This is the script of this morning’s Thought for the Day on BBC Radio 4’s Today Programme.

The other day I was browsing the German political journal Der Spiegel and found my attention arrested by an article the like of which I have not seen before. It was written by Niklas Frank, son of Hitler’s notorious General Governor of Poland Hans Frank. His father, a politician and lawyer, was executed as a war criminal at Nürnberg in October 1946.

The thrust of the article is that at the age of 80, having thought his father’s legacy had gone from the earth, he now discovers echoes of the same rhetoric in the mouths of some extreme right-wing politicians in Germany. And he is a very worried man.

The poet and playwright Bertolt Brecht ended his play ‘The Resistible Rise of Arturo Ui’ with the warning that the end of Nazism did not mean that its ideology died in a Berlin bunker. And here is Niklas Frank’s concern: that the same old ideas find their way back into our discourse while we are not looking, and sound reasonable in the midst of current uncertainties, crises and fears.

One of the things I began to learn many years ago is that my children might well have to forgive me for the wrong things I have said or done to them or others. Parents always make it up as they go along, seeking advice and trying their best. But, I doubt if any of us looks back with smug satisfaction at having got everything right. But, that is a far cry from having to live with the knowledge of a father’s crimes against humanity and the legacy this left for the whole world for ever.

When Shakespeare wrote in the Merchant of Venice that “the sins of the father are to be laid upon the children,” he was echoing the Hebrew Scriptures when they describe – rather than prescribe – reality. We inherit and cannot escape from the consequences of the sins of the fathers and mothers, and maturity involves coming to terms with this and living with or despite it.

For Niklas Frank, however, the matter cannot be left there. His inheritance, he believes, imposes on him a moral obligation to see through his father’s eyes the language and rhetoric that would have been as familiar as it was effective. So, when political language betrays a view of human beings that dehumanises them or dismisses their dignity, Frank sees the urgent need to identify where this thinking led in the past – his own family’s past.

I guess he would sympathise with WH Auden who once wrote: “All I have is a voice to undo the folded lie”. This tells me that I don’t have to have had a murderous father before listening for the language that turns people into numbers or objects, converts their inconvenience into disposability, or elevates my own self-righteousness above the dignity of those who have less power.