Sartre, the world's second ugliest philosopher, tells us that: "Hell is other people." Unlike the world's ugliest philosopher, everyone's favorite wall-eyed Stalinist was not always precise. If you look closely at No Exit, the play in which this clever thesis gets tested, you'll find that hell is in fact housemates.

Other people won't do. Other people are often far away. Ah, but the guy who shares your house: if he's a nightmare, he's your nightmare. And you don't wake from this hell until you move out, or he does, or one of you commits suicide. Or murder.

Trading subhuman housemate anecdotes generally escalates into a competition, and it's one that I have never lost.

I'll call my cohabitant "Marcus." His real name, for what it's worth, is derived from the Gaelic for "crooked nose." And his joyous, willful flatulence in the kitchen was the least of his sins.

My encounter with London, then the capital of an otherwise pleasant nation, was a nasty business long before Marcus made the scene. This was not Cool Britannia. It was Thatcher's London, mid-eighties: the London of newly coined yuppies whooping it up in wine bars, of Cats and Les Mis. A place even Dickens would have found too dreary to put at the center of a novel.

Also, in Thatcher's England they did not have sex. My theory is that in order to perpetuate the species, they would cross the Channel to procreate in French hotels; certainly they did not have sex in London. And if they did have sex in London, it was not with colonials. All of this left me feeling very, very colonial.

I was studying architecture, and living near Hampstead Heath. The poet Keats had lived in my neighborhood, and had -- fortunately for him -- died before Marcus moved in. I was renting an apartment with another architecture student; her boyfriend would soon be joining us. "You'll like Marcus," she informed me. "He's very smart. And like you, he's interested in philosophy."

This described ninety per cent of the people I knew -- I had completed an MA in philosophy -- and at least two thirds of those people were insufferable. But I remained open.

One fine English day -- it was drizzling, and my clothes had been blackened per usual by rubbing up against ordinary bits of London -- I arrived to find Marcus sitting at a table in the tiny dining area in front of our kitchen. He had just come down from Glasgow, where he had met up with his girlfriend. (We'll call her Eve, after a famous woman who was seduced by a snake.)

My first impression was neutral. A smallish guy, with horn-rimmed glasses (an affectation, but I'm pro-affectation), and with a dour expression (fine, I'm okay by dour expressions). He did not look at me.

"Hi," I said cheerfully. I have decent manners. This is a custom worldwide, and has been for some centuries: the cheerful greeting. ("Salve," etc.) I don't remember if he responded. In retrospect, I don't think he did. Certainly he did not rise to shake my hand (another long-established tradition). "You must be Marcus. I guess you guys just got back from Glasgow. I've always wanted to go -- did you get to the Mackintosh art school?"

In response to this -- the fact that I knew, well, a fact about Glasgow -- he launched into an aggressive short history of the place. This with a sour insolent air; he did not meet my eyes. He had a high-pitched voice, for which he compensated, I imagined, by a sour insolent air.

I'm not one to judge people -- not immediately. So he knew some very interesting things about Glasgow. I'm always happy to learn new things about Glasgow. Yes, he delivered this spiel as if he had just read a guidebook on the train up, and had assiduously memorized every detail, but that was okay by me: I like guide books.

That night, however, judgment began to occur to me. We were walking through the Heath -- my first outing with my new housemate and his girlfriend -- and I mentioned that a Canadian writer was up for the Booker Prize: Robertson Davies had been nominated for a book I had just heard of called It's Bred in the Bone.

"The title is 'What's Bred in the Bone.'"

I shrugged. "Ah. 'What's Bred in the Bone.'"

"That is correct."

That is correct? Oh. My. God. And it was not just the phrase, which is noxious, but the sheer gradgrindery of the delivery: 'although you are unworthy, I have deigned to provide you with a fact.' Now, in general I like to be corrected; that's the way you learn. And people who hate to be corrected tend to be secretly insecure, intellectually, whereas I'm usually thought to be the opposite (especially by people who don't like me). But this statement, every syllable pronounced with careful high-pitched disdain, was an undeniable sign of the domestic harmony to come: my housemate, brilliant guy I'm going to like, is in fact a gruesome little pedant. At the time, I probably would have told you that the Gruesome Little Pedant was my least favorite kind of human being. Soon, however, I was moved to modify this hierarchy. The preening bespectacled dwarf is a relatively pleasant type, in my books, next to what Marcus proved to be. And it's not just the supercillious midget who farts with celebratory gusto in the kitchen. No, even this species I can now embrace with affection, with the proviso that they not share any further attributes with my housemate. Give me a stunted pedantic castrato who doesn't call his girlfriend "Whore," for instance, and I'll move in with him right now.

The Sartrean household is a familiar motif in art and literature. The Taming of the Shrew and Tartuffe exhibit the immensely various possibilities in the treatment of this theme. Dickens made a specialty of the Bleak Housemate.

If we extend this situation to include shared apartment buildings, we can include Rosemary's Baby and The Tenant: Roman Polanski's best work, and masterpieces of the genre. The Tenant offers an archetypal scene: a distraught man begs the guy living below to please keep the noise down, as his wife is desperately ill and trying to sleep; his neighbor, in libertarian indignation, refuses to have his behavior curtailed -- or even criticized -- so he pulls out a trumpet and proudly serenades the ceiling.

Is there any way we can find this behavior admirable? This is worth contemplating: perhaps our condemnation of the repulsive housemate is a form of slave morality. Is it possible that this is mere ressentiment on our part, a feeling of inadequacy beside the superior man, the man who transcends good and evil?

Let us briefly contemplate this possibility. Okay, that was long enough.

No, even the ubermensch, if we accept that construct, is only admirable if he chooses not to pass loud and festive gas in the kitchen. If he decides to murder a nasty miser -- well, I don't approve, but you can see the attraction. Perhaps he's inspired to Hellenize half the world, or send his hordes out from Mongolia to boil his enemies alive and create a nice little empire for himself. Now that's commendable. It's the kitchen thing which just doesn't cut it. Even Nietzsche did not admire the man who transcends good taste.

And when it comes to defining Marcus's grotesque soul, the term "bad taste" is much much too polite.

Marcus, on one of his special days, was going on about -- and I quote -- "fucking" his girlfriend. Which would have been appalling enough, had she not been standing a few feet away. Now, Marcus was being supported by his girlfriend -- that is, living off her -- because he was convinced he had some debilitating illness, perhaps AIDS. (He didn't.) Certainly it's acceptable, sort of, to laze about and live off your girlfriend when you're dying. (He wasn't.) This "fucking" business was a way of dissolving, I suppose, those tensions that generally arise is situations like this. It was perhaps to demonstrate further that he was not humiliated by his economic dependence, that he loudly called her to his side: "Whore, come here!"

Eve was disturbed, clearly, and made a few feeble protestations to the effect that this was "confusing," but she did not fight back. Battered women, I am told, can be like this, and battery need not be physical.

I, in retrospect, should have taken a corkscrew to his genitals. But again, I was not really at my best: weakened considerably by clinical depression and sexual deprivation (as I say, Marcus may have been "fucking" in London, but no one else was), I was in no condition to assault anyone. And I'm not much of a fighter to begin with, to be honest. Moreover, Marcus had a brown belt in one of the martial arts -- judo, I think. Which made him not your average stunted bore with a high voice: he was a dangerous stunted bore with a high voice.

Still, not to have at least attempted to put a fork up his nose was unforgivable. I look back on this period as a sort of hallucinatory break with ordinary reality. I was not so much a human actor as an emaciated parody of Prometheus, chained to a rock, with a rancid miniature vulture dining on my appendix. This is the only way that I can explain why I did almost nothing in the face of this housemate's oozing faults, both large and small.

