The Will to Power · Friedrich Wilhelm Nietzsche
488.
_The psychological origin of our belief in reason.--_The ideas "reality," "Being," are derived from our _subject-_feeling. "Subject," interpreted through ourselves so that the ego may stand as substance, as the cause of action, as the _agent._ The metaphysico-logical postulates, the belief in substance, accident, attribute, etc. etc., draws its convincing character from our habit of regarding all our actions as the result of our will: so that the ego, as substance, does not vanish in the multiplicity of changes.--_But there is no such thing as will._ We have no categories which allow us to separate a "world as thing-in-itself," from "a world of appearance." All our _categories of reason_ have a sensual origin: they are deductions from the empirical world. "The soul," "the ego"--the history of these concepts shows that here, also, the oldest distinction ("_spiritus_," "life") obtains.... If there is nothing material, then there can be nothing immaterial. The concept no longer _means_ anything. No subject-"atoms." The sphere of a subject _increasing_ or _diminishing_ unremittingly, the centre of the system continually _displacing_ itself, in the event of the system no longer being able to organise the appropriated mass, it divides into two. On the other hand, it is able, without destroying it, to transform a weaker subject into one of its own functionaries, and, to a certain extent, to compose a new entity with it. Not a "substance," but rather something which in itself strives after greater strength; and which wishes to "preserve" itself only indirectly (it wishes to _surpass_ itself). Everything that reaches consciousness as an entity is already enormously complicated: we never have anything more than the _semblance of an entity._ The phenomenon of the _body_ is the richer, more distinct, and more tangible phenomenon: it should be methodically drawn to the front, and no mention should be made of its ultimate significance.
Text from Project Gutenberg, public domain in the United States.