Pauli replies to Fierz's letter of the 21 November 1957.

Pauli writes on a certain isomorphic relation (conservation of baryon number and rotary group of isotopic spin). He talks about his intensive work a new theoretical interpretation of the isospin-space.

Pauli reacts positively to the idea of Fierz's going to CERN. He expresses on the whole a favourable opinion on the work and on the atmosphere in CERN.

Pauli is positive about Fierz's ideas which seem to be promising for weak coupling.

Pauli asks questions about the unitary representations of the Lorentz group.

In this letter Pauli writes on the role of the unconscious in the unity of the individuum. He adds Bohr's view on this problem.

Pauli writes on his meeting with Fierz in Basel.

Pauli writes on Schwinger's impending visit to Zürich.

Pauli makes more comments on a paper written by Heisenberg.

Pauli writes on a talk he had with Bargmann on group theoretical problems.