Pauli replies to a letter of the 25 July 1954. He explains his critical attitude to ontology but he conceeds that ontology reflects an intrinsic need of man to overcome the tension between the "Internal" and the "External".

Pauli discusses "Part IV" of Heisenberg's S-matrix theory published in: Zeitschrift für Naturforschung: 1, 608.

Pauli thanks Hulthén for sending the French edition of Lagervist's work on the Lamb shift.

Pauli states again his conjecture that a penetrative radiation is emitted in the Beta-decay. He also repeats his more important that conservation of energy and momentum in nuclear processes is conservation of all quantized quantities and the law that the symmetry character of the total system is not changed. by such a problem. He discusses relations between proton and neutron, and in great detail, the theory of holes.

Pauli gives some suggestions for a joint meeting with Born in Bolzano. He comments on the theory of holes in the light of Peierl's results.

Pauli congratulates Heisenberg on the receipt of the Nobel prize. He gives some comments and calculations on the theory of holes. he believes that the problem of the neutrino is connected with that of holes.

Pauli doesn't accept Heisenberg's arguments in his letter of the 12 November 1933 and shows by calculations his objections.

Pauli compares Heisenberg's formalism with that of Dirac and gives some calculations of certain matrices.

Pauli makes additional remarks to the calculations on the theory of holes.

Pauli writes of his impression of Dirac's manuscript and gives a short precis of Dirac's ideas. He makes more remarks on the problem of self-energy.