‘W.’, in the vocative, best serves to summon and summarise your mythical personality. In 1951, when I was first intrigued by Moral Sciences – as Cambridge formality (following David Hume) then termed philosophy – you had just left the scene, messiah whose apostles took him to have relegated metaphysics to the old curiosity shop. I was a callow twenty-year-old, apt with parodic proses and verses in Latin and Greek, bent on fiction, hot for the exit of ideology, including religion. The end of the war had seemed to promise a freshly levelled playing field. You were cast as Reason’s referee, decisive with the whistle at any flash of supposititious fancy. I took Freddie Ayer, author of the razor-edged Language, Truth and Logic, to be your linesman.

You had been barely twenty in 1911, when Bertrand Russell was approached, in Trinity, by a shriven Germanic pilgrim and, pretty soon, disconcerted by him. G.E. Moore suspected your rare quality when you alone looked puzzled in his lectures. Not long afterwards, the author of Principia Ethica, Bloomsbury’s secular gospel, went with you on a Norwegian retreat on which he, a full professor, played your amanuensis. What other incursion into Britannia’s philosophical élite has matched yours for disruptive intensity? I read you as possessed with passion for once and for all truthfulness, the stripping out of fancy. Philosophy, you said later, ‘leaves everything as it is’; but you left philosophy quite other than it had been (Bertrand Russell too).

Displacement of morals and ethics in favour of engineering, ...