scatterers like SRRs must be described by magneto-electric point-dipole interactions. Hence, simple LC circuit models with dipolar coupling terms are the second main interpretative tool to predict, e.g., frequency shifts due to electric and magnetic dipole-dipole interactions in lattices and oligomers [@Sersic09; @Giessen09; @Feth10; @guo07]. To rationalize this LC circuit intuition, several authors have analyzed current distributions obtained by FDTD simulations in order to retrieve the microscopic parameters (*i.e.*, the polarizability) underlying such a dipolar interaction model, and in order to estimate multipolar corrections [@Giessen10; @Rockstuhl06b; @Rockstuhl07; @Zhou07; @Corrigan08; @Pors10; @RockstuhlMulti].

While there is general consensus that to lowest order, metamaterial interactions must essentially be magneto-electric point dipole interactions, we note that the dipolar circuit models in use so far have some significant shortcomings. Strictly speaking, the electric circuit theories lack the velocity of light $c$ as a parameter. Hence, they contain no retardation or interference, they violate the optical theorem, do not predict quantitative cross sections, and fail to predict the effects of super- and subradiant damping on resonance linewidths. A fair comparison of intuitive point-dipole ideas with actual data is therefore impossible, unless a fully electrodynamic theory for magneto-electric point dipoles is derived. Such a theory would generalize 