Fierz writes on the elaboration of the concepts of polar opposites and complementary opposites. He refers to Kant and Leibniz.

Fierz sends some calculations with reference to Chandra's work on the infinitesimal Lorentz group.

Fierz summarizes Harish-Chandra's work on simplified integration of symmetric-tcp wave functions by Lorentz transformation.

Fierz makes some remarks about top-functions.

Fierz withdraws an incorrect remark from his letter of the 17 October 1952.

Fierz replies to Pauli's letter and manuscript of his paper "On the Hamiltonian structure of non-local field theories."

Fierz investigates whether the non-statistical H-curve has the properties demanded by Boltzmann.

Fierz writes on Newton's philosophical background, between Descartes' rationalism and Hume's scepticism.

Fierz writes on gravitational waves, on the symbolic significance of the blue colour and on Henry More's third "Divine Dialogue".

Fierz writes on Goethe and the blue colour. He makes further remarks on Henry More and Newton and on their rejection of Descartes' mechanistic world picture.