The smaller ones were, subtly, almost as debilitating, if only because they were so relentless. Marcus had a tendency to deliver relentless monologues, for instance. On numerous subjects, some of which would have been interesting in any other mouth.

Marcus was particularly proud of his aesthetic discernment. He would go on and on about the artists he found worthy of his respect. He would expostulate at some length, for instance, on the excellence of Steely Dan. Marcus had a tendency to announce this kind of fact self-referentially: Steely Dan was one of the few bands whose complete works graced his collection. You sensed that the excellence of this group was contingent upon his approval.

It is impossible to convey how much I have always loathed "the Dan." I can think of very few bands whose music makes me actually want to leave the room. The only function that group has ever served, as far as I can tell, is to justify Lite Rock to smart people. The lyrics, being clever and cynical, make it easy for self-styled thinkers to mask the truth: that, secretly, they've always been moved by insipid music. Barry Manilow will never be cool, so Steely Dan satisfies the craving.

When he strayed away from his lectures on pop music, however, Marcus did in fact do me a service -- he validated a couple of my sketchier opinions. Now, we all have our embarrassing admissions: great artists whose work we just don't like. Their greatness tends to come with impeccable credentials. We all have these lacunae; they often make us feel inadequate, but they shouldn't really be a cause for shame. Nabokov, for instance, was no less an artist or a human being for loathing Dostoevsky, or -- yes, this is true -- disliking music.

Two of Marcus's very favorite artists, judging by the length of the monologues, were Glenn Gould and Caravaggio. He was not alone in his adulation, of course.

Here is where Marcus did me a favor. After enduring some hours worth of lectures on how these artists had been admitted into his pantheon, I began to no longer feel bad about disliking them. Perhaps it's okay, even for a Canadian, to find Gould cold, mathematical, and perverse. And to find Caravaggio a slightly vulgar if necessary step on the path from the High Renaissance to Rembrandt.

Thanks to Marcus's flatulent praise of Gould -- Marcus had once admitted Sviatoslav Richter into his collection, but now pronounced him "greasy" -- I found myself feeling quite good about preferring my less obvious heroes. Nobody ever suggested they send Dinu Lipatti's recording of the Chopin Waltzes into space, yet I vastly prefer this disk to Gould's Pluto-bound Goldbergs. Beside Edwin Fischer's Emperor Concerto, Gould's performance with Stokowski is clown-work.

And then there's Vladimir Horowitz. It's perhaps interesting to ponder what divides people between Horowitz and Gould. It's almost analogous to Dan-worship: I sense, perhaps unfairly, that people overly enamored of Gould are flattering their own mental powers -- they, you see, like the smart pianist. Horowitz was not, in fact, an overwhelming intellect. He once explained how he had never experienced anti-Semitism at school, because he never made anyone else feel stupid. No, Horowitz was merely a genius.

I adore Horowitz. And, thanks to Marcus, I find myself very much satisfied with my preference for greasy pianists. (What the hell does that mean?) I don't feel too bad about my Gould deafness. If Marcus approves of him, then there is good reason to believe that my defect is completely respectable.

Caravaggio, however, is a problem. Here I've always felt a bit confused. I should like Caravaggio, if only for the astonishing biography: I'm always partial to sickly, knife-fighting bohemians. I love that Caravaggio gave a painting of his own severed head to the Pope in order to obtain a pardon for killing a guy. Unfortunately, I don't love that painting.

Yes, I understand objectively why Caravaggio is important. And lots of people I do respect speak of him with reverence. But all those plump sybaritic boys with their heavy eyelids and ripe grapes: they've always struck me as the early Baroque equivalent of high camp. With the exception of a few paintings (that perfect St. Jerome in the Villa Borghese, for instance, and those glorious spotlit conversions of various saints), I find Caravaggio's work flaccid, decadent and, um, greasy.

Marcus would not shut up on the subject of Caravaggio. What was odd was that he had nothing all that profound to say about the artist, except that he considered Caravaggio first among the great painters (an opinion even the most partisan connoisseur would probably find a bit much).

Whenever I'm in Rome I still make a habit of seeking out Caravaggio, in hopes of a spotlit conversion of my own -- it would be nice to find another painter to worship -- but thanks to Marcus I don't lose much sleep over the issue. (In fact, for many years the rest of the world agreed with me: after his contemporary cult, Caravaggio was not rated very highly until modern times.)

You might wonder why I did not simply leave the room when the midget was on a pompous tear. I assure you: sometimes I did. It was, however, my apartment. I lived there. I could not simply vacate the premises every time my cohabitant trumpeted with glee in the kitchen or sent me into an irritated coma with his pronouncements.

Also, Marcus had no trouble inviting himself into my room. He had a tendency to scrutinize my bookshelf, in order to announce which of the books he had devoted his mind to, as proof of both his and the author's superiority. I happened to have many of my university texts with me in the apartment, including a Greek edition of the The Odyssey. He stopped at this book, one day, and I mentioned that I'd liked that class a lot -- we had worked our way through a long section of the The Odyssey in the original. Marcus turned to me, with an expression of withering contempt. "I love Homer," he said.

By which he meant that I had simply liked reading Homer, which was not nearly enough. I did not have it in me to love Homer, as he did. What is comical about this is that a character in Donna Tartt's The Secret History (an underrated book) says precisely this, in the same insufferable tone, when his seriousness is being established by the novelist: "I love Homer." Perhaps this is code, binding a fraternity of assholes?

It is time to give consideration to the word "asshole." I am convinced that the term names a philosophical category, like "substance" or "virtue." I encountered a friend of Marcus's some years later -- yes, he had a couple of these -- and I suggested to him that Marcus was an "asshole." To which he replied, annoyed: "He's not an asshole; he's difficult." This friend, a mustachioed lawyer with big hair and a gun fetish, was, like Marcus, a serious devotee of the Great Books.

"Difficult." You hear this word often, as a sort of refutation of the term "asshole." It implies genius. Beethoven, for instance, was not an asshole, despite his widely confirmed rudeness -- he was "difficult." I agree with this: genius ought to be given a great deal of leeway, in terms of social behavior. Great men are often not pleasant. When not-so-great men behave in this way, however, "difficult" is a euphemism. It is a mendacious substitute for the term "asshole." And Marcus, I assure you -- despite tangible intellectual gifts -- was an asshole.

No, he was not a genius. I am still not entirely sure whether he was aware of this. He avoided this self-confrontation. The joy he took in condescension, for instance, required him to surround himself with people who were not quite as clever as he was. People who would gape with awe at his every pronouncement. Steely Dan the most important band of all time? Who knew! But the ugly truth is that Marcus, who was a decade or so older than I was, had not accomplished anything. He was thirty-something, sponging off his twenty-three-year-old girlfriend, and did not have a single achievement to his name. Now, I suppose people like this imagine that they are leading the contemplative life, which is a sufficient accomplishment in itself -- after all, Socrates never did anything but think and speak -- but Marcus, I assure you, was no Socrates. Had Marcus attempted to educate Plato, he would have ended with a fork up his nose.

Insofar as I would not admit to my housemate's superiority, I was a serious problem. Yes, I was sharing an apartment with a noisome slob -- but he was sharing an apartment with a guy who considered himself just as bright. Or -- was this even possible? -- a touch brighter.

When you live in Manhattan, you tend to meet some truly impressive thinkers. I've had occasion to meet Nobel prizewinning writers and scientists; the world's greatest Chinese historian; artists and architects who have already carved a place in the textbooks. I have no difficulty deferring, in all sorts of areas, to a certain kind of intellect. Unfortunately for Marcus, his was not one of these.

Yes, he was certainly intelligent. But intelligence is like strength: lots of very strong people are terrible athletes. And some of the shallowest people I know have soaring IQ's. Seriousness of purpose, as well, is not sufficient to prove a man's worth. Lots of earnest, self-regarding types, with great natural gifts, accomplish nothing.

Marcus was, no doubt, a very serious human being. When his brother offered to introduce him to his tailor, for instance, Marcus was disgusted. This is an important ritual in London: you don't simply go to the best tailor; you require an introduction. It is an honor to be introduced. For my housemate, however, this was an inexcusable elevation of one of life's most insignificant aspects: fashion. (I find it humorous that Marcus has since, I am told, become a wine merchant. Fashion may be frivolous, but wine, now: there's a serious business.)

So, Marcus was very bright, and very serious. And yet, for some reason, he did not quite merit the word "difficult." This became clearest during a late-night conversation about Plato: coincidentally, one of those rare occasions in which we engaged in an actual dialogue. Both Marcus and I were obsessed with Plato's great protagonist, the world's ugliest philosopher (Socrates is said to have made Sartre look like Brad Pitt). I would even go so far as to say "I love Plato." Although I probably wouldn't say it aloud.

Needless to say, it was important to Marcus that he understand Plato better than anyone else. Unfortunately for my housemate, I had -- as I have said -- a couple of degrees in philosophy. And, although this skill has since evaporated, I was capable of stumbling my way through Plato in Greek, and Augustine in Latin. Marcus's understanding of Plato's Republic, though decent enough for an autodidact, would not have been sufficient to impress any graduate student in philosophy or classics. And, by the end of an hour's discussion, he knew that I had come to this conclusion.

So the next day he assaulted me in the kitchen. 'Assault,' as in physical violence -- no metaphor here. It was as if his kitchen behavior for the past months had simply been preparation for this crescendo: out of nowhere, Marcus came at me like an explosive crepitation, and within a millisecond I was on the floor. This is one of those annoying things about judo -- you don't even get the opportunity to land a punch. It is also one of those annoying things about a completely unexpected attack.

Later he "explained" that it had upset him that I knew what I did about Plato.

I have to admit something here, and it is difficult. It has been some twenty years since I openly wept; and this episode is what last put me over the edge. What can I say: I sobbed. I was in a city where joy was a distant memory frozen in literature; where Canadians might as well have been capons; and where I was sharing my home with by far the most repulsive person I had ever met -- and would ever meet in the years since. When Sartre said that hell was other people, he very specifically meant Marcus.

All of the above is meticulously factual (otherwise this sort of thing inspires lawsuits). Here, however, I'd like to depart from the facts briefly, to imagine The Life of Marcus during the twenty years since I left that vile home. (Yes, his poisonous presence finally drove me out, and he in fact owes me my deposit.) I can see him in his capacity as wine merchant: sounding off about residual sugar and obscure vineyards in the valleys of Mosel-Saar-Ruwer, while his victim weeps quietly into her Eiswein. "Whore, pour this woman another glass." When more talented sommeliers come to purchase stock, Marcus goes sullen and sour, and occasionally wrestles them to the floor. I can see Robert Parker Jr. in a full nelson, his head wedged between Jeroboams of Chateau Margot.

Lately I have had occasion to use my Marcus experience, in order to parry a couple of virtuosic attempts to win the gruesome housemate contest. A recent girlfriend, for instance, had a fine story about coming to Toronto as a teenager to study dance, and within days overhearing her three new housemates -- graceful ballerinas -- plotting to beat her up. Not bad. But not Marcus. One violinist friend arrived home one day to find that his new housemate had severed his own penis. Horrible, yes, but in a completely different way: you are moved to pity (and spastic squirming), but not to full-on loathing.

No, I suspect I shall always have this to comfort me for those months of Merry Old England: nobody will ever be able to trump what is, I firmly believe, the most spleen-rending tale of domestic misfortune in the literature. I knew Marcus. I own this genre.