There’s this wonderful anecdote in Life with Lacan, a book published by Catherine Millot, the French philosopher’s long-suffering mistress.

So one day Millot and other people including the German philosopher Martin Heidegger visit the apartment and Lacan’s wife — Millot explains — insisted that the visitors put on slippers. Once seated, Lacan launched into a lengthy disquisition on entangled Borromean knots, which, as Millot says, became a crucial feature of his thought and is to this day a really boring one.

Lacan, always a shocking bore himself, even took out a piece of paper to draw his knots, while Heidegger, reclining on a chaise longue, like a subject of analysis subjected to radical measures by a desperate psychiatrist, closed his eyes and didn't say a word.

"I wondered if this was his way of expressing his lack of interest or if it was due to the decline of his mental faculties," Millot reflected.

In any case, Lacan ("who was not a man to give up") persisted with his obsessions until Frau Heidegger, worried that the visit was tiring her husband, ushered them out of the house, but not before demanding the slippers.

Such was the one and only encounter between two great European intellectuals. We will never know if Heidegger's silence implied a rejection of Lacanian's later psychoanalytic theory.