Pauli letter collection: letter to Niels Bohr

Pauli was glad to have Bohr's recent letter and was particularly glad to hear that part II of the joint paper by Bohr and Rosenfeld made such good progress. However, he goes on to say that "there is one important point regarding the consequences of the quantum-electrodynamical formalism for charge- (and current-) fluctuations (positron-theory) on which he cannot agree with you: according to my opinion Heisenberg was entirely right in his claim of unsharp limitations of either the space or the time domain in which the charge (or current) fluctuation is considered in contrast to the case of energy (and momentum) fluctuation of the radiation (where a sharp limitation of the space-time region is sufficient to guarantee a finite value of the square of the mean value of the field strenght over this domain)". The letter also contains other scientific problems.