"What's strange about the reception of this book," says David Bellos, the translator of Hélène Berr's Journal, "is the idea that Hélène is the French Anne Frank."

One can see why the idea might arise. The Journal, which Bellos has just translated into English, is the personal diary of a young Jewish woman, written between 1942 and 1944. It ends with a final letter to her sister after her arrest and a story told by others of her time in Auschwitz, Bergen-Belsen and of her death, five days before the liberation of the camp. It is, like Anne Frank's diary, a record of youth and freshness, which becomes heartbreaking to read as more of her friends are arrested and her fate becomes clearer.

But Bellos is right. Hélène Berr is not Anne Frank. Hélène was 21 years old when she began writing the journal, a distinguished student of English literature at the Sorbonne, and, crucially, not living under house arrest. Rather, she moved in the thick of Paris's cutural mileu; playing the violin, discussing literature at lunch and tea with her friends, falling in love, and then, later, working in the underground network that smuggled children out of Paris. Her story is so sad precisely because she is so wrapped up in other things, her writing is interesting for its insights into life in general - only gradually do Nazi mechanisms encroach on her.

On May 9, 1942, she listens to Beethoven's Quartet No. 14 and has a "wonderful tea with frothy milk chocolate” while “Jean Morawiecki handed round Egyptian and Russian cigarettes", but by June 8, she has to wear her yellow star in public for the first time. "My God," she writes, "I never thought it would be so hard," before describing the pointing in the street, being called "disgusting", and sent to the last carriage on the metro. And so the diary unfolds, a succession of incongruities. Her father is interned at Drancy for a spell, and she writes of the gap "yawning open" between the Papa of home and the man writing asking for woollens, but then he is released and she finds time to write of Keats and her friends again.

The book was published in France in January this year, after Hélène's relatives and Jean Morawiecki, who became her fiance, decided to make the manuscript public. It is now translated into English by David Bellos, who won the Man Booker International prize for translation in 2005. Meeting him, the impact that reading the diary had on him is clear.

On being given the manuscript, he said that, by "page 30 or so," he found himself impressed by the sharpness of Hélène's mind, and by page 40 he thought, "My God, she knows what's happening – but she doesn't know what's happening." From that point on, he says, "it was so moving, I found I had to stop every few pages to wipe away a tear. The end," he says, "is manifestly forseeable but at the same time completely horrifying."

Increasingly life is dictated by the Nazis of Paris who produce surges in Hélène "not of hatred, for I do not know hatred, but of protest, revulsion and scorn...the Nazi leaders who have gone so far in self-abasement, despiritualisation and stupidity as to become no more than brainless automata." But the Journal is a valuable piece of evidence that even the most intelligent, aware people could fail to see the full extent of what was happening around them. Hélène writes honestly about what goes on around her, she sees fellow Jews being deported, but she cannot imagine where they are going, nor, for a long time, that every Jew was a target.

"It is," says David Bellos, "a document of denial in several senses." Hélène never, for example, imagines the systematic mass executions at the camps, and will not leave Paris. Although she writes bravely of the possibility of her own death, it never seems as inevitable to her as it does to the reader. "It should make us a little more attentive to the many historical records we have of occupied countries and of Germany itself during the Second World War, where people have said, 'we knew nothing',” Bellos argues. “Often, we just turn around and say 'oh yeah?' Well, this book shows you what that means. You can actually know and not know."

Hélène is a striking diarist in many ways: she is brave and unselfish and writes lucid, lovely prose. Early in the book, she is discussing the war with a friend and declares that: "We do not have the right to think only of poetry on this earth. It is magical, but it is utterly selfish." And yet, as things get worse, she draws on literature and music to help her express herself and understand her grim world. In writing of her own death, she recalls how Montaigne "outwitted Time itself", by writing about his death. And when she realises that she is writing this diary for her lover to read should she die, she recalls Keats' poem, This Living Hand:

This living hand, now warm and capable
Of earnest grasping, would, if it were cold
And in the icy silence of the tomb,
So haunt thy days and chill thy dreaming nights
That thou would wish thine own heart dry of blood
So in my veins red life might stream again,
And thou be conscience-calm'd - see here it is
I hold it towards you -

What strikes Bellos is “how wonderful it is to have a well-filled life. This is a life that consists of study, friendship, music, literature, learning, it's a life which is full, 24 hours a day. We should all seek to live that way, because even in German-occupied Nazi Paris when you're being hunted down, you can still use the 24 hours that you have.

"Hélène is beginning to realise how bad the situation is," Bellos continues. “As things get worse and worse, then her memories of music and poetry become more and more important. and give her succour, give her nourishment." There are tears in his eyes as he speaks.

Jean Morawiecki, Hélène's fiance, escaped Paris and fought for the Free French. He is still alive and has quietly helped to make the diary public. In May this year, he wrote to Hélène's cousin: "The Journal has appeared, and we both know the impact it has had. At long last, I can look at the frozen hand that has now come back to life in people's memory and think: 'And thou be conscience-calm'd - see, here it is -' "

Hélène Berr was not Anne Frank, just as none of the other victims of the Holocaust were Anne Frank. They all have their story – we are lucky that Hélène chose to tell her own.

Journal by Hélène Berr
translated by David Bellos
Quercus, £16.99 Buy the book

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