Quantum Theory of Magnetism is the only book that deals with the ohenomenon of magnetism from the point of view of "linear response". That is, how does a magnetic material respond when excited by a magnetic field? That field may be uniform, or spatially varying, static or time dependent. Previous editions have dealt primarily with the magnetic response. This edition incorporates the resistive response of magnetic materials as well. It also includes problems to text the reader's (or student's) comprehension.