When I first went to Auschwitz, the earth was still white with calcined bone, while thousands of rusting spoons and forks lay on the site of the storehouses. Today, the earth is normal brown, the spoons have gone and the scrawny poplars planted by the SS to hide the gas chambers have become tall and beautiful. Nature wants us to forget, but human beings want to know everything that happened here and then fix it unalterably in the memory of our species.

Half the British population, apparently, have never heard of Auschwitz. Some of the other half think that there is nothing left to say about it. But Laurence Rees, author of this book and director of the TV documentary series on Auschwitz which started on BBC2 last Tuesday, shows that there is a great deal left to discover. Some of this comes from his admirable hunt for witnesses, both survivors and SS perpetrators.

Makers of documentaries have been using - or trying to use - these individuals for decades, with varying success, but Rees has spent years patiently coaxing them to talk as the end of their lives approaches.

Anyway, they no longer worry about consequences. SS staff who used to deny all responsibility and took refuge behind 'higher orders' now talk openly to Rees about what they did and often reveal that they have no regrets. In a deeper way, there will always be fresh answers to be discovered to the big questions: 'How could human beings have done these things?' and: 'Who decided that all the Jews must be killed and when?'

This is because we can only peer at history through the confusingly reflective pane of our own times. Once, it was assumed that the Germans who ran and guarded the camp were psychopathic sadists and that Hitler must have given a direct extermination order to robot-like henchmen. Today, Laurence Rees and Sybille Steinbacher both subscribe to the 'cumulative radicalisation' theory (he says historian Martin Broszat invented it, while she says it came from Hans Mommsen).

Put simply, this theory says that one thing led to another. Vast Nazi plans ran into trouble and provoked even more extreme solutions to get out of the trouble. Often, these actions were improvised by local officials. It was the SS leaders on the spot as much as Hitler and Himmler who turned deportation into shooting, shooting into gassing, gassing into a programme of total extermination. The horrible truth is that Europe's Jews were murdered as much to solve problems of living space and food in occupied Poland as to fulfil Hitler's crazed anti-semitism. In the end, the question for the Nazis was not: 'Why we must kill all the Jews', but a worse one - 'Why not?' Their presence had become a problem, so abolishing them was the obvious radical solution. After all, they were not fully human.

Rees gives much space to the French deportation of foreign Jews to the gas chambers, a digression from his subject, but no more shocking account has been written. He goes at great length into the tangled 'lorries for Jews' affair in Hungary, another digression but one which doesn't add anything new.

Both books are at their best when sorting out what actually took place at Auschwitz. The great camp, eventually covering a landscape with its extensions and outstations, began operations in 1940 and was liberated by the Red Army 60 years ago, on 27 January 1945. More than a million people were killed there, 90 per cent of them Jews. But murdering Jews was not the original intention of the camp, which was, at first, used mainly for Polish and Soviet prisoners.

The first trainload of Jews destined for the new gas chambers in Auschwitz-Birkenau arrived in spring 1942. Most of the Final Solution victims died elsewhere, before the firing squads on conquered Soviet territory or in the three temporary death camps of Operation Reinhard (my link) which gassed 1.65 million defenceless men, women and children within little more than a year.

As these books make clear, Auschwitz was both an industrial killing factory and a place of slave-labour imprisonment where life expectancy was only a few months. The living, under a regime whose savagery and sadism remain almost unimaginable, were entitled to envy the dead. And yet - as these books show - the prisoners fought, sometimes horribly and sometimes nobly, to stay alive.

Rees fails to mention the political resistance networks within Auschwitz, which Steinbacher summarises well. The two also disagree about whether Allied bombing of railway lines or crematoriums could have saved many victims. Rees calls this 'a new myth'; by the time detailed information about the camp's layout reached the Allies in June-July 1944, the main deportations to the gas chambers had finished. Steinbacher points out that Auschwitz still held 155,000 people and that killings went on all summer and autumn. She also records that the Polish resistance was carrying out attacks on the rail spur leading to Birkenau.

In spite of his long familiarity with this period, Rees was still shaken by what he found. For example, the aftermath of Auschwitz was also hideous. Through witness interviews, he records the wave of vicious, sometimes murderous, anti-semitism which swept across eastern Europe after liberation, as the Jewish survivors returned to what had been their homes.

He describes the gold rush at Auschwitz as local Poles sieved the soil of the camp for coins or teeth, and the shame felt by those who had hidden Jews during the Nazi occupation and did not want their neighbours to know. Those neighbours would assume they had done it for Jewish gold and hate them as millionaires.

As he says, what we learn here about human beings 'is mostly not good'. His conclusion is that we underestimate the power of situations, especially extreme ones, to change not only behaviour but character. Else Baker, one of his interviewees who was sent alone to Auschwitz at the age of eight because her grandmother had been a gypsy, puts it more shortly: 'The level of human depravity is unfathomable.'

[From The Guardian]