Today, Teresa and I join all Americans in marking the 70th anniversary of the liberation of Auschwitz-Birkenau, and in honoring the memory of all the victims of the Holocaust.

We bow our heads in remembrance of the six million Jews and the millions more murdered by the Nazis – including Poles, Roma, LGBT people, persons with disabilities. I do so with the added weight of knowing more than I ever have before about the losses my grandfather’s family suffered in the Holocaust, a history my brother Cam passionately helped unearth in his own visit to the Czech Republic. Whether our own families have personal connections to these horrors or not, none of us should ever forget that behind each of the victims was not a number, but a name and the story of a life cut short, a future not realized, a family bereft, and an irredeemable loss of talent and love.

We owe it to each of them to keep their stories alive so the world will never again tolerate such evil. We keep faith with the survivors who emerged from the cauldron of Holocaust and war to build institutions and order dedicated to the principle that never again should crimes of such horror and magnitude be committed on this Earth.

Edward R. Murrow referred to the Holocaust as “a horror beyond what imagination can grasp.” And yet the reality is that the Shoah was not only imagined, it was carried out by one group against another. In founding the United Nations, President Truman reminded us that “it is easier to remove tyrants and destroy concentration camps than it is to kill the ideas which gave them birth and strength.”

Today, none of us can be satisfied that the lessons of the Holocaust have been adequately learned. Anti-Semitism is again on the rise, and hate is still the dominant force in too many hearts. Too many people still suffer not because of anything they have done, but simply because of who they are.

That is why today is more than a time for reflection. The duty we have is an active one: to confront and defend against those who attack others on the basis of race or religion; unite against anti-Semitism and all forms of bigotry and sectarian hate; insist on the rule of law in relations among states and between people; and reaffirm our commitment to the fundamental rights and dignity of every human being.