Pauli criticises a paper by three pupils of Heisenberg on "the formulation of quantized field theories". He makes some remarks on Lee's model.

Pauli gives more calculations and questions about Heisenberg's formalism.

Pauli comments on a letter by Källén and his problem of two N-particles.

Pauli talks more about the indefinite metric which Pauli rejects.

Addendum to appendix of last letter, giving Pauli' conclusion. The discussion with Heisenberg has not brought him nearer to a possibility of interpreting physically the formulae derived from the indefinite metric.

Pauli suggests suspending the discussion until new points of view emerge.

Pauli is pleased whith Heisenberg's letter of 24 February and continues the discussion.

Pauli replies to Heisenberg's letter of 27 February. He thinks that understanding between him and Heisenberg may be impossible, because he regards Heisenberg's calculations and interpretation as "wishful thinking". There is a discussion of the parity problem.

Pauli talks about a possibility of meeting Heisenberg at the end of the month. He wants to discuss with him the influence of the finiteness of masses on the form of the potential, the wave-mechanical V-N-scattering problem indefinite metric and the paper and lecture by Nishijima.