Should not all philosophy ultimately disclose the first principles on which the reasoning processes depend?--that is to say, our _belief_ in the "ego" as a substance, as the only reality according to which, alone, we are able to ascribe reality to things? The oldest realism at length comes to light, simultaneously with man's recognition of the fact that his whole religious history is no more than a history of soul-superstitions. _Here there is a barrier;_ our very thinking, itself, involves that belief (with its distinctions--substance, accident, action, agent, etc.); to abandon it would mean to cease from being able to think. But that a belief, however useful it may be for the preservation of a species, has nothing to do with the truth, may be seen from the fact that we _must_ believe in time, space, and motion, without feeling ourselves compelled to regard them as absolute realities. 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). 489. 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. 490.