I cannot say when it was exactly that I became Axel Vander, I mean when I began to think of myself as him and no longer as myself. Not when I gave his name as mine to Max Schaudeine that day when we stood together in the snow-blue light of my parents' emptied bedroom; I had no thought, then, of taking on Axel's identity, the assumption of his name alone being enough excitement for one day. Was it in Liège that freezing November twilight when the old forger with the diffident shrug of the true artist produced my – my! – passport, ready-worn, with a crease along the cover, and Axel's name under my picture? Was it when I was with Lady Laura in bed the first time and in a rush of post-coital candour was about to tell her the truth of who I really was and then smoothly, without so much as a missed breath, changed my mind? Perhaps it is not possible to identify one certain moment of decision. Do we not on countless occasions every day step effortlessly into other selves without even noticing it? The man who rises from his lover's bed is not the same man who half an hour later meets his mortal enemy. Anyway, what interests me more than when is the question why. How I worked at it, this senseless deception. I became a virtuoso of the lie, making my instrument sing so sweetly that none could doubt the veracity of its song. Such grace-notes I achieved, such cadenzas! I lied about everything, even when there was no need, even when the plain truth would have been more effective in maintaining the pretence. I made up details of my made-up life with obsessive scruple and inventiveness, building an impregnable alibi for a case that no court was ever likely to be called upon to try. Yet I am fascinated by the paradox that even as I laboured to maintain the façade, at the same time it would not have mattered to me in the slightest if someone had suddenly stepped forward with irrefutable proof of my imposture. I would have laughed in his face and owned up with a shrug. Or her face, as the case might be. I ask what I have asked already: what did it benefit me to take on his identity? It must be, simply, that it was not so much that I wanted to be him – although I did, I did want to be him – but that I wanted so much more not to be me. That is to say, I desired to escape my own individuality, the hereness of my self, not the thereness of my world, the world of my lost, poor people. This seems to matter much. Yet I have lived as him for so long I can scarcely remember what it was like to be the one that I once was… I pause in uncertainty, losing my way in this welter of personal, impersonal, impersonating, pronouns. Do not imagine I meant to perpetuate his memory, or to live the life for him of which he had been deprived; no, nothing like that, I would not be so loyal, so large-hearted. I would have defended him, yes, I would have tried to protect his name, but had I been exposed I would have slithered out of him with the ease of a secret agent discarding his cover and stepping into another.

So many questions, so many quiddities, yet I am no further along. The mystery remains, as always: why? If, as I believe, as I insist, there is no essential, singular self, what is it exactly I am supposed to have escaped by pretending to be Axel Vander? Mere being, that insupportable medley of affects, desires, fears, tics, twitches? To be someone else is to be one thing, and one thing only. I think of an actor in the ancient world. He is a veteran of the Attic drama, a spear-carrier, an old trouper. The crowd knows him but cannot remember his name. He is never Oedipus, but once he has played Creon. He has his mask, he has had it for years; it is his talisman. The white clay from which it was fashioned has turned to the shade and texture of bone. The rough felt lining has been softened by years of sweat and friction so that it fits smoothly upon the contours of his face. Increasingly, indeed, he thinks the mask is more like his face than his face is. At the end of a performance when he takes it off he wonders if the other actors can see him at all, or if he is just a head with a blank front, like the old statue of Silenus in the marketplace the features of which the weather has entirely worn away. He takes to wearing the mask at home, when no one is there. It is a comfort, it sustains him; he finds it wonderfully restful, it is like being asleep and yet conscious. Then one day he comes to the table wearing it. His wife makes no remark, his children stare for a moment, then shrug and go back to their accustomed bickering. He has achieved his apotheosis. Man and mask are one.

Today at last he addressed me, my camel-haired doppelganger, as I knew he would, eventually. I had stopped to gaze into the window of a butcher's shop on the Via Barbaroux. I have always been fascinated by these cheerfully shameless displays of cloven flesh and blood and bone – they are always so eerily well-lit. "A barbarous sight, signore," a voice said behind me. I turned my head and there he was, the punster, in his expensive, old-fashioned coat, leaning crookedly on his cane. He bears a marked resemblance to Stravinsky in old age. When he smiles, his wide, thin lips roll back from his teeth in an unnervingly equine fashion. We went to that little caffè behind the church in the Piazza della Consolata and drank hot chocolate spiked with grappa, for the day was bitterly cold. He tells me the place is very old, and has always been owned and run exclusively by women. N., I am interested to learn, used to come here to drink his morning coffee and read the newspapers. I said I wondered if he brought his whip with him, and my new friend chuckled, and dropped cigarette ash on his lapel. He is not a Torinese, not even Italian, but I cannot place his accent. He enquired, as everyone does, if I have been to view the Shroud. I told him I had once made an attempt to see it but had failed. He said, glancing over his shoulder and lowering his voice, that he can arrange a private viewing for me, if I wish. He might have been offering me contraband, or a woman. I let the subject drop. He told me his name but I did not catch it; sounded like Zoroaster. He is a doctor, he says. I think he knows who I am. I shall have a hard time avoiding him, from now on.

I should not have stolen Laura's money. It was too easy to be resisted, a matter of a few forged cheques and some judicious pawnings – the house in Belgravia was a jewel box stuffed with unconsidered and certainly unguarded bibelots. I felt it was my due to awaken some of this slumbering wealth. She trusted me, did Laura. Which is to say she found it inconceivable that anyone, or at least anyone she knew, would be so tasteless as to steal from her. She was quite mean – have I mentioned it? – in the way that only the very rich can be. She saved candle stubs, stopped runs in her stockings with dabs of nail polish, that kind of thing. And refused to insure her diamonds. Pity. She might have spared us both a deal of pain and expense. Expense on her part, pain on mine.

My plan was to get to America, as quickly as possible. That was where I had been aimed at all along. I was not your usual hopeful refugee from a fouled and foundering Europe. America for me was not the land of liberty, bright prospects, new beginnings. No: America was emptiness. In my image of it the country had no people anywhere, only great, stark, silent buildings, and gleaming machinery, and endless, desolate spaces. Even the name seemed a nonce-word, or an unsolvable anagram, with too many vowels in it. In America, I would not be required to be anyone, or to believe anything. No cause would clamour for my support, no ideology would require my commitment. I would be pure existence there, an affectless point moving through time, nihilism's silver bullet, penetrating clean through every obstacle, shooting holes in the flanks of every moth-eaten monument of so-called civilisation. Negative faith! That was to be the foundation of my new religion. A passionate and all-consuming belief in nothing. What I pilfered from Laura I thought of as her contribution to my Church of the Singular Soul. My due, her dues.