  We consider a diffeomorphism invariant theory of a gauge field valued in a
Lie algebra that breaks spontaneously to the direct sum of the spacetime
Lorentz algebra, a Yang-Mills algebra, and their complement. Beginning with a
fully gauge invariant action -- an extension of the Plebanski action for
general relativity -- we recover the action for gravity, Yang-Mills, and Higgs
fields. The low-energy coupling constants, obtained after symmetry breaking,
are all functions of the single parameter present in the initial action and the
vacuum expectation value of the Higgs.
