Progress . . . is to be measured by the accuracy of man’s knowledge of nature’s forces. If you examine this sentence carefully you will observe that I conceive progress as a sort of process of disillusion. Man gets ahead, in other words, by discarding the theory of to-day for the fact of to-morrow.
H. L. Mencken, in Robert Rives La Monte and Mencken, Men versus The Man (1910).