Calica keeps cursing the filth and, whenever he treads on one of the innumerable turds lining the streets, he looks at his dirty shoes instead of at the sky or a cathedral outlined in space. He does not smell the intangible and evocative matter of which Cuzco is made, but only the odor of stew and excrement. It's a question of temperament.
Letter to his mother from Cuzco, Peru (22 August 1953); as quoted in "Making of a Marxist" in The Guardian (16 June 2001) - Various