What then is truth? A mobile army of metaphors, metonyms, and anthropomorphisms — in short, a sum of human relations, which have been enhanced, transposed, and embellished poetically and rhetorically, and which after long use seem firm, canonical, and obligatory to a people: truths are illusions about which one has forgotten that is what they are; metaphors which are worn out and without sensuous power; coins which have lost their pictures and now matter only as metal, no longer as coins.
We still do not know where the urge for truth comes from; for as yet we have heard only of the obligation imposed by society that it should exist: to be truthful means using the customary metaphors – in moral terms, the obligation to lie according to fixed convention, to lie herd-like in a style obligatory for all…
‘On truth and lie in an extra-moral sense,’ The Viking Portable Nietzsche, p.46-7, Walter Kaufmann transl.