This work considers strongly dissipative reaction diffusion systems with constitutive equations given by Edelen's diSSipation potentials, whose existence is tantamount to nonlinear Onsager symmetry. As the main goal of thiS work, it is shown that the associated extremum principle yields the relevant steady-state species lialances and concentration fields for well-mixed teactOrs as well as for Spatially inhomogeneous reactions accompanied by diffusion. The above principle is contrasted briefly with the popular notion of maximum entropy production. Potential applications of the theory to a wide range of roCtion diffusion systems are discussed, and questions are raised as to the possible breakdown of strong dissipation and nonlinear Onsager symmetry arising from reversible chemical or chemomechanical couplings.