The Will to Power · Friedrich Wilhelm Nietzsche
480.
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.
Text from Project Gutenberg, public domain in the United States.