Many years ago, when I was looking over Piranesi's Antiquities of Rome, Mr. Coleridge, who was standing by, described to me a set of plates by that artist ... which record the scenery of his own visions during the delirium of a fever: some of them (I describe only from memory of Mr. Coleridge's account) representing vast Gothic halls, on the floor of which stood all sorts of engines and machinery, wheels, cables, pulleys, levers, catapults, etc., etc., expressive of enormous power put forth, and resistance overcome. Creeping along the sides of the walls, you perceived a staircase; and upon it, groping his way upwards, was Piranesi himself: follow the stairs a little further, and you perceive it come to a sudden abrupt termination, without any balustrade, and allowing no step onwards to him.

Thomas De Quincy, Confessions of an English Opium Eater