  John von Neumann's transformation from a logician of quantum mechanics (QM)
in the 1920s to a natural philosopher of computation in the 1950s is discussed.
The paper argues for revision of the historical image of Neumann to portray his
change to an anti formalist philosopher of computation. Neumann abandoned
Hilbert's programme that knowledge could be expressed as logical predicates.
The change is described by relating Neumann's criticism of Carnap's logicism
and by discussing Neumann's rejection of the Turing Machine model of
computation. Probably under the influence of the founders of modern physics in
particular Wolfgang Pauli and Werner Heisenberg at the Advanced Study
Institute, Neumann changed to a natural philosopher of computation. Neumann's
writings from his development of the now almost universal von Neumann computer
architecture are discussed to show his 1950s view of algorithms as physicalized
entities. The paper concludes by quoting Neumann's statements criticizing
mechanistic evolution and criticizing neural networks.
