"But still, we encounter difficulties. The nature of the city operates against us. Venice owes its very existence to the art of illusion—which is one of the Black Arts. It is a city of mirrors; the canals reflect the buildings, the windows reflect the canals. Distances slide and twist, earth and water interpenetrate. Venice advertises its falsehoods and conceals its truths. In a city like this, events cannot be predicted as in Genoa or Milan. The relative and conditional are apt to turn into the absolute and irrevocable without notice."