Pauli comments on a philosophical manuscript by Fierz concerning the methods of classical physics and of quantum physics.

Pauli writes of another possibility of mixing Hamilton functions in special reflections.

Pauli makes some suggestions for a seminar talk to be given by Fierz.

Pauli writes on the question of the conservation of lepton charge in connection with Majorana's theory.

Pauli continues his discussion with Fierz about his mathematical treatment of the particle-antiparticle problem.

Pauli admits his blunder in predicting the conservation of parity and attempts to explain the psychological background. He writes on the symbolism of mirror-images, on his recent correspondance with Heisenberg on the dipole ghosts and psychological remarks about it.

Pauli asks about a letter by two Italian physicists concerning Neumann's macro-observables. He writes on a gnostic myth about the mirror image of Nous which appears as Physics. This symmetrical relation forms the basis of physics.

Pauli writes about a brief question concerning a paper by two Italians.

Pauli writes on the physical ideas of the Stoics, their "pneuma" and determinism and field physics as against the Greek atomism. The modern field physics is a direct descendent of the Stoa and the old conflict between atomists and continuists still exists today.

Pauli replies to Fierz's letter of the 21 November 1957.