The Spirits' Book
Book Two - The Spirit World
Chapter I - Spirits
Origin and Nature of Spirits
82. Is it accurate to say that spirits are immaterial?
“How could something for which no terms of comparison exist, and that your language is unable to express be defined? Can someone born blind define light? Immaterial is not the right word, perhaps incorporeal would be more accurate, for a spirit, since it is a creation, it must be something real. The spirit is quintessentialized matter existing in a state that has no equivalent within your scope of comprehension, and it is so ethereal that it transcends your senses.”
We say that spirits are immaterial, because their essence differs from everything that we know as matter. A nation of blind people has no way of expressing light and its effects. For someone who is born blind, the only methods of perception are sound, smell, taste, and touch. He does not understand the ideas that would be perceived by a sense that he lacks. Accordingly, with respect to the essence of superhuman beings, we are truly blind. We can only define them by comparisons that are imperfect or the product of our imagination.