Pauli letter collection: letter to Wolfgang Pauli

Heisenberg objects to Pauli's analogy between quantum mechanics on the one hand and quantum electrodynamics and classical Maxwell theory on the other hand. There is not only Maxwell's equations must be quantized, but also the De Broglie Waves. He explains his ideas on the intuitive meaning of quantum mechanics: 1) position of the electron 2) "orbit" of the electron. He agrees with Dirac that their experiments introduce statistics 3) on the "velocity" of the electron. 4)the transition from micro- to macro-mechanics. He writes that every new observation defines a new state. There are a few examples as illustrations.