Pauli gives further analysis of the entropy concept. The entropy of an ensemble is identical with the entropy of a single system. This under the condition that it concerns the measure of the information corresponding to the same ensemble.

Pauli is preparing for his lecture in Mainz. He has read a book by R Otto on "West-eastern mysticism" (1926), and he writes about its contents. He writes a long excursion on the problem of salvation versus science. He believes cognition and scientific cognition tend to come nearer to each other.

Pauli comments on a paper by Farquhar and Landsberg "On the Quantum statistical ergodic and H-theorem" which refers to Fierz's work. He also makes additional remarks on Fierz's paper on the H-theorem.