Pauli rejects Fierz's criticism of his physical interpretation of complex energy values for an indefinite metric. To prove his case, he treats the interaction with the help of perturbation theory.

Pauli explains to Fierz why he believes that the elimination of non-physical states in the quantized field theory is only possible if the space-time description is dropped, i.e. in a pure S-matrix theory.

Pauli writes an appendix to the last letter of the 6 April 1958 and comments on a letter by Symanzik.

Pauli writes a circular letter dissociating himself from the contents of the preprint on the isospin-group in the theory of elementary particles and from his co-author ship with Heisenberg.

Pauli writes on his impressions from the Geneva conference where he was chairman. He talks about the failure of the younger generation vis-à-vis the problem of elementary particles and about his talk with Lehmann.

Pauli writes an appendix to the last letter of the 24 September 1958. He gives more remarks about van Hove's paper.

Pauli describes a dream which he had shortly after his return from the USA.

Pauli writes on Majorana's paper published in: Nuovo Cimento: 1932, with special reference to unitary representations of the Lorentz group. He adds some comments on his and Jauch's calculations concerning electron scattering experiments.

Pauli writes on the unitary representations of the Lorentz group and on the meson theory.

Pauli comments on a paper writtent by Davydov published in: Russian Journal of Physics. The papers concern irreversibility in quantum mechanics. He also writes on the recent results in cosmic-ray physics by Powell.