In general outline at least the historical record is not in dispute. In 1946 Karl Popper addressed the Cambridge Moral Sciences Club on the subject Are There Philosophical Problems?. The subsequent discussion, chaired by Russell, is known to have been lively. At one point Wittgenstein, brandishing a poker, is said to have demanded of Popper that he offer an example of a moral rule: “Not to threaten visiting lecturers with pokers”, Popper is said to have replied. At which point Wittgenstein, perhaps deciding it was a case of “thereof one must be silent”, stormed out. It has been suggested that the title and content of Popper’s paper were intended to provoke Wittgenstein who by this time is thought to have become sceptical of the existence of philosophical problems, and to believe that such “problems” were instead reducible to the misuse of language. Whether his scepticism was as well defined as many think is open to question. An alternative reading of Wittgenstein might be that he was developing a metaphilosophical perspective from which standard philosophical problems were drained of their force. Thus in the Blue and Brown Books he remarks that “philosophy really is purely descriptive”. Presumably, also, Popper thought that Wittgenstein, a former pupil of Russell and Moore, and by this time a Cambridge Don, had never come across a philosopher who took seriously the existence of philosophical problems. None of this is important of course. What is most notable about the “Poker incident” is its delicious status as an originator of that most wonderful thing: the philosophical feud.
more from Andy Walsh at Talking Philosophy here.