Pauli comments on an essay by Erich Neumann in the Eranos-Yearbook of 1948.

Pauli returns to a problem discussed at the Florence conference concerning irreversibility and the H-theorem.

Pauli refers to questions regarding the equivalence of pseudovector coupling.

Pauli confirms that there will be a physics meeting in Basel in September. Schwinger, Rabi, Fermi, Cockcroft, Dyson and others have promised to come. Pauli is going to Princeton in November, but he will be back in May 1950. He gives some comments on his own latest work.

Pauli thanks Weyl for his book on the philosophy of mathematics and natural science. He makes two critical remarks: 1) It is not correct to connect Leibniz with the principle of exclusion. 2) There is no asymmetry of the past-future relation in spontaneous radiation processes, but the concept of spontaneity needs a better definition.

In this letter, Pauli gives further remarks on Weyl's parallel between Leibniz's principle and the exclusion principle. He also writes on Jung's synchronicity and its relation to causal events. It's said that the "elimination of all uncontrolable factors necessarily leads to destruction of the significance of synchronicity".

Comments on Bohr and Rosenfeld's article 'Field and charge measurements in quantum electrodynamics'.

About a report or speech by E. von Kahler on history. Remarks on the concept of history.