"A knowledge of the existence of something we cannot penetrate, of the manifestations of the profoundest reason and the most radiant beauty, which are only accessible to our reason in their most elementary forms--it is this knowledge and this emotion that constitute the truly religious attitude."
In the classic Dickens story, A Christmas Carol, Ebenezer Scrooge sees a ghost. Skeptic that he is, he does not believe what he sees. When the ghost asks him why he doubts his senses, he replies: "Because, a little thing affects them. A slight disorder of the stomach makes them cheats. You may be an undigested bit of beef, a blot of mustard, a crumb of cheese, a fragment of an underdone potato."