Pauli letter collection: letter to Werner Heisenberg

Pauli replies to some points in Heisenberg's letters (18th April 1947 and 20th June 1947). The idea of an analytical continuation of the S-matrix is a failure. He is scepticalabout future theories, especially as the problem of the dimensionless constant e2/(n.c) is not solved. He doesn't believe in the existence of a universal length. He does not believe either in the mathematical existence of a convergent quantum electrodynamics with arbitrary e2/(n.c). He writes of his impending visit to Sweden and Copenhagen.