On Simon Blackburn’s offbeat personal website, there are no buttons to click on, only paintings and portraits, including an animated one of the Scottish Enlightenment philosopher David Hume with a winsome wink and a smile. At the top of the page is a photograph of Prof Blackburn himself, also smiling – not like Hume, but in the manner of a convincing psychopath. The caption reads: “Here is a picture of me about to pounce on someone with a quick dialectical jab to the cortex.”

When not having to pose for the camera, Blackburn, master philosopher and skilled writer, smiles easily and naturally. His voice is smooth and creamy, with a touch of gravel, like sand in a sorbet. The dress style – blue blazer and open-necked shirt – is smart but not over-considered and his spectacles are firmly attached to a fabric lanyard. He comes across very differently from the rather twitchy philosophy professors of my student days, men who were often challenged by normal human intercourse. Blackburn’s authority is carried naturally – it seems to attach itself to him unbidden, cast casually over the shoulders like a well-worn scholar’s gown.