Energy-based formulation of the stresses in nonlinear polarizable fluids

Macroscopic force density and stress tensor expressions recently proposed for soft polarizable fluids are rearranged to give an energy-based formulation which is divorced from association with a particular molecular model. The recent work is thus shown to be in agreement with approaches put forward in Germany early in the century and to yield naturally as a special case the stress system of Helmholtz for linear fluids.