Three quarters of a century ago, a genocide took place in Europe. This genocide, in other words, the explicit decision to destroy a people, was aimed at the Jews. Before them, there was the genocide of the Native Americans by the Spanish and the English. Then there was the genocide of several African tribes by the English, Belgians, and Germans. After that, there was the genocide of the Armenians by the Turks. And so many others.

The genocide of the Jews is a particular case, insofar as it led to, on European soil, the death of half of a group of European people, murdered by another group of European people. It is something that more and more Europeans are doing everything to forget.

Lest we forget that we had nothing to reproach these people, except that they existed and were who they were. Lest we forget that anti-Semitism is based on the desire to get rid of a people to whom the other monotheistic religions owe the idea of a single god, the book that recounts the feats of this god, and the city at the center of this faith. Lest we forget that we also owe them for conceiving the idea of hope, and in particular the idea of progress; hence their obligation to play, through no fault of their own, the role of banker.

In order to make people forget that we owe them for all of this, they had to disappear. And we have used this in Europe whenever it was necessary to select a convenient scapegoat for the misfortunes of the world.

Lest we forget that the most recent of these anti-Semitic massacres led to the death of half of the Jews, six million people, one million of them in Auschwitz alone. Six million people, almost all of whom were extremely poor, with no power or influence in the world, contrary to what they were accused of. Lest we forget that they were killed with knives, rifles, machine guns, and by a thousand other means, including gas chambers, by hundreds of thousands of executioners, mostly Germans, with Polish, Russian, Hungarian, Belgian, Ukrainian, French and many others in their ranks.

We forget that, when it was still possible to save them, those who could have done so attempted nothing; neither in 1933 to put down the Hitlerian regime, when it was still possible; nor in 1938 to shelter the future victims, whose future executioners were still willing to let go ; nor in early 1944, when it would have been possible to destroy the gas chambers, which we knew existed, by aerial bombardment and thus prevent the death of the hundreds of thousands of Hungarian, Czech and French Jews who were to be sent there.

And what about today? What lessons can we learn from this? At least, six:

1. Anyone placed in certain circumstances can become an executioner. We saw this in the last years of French Algeria and more recently in the former Yugoslavia. And we see it every day in Syria, Iraq and many other countries.

2. Anyone placed in the same above-mentioned circumstances can become a hero. We have seen it, and we see it in these same countries.

3. Culture cannot protect against barbarism: Some of the Nazi leaders, including the most appalling concentration camp leaders, were highly cultured. This was also the case for the Khmer Rouge leaders. And other modern tyrants.

4. The signs of a return of anti-Semitism are there: the global economy is sick; globalization and migration are worrying; inequalities are intolerable; and there are people who need scapegoats again.

5. Other people, besides Jews, could become scapegoats and be victims of mass massacres, more or less explicit. Among them, in China, the Uighurs; in Brazil, the indigenous tribes; in Europe, migrants; in the Middle East, the Palestinians. And many others.

6. Finally, a completely different type of genocide has begun: humanity, as a whole, is murdering a very large number of living species at this very moment, with the same barbarity and cynicism of executioners and the same indifference of almost all the others. As if the Nazi death industry was just the crudest form of what is being set in motion today to destroy many living species.

It is to be hoped that these murderers will one day be judged by an international court; at least it will be proof that humanity had survived these future massacres. Unless, of course, it is already dead. In Auschwitz.

For this not to become true, for humanity to have a future, it would suffice to just not forget the genocides of the past. And to use our memory to think about our future.