what is dupin's attitude toward Monsieur G?

Dupin doesn't think that the prefect is an idiot or incompetent. He thinks that he, as a policeman, thinks one dimensionally. Dupin suggests that the police cannot think outside their own standard procedures. Dupin says that Monsieur G does all the right procedural actions but fails to think outside the box, so to speak. Dupin demonstrates the rather tired old adage of, "to catch a criminal one has to think like a criminal". Well, I suppose it wasn't tired back in 1844. There is a bit of arrogance to Dupin. He narrates his own genius like the prefect is way out of his league but I suppose he does retrieve the letter when the whole Paris police force could not.