Magnetism and electrostatic forces were regarded as occult action at a distance from ancient times and the inquiry into it waned when Christianity that banned magic had strong power. Since the Renaissance, however, researchers dared to study the occult magic and thus they pioneered modern electromagnetism and mechanics. Newton and Coulomb recognized gravitation and electromagnetism as action at a distance but today they are explained as action through medium. The lesson we must learn from history of electromagnetic theory is that we should not refuse study in occult phenomena because of its occult appearances but, as accepting action at a distance is not science but occultism, it should be explained as action through medium.