Tony Judt opens this essay on the late historian Leszek Kolakowski with this anecdote, which I enjoyed:

I heard Leszek Kolakwoski lecture only once. It was at Harvard in 1987 and he was a guest at the seminar on political theory taught by the late Judith Shklar. Main Currents of Marxism had recently been published in English and Kolakowski was at the height of his renown. So many students wanted to hear him speak that the lecture had been moved to a large public auditorium and guests were permitted to attend. I happened to be in Cambridge for a meeting and went along with some friends.
The seductively suggestive title of Kolakowski’s talk was “The Devil in History.” For a while there was silence as students, faculty, and visitors listened intently. Kolakowski’s writings were well known to many of those present and his penchant for irony and close reasoning was familiar. But even so, the audience was clearly having trouble following his argument. Try as they would, they could not decode the metaphor. An air of bewildered mystification started to fall across the auditorium. And then, about a third of the way through, my neighbor—Timothy Garton Ash—leaned across. “I’ve got it,” he whispered. “He really is talking about the Devil.” And so he was.
It was a defining feature of Leszek Kolakowski’s intellectual trajectory that he took evil extremely seriously…