On Sunday it will be 74 years since the first outriders of the Red Army reached the infernal universe of Auschwitz-Birkenau. 27 January is not a date in the Hebrew calendar, – that is 27 Nissan, Yom Hashoah. But it has become a critical and essential date in the moral history of humanity.

Every year I reread Primo Levi, whose accounts in If This Is A Man and The Truce will always remain among the most discomfortingly perceptive testimony to the vast, unfathomable multitude of crimes which is the Holocaust:

for us even the hour of liberty rang out grave and muffled, and filled our souls with joy and yet with a painful sense of pudency, so that we should have liked to wash our consciences and our memories clean from the foulness that lay upon them; and also with anguish, because we felt that this should never happen, that now nothing could ever happen good and pure enough to rub out the past…

It is poignant to note that 74 is signified in Hebrew by the letters ayin and dalet, which together form the word ed, witness. This is precisely at a point when we are acutely aware that the last survivors of the Shoah are in their eighties and nineties and will not be with us forever. Who will testify then?

In a moving ceremony at the Foreign office earlier this week, Lord Eric Pickles, special envoy for post-Holocaust issues, noted that the website of the Holocaust Museum in Washington is the second most visited site on the subject. One might have thought that above it would come Yad Vashem or the museum and memorial at Auschwitz itself. But this is not the case; first place on the subject is taken by a Holocaust denial site.

There is no guarantee that what history records over the long elapse of time is actually the truth.

Therefore, the commemoration of the hour of liberty must still ring out grave and muffled for humankind, because we cannot and must not wash the wrongs of the past out of our memory and conscience.

The reason is not to preserve a sense of victimhood, or to make a moral claim against other nations, or agents, though the latter may sometimes remain important for the sake of the vindication of truth. Nor is it solely or primarily for the sake of the Jewish People. The matter goes far wider. There have been genocides since the Shoah, notable 40 years ago in Cambodia and 25 years ago in Rwanda. Each unique in its particular context and the nature of the cruelties practised upon its powerless victims, crimes of indescribably brutality and scale continue in the world today.

At stake is not the past but the present and future of humanity, in fact the very meaning of what being human is. Perhaps never since 1945 has this been so acutely the case. If we don’t want to succumb to the rallying cries of resurgent racism and xenophobia across the world, if we don’t want our conscience to be sucked in and dissolved in the acid stomach of hatred, we need to listen, learn and act.

Action begins with little things, noticing our own prejudices, not ignoring the person who seems lonely, bullied or left out; not being oblivious to the daily realities of being destitute, homeless, a refugee; not being seduced by the comfort of thinking we belong to the safe ‘us’, the comfortable majority at liberty to denigrate whoever the current ‘them’ might be.

We are one another’s guarantors; the safety and human dignity of others lies in our hands, words, hearts and deeds. Only by standing up for each other’s humanity can we truly assure our own. There is nothing else between degradation, humiliation and persecution, whether we become victims or perpetrators.

‘This isn’t about the past’, Lord Pickles said, ‘It’s about now’.