Man soon finds what he wants to find. If he cannot find it otherwise, he creates it for his special enjoyment: for instance, if a man wants to see a ghost, he need only promulge his wish some night around a decaying fire, with a few alarmed and shocked listeners. Then let him ascend in the dark to a remote chamber, carefully looking over his shoulder every few moments; and if he will not see a ghost, he will feel as if he saw one, and that will be tantamount thereto.

The Philosophical Emperor, a Political Experiment, or, The Progress of a False Position: (1841)