"Sir William Grove... in a lecture at the London Institution, in 1842, was the first to show that "heat, light, may be considered as affections of matter itself, and not of a distinct ethereal, 'imponderable,' fluid [a state of matter now] permeating it." Yet, perhaps, for some Physicists... Force and Forces were tacitly "Spirit [and hence Spirits] in Nature." What several rather mystical Scientists taught was that light, heat, magnetism, electricity and gravity, etc., were not the final Causes of the visible phenomena, including planetary motion, but were themselves the secondary effects of other Causes, for which Science in our day cares very little, but in which Occultism believes; for the Occultists have exhibited proofs of the validity of their claims in every age. And in what age were there no Occultists and no Adepts? p. 525"