 In the final Chapter VI of his book (von Neumann 1932), von Neumann provided a systematic discussion of quantum mechanics with collapse upon measurement (described by what he calls an intervention of type \(\mathbf{1})\), as distinct from the Schrödinger equation (intervention of type \(\mathbf{2})\), and traditionally associated with a role for conscious observation. (The two types of interventions are introduced already in Section V.1, but von Neumann postpones their conceptual discussion to the final chapter.)