If, then, all numbers are only zero in a state of extension, and are consequently identical with it, the question arises, what are the first finitings of zero, or as what does it appear when it is no longer merely ideal or indefinite; in short, what is the first form of the real zero, or of the essence in general? ESSENCE OF NOTHING. 41. The ideal zero is absolute unity, or monas; it is not a singularity, such as one individual thing, or as the number 1; but an indivisibility, a numberlessness, in which neither 1 nor 2, neither a line nor a circle can be found; in short, an unity without distinction, an homogeneity, brightness, or translucency, a pure identity. 42. The mathematical monas is _eternal_. It succumbs to no definitions of time and space, is neither finite nor infinite, neither great nor small, neither quiescent nor moved; but it is and it is not all this. That is the conception of eternity. Mathematics is thus in possession of an eternal principle. 43. Since all the sciences are equivalent to mathematics, nature must also possess an eternal principle. The principle of nature, or of the universe, must be of one and the same kind with the principle of mathematics. For there cannot be two kinds of monades, nor of eternities, nor of certainties. The highest unity of the universe is thus the Eternal. The Eternal is one and the same with the zero of mathematics. The Eternal and zero are only denominations differing in accordance with their respective sciences, but which are essentially one. 44. The Eternal is the _nothing_ of Nature. As the whole of mathematics emerges out of zero, so must everything which is a Singular have emerged from the Eternal or nothing of Nature. The origin of the Singular is nothing else than a manifestation of the Eternal. Thereby unity, brightness, homogeneity are lost, and converted into multiplicity, obscurity, diversity. Unity posited manifoldly is an expansion without termination, but one that always remains the same. Realization or manifestation is an expansion of the Eternal. FORMS OF NOTHING. 45. The first form of the expansion or manifestation of the mathematical monas, or of 0 is +-. The +-is nothing else than the definition of 0. 0 is the reduction of the positive and negative series of numbers, upon which the whole of arithmetic depends. A series of numbers is, however, nothing else than a repetition of a + 1 or a-1; consequently, the whole of arithmetic reduces itself to + 1-1.