On 12 June 1940, as the Germans broke through the French lines and
Paris lay open before their advance, [Isaiah] Berlin went on to
deliver a paper on `Other Minds’ to the Moral Sciences club
in Cambridge. In Oxford, the imminent fall of France was on
everyone’s mind. In Cambridge, the otherworldliness of the dons
was unreal.

All of the Cambridge philosophers turned out – Braithwaite,
Broad, Ewing, Moore, Wisdom and a sixth figure, small and handsome of
feature, who appeared surrounded with acolytes in tweed jackets and
white open-necked shirts identical to his own. This was Ludwig
Wittgenstein. Berlin delivered his paper on the problem of how one
could have knowledge of others’ inner mental states. It was, he
remembered `terribly boring’. After a few initial questions,
Wittgenstein became impatient and took over the discussion. Berlin
remembered him saying `No, no, that is not the way to go about it
at all. Let me see. Don’t let’s talk philosophy. Let’s talk business
with each other. Ordinary business. In ordinary circs, I say to
you, “You see a clock. The minute hand and the hour hand are both
nailed to the clock face to certain ciphers. The whole face goes
round, but the time remains the same.” No? That is solipsism.’

It was idiotic, Wittgenstein was saying, to claim that time had
stopped simply because the hands of the clock remained motionless.
Time changed whatever the clocks, whatever the sense data happened to
record. This was a vintage demolition of Ayer’s type of
verificationism. No one else spoke. `Broad sat there like a
boiled lobster looking angry. G.E. Moore, old and decrepit, looked
open-mouthed.’ Isaiah parried as best he could and the acolytes
hung on every word and dared not interrupt. After an hour,
Wittgenstein rose to his feet, his acolytes rose with him, and he
leaned over the table and shook Isaiah’s hands. `Very
interesting discussion. Thank you.’ With that, other participants
crowded around and said how rare it was to be complimented in this
way. But Berlin was not fooled. Wittgenstein hadn’t been much
impressed with the paper or Isaiah’s arguments afterwards. But he
did seem to think that Berlin had been honest and sincere, not trying
to show off, as Freddie Ayer might have done. Wittgenstein’s
judgment was Berlin’s own, and their encounter marked the
symbolic, if not the actual, end of Isaiah’s active philosophical

(Memorandum of interview, Michael Ignatieff with Isaiah 
Berlin, 7 Feb 1990)