The Will to Power · Friedrich Wilhelm Nietzsche
556.
A "thing-in-itself" is just as absurd as a "sense-in-itself," a "meaning-in-itself." There is no such thing as a "fact-in-itself," _for a meaning must always be given to it before it can become a fact._ The answer to the question, "What is that?" is a process of _fixing a meaning_ from a different standpoint. The "_essence_" the "_essential factor,_" is something which is only seen as a whole in perspective, and which presupposes a basis which is multifarious. Fundamentally the question is "What is that for me?" (for us, for everything that lives, etc. etc.). A thing would be defined when all creatures had asked and answered this question, "What is that?" concerning it. Supposing that one single creature, with its own relations and standpoint in regard to all things, were lacking, that thing would still remain undefined. In short: the essence of a thing is really only an _opinion_ concerning that "thing." Or, better still; "_it is worth_" is actually what is meant by _"it is"_ or by "that is." One may not ask: "_Who_ interprets, then?" for the act of interpreting _itself_ as a form of the Will to Power, manifests itself (not as "Being," but as a _process,_ as _Becoming_) as a passion. The origin of "things" is wholly the work of the idealising, thinking, willing, and feeling subject. The concept thing as well as all its attributes.--Even "the subject" is a creation of this order, a "thing" like all others: a simplification, aiming at a definition of the _power_ that fixes, invents, and thinks, as such, as distinct from all isolated fixing, inventing, and thinking. Thus a capacity defined or distinct from all other individual capacities; at bottom action conceived collectively in regard to all the action which has yet to come (action and the probability of similar action).
The qualities of a thing are its effects upon other "things." If one imagines other "things" to be non-existent, a thing has no qualities. That is to say; _there is nothing without other things._ That is to say; there is no "thing-in-itself." The thing-in-itself is nonsense. If I think all the "relations," all the "qualities" all the "activities" of a thing, away, the thing itself does _not_ remain: for "thingness" was only _invented fancifully_ by us to meet certain logical needs--that is to say, for the purposes of definition and comprehension (in order to correlate that multitude of relations, qualities, and activities). "Things which have a nature _in themselves_"--a dogmatic idea, which must be absolutely abandoned. That things should have a _nature in themselves,_ quite apart from interpretation and subjectivity, _is a perfectly idle hypothesis_: it would presuppose that _interpretation_ and the _act of being subjective_ are not essential, that a thing divorced from all its relations can still be a thing. Or, the other way round: the apparent _objective_ character of things; might it not be merely the result of a _difference of degree_ within the subject perceiving?--could not that which changes slowly strike us as being objective, lasting, Being, "in-itself"?--could not the objective view be only a false way of conceiving things and a contrast _within_ the perceiving subject?
Text from Project Gutenberg, public domain in the United States.