Jan Karski became somewhat well known after the release of Claude Lanzmann's Shoah, where Karski is an anxious, halting, intense presence in the second half of the film, with an unforgettably creased face and adz-shaped head. He was a member of the Polish underground government--one of its couriers from inside the Nazi-occupied nation after 1939. In 1942 he met with two Jewish leaders who told him what was happening to the European Jews. He listened, then visited the Warsaw ghetto twice, and then set off for London and Washington with the goal of persuading the allied governments to stop the genocide. He did not succeed, and knew from the start that "The truth might not be believed," as he put it in a document he wrote a little later.Here is a passage from that document:
This was the solemn message I carried to the world. They impressed it upon me so that it could not be forgotten. They added to it, for they saw their position with the clarity of despair. At that time more than 1,800,000 Jews had been murdered. These two men refused to delude themselves and foresaw how the United Nations might react to this information. The truth might not be believed. It might be said that this figure was exaggerated, not authentic. I was to argue, convince, do anything I could, use every available proof and testimonial, shout the truth till it could not be denied.
They had prepared me an exact statistical account of the Jewish mortality in Poland. I needed some particulars.
"Could you give me," I asked, "the approximate figures of the murder of the ghetto population?"
"The exact figure can be very nearly computed from the German deportation orders," the Zionist leader informed me.
"You mean that every one of those who were presumably deported was actually killed?"
"Every single one," the Bund leader asserted.
A longer excerpt can be found here.
"I teach horizontally, meaning that while I might begin with a fixed idea of what I'm going to teach that day, I let it drift rhizomatically way off topic, often pulling it back when it gets too far. I rely on non-fixed materials to teach this way; the whole world is at my fingertips. Should I go off on a tangent about John and Rauschenberg and their love relationship as expressed in Rauschenberg's bed, an image of that bed is always a click away. From there, we can head anywhere into the non-fixed universe, be it film, text or sound. And of course, that always takes us elsewhere. As Cage says, 'We are getting nowhere fast.'" 
that anyone has yet got the imaginative measure of that terrifying day six years ago. Certainly our Tolstoy has not crawled out of the rubble. The closest we have, Don DeLillo, succeeded as an essayist-journalist ("In the Ruins of the Future: Reflections on Terror and Loss in the Shadow of September,” Harper’s, December 2001) but, to my mind, failed as a novelist ("Falling Man"). One reason, perhaps, is that the remembered emotion was instantly buried under a pile of cultural junk.' - Tod Gitlin in his review of Susan Faludi's The Terror Dream (written for 
