Not Me: Memoirs of a German Childhood, By Joachim Fest, trans. Martin Chalmers

Can this historian's proud record of his family and youth show why Germans fell for Hitler?

Joachim Fest was a man with an alibi. The title of his posthumously published autobiography is drawn from the gospel of St Matthew, 26:33, "Even if all others do – not I." He intended it to encapsulate the non-conformist ethos that infused his upbringing and immunised him against National Socialism. But of course it can mean something else, as in "Not me, guv."

Yet it would be unfair to reduce his reminiscences to this ambiguity. Not Me is a richly evocative family history, dominated by his father. It is equally the biography of an upright man intent on preserving his family from the moral canker of Nazism. Johannes Fest was a teacher, a wounded veteran of the Great War, and a staunch defender of the Weimar Republic. His son notes that men like him fought the Communists and the Nazis every step of the way, but when Hitler came to power legally, their own values inhibited them from further opposition.

Germany's new rulers soon suspended Johannes from headship of a Berlin elementary school and then banned him from any teaching activity. Despite harassment, he refused to make peace with the regime. Johannes kept his sons out of the Hitler Youth and continued to meet each month with a circle of fellow-dissidents.

These men typified the Germans who embarked on "inner emigration", preserving their own purity by establishing distance between themselves and the "national community". They were constantly frustrated by Hitler's luck and the ineptitude of the powers that confronted German expansion. But they were also undermined by sympathy for his initial goals. Johannes welcomed the unification of Austria with the Third Reich in 1938 and relished the defeat of France two years later.

Meanwhile, he urged his Jewish friends to leave. Johannes was appalled by BBC broadcasts in December 1942 reporting that Jews were being deported to the east and murdered. At first he was incredulous; but he was sufficiently concerned to check for himself. The truth rocked him. Towards the end of the war he was called up for labour service and was captured by the Russians. When Joachim was reunited with his father in 1946, he found a shattered man.

Joachim himself was aged seven and noticed little change when Hitler came to power. But his father showed him the burned-out Reichstag building, presaging total repression, and introduced a "second dinner" at which he could talk frankly with his older children. Joachim's own rebelliousness got him into trouble at school.

In February 1944, he was called up to serve in a flak battery. Later he survived a brief, inglorious engagement with American troops at the Remagen Bridge in March 1945. He spent nearly two years in a POW camp in France. Once released, he studied law, and began a career in journalism.

The memoir ends with his reflections on what made the Third Reich possible. To him it was not because Germans shared Nazi ideology. They were driven towards Hitler by national humiliation, economic despair, and fear of civil war. But is Fest the best judge? His family's contempt for the Volksgemeinschaft, the national community, renders him ill-suited to understand why most Germans found Nazism genuinely satisfying.

Fest claimed that after 1945 he was out of tune with most Germans because his family had nothing to feel guilty about. "We had the dubious advantage of remaining exactly who we had always been". Unfortunately, though, there are signs that Fest was not as innocent of denial as he liked to boast. His father had encouraged him to befriend a wealthy, cultured Jew named Dr Meyer. Fest learned from him, but remarks that Jews like Meyer were passive, credulous and ignored warnings to go. So, in a sense, they brought their fate on their own heads. Not me, guv.

When he recalls his father's hunt for proof of mass murder he admits it was plain "to anyone who kept his eyes open". However, "gas chambers were never mentioned". He berates the BBC for not alerting Germans to the truth. This is incorrect, but Fest's faulty recollection enables him to suggest that Germans were kept in the dark by the Allies. Again, Not me, guv. What this memoir ultimately reveals is not only the exceptionality of an honourable family, but also the universal desire among Germans for an alibi that will get them off the hook of the Third Reich.

David Cesarani is writing a book about the fate of the Jews, 1933-1949, for Macmillan