“The capacity for discerning the essential truth, in fact, is as rare among men as it is common among crows, bullfrogs and mackerel. The man who shows it is a man of quite extraordinary quality—perhaps even a man downright diseased. Exhibit a new truth of any natural plausibility before the great masses of men, and not one in ten thousand will suspect its existence, and not one in a hundred thousand will embrace it without a ferocious resistance. All the durable truths that have come into the world within historic times have been opposed as bitterly as if they were so many waves of smallpox, and every individual who has welcomed and advocated them, absolutely without exception, has been denounced and punished as an enemy of the race. Perhaps “absolutely without exception” goes too far. I substitute “with five or six exceptions.” But who were the five or six exceptions? I leave you to think of them; myself, I can’t…. But I think at once of Charles Darwin and his associates, and of how they were reviled in their time. This reviling, of course, is less vociferous than it used to be, chiefly because later victims are in the arena, but the underlying hostility remains. Within the past two years the principal Great Thinker of Britain, George Bernard Shaw, has denounced the hypothesis of natural selection to great applause, and a three-times candidate for the American Presidency, William Jennings Bryan, has publicly advocated prohibiting the teaching of it by law. The great majority of Christian ecclesiastics in both English-speaking countries, and with them the great majority of their catachumens, are still committed to the doctrine that Darwin was a scoundrel, and Herbert Spencer another, and Huxley a third—and that Nietzsche is to the three of them what Beelzebub himself is to a trio of bad boys. This is the reaction of the main body of respectable folk in two puissant and idealistic Christian nations to the men who will live in history as the intellectual leaders of the Nineteenth Century. This is the immemorial attitude of men in the mass, and of their chosen prophets, to whatever is honest, and important, and most probably true.

But if truth thus has hard sledding, error is given a loving welcome. The man who invents a new imbecility is hailed gladly, and bidden to make himself at home; he is, to the great masses of men, the beau ideal of mankind. Go back through the history of the past thousand years and you will find that ninetenths of the popular idols of the world—not the heroes of small sects, but the heroes of mankind in the mass—have been merchants of palpable nonsense. It has been so in politics, it has been so in religion, and it has been so in every other department of human thought. Every such hawker of the not-true has been opposed, in his time, by critics who denounced and refuted him; his contention has been disposed of immediately it was uttered. But on the side of every one there has been the titanic force of human credulity, and it has sufficed in every case to destroy his foes and establish his immortality.”

— Mencken: Meditation on Meditation. In: Prejudices, Third Series.]

“Truth, indeed, is something that is believed in completely only by persons who have never tried personally to pursue it to its fastnesses and grab it by the tail. It is the adoration of second-rate men—men who always receive it at second-hand. Pedagogues believe in immutable truths and spend their lives trying to determine them and propagate them; the intellectual progress of man consists largely of a concerted effort to block and destroy their enterprise. Nine times out of ten, in the arts as in life, there is actually no truth to be discovered; there is only error to be exposed. In whole departments of human inquiry it seems to me quite unlikely that the truth ever will be discovered. Nevertheless, the rubber-stamp thinking of the world always makes the assumption that the exposure of an error is identical with the discovery of the truth—that error and truth are simple opposites. They are nothing of the sort. What the world turns to, when it has been cured of one error, is usually simply another error, and maybe one worse than the first one. This is the whole history of the intellect in brief. The average man of to-day does not believe in precisely the same imbecilities that the Greek of the fourth century before Christ believed in, but the things that he does believe in are often quite as idiotic. Perhaps this statement is a bit too sweeping. There is, year by year, a gradual accumulation of what may be called, provisionally, truths—there is a slow accretion of ideas that somehow manage to meet all practicable human tests, and so survive. But even so, it is risky to call them absolute truths. All that one may safely say of them is that no one, as yet, has demonstrated that they are errors. Soon or late, if experience teaches us anything, they are likely to succumb too. The profoundest truths of the Middle Ages are now laughed at by schoolboys. The profoundest truths of democracy will be laughed at, a few centuries hence, even by school teachers.”

— Mencken: Footnote on Criticism. In: Prejudices, Third Series]