Friedrich Nietzsche - On the Genealogy of Morality (Chap. 4.12) lyrics

Given that such a living desire for contradiction and hostility to nature is used to practise philosophy, on what will it discharge its most inner arbitrary power? It will do that on something it perceives, with the greatest certainty, as true, as real. It will seek out error precisely where the essential instinct for life has established its most unconditional truth. For example, it will demote physical life to an illusion, as the ascetics of the Vedanta philosophy did. Similarly it will treat pain, the multiplicity of things, the whole ideational opposition between “subject” and “ object” as error, nothing but error! To deny faith in one's own self, to deny one's own “reality”—what a triumph!—and not just over the senses, over appearances, but a much loftier kind of triumph, an overpowering of and act of cruelty against reason: a process in which the highest peak of delight occurs when ascetic self-contempt and self-mockery of reason proclaims: “There is a kingdom of truth and being, but reason is expressly excluded from it” . . . (By the way, even in the Kantian idea of the “intelligible character of things” there still remains something of this lecherous ascetic dichotomy, which loves to turn reason against reason: for the “intelligible character” with Kant means a sort of composition of things about which the intellect understands just enough to know that for the intellect it is—wholly and completely unintelligible).—But precisely because we are people who seek knowledge, we should finally not be ungrateful for such determined reversals of customary perspectives and evaluations with which the spirit has for so long raged against itself with such apparent wickedness and futility. To use this for once to see differently, the will to see things differently, is no small discipline and preparation of the intellect for its coming “objectivity”—the latter meant not in the sense of “disinterested contemplation” (which is inconceivable nonsense), but as the capability of having power over one's positive and negative arguments and of raising them and disposing of them so that one knows how to make the very variety of perspectives and interpretations of emotions useful for knowledge. From now on, my philosophical gentlemen, let us protect ourselves better from the dangerous old conceptual fantasy which posits a “pure, will-less, painless, timeless subject of cognition”; let's guard ourselves against the tentacles of such contradictory ideas as “pure reason,” “absolute spirituality,” “knowledge in itself”—those things which demand that we think of an eye which simply cannot be imagined, an eye which is to have no direction at all, in which the active and interpretative forces are supposed to stop or be absent—the very things through which seeing first becomes seeing something. Hence, these things always demand from the eye something conceptually absurd and incomprehensible. The only seeing we have is seeing from a perspective; the only knowledge we have is knowledge from a perspective; and the more emotions we allow to be expressed in words concerning something, the more eyes, different eyes, we know how to train on the same thing, the more complete our “idea” of this thing, our “objectivity,” will be. But to eliminate the will in general, to suspend all our emotions without exception—even if we were capable of that—what would that be? Wouldn't we call that castrating the intellect?