Whatever Nature undertakes, she can only accomplish it in a sequence. She never makes a leap. For example, she could not produce a horse if it were not preceded by all the other animals on which she ascends to the horse’s structure as if on the rungs of a ladder. Thus every one thing exists for the sake of all things and all for the sake of one. For the one is of course the all as well. Nature, despite her seeming diversity, is always a unity, a whole. And thus, when she manifests herself in any part of that whole, the rest must serve as a basis for that particular manifestation, and the latter must have a relationship to the rest of the system.