Vinelott became secretary of the Cambridge Moral Science Club, a twice-weekly philosophical discussion group. He regarded his role at these discussions as being to ask the idiotic questions which Wittgenstein and Bertrand Russell would then demolish.
Vinelott was present at the celebrated occasion in 1946 when Karl Popper came to deliver a paper on "Are there philosophical problems?" and became embroiled in a row with Wittgenstein over the fundamental nature of philosophy; by some accounts, the dispute led to the two men battling for supremacy with red hot pokers.
The incident, referred to in Popper's intellectual biography Unended Quest, sparked an acerbic exchange of letters between those who had attended the meeting, which gave conflicting testimonies of exactly what had taken place.
The irony was that the dispute had arisen between people who were expert in theories of epistemology (the grounds of knowledge).
According to the philosopher Peter Geach, "Wittgenstein picked up the poker and said 'Consider this poker'. He found discussion with Popper futile and put the poker down" before walking out.
But Vinelott supported Popper's account, which had Wittgenstein seizing a poker and challenging Popper to "give an example of a moral rule".
"Not to threaten visiting lecturers with pokers," Popper replied, whereupon Wittgenstein, in a rage, threw the poker down and stormed out of the room, banging the door behind him.
[Magee's book, below, is a good guide to Popper's philosophical work.]