517.
In order to be able to think and to draw conclusions, it is necessary to acknowledge that which exists: logic only deals with formulæ for things which are constant. That is why this acknowledgment would not in the least prove reality: "that which is" is part of our optics. The ego regarded as Being (not affected by either Becoming or evolution).
The assumed world of subject, substance, reason, etc., is necessary, an adjusting, simplifying falsifying, artificially-separating power resides in us. "Truth" is the will to be master over the manifold sensations that reach consciousness; it is the will to classify phenomena according to definite categories. In this way we start out with a belief in the "true nature" of things (we regard phenomena as real).
The character of the world in the process of Becoming is not susceptible of formulation; it is "false" and "contradicts itself." Knowledge and the process of evolution exclude each other. Consequently, knowledge must be something else: it must be preceded by a will to make things knowable, a kind of Becoming in itself must create the illusion of Being.
518.
If our "ego" is the only form of Being, according to which we make and understand all Being: very good! In that case it were very proper to doubt whether an illusion of perspective were not active here—the apparent unity which everything assumes in our eyes on the horizon-line. Appealing to the body for our guidance, we are confronted by such appalling manifoldness, that for the sake of method it is allowable to use that phenomenon which is richer and more easily studied as a clue to the understanding of the poorer phenomenon.
Finally: admitting that all is Becoming, knowledge is only possible when based on a belief in Being.
519.
If there is "only one form of Being, the ego," and all other forms of Being are made in its own image,—if, in short, the belief in the "ego," together with the belief in logic, stands and falls with the metaphysical truth of the categories of reason: if, in addition, the "ego" is shown to be something that is evolving: then——
520.