§ 35. In order to gain a deeper insight into the nature of the world, it is absolutely necessary that we should learn to distinguish the will as thing-in-itself from its adequate objectivity, and also the different grades in which this appears more and more distinctly and fully, _i.e._, the Ideas themselves, from the merely phenomenal existence of these Ideas in the forms of the principle of sufficient reason, the restricted method of knowledge of the individual. We shall then agree with Plato when he attributes actual being only to the Ideas, and allows only an illusive, dream-like existence to things in space and time, the real world for the individual. Then we shall understand how one and the same Idea reveals itself in so many phenomena, and presents its nature only bit by bit to the individual, one side after another. Then we shall also distinguish the Idea itself from the way in which its manifestation appears in the observation of the individual, and recognise the former as essential and the latter as unessential. Let us consider this with the help of examples taken from the most insignificant things, and also from the greatest. When the clouds move, the figures which they form are not essential, but indifferent to them; but that as elastic vapour they are pressed together, drifted along, spread out, or torn asunder by the force of the wind: this is their nature, the essence of the forces which objectify themselves in them, the Idea; their actual forms are only for the individual observer. To the brook that flows over stones, the eddies, the waves, the foam-flakes which it forms are indifferent and unessential; but that it follows the attraction of gravity, and behaves as inelastic, perfectly mobile, formless, transparent fluid: this is its nature; this, _if known through perception_, is its Idea; these accidental forms are only for us so long as we know as individuals. The ice on the window-pane forms itself into crystals according to the laws of crystallisation, which reveal the essence of the force of nature that appears here, exhibit the Idea; but the trees and flowers which it traces on the pane are unessential, and are only there for us. What appears in the clouds, the brook, and the crystal is the weakest echo of that will which appears more fully in the plant, more fully still in the beast, and most fully in man. But only the essential in all these grades of its objectification constitutes the Idea; on the other hand, its unfolding or development, because broken up in the forms of the principle of sufficient reason into a multiplicity of many-sided phenomena, is unessential to the Idea, lies merely in the kind of knowledge that belongs to the individual and has reality only for this. The same thing necessarily holds good of the unfolding of that Idea which is the completest objectivity of will. Therefore, the history of the human race, the throng of events, the change of times, the multifarious forms of