 In a strict sense, a body is considered by Wolff to be a composite of composites. The interacting atomic elements (conceived as unextended points of force) give rise to primitive corpuscles and from the cohesion of corpuscles, a body is thereby constituted at the level of appearance. Wolff writes, “ … each body has its origin in that which is not extended, although it is itself extended” (Cosmologia, §223). At the level of appearance, bodies display a number of determinate properties. Each body has a specifiable size or magnitude (i.e., it can be measured), it occupies a fixed space or place (insofar as it is extended), it displays a certain shape, and it is divisible to the primitive corpuscles from which it is composed. Yet, according to Wolff, the properties of bodies should not be considered as the accidents of anything substantial because bodies are merely phenomenal manifestations of real, interacting, atomic elements. Even the principal properties of bodies used in the analysis of bodily change and motion (i.e., the properties used in mechanics), such as extension, the force of inertia, and motor force, are deemed by Wolff to be phenomenal properties.