There are no such things as "mind," reason, thought, consciousness, soul, will, or truth: they all belong to fiction, and can serve no purpose. It is not a question of "subject and object," but of a particular species of animal which can prosper only by means of a certain exactness, or, better still, regularity in recording its perceptions (in order that experience may be capitalised)....
Knowledge works as an instrument of power. It is therefore obvious that it increases with each advance of power....
The purpose of knowledge: in this case, as in the case of "good" or "beautiful," the concept must be regarded strictly and narrowly from an anthropocentric and biological standpoint. In order that a particular species may maintain and increase its power, its conception of reality must contain enough which is calculable and constant to allow of its formulating a scheme of conduct. The utility of preservation—and not some abstract or theoretical need to eschew deception—stands as the motive force behind the development of the organs of knowledge; ... they evolve in such a way that their observations may suffice for our preservation. In other words, the measure of the desire for knowledge depends upon the extent to which the Will to Power grows in a certain species: a species gets a grasp of a given amount of reality, in order to master it, in order to enlist that amount in its service.
(c) The Belief in the "Ego." Subject.
481.
In opposition to Positivism, which halts at phenomena and says, "These are only facts and nothing more," I would say: No, facts are precisely what is lacking, all that exists consists of interpretations. We cannot establish any fact "in itself": it may even be nonsense to desire to do such a thing. "Everything is subjective," ye say: but that in itself is interpretation. The subject is nothing given, but something superimposed by fancy, something introduced behind.—Is it necessary to set an interpreter behind the interpretation already to hand? Even that would be fantasy, hypothesis.
To the extent to which knowledge has any sense at all, the world is knowable: but it may be interpreted differently, it has not one sense behind it, but hundreds of senses.—"Perspectivity."
It is our needs that interpret the world; our instincts and their impulses for and against. Every instinct is a sort of thirst for power; each has its point of view, which it would fain impose upon all the other instincts as their norm.