In the First Book, the world was presented as mere representation, object for a subject; in the Second Book we considered this world from its other side and found that it is also will, and this proved to be the only thing the world is, apart from representation. In recognition of this fact we went on to name the world as representation (both as a whole and in its parts) the objecthood of the will, which accordingly means: the will become object, i.e. representation. We may further recall that such an objectivation of the will had many, albeit determinate, levels at which the essence of the will enters representation (i.e. presents itself as an object) with gradually increasing degrees of clarity and perfection. We already recognized these levels as Plato's Ideas, in so far as they are nothing but particular species, or the original, unchanging forms and qualities of all natural bodies, inorganic no less than organic, as well as the universal forces that manifest themselves according to natural laws. Taken together, these Ideas present themselves in countless individuals and details, relating to these as model to imitations.