Maxwells equations along with the space-time symmetry in normal conducting materials reveal that the electric permittivity and magnetic permeability tensors of rank 2 are fully determined from the conductivity tensor of rank 2, and therefore one needs a dynamical model only for the latter. We elucidate this unification of response tensors and study its ramifications by explicit constructions for the cubic, tetragonal, and orthorhombic classes of crystals. We next use the Boltzmann transport equation in conjunction with a semiclassical model for the statistics of fermionic charge carriers in the material to obtain an analytical expression for the wave vector and frequency-dependent conductivity tensor and thence the permittivity and permeability tensors for metals possessing spherical and nonspherical Fermi surface. We find, inter alia, the spatial dispersion in various response tensors as an important component for a realistic description of optical properties of metals. We ascertain the efficacy of the present theory by computing frequency and wavevector-dependent response tensors and other optical properties of a model metallic system, as a representative example. Final expressions for response tensors are suitable for immediate use in Maxwells equations to study problems, for example, in subwavelength and near-field optics, plasmonic devices, photonic crystals, and surface-enhanced spectroscopies. © 2014 American Chemical Society.