I may say of a tree that "it is" in distinction to things which are not trees; I may say "it is coming to be" in distinction to itself seen at a different time; I may even say "it is not," as for example in "it is not yet a tree" when I am looking at a shrub. Words are but symbols for the relations of things to one another and to us; nowhere do they touch upon absolute truth. Above all, the word "being" designates only the most general relationship which connects all things, as does the word "nonbeing." But if the existence of things themselves cannot be proved, surely the inter-relationship of things, their so-called being or nonbeing, will advance us not a step toward the land of truth. Through words and concepts we shall never reach beyond the wall of relations, to some sort of fabulous primal ground of things. Even in the pure forms of sense and understanding, in space, time and causality, we gain nothing that resembles an eternal verity. It is absolutely impossible for a subject to see or have insight into something while leaving itself out of the picture, so impossible that knowing and being are the most opposite of all spheres.