essence of the world.  Like our body, the whole world is the visibility of will.  The human will is the highest stage in the development of the same principle which manifests its activity in the various forces of nature, and which properly takes its name from the highest species.  To penetrate further into the inner nature of things than this is impossible.  What that which presents itself as will and which still remains after the negation of the latter (see below) is in itself, is for us absolutely unknowable.

The world is per se will.  None of the predicates are to be attributed to the primal will which we ascribe to things in consequence of our subjective forms of thought—­neither determination by causes or ends, nor plurality:  it stands outside the law of causality, as also outside space and time, which form the principium individuationis.  The primal will is groundless, blind stress, unconscious impulse toward existence; it is one, the one and all, [Greek:  en nai pan].  That which manifests itself as gravity, as magnetic force, as the impulse to growth, as the vis medicatrix naturae, is only this one world-will, whose unity (not conscious character!) shows itself in the purposiveness of its embodiments.  The essence of each thing, its hidden quality, at which empirical explanation finds its limit, is its will:  the essence of the stone is its will to fall; that of the lungs is the will to breathe; teeth, throat, and bowels are hunger objectified.  Those qualities in which the universal will gives itself material manifestation form a series with grades of increasing perfection, a realm of unchangeable specific forms or eternal Ideas, which (with a real value difficult to determine) stand midway between the one primal will and the numberless individual beings.  That the organic individual does not perfectly correspond to the ideal of its species, but only approximates this more or less closely, is grounded in the fact that the stadia in the objectification of the will, or the Ideas, contend, as it were, for matter; and whatever of force is used up in the victory of the higher Ideas over the lower is lost for the development of the examples of the former.  The higher the level on which a being stands the clearer the expression of its individuality.  The most general forces of nature, which constitute the raw mass, play the fundamental bass in the world-symphony, the higher stages of inorganic nature, with the vegetable and animal worlds, the harmonious middle parts, and man the guiding treble, the significant melody.  With the human brain the world as idea is given at a stroke; in this organ the will has kindled a torch in order to throw light upon itself and to carry out its designs with careful deliberation; it has brought forth the intellect as its instrument, which, with the great majority of men, remains in a position of subservience to the will.  Brain and thought are the same; the former is nothing other than the will to know, as the stomach is will to digest.  Those only talk of an immaterial soul who import into philosophy—­where such ideas do not belong—­concepts taught them when they were confirmed.