things is equally a primordial as well as an old error of everything organic. But inasmuch as all metaphysics has concerned itself chiefly with substance and the freedom of will, it may be designated as the science which treats of the fundamental errors of mankind, but treats of them as if they were fundamental truths. 19. NUMBER.--The discovery of the laws of numbers is made upon the ground of the original, already prevailing error, that there are many similar things (but in reality there is nothing similar), at least, that there are things (but there is no "thing"). The supposition of plurality always presumes that there is something which appears frequently,--but here already error reigns, already we imagine beings, unities, which do not exist. Our sensations of space and time are false, for they lead--examined in sequence--to logical contradictions. In all scientific determinations we always reckon inevitably with certain false quantities, but as these quantities are at least constant, as, for instance, our sensation of time and space, the conclusions of science have still perfect accuracy and certainty in their connection with one another; one may continue to build upon them--until that final limit where the erroneous original suppositions, those constant faults, come into conflict with the conclusions, for instance in the doctrine of atoms. There still we always feel ourselves compelled to the acceptance of a "thing" or material "sub-stratum" that is moved, whilst the whole scientific procedure has pursued the very task of resolving everything substantial (material) into motion; here, too, we still separate with our sensation the mover and the moved and cannot get out of this circle, because the belief in things has from immemorial times been bound up with our being. When Kant says, "The understanding does not derive its laws from Nature, but dictates them to her," it is perfectly true with regard to the idea of Nature which we are compelled to associate with her (Nature = World as representation, that is to say as error), but which is the summing up of a number of errors of the understanding. The laws of numbers are entirely inapplicable to a world which is not our representation--these laws obtain only in the human world. 20.