Howard Jacobson: No need to be surprised when a house of horrors turns up on a quiet provincial street

How could this happen here, they are asking in the unremarkable provincial Austrian town of Amstetten, home to Josef Fritzl, dungeon to his daughter and their incestuous offspring. And to think that such a thing could have been taking place under our very noses, and he such a charming man, and they – those that were visible – such lovely, quiet people.

The good citizens of Amstetten, of course, knew nothing. They never do. And the wife of the man who fathered and fed another family in a cellar below her feet for 25 years knew nothing either. You'd have to be pretty incurious, one would think, not to suspect or notice something for all that time – such as why your husband buys groceries for 10 of you when there are five of you, why he regularly takes half the shopping to a part of your house you have never asked to see or been allowed to visit, and why grandchildren keep appearing on your doorstep – but it is not for us to be judge and jury. If she didn't know, she didn't know. If she didn't ask, she didn't ask. Ignorance of a crime is not a crime.

It's all a touch uncomfortably reminiscent, though, of other questions the respectable, peace-loving burghers of Austria never asked, and other chambers of horrors they didn't know – or didn't choose to know – a blind thing about. Questioned recently on television as to why such things seem to keep happening in Austria, Natascha Kampusch – herself kidnapped and kept concealed in Vienna for eight years and therefore something of an expert on the subject – said she thought it was "a ramification" of the Second World War. "At the time of National Socialism," she said, "the suppression of women was propagated. An authoritarian education was very important."

Brave of her to have mentioned the unmentionable. But if what she said sheds light on the psychology of Austrian men who get off on kidnapping and jailing women, it still leaves the larger sociological question of not-noticing to be addressed. As chance would have it – let's call it chance, anyway – the unremarkable provincial Austrian town of Amstetten has looked away before. There was a concentration camp in Amstetten. Not a big one. Just a sub-camp of Mauthausen, of which there were approximately 50 dotted around lower and upper Austria. Since Mauthausen's speciality was extermination by means of slave labour, in particular the extermination of politically educated and vocal enemies of the Reich, we might fairly assume that Amstetten's speciality was the same. It is also worth noting that Amstetten was a camp for women.

Whether it is equally worth noting that the Polish Catholic radio station Radio Maryja – a continual embarrassment to the Vatican on account of its nationalistic and anti-Semitic utterances – has opened several bases in the Austrian Tyrol, the first of them in Amstetten, I don't know. It could merely be geography that explains why Amstetten has more than once been selected to be a sub-base for the active expression of racist hatred.

As a general rule, whatever one makes of these historical coincidences, it is never a good idea to express surprise that anything horrible has been happening near you. That will only lead to people nosing around and discovering that horror is in fact your speciality. A better tactic is to express no surprise at all. Of course there are streets full of deviants and torturers in our respectable little town, you should say. What else do you think is going to happen in so repressed a place? Our quiet and unremarkable respectability pretty much guarantees that half our population is deranged and the other half is still thinking about it.

I lived in a small town myself once. Today I live in Soho. Block for block, house for house, family for family, people behaved much worse in the small town. Certainly if it's strange sex you're after, animalism, brutality, incest, an all-round disregard for barriers and disrespect for decency, you're better off in the country than in Soho. Nothing else to do there, and Amstetten, presumably, the same.

But I might be being unfair on small provincial towns. The truth is that sex itself is to blame for the horrors perpetuated in its name. We flatter ourselves that we have tamed the beast and men like Josef Fritzl are the anomaly, but the degree to which the logistics of this story fascinate us – the hows as interesting as the whys – proves we know the dungeon is never very far away.

Go and take a look at a terrific exhibition entitled Modern Painters: The Camden Town Group currently at Tate Britain. The paintings I'm thinking of in particular are those to which that great painter Walter Sickert gave the series title The Camden Town Murder. Dark, despondent, oppressed, painted in stickily encrusted oils as though there's a film of moral grease over every encounter between men and women, these works depict human sexuality more savagely than all the Last Judgements in all the cathedrals of Europe put together. In every canvas a naked woman lies on the bed and a man either stands over her, lost in the dark confusion of his desire or lack of it, or sits on the edge of the bed, though whether harbouring murderous intentions, or loaded with remorse, or unable to pay, if the woman is a prostitute, or impotent, or sorrowing, or disgusted, or heartbroken, there's no telling. All those things, one is tempted to surmise, all those things at one and the same time. For such it is, sometimes, to be a man.

Though these incomparably dismal works address obliquely an actual murder that had all London by the ears, Sickert's famous Ennui, painted a few years later, is no less murderously stifling though it is without any sensational content and simply shows a domestic interior, a man in his chair smoking, looking nowhere, a woman turned away from him, leaning on the sideboard, a silence – for Sickert is a wonderful painter of silence – so intense you hear your own nerves snapping. That either of them might, out of frantic boredom, do something terrible to the other, is also contained within the narrative. And so it is in every house on every street in Camden Town or Amstetten.

Lost love, too much love, jealousy or what's left of it, apathy, longing without name or object, desire embittered and turned into rage. We live with these as best we can. Yes, Fritzl is a monster, perhaps born of monstrous history, but I still consider it astonishing, all things considered, not that such a man exists, but that more don't.

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