  The formalism of electric - magnetic duality, first pioneered by Reinich and
Wheeler, extends General Relativity to encompass non-Abelian fields. Several
energy Tensors T^uv with non-vanishing trace matter are developed solely as a
function of the field strength tensor F^uv, including the Euler tensor, and
tensors for matter in flux, pressure in flux, and stationary pressure. The
spacetime metric g_uv is not only a solution to the second-order Einstein
equation based on T^uv, but is also constrained by a third-order equation
involving the Bianchi identity together with the gravitational energy
components kappa_u for each T^uv. The common appearance of F^uv in all of the
T^uv and kappa_v makes it possible to obtain quantum solutions for the
spacetime metric, thereby geometrizing quantum physics as a non-linear theory.
