Jordan replies to Pauli's letter of the 17 July 1953. He gives certain results of the calculations of Schücking, which are based on Jordan's cosmological equation.

The letter talks about Pauli's visit to Copenhagen in April and about the progress he made in the kinetic of heat conduction in solids.

Bohr thanks Bohr for his letter of the 25th September.

Pauli capitulates to Bohr and Thomas and suggests some improvements in Thomas' manuscript. He also plans to visit Copenhagen. At the end of the letter Pauli writes to Kramers.

Pauli suggests postponing his visit to Copenhagen. He talks about his work on quantum electrodynamics and makes a criticism of Klein's paper in the Zs. f. Phys. Pauli thinks that Klein is not ready to see the use of multidimensional spaces as an inherent part of the approach of quantum phenomena.

This letter is a reply to Bohr's letter of the 15th July. Pauli writes about Jordan's manuscript. He criticises its last paragraph where Jordan does not distinguish between the particles (de Broglie field) and the electromagnetic field. He talks about Jordan's and his own work on radiation electrodynamics in the absence of charged particles. He also writes about a paper by de Broglie in the Journ. de Phys. which attempts to harmonize between dualism of waves and corpuscles on the one hand and complete determinism of physical events on the other hand.