If there is one city that might be said to embody both reason and desire, it would surely be Venice: a thousand-year triumph of rational legislation, aesthetic and sensual self-expression, and self-creation--powerful, lovely, serene. Unique in so many ways, Venice is also unique in its relation to writing. London has Dickens, Paris has Balzac, Saint Petersburg has Dostoevsky, Dublin has Joyce, but there is simply no comparable writer for, or out...