Friedrich Nietzsche, Menschliches, Allzumenschliches, Chapter I, "Von den ersten und letzten Dingen," aphorism 31, the original and then my translation:
"Das Unlogische notwendig. — Zu den Dingen, welche einen Denker in Verzweifelung bringen können, gehört die Erkenntnis, dass das Unlogische für den Menschen nötig ist, und dass aus dem Unlogischen vieles Gute entsteht. Es steckt so fest in den Leidenschaften, in der Sprache, in der Kunst, in der Religion und überhaupt in Allem, was dem Leben Wert verleiht, dass man es nicht herausziehen kann, ohne damit diese schönen Dinge heillos zu beschädigen. Es sind nur die allzu naiven Menschen, welche glauben können, dass die Natur des Menschen in eine rein logische verwandelt werden könne; wenn es aber Grade der Annäherung an dieses Ziel geben sollte, was würde da nicht Alles auf diesem Wege verloren gehen müssen! Auch der vernünftigste Mensch bedarf von Zeit zu Zeit wieder der Natur, das heißt seiner unlogischen Grundstellung zu allen Dingen."
"The Illogical is Necessary. - Among the things which can bring a thinker to despair is the realization that the illogical is necessary for people, and that much which is good comes from the illogical. It is so deeply embedded in the passions, in language, art, religion and in everything that gives value to life that one cannot remove it without doing irreparable harm to these beautiful things. Only very naive people can believe that the nature of people can be transformed into a purely logical nature; if this goal were even nearly approached by degrees, what all would not be lost along the way! Even the most logical person has the need from time to time for nature, that is to say, for his fundamentally illogical relationship to all things."
As translations go, I think that one wasn't bad. I'm sure some people would strongly disagree, in large part because translation is a subjective thing, and if they had translated the passage themselves they would've done it differently. You might've noticed how many more commas there are in the original German aphorism than in my translation. I hate to say, but I suspect some translators would take me to task for that. What would I answer to them?
Well, the thing is, I would try to avoid the conversation to begin with. I can't imagine many more dreary debates. "To write is to fail," said Samuel Beckett. I think that what he meant is that even the very best writing will by its nature leave much to be desired -- by its creator, if by no one else. They say that something is always lost in translation, and I believe they're right about that. And so to translate is to doubly fail, to compound imperfection. I can't do justice to that passage by Nietzsche as a translator. It's hard enough for a reader fluent in German to do justice to the original. Translation is a poor substitute for learning the original language. It always is. I believe that firmly.