Footnote q1

q1. In a letter to a fellow physicist, Henry P. Stapp, Werner Heisenberg tells of his differences with Russell.

I think that you [Stapp] have too much confidence in the possibilities of language. I think that the attitude which is behind the Copenhagen interpretation [of quantum physics] is not compatible with the philosophy of Wittgenstein in the Tractatus. It may be compatible with the philosophy contained in the later papers of Wittgenstein. As you probably know, Bertrand Russell liked the Tractatus of Wittgenstein, but disapproved of the later papers, and therefore I could never come to an agreement with Russell on these philosophical questions.

From Mind, Matter and Quantum Mechanics, 3rd Edition, by Henry P. Stapp (Springer 2009).

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