“I have often had occasion to notice how, where a direct question would fail to elicit a response, a false assumption brings instant information in the form of a contradiction.”

“I have always noticed that these artists and writers are very unbalanced”

“You're a man milliner, Poirot. I never notice what people have on.""You should join a nudist colony”

“I suppose next time I come home I shall find you wearing false moustaches—or are you doing so now?' Poirot winced. His moustaches had always been his sensitive point. He was inordinately proud of them. My words touched him on the raw. 'No, no, indeed, mon ami. That day, I pray the good God, is still far off. The false moustaches! Quelle Horreur!’ He tugged at them vigorously to assure me of their genuine character. 'Well, they are very luxuriant still,' I said. 'N’est-ce pas? Never, in the whole of London, have I seen a pair of moustaches to equal mine.' A good job too, I thought privately.”

“Too much mercy... often resulted in further crimes which were fatal to innocent victims who need not have been victims if justice had been put first and mercy second.”

“Intuition is like reading a word without having to spell it out. A child can't do that because it has had so little experience. A grown-up person knows the word because they've seen it often before.”

“It often seems to me that's all detective work is, wiping out your false starts and beginning again.""Yes, it is very true, that. And it is just what some people will not do. They conceive a