Metrology is a discipline of expunging impurities. The mid-nineteenth century French physicist Henri-Victor Regnault created a whole new way of doing experiments, attempting to produce standards physically by the “direct method.” His immodest ambition to control all disturbing parameters represents a relict in the physical sciences of Romantic hopes for an all-embracing, artistic and aesthetic approach to nature, expressed in the absolute, eternal determination of nature's constants and their numerical relationships. The novelist Gustave Flaubert, whose rejection of metaphysics, love for finest detail, concern for impartial treatment of the human psyche, and perfectionism, made him Regnault's literary complement, likewise hoped for this utopian union of science and art. There is a romantic and a modern ring to their ideals which were not to be achieved by optimism, but by introducing systematic doubt, by thoroughly studying impurities and expunging them. Nature did not speak clearly, but hid behind a multitude of disturbing effects—revealed only by the experimenter's or writer's voluntary restraint and self-denial, a disinterestedness Regnault and Flaubert celebrated as the highest and holiest morality. For them, attention to secondary matters became primary, because they expected them to lead the way to the grail.