherché sex acts and twisted relationships, men (it is always men) who are turned on by it are left with only two self-destructive choices: perversion, if they give in to their desires; self-deception, if they resist them. Porn-enhanced masturbation, as described here, is an actual addiction; for Clint’s sessions, the term “self-abuse” is not metaphorical:

He knew that the distance between himself and the world of women was getting greater. Each night, as he entered the Borgesian metropolis of electronic pornography—with its infinities, its immortalities—Clint was, in a sense, travelling towards women. But he was also travelling away from them.

As readers of Time’s Arrow will remember, Amis is at his most brilliant when exploiting paradoxes like these, those moments when life seems to make as much sense if it’s run backward or turned inside out. As when Karla White says of herself and other X-rated stars: “When we watch porno, we fast-forward through the sex to get to the acting.” Or when the gangster Joseph Andrews describes Britain’s postwar economy: “Things opened up beautifully after the war, with all the austerity.”

The major drama of Yellow Dog, involving Xan, centers on a more gruesome paradox: The way the world often rewards wanton abuse of power and leaves its victims unaware that they are even victims—in sex as in crime. This means impunity, which sparks a mimetic cycle of sin. Amis has in recent years been interested in child abuse, which shows up not just in certain eerie scenes in The Information but also in Experience (2001), where he described his own molestation at the hands of one of his parents’ houseguests in New Jersey. And in Yellow Dog, when a discombobulated Xan begins to worry about his daughters’ mortality, his thoughts travel in macabre directions. “I can’t protect them,” he thinks. “They’re mine, and I can’t protect them. So why not rend them? Why not rape them? … He thought he knew, now, why an animal would eat its young. To protect them—to put them back.” This is only the beginning of the hell that Xan’s mind becomes, as he begins to superimpose images of his daughters at play with the unnatural acts of pornography.

Amis has a deadly serious moral point to make here. But it is by no means certain that anyone will want to hang around to hear it. Pornography so suffuses the book that the narrative voice itself is never uncontaminated by it. (“As he climbed from the car a boobjob of a raindrop gutflopped on his baldspot.”) Every observation partakes of the solitude of pornography. Surely this spiritual claustrophobia is just what Amis means to evoke, and the way Amis manages to leach all moral sensibility out of the novel’s voice is an extraordinary technical achievement. But it is a self-defeating one. Yellow Dog is likely to be least endurable to those most sympathetic to Amis’ anguish. Since, in the world Amis creates, casual exposure to pornographic images puts people on a steep and slippery slope, one wonders what he thinks he’s doing in forcing such imagery on the reader. Amis’ subject matter so raises the stakes that this must be either a moral book or a dirty one. It winds up being both. The book is the equivalent of one of those partial-birth-abortion posters waved around at political conventions. It unleashes more than most intelligent readers can be expected to assimilate—and certainly more than any self-respecting reader should be asked to endure.