Lessing, the most honest of theoretical men, dared to state openly that searching for the truth meant more to him than truth itself; thereby the fundamental secret of science is revealed, much to the astonishment, indeed annoyance, of the scientifically minded. Admittedly, alongside this isolated recognition (which represents an excess of honesty, if not of arrogance), one also finds a profound delusion which first appeared in the person of Socrates, namely the imperturbable belief that thought, as it follows the thread of causality, reaches down into the deepest abysses of being, and that it is capable, not simply of understanding existence, but even of correcting it. This sublime metaphysical illusion is an instinct which belongs inseparably to science, and leads it to its limits time after time, at which point it must transform itself into art; which is actually, given this mechanism, what it has been aiming at all along.
Nietzsche, The Birth of Tragedy, chapter 15. [In the Cambridge edition edited by Geuss and Speirs, pg 73.]