Pauli has come to the conclusion that the results of his last letter were wrong, self-energy remains infinite. But it is different with the self-energy of charged particles.

Pauli comments in detail on the paper by Einstein-Podolski-Rosen and suggest that Heisenberg should write a reply. He analyzes the problem of composition and separation of systems in quantum mechanics. He is against Laue's and Einstein's idea that quantum mechanic is correct but incomplete. He comments on Wick's paper on the magnetic moment of the proton.

Pauli gives a detailed exposition of his calculation of the energy eigenvalues in Fermi's theory, and adds some hypothetical conclusions to this.

Pauli writes about an unpublished lecture by V Neumann where the mathematics of the density matrix is developed.

Pauli makes some remarks on Heisenberg's letter of the 7th November, based on his own former calculations.

Pauli thinks that Heisenberg's letter of the 19th November contains terrible nonsense.

Pauli makes a recapitulation of the properties of Pauli's and Heisenberg's model and gives a critical consideration of Fermi's theory of Beta-radioactivity. He makes remarks on recent publications on nuclear forces.

Pauli talks about further discussion of the Bethe-Heitler formula. He comments on the hard component of the primary cosmic radiation.

Pauli writes on the problem of wave-quantization as the fundamental problem of physics. He is inclined to drop the idea of the existence of a universal length, because such an assumption cannot lead to finite energy values in a quantized wave theory. He talks about the interpretation of recent results of shower-measurements.

Pauli makes a short acknowledgement of Heisenberg's letter of the 12 March.