Pauli is ready to contribute to the Festschrift for Sommerfeld. In connection with experiments in the U.S.A. on the shift of S-terms in the H-atom he has returned to quantum electrodynamics.

Pauli thanks Jordan for sending him the booklet on "Komplementarität und Verdrägung". He writes of C G Jung's interest in these questions as well as in Rhine's experiments. He talks about Jung's "synchronistic" phenomena.

Pauli criticizes certain passages in Heisenberg's manuscript of the Dialectica-article, and asks to correct them. He writes about the "fundamental length" in quantum theory. The problem is not how to introduce such a length, but how to get rid of the multitude of lengths (Compton-length for each particle) in the present theory.

Pauli comments on the treatment of a certain integral. He writes about the structure of a future theory which will describe simultaneously all elementary particles and their masses.

Pauli's letter is on existensialism, on the process of cognition and the idea of God, on the concept of reality, and the reality of symbols, on the relation of physics and psychology and on Jung's reaction on Pauli's ideas.

Pauli talks about questions concerning the "Dialectica" issue. He also writes about recent progress in theoretical work on electrodynamics and mesonic problems. He reminds Bohr to not forget Sommerfeld's 80th birthday on the 5th December 1948.

Pauli thanks Bohr for his letter of November 26. He is expecting now almost every day the appearance of the issue of "Dialectica". He is not sure whether it was really a good idea to send him some manuscripts by Born.

Pauli writes about papers written by Schwinger on vacuum polarization and self-energy. He adds remarks words on Dyson and Feynman.

Pauli received an elaboration of Jauch's lecture.

Pauli discusses on his work on unipolar induction and on his reactions to Dirac's theory of the single magnetic pole.