About H. Thirring's 70th birthday, H. Thirring's son, Pauli and H. Thirring's departure from Austria.

Pauli asks some organizational questions in connection with the CERN conference. He writes about Weisskopf's visit to Israel.

Pauli writes about his decision not to co-publish with Heisenberg the investigation on the isospin-group. He talks about very strong criticism of the mathematical methods and the physical approach of Heisenberg and his collaborators. He gives suggestions about the possible line of research to be followed.

Pauli replies to Källén's letter of the 18 March 1958. He is now sure that the explanation of strange particles having half-integer difference of spin and isospin by means of a degenerate vacuum is wrong. This changes his view on the one-spinor model with "Pauli-invariance", from which only particles with integer difference of spin and isospin can result (i.e. no$\lambda_{o}$-particles).

Pauli replies to Wentzel's letter which gives hope that Schafroth, Bardeen, Bogoljubow and Wentzel will find a model of supra-conductivity. He writes about the Max Planck medal.

Pauli writes of his work with Gürsey. He writes about Glaser's idea to introduce indefinite metric into the Uhlenbeck-Pais's models.

About leaving Berkeley (University of California) to Brookhaven National Laboratories, and then going back home. W. Pauli mentions he has heard about biology, also from von Delbruck in Pasadena. Contains a passport photograph (copy) for his travel to USA in 1940 (comment from the hand of Franca Pauli).

Reprinted from the proceedings of the National Academy of Sciences, vol. 42, No 11, pp. 811-919. November 1956.