It is wrong to dwell incessantly on the excesses of an increasingly distant past. Yet awareness of its past continues to haunt discussions in Germany about modern biology, particularly stem-cell techniques. And a history of barbaric science willingly carried out under tyranny may be all too relevant elsewhere today and in the future. So a statement last week by the head of Germany's most prestigious scientific institution deserves widespread attention.

Hubert Markl's thoughtful apology (see page 726) for the violations of human dignity perpetrated by scientists of the Kaiser Wilhelm Society, which was dissolved after the Second World War and re-established as the Max Planck Society (MPS), was well expressed. Avoiding self-serving rhetoric, he reflected that no one has the right to seek forgiveness, or alleviation of guilt, for “inextinguishable shame”; they can only express recognition of responsibility, and regret. In his speech to science historians and survivors of Josef Mengele's experiments in Auschwitz, Markl expressed a truth that Germans often flinch from articulating: that Germany was not the first and, tragically, not the last to develop an inhuman, racist regime that used genocide as a political instrument.

When his presidency of the MPS ends next year, Markl can take pride in his achievement of having opened up not just the archives of the MPS to independent historians, but also a better-informed debate on how German scientists can appropriately reflect on the Nazi past while embracing a confident future.