Polish resistance hero Jan Karski speaking to a 1981 conference on the Holocaust at the US State Department. Photo: Screenshot.

Footage of one of the most celebrated Polish resistance fighters describing the Holocaust as humanity’s “second original sin” was widely shared this week, as the world marked the 75th anniversary of the liberation of the Auschwitz death camp.

“My faith makes me say that humanity has committed a second original sin by allowing the Holocaust,” said the late Jan Karski — a devout Catholic who publicized the facts of the Nazi extermination of the Jews at great personal risk — in an address to Holocaust scholars at the US State Department in 1981.

“This sin will haunt humanity until the end of the world. It haunts me. I want it to stay that way,” Karski said.

The video was being promoted by the Jan Karski Society — an NGO based in the Polish city of Kielce that promotes ethnic and religious tolerance in tribute to Karski’s legendary career.

“The Jan Karski Society believes that these words should be heard even louder today,” the group said in a statement on Monday.

Born Jan Kozielewski in 1914 in Lodz, Karski  fought in the Polish army in 1939 when he was captured by the German invading forces. While being deported to a POW camp, Karski escaped, and went on to serve the Polish underground resistance.

In 1942, Karski was smuggled into the Warsaw Ghetto on two different occasions, providing essential eyewitness accounts of the suffering of its Jewish population. The following year, Karski met with President Franklin D. Roosevelt in Washington, DC, famously recounting afterward that the American leader had asked about the condition of horses in Poland, but not the country’s Jews.

Karski moved to America after the war, becoming a professor at Georgetown University. He passed away in 2000.

“This Sin Will Haunt Humanity Until the End of Time” — Watch Jan Karski’s 1981 speech below: