The Will to Power · Friedrich Wilhelm Nietzsche
569.
The nature of our psychological vision is determined by the fact-- (1) That _communication_ is necessary, and that for communication to be possible something must be stable, simplified, and capable of being stated precisely (above all, in the so-called _identical_ case). In order that it may be communicable, it must be felt as something _adjusted,_ as "_recognisable_." The material of the senses, arranged by the understanding, reduced to coarse leading features, made similar to other things, and classified with its like. Thus: the indefiniteness and the chaos of sense-impressions are, as it were, _made logical._ (2) The _phenomenal_ world is the adjusted world which _we believe to be real,_ Its "reality" lies in the constant return of similar, familiar, and related things, in their _rationalised character,_ and in the belief that we are here able to reckon and determine. (3) The opposite of this phenomenal world is not "the real world," but the amorphous and unadjustable world consisting of the chaos of sensations--that is to say, _another kind_ of phenomenal; world, a world which to us is "unknowable."
(4) The question how things-in-themselves are constituted, quite apart from our sense-receptivity and from the activity of our understanding, must be answered by the further question: how were we able to know _that things existed?_ "Thingness" is one of our own inventions. The question is whether there are not a good many more ways of creating such a world of appearance--and whether this creating, rationalising, adjusting, and falsifying be not the best-guaranteed _reality_ itself: in short, whether that which "fixes the meaning of things" is not the only reality: and whether the "effect of environment upon us" be not merely the result of such will-exercising subjects.... The other "creatures" act upon us; our _adjusted_ world of appearance is an arrangement and an _overpowering_ of its activities: a sort of _defensive_ measure. _The subject alone is demonstrable_; the _hypothesis_ might be advanced _that subjects are all that exist,_--that "object" is only a form of action of subject upon subject ... a _modus of the subject._ _(k)_ The Metaphysical Need. If one resembles all the philosophers that have gone before, one can have no eyes for what has existed and what will exist--one sees only what _is._ But as there is no such thing as Being; all that the philosophers had to deal with was a host of _fancies,_ this was their "world." To assert the _existence_ as a whole of things concerning which we know nothing, simply because there is an advantage in not being able to know anything of them, was a piece of artlessness on Kant's part, and the result of the recoil-stroke of certain needs--especially in the realm of morals and metaphysics.
Text from Project Gutenberg, public domain in the United States.