Took part in a balloon debate for English PEN last week. You know the sort of thing – balloon containing four writers in trouble, one writer has to be thrown over the side, then another, then another, until only one writer left. Bad luck if you happen to be sitting underneath.

Reminds me of that dog falling out of an aeroplane in Aldous Huxley's Eyeless in Gaza, which I always confuse with that other dead dog Graham Greene describes finding by his pram in the first volume of his autobiography, A Sort of Life. It marks you, an experience like that. But imagine if it was Agatha Christie falling on your pram. You'd spend your whole life wondering who'd pushed her.

Kate Mosse – the novelist not the sniffer – stood up for Christie. Louisa Young chose James Meek, a writer a bit new on the scene to be subjected to trial by balloon. John O'Farrell took on George Orwell and I, of course, was DH Lawrence. It came down in the end to those last two. Should have been no contest. But Orwell stole it. Good thinker, Orwell, but not a writer in the sense that Lawrence was a writer, new creating all he saw. But there you are. The feminists did for Lawrence 30 years ago and it was a miracle, all things considered, that he wasn't thrown out of the balloon sooner. Imagine DH Lawrence falling on your pram.

I've been in a depression ever since. Not because I don't like losing. I don't, as it happens, but that's not to say I'm Ricky Ponting. I don't look for ways of giving the opposition nervous breakdowns rather than not win. A loss, though, is a loss and when you lose on behalf of someone else – and that someone else is DH Lawrence – you feel it doubly keenly.

I doubt that Lawrence would have given me the time of day, let alone fought to keep me in a balloon, but I am a Cambridge man, I date from the 1960s, and Cambridge men who date from the 1960s retain a zeal for DH Lawrence. He is, for us, the measure of creative seriousness, he defines what we mean by Englishness and by art. So to have lost in his name is to have failed Eng Lit. I'm sorry, that's all I can say. But sorry, when you've let down Eng Lit, is not enough.

They were all persuasive, the other speakers. So I was not the sole reason for Lawrence's ejection. I have been wondering, however, whether my confession that I had no time for Agatha Christie though I hadn't read her was what did for me. People don't like you making judgements about writers you haven't read. I argued that the others were making judgements about Lawrence without having read him – really read him, I mean, read him in the 1960s Cambridge sense. But people don't like you when you say that either.

Notwithstanding which I will say it again: there is deep and there is shallow reading. And in an age where it's considered perfectly respectable to call a book "a good read", there is only a slim hope of readers reading Lawrence with the attention – with what one might call the collaborative creativity – he requires. What is generally called a "good read" I now routinely assume to be a bad read. Which is another thing people don't like you saying.

But you can't read everything, and a recommendation which is no recommendation – for where's the virtue in that experiential passivity "a good read" implies? – saves you going to the bother yourself. It was for this reason that I was happy to confess I hadn't read Agatha Christie but still wanted her out of the balloon. I associated her with reading that wasn't reading, and if I was wrong to do so the fault lay in the readers who championed her.

Not Kate Mosse, who argued so well for her I was tempted to change my mind mid-air, but all the readers who had gone before. Sometimes there will be injustices in this method, though mainly a writer attracts the readers he or she deserves. No one would call Dostoevsky "a good read". And that's the first clue that he might be worth your time.

The French literary critic Pierre Bayard has recently published a book entitled How to Talk About Books You Haven't Read, which sounds like a bluffer's guide, a sort of Great Literature for Dummies, but isn't. Bayard – who coincidentally has written a book about Agatha Christie called Who Killed Roger Ackroyd? (which should be read, or not read, in conjunction with Edmund Wilson's essay Who Cares Who Killed Roger Ackroyd?) – agrees with me that you can't read everything and shouldn't try. Furthermore, not only shouldn't you feel guilty about it, you shouldn't allow the fact of your not having read a book to stop you passing an opinion on it.

I make a distinction here myself between passing an opinion – which is a lightweight activity, swapping hearsay for hearsay – and making a judgement, which is serious, considered, contemplative, and expects judgement in return. You cannot pass an opinion on a writer like DH Lawrence because writing of his adventurousness can be encountered only in an act of judgement. Whereas you can pass an opinion on Agatha Christie, such as I don't give a monkey's who killed Roger Ackroyd, because you believe the killing of Roger Ackroyd to be a trivial matter, and no one has so far persuaded you otherwise.

So how does one know, without reading it, what book is worthy only of your opinion and which solicits nothing less than the considerations of true judgement? The ether, partly. The buzz, the to and fro of enthusiastic review and recommendation and the quality of that enthusiasm. Thus, if enough people burble on about The Kite Runner being a "good read", you know it isn't what you mean by a read at all.

I myself have other reasons for not reading The Kite Runner. I don't approve "international" novels with perfectly timed and calibrated ethnic content. I am generally put off novels entitled The Something-er,especially when the Something in question implies innocent and wonderment. And I don't like anything a particular friend of mine likes, and he adores The Kite Runner. Isn't this what friends are for? They only have to say you absolutely must read such-and-such and you know you mustn't.

I am not telling anyone they absolutely must read Pierre Bayard.I haven't read a word of How to Talk About Books You Haven't Read myself. I feel I owe him that.