  In summer 1923, a year after his lectures on the `New Foundation of
Mathematics' and half a year before the republication of his two notes on the
`Foundations of Physics,' Hilbert delivered a trilogy of lectures in Hamburg.
In these lectures, Hilbert expounds in an unusually explicit manner his
epistemological perspective on science as a subdiscipline of an all embracing
science of mathematics. The starting point of Hilbert's considerations is the
claim that the class of gravitational and electromagnetic field equations
implied by his original variational formulation of 1915 provides valid
candidate `world equations,' even in view of attempts at unified field theories
\'a la Weyl and Eddington based on the concept of the affine connection. We
give a discussion of Hilbert's lectures and, in particular, examine his claim
that Einstein in his 1923 papers on affine unified field theory only arrived at
Hilbert's original 1915 theory. We also briefly comment on Hilbert's
philosophical viewpoints expressed in these lectures.
