Hercule Poirot Quote Photo LitQuotes Blog Posted on September 2, 2013 by LitQuotesSeptember 2, 2013 “Instinct is a marvellous thing,” mused Poirot. “It can neither be explained nor ignored.” ~ The Mysterious Affair at Styles by Agatha Christie I hope you enjoy this quote photo. Wondering about the spelling of the word marvellous? It’s the British spelling. By the way, I’ve also posted this on the LitQuotes Facebook page as well as the LitQuotes Google Plus page for easier sharing.