 The notion of “extended-composite”, as already mentioned, is what ultimately stands at the heart of Wolff’s doctrine of the world-whole. Insofar as the world is a composite being, it follows from the principles of Wolff’s ontology that the world’s essence consists in the manner in which its parts are linked together. The world’s parts, as described from the standpoint of appearance, are simply the multitude of interacting physical bodies that are perceived in everyday life. And, if described from a metaphysical standpoint, the world’s parts are conceived by Wolff to be the interacting unextended points of force that occupy his atomic level. Yet regardless of what standpoint or level of description is employed, it is clear that a necessary condition of the world’s existence is that its parts need to be interconnected. According to Wolff, the world is conceived as a substantial whole (totum substantiale) by virtue of the fact that all of its parts form real reciprocal connections with one another. On the basis of this “interconnection-thesis” the world is defined formally by Wolff as “a whole which is not also a part”.