" My argument against a naive form of empiricism was essentially anticipated by Mark Twain. On his first appointment as a reporter, he tells us, the editor of the newspaper instructed him never to report anything unless he could verify it or confirm it by personal knowledge. So he described a social event as follows: 'A woman giving the name of Mrs James Jones, who is reported to be one of the society leaders of the city, is said to have given what purported to be a party yesterday to a number of alleged ladies. The hostess claims to be the wife of a reputed attorney.'

One sees that Mark Twain was quick to realize the silliness of the naive empiricist (verificationist) theory of the sources of our knowledge. "

― Karl Popper , Conjectures and Refutations: The Growth of Scientific Knowledge