Electrodynamic Properties of a General Physical System -- General Properties of the Linear Optical Response -- Kramers-Kronig Relations and Sum Rules in Linear Optics -- General Properties of the Nonlinear Optical Response -- Kramers-Kronig Relations and Sum Rules in Nonlinear Optics -- Kramers-Kronig Relations and Sum Rules for Harmonic-Generation Processes -- Kramers-Kronig Relations and Sum …