  We argue that symmetry and unification can emerge as byproducts of certain
physical constraints on dynamical scattering. To accomplish this we
parameterize a general Lorentz invariant, four-dimensional theory of massless
and massive scalar fields coupled via arbitrary local interactions. Assuming
perturbative unitarity and an Adler zero condition, we prove that any finite
spectrum of massless and massive modes will necessarily unify at high energies
into multiplets of a linearized symmetry. Certain generators of the symmetry
algebra can be derived explicitly in terms of the spectrum and three-particle
interactions. Furthermore, our assumptions imply that the coset space is
symmetric.
