Beyond Good and Evil by Friedrich Nietzsche Chapter 1 Page 7

And behind all logic and its seeming sovereignty of movement, there are valuations, or to speak more plainly, physiological demands, for the maintenance of a definite mode of life For example, that the certain is worth more than the uncertain, that illusion is less valuable than “truth” such valuations, in spite of their regulative importance for US, might notwithstanding be only superficial valuations, special kinds of niaiserie, such as may be necessary for the maintenance of beings such as ourselves. Supposing, in effect, that man is not just the “measure of things.”

4. The falseness of an opinion is not for us any objection to it: it is here, perhaps, that our new language sounds most strangely. The question is, how far an opinion is life-furthering, life-preserving, species-preserving, perhaps