If, this time last week, you’d asked me to compile a list of my favourite living writers, it would have included, in alphabetical order: Martin Amis, William Boyd, A.S. Byatt, Jonathan Coe, Nick Hornby, Kazuo Ishiguro, Hari Kunzru, Rohinton Mistry, Salman Rushdie, David Sedaris, Zadie Smith, William Sutcliffe and William Trevor.

But David Sedaris no longer makes the cut; a development, I suspect, that will prove significantly more painful for me than for Sedaris.

After all, while I have lost the genuine pleasure of sending his brilliant books to friends, the American writer, who has written quirky, autobiographical stories about, among other things, his upbringing in the suburbs of Raleigh, North Carolina, his Greek background, and his experiences working as an elf at Macy’s department store during Christmas in New York, can console himself with that fact that he has sold more than seven million books in 28 countries, that five volumes of stories have made the bestsellers list in The New York Times, and that thousands of people turn up to his readings, sometimes paying hundreds of dollars for the privilege of doing so.

But the demotion is necessary because the other day I was forwarded an interview with the 52-year-old in which he made the following remark: “If you tell a funny story at the dinner table in front of ten people, nine will laugh, and one will say: ‘That’s not true.’ I’ve always hated that person.”

Now, Sedaris isn’t, of course, the first non-fiction writer in the world to have confessed to a difficult and complex relationship with “truth”.

Owing to the fact that people remember things differently, that memory is unreliable, that all history is subjective, that you can’t always prove things, that human beings make mistakes and that one sometimes needs to change details to protect the privacy of innocent parties, throughout history non-fiction writers have had to find all sorts of different ways of answering the question “what is truth?”

In her brilliant 1957 autobiography, Memories of a Catholic Girlhood, for instance, Mary McCarthy highlighted the subjectiveness of truth by detailing at the end of each chapter the events that relatives remembered differently, and highlighting segments where she embellished material or narrated events out of sequence.

More recently, Dave Eggers did something similar in his exhilarating and self-conscious memoir, A Heartbreaking Work of Staggering Genius, Clive James tackled the issue head-on by entitling his autobiographical writing Unreliable Memoirs and James Delingpole played around with the notion of truth by presenting various life experiences as an entertaining novel entitled Thinly Disguised Autobiography.

Other writers have talked about “faction”, “emotional truth” and “truthiness”, and prefaced their accounts with elaborate disclaimers reminiscent of the small print on the back of credit card statements, a tendency parodied by Toby Young in How To Lose Friends And Alienate People, which begins with the following statement: “I was thinking of beginning with one of those postmodernist disclaimers that call into the question the whole notion of objective truth, but nearly everything that takes place in this book happened exactly the way I’ve described it. I say ‘nearly everything’ because I’ve occasionally given things a slight comic twist.”

In my case, when it came to writing a memoir, I used several of the above strategies, and I agree with Sedaris to the degree that there are more kinds of “truth” than of the kind that appears between the pages of newspapers or novels. But, having said that, there are two profound problems with Sedaris’s position, the first being that he is inconsistent.

While seemingly conceding that he exaggerates for comic effect and makes things up, emphasising that he is a humorist and not a reporter, at the same time he claims to be writing truth, with his 1997 collection Naked beginning with the claim that “the events described in these stories are real”, and the man himself remarking in the aforementioned interview that “the only difference between me and everyone else is . . . I write things down”. He needs to make his mind up.

Perhaps more problematic is Sedaris’s strange and repeated claim that truth just doesn’t matter. A few years ago, he told The Financial Times: “Somebody could tell a story at the dinner table and somebody could say ‘that’s not true’. I would never say that. It is either a good story or it’s not. It doesn’t matter if it’s true or not.”

In another interview he remarked he “wouldn’t care a bit if he found out that Frank McCourt’s Angela’s Ashes was written by ‘some guy in Montana who made the whole thing up’ because the tale he spins is so beautiful.”

And in reference to the controversial “memoir” A Million Little Pieces, which actually turned out to be a work of fiction, he remarked: “I really squirmed for that James Frey guy. It seems a bit silly to me that everyone gets their panties in a knot because, like, a first-time memoirist lied! You’ve got all these people saying ‘that drunk lied to us!’ Well, yeah, he’s a drunk!”

Sedaris is wrong. It doesn’t matter if non-fiction authors exercise literary or poetic licence, if they omit things, if they fill in details, if they play around with minor facts, even if they exaggerate for comic effect, as long as they acknowledge it in some way, and are consistent about it, but it matters hugely if they are making things up and not admitting to doing so.

Angela’s Ashes is a brilliant book because it is fundamentally a true story, even if the details are not precisely accurate, and as a novel it wouldn’t be half as good. James Frey’s A Million Little Pieces would be a brilliant and unique memoir, but as a novel it is virtually worthless. And while I rated Sedaris very highly as a memoirist, now that it transpires his funny little stories about being taught to play guitar by a midget and working for a removals company may be fiction, I don’t.

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