The Lunatic by Hilaire Belloc — Read

Those who are interested in what simple straightforward people call the Pathology of Consciousness have gathered a great body of evidence upon the various manias that affect men, and there is an especially interesting department of this which concerns illusion upon matters which in the sane are determinable by the senses and common experience. Thus one man will believe himself to be the Emperor of China, another to be William Shakespeare or some other impossible person, though one would imagine that his every accident of daily life would convince him to the contrary.

I had recently occasion to watch one of the most harmless and yet one of the most striking of these illusions in a private asylum which has specialized, if I may so express myself, upon men of letters. The case was harmless and even benign, for the poor fellow was not of a combative disposition to begin with, was of too careful and dignified a temperament to show more than slight irritation if his delusion were contradicted. This misfortune, however, very rarely overtook him, for those who came to visit him were warned to humour his whim. This eccentricity I will now describe.