Rowan Pelling: Oh, Nigella, how could you? Your books are who you could be

Underneath Nigella Lawson's cantilevered eiderdown of a bosom must lurk the steely heart of a domestic rationalist. How else could she divest herself of the 200 books which have just turned up in a house clearance shop on the Wandsworth Road? The news was akin to someone blithely telling you that they'd sent their doddery Labrador to Battersea Dogs Home. Of course, like mutant puppies, there are odd books better strangled at birth. DM Thomas's The White Hotel springs to mind. But books otherwise tend to occupy a sacred spot in the roll-call of household possessions, which make them as demonstrably part of the owner's life history as Christian's burden in The Pilgrim's Progress.

For that very reason they can lie equally heavy on one's soul. Rummaging through your library can be as much of a shock to the system as undergoing psychotherapy to retrieve long-suppressed memories. Did I truly once believe that Midnight's Children was the most masterly book in the English language? Was that pre-finals week spent devouring Interview with the Vampire when I should have been immersed in Piers the Ploughman? Even now, to stumble across Charlotte's Web is to crumple as I remember my mother reading aloud the most heart-rending passage in literature: "Nobody, of the hundreds of people that had visited the fair, knew that a grey spider had played the most important part of all. No one was with her when she died." Somehow, the memory is insufficient without the dog-eared evidence on a shelf.

And then there are the books that are talismans of the people who gave them. Nancy Mitford's collected works passed on by my granny, who would rather have died than say the word "toilet", and the Carlos Castaneda volume given by the barmy hippie boy who wanted to instruct me in astral projection: works that speak louder than any diary entries.

Of course, I understand how cathartic it might be to rid oneself of an unseemly literary past. Who would not sympathise with Nigella's decision to discard A Feast of Floyd, Fat is a Feminist Issue and Margaret Atwood's The Edible Woman? While I have never let myself slip enough to allow an Atwood novel permanent house space, I must confess to possessing equally incriminating volumes: The Coronation Street Cook Book and Damon Hill's My Championship Year have scant claim to membership of the canon. So there's a certain temptation to nip them down to Oxfam - were it not entirely against the natural order of things.

Books should filter into second-hand shops in one of two ways: either the owner dies or they were review copies. Throwing books out in a mid-life restructuring exercise is an unconvincing way of denying the part of you that was once so desperate to see Damon Hill triumph that you dropped to your knees in church and prayed for him (sad but true).

Your shelves may look pleasingly Zen without that marmalade-stained copy of The Magus but the general effect may be like stripping ivy from your house: a prudent move that makes your whole façade look bland. Life may well be too short to re-enact the mistake of reading Gravity's Rainbow - but how will your offspring understand the forces that helped shape you if the book is banished altogether?

Playing them bootleg tapes of the Grateful Dead will not suffice. Or that's what I tell my husband every time he gets that furtive look which means he's called his friend the book dealer. I tell him psychological space is more important than physical space: our library is our hinterland. But I suspect the deeper truth is that my books are the only things that justify a lifetime's supine posture. I may not have achieved much, but at least I was once the kind of girl who read both Flowers in the Attic and Horace in the original. By hanging on to those books I keep alive the vain hope that I may yet be that person.