  We discuss a possible framework for the construction of a quantum gravity
theory where the principles of QFT and general relativity can coexist
harmonically. Moreover, in order to fix the correct gauge group of the theory
we study the most general one, the affine group and its natural reduction to
the orthogonal group. The price we pay for simplifying the geometry is the
presence of matter fields associated with the nonmetric degrees of freedom of
the original setup. The result is independent of the starting theory.
