Not many are able to find the spirit in the vacuum, yet in the vacuum a phenomenon can be observed; for instance, in the vacuum of an apple is to be found the essence of the whole fruit. It was not, therefore, only imagination when ancient peoples believed in the spirits of trees and plants, in the spirits of the mountains and hills; for there is nothing existing which has no spirit, although that side of the object is veiled and we cannot see it. We see only the outside, but there is a spirit behind it just the same, and by tracking it we shall find it one day.