This year marks the 75th anniversary of the liberation of Auschwitz, a Nazi concentration camp whose chief function was the murder of Europe's Jews.
The number of people murdered at Auschwitz, is often given as 1.2 million, nearly 1 million Jews.
While many non-Jews were also killed, including Roma,Poles, Russians, Czechs, the unique situation of the Jews, was that they were the only group targeted in the Nazi plans for complete annihilation.
Like others, I must concede that the Holocaust is incomprehensible.
Seemingly impossible to understand how the German nation which at the turn of the 20th century was at the forefront of science and the arts, a nation which had produced the likes of Schiller, Goethe and Beethoven, could in a few short decades descend into such barbarism.
Dr Jacob Bronowski attempts an answer in the BBC series Ascent of Man, his presentation on science. His answer, given while standing in a stream at Auschwitz, where his family members' ashes were strewn, is straightforward. It is thinking that is the opposite of science, which he describes as tentative in its conclusions.
Bronowski attributes the inhumanity to a dogmatic belief in absolutes carried to extremes and abetted by the immorality of allowing ends to justify means.
My own imperfect understanding is about the way in which deception played such a central part in implementation of the Nazi plan.
In his monumental film Shoah, Claude Lanzmann interviews survivors, witnesses and perpetrators.
The Shadows of Shoah exhibition.
The result is direct evidence of the way in which the Nazis used divisiveness and separation of their potential Jewish victims from fellow citizens, along with language designed to lull suspicion every step of the way from the cities to the ghettos to transit camps and from transit camps to death camps.
Even to each other the Nazis spoke of "the final solution," meaning murder and of "shipment to the east," for Auschwitz, and its gates claiming "Arbeit Macht Frei" (work means freedom).
The prospective victims would not, could not believe, the report of rare witnesses. It was their own very human sense of hope which fostered their gullibility until it was too late to resist.
Stalin said "one person's death is a tragedy, the death of millions is a statistic."
Those statistics contain the murder of nine members of my immediate family but not the singular example of my cousin Leo, who spent two years, as a child along with his mother Soucha in one of the Nazi masterworks of deception, Thereseinstadt, just outside Prague.
The camp is famous for its use by Adolf Eichmann as a stage set, a model concentration camp, designed to fool the visiting Swiss Red Cross who reported it as tolerable.
In reality it was a transit camp, with most inmates shipped on to death camps. Of the 15,000 children who passed through, only 35 survived. Leo is one of those survivors by virtue of his mother's heroism. At liberation, he was 10 years old.
In 2008 as Leo was rounding on his 75th year, he invited my family along with his to visit his former concentration camp, in order to help his children and grandchildren and my family understand what he had endured.
Marking the anniversary of the Holocaust.
Today, while he bears some scars of his experience, he hasn't allowed it to distort his outlook.
Leo has had a distinguished career as a pharmacologist. He has a loving wife, a family of devoted daughters and five granddaughters. For him, as for British poet, George Herbert, living well is the best revenge.
Since Auschwitz, the world has witnessed several genocides — Indonesia, Cambodia, Rwanda, Myammar (formerly Burma) – with minimal consequence, despite the resolution of "never again."
The very least we can do is to be better witnesses, to secure the facts of what happened and not to look away or be deceived.
We must be in pursuit of the truth, especially when it leads to dark places. Only by bringing light to bear on the darkness can we strive to retain our common humanity.
