§ 61. It may be remembered from the Second Book that in the whole of nature, at all the grades of the objectification of will, there was a necessary and constant conflict between the individuals of all species; and in this way was expressed the inner contradiction of the will to live with itself. At the highest grade of the objectification, this phenomenon, like all others, will exhibit itself with greater distinctness, and will therefore be more easily explained. With this aim we shall next attempt to trace the source of _egoism_ as the starting-point of all conflict. We have called time and space the _principium individuationis_, because only through them and in them is multiplicity of the homogeneous possible. They are the essential forms of natural knowledge, _i.e._, knowledge springing from the will. Therefore the will everywhere manifests itself in the multiplicity of individuals. But this multiplicity does not concern the will as thing-in-itself, but only its phenomena. The will itself is present, whole and undivided, in every one of these, and beholds around it the innumerably repeated image of its own nature; but this nature itself, the actually real, it finds directly only in its inner self. Therefore every one desires everything for himself, desires to possess, or at least to control, everything, and whatever opposes it it would like to destroy. To this is added, in the case of such beings as have knowledge, that the individual is the supporter of the knowing subject, and the knowing subject is the supporter of the world, _i.e._, that the whole of Nature outside the knowing subject, and thus also all other individuals, exist only in its idea; it is only conscious of them as its idea, thus merely indirectly as something which is dependent on its own nature and existence; for with its consciousness the world necessarily disappears for it, _i.e._, its being and non-being become synonymous and indistinguishable. Every knowing individual is thus in truth, and finds itself as the whole will to live, or the inner being of the world itself, and also as the complemental condition of the world as idea, consequently as a microcosm which is of equal value with the macrocosm. Nature itself, which is everywhere and always truthful, gives him this knowledge, originally and independently of all reflection, with simple and direct certainty. Now from these two necessary properties we have given the fact may be explained that every individual, though vanishing altogether and diminished to nothing in the boundless world, yet makes itself the centre of the world, has regard for its own existence and well-being before everything else; indeed, from the natural standpoint, is ready to sacrifice everything else for this—is ready to annihilate the world in order to maintain its own self, this drop in the ocean, a little longer. This disposition is _egoism_, which is essential to everything in Nature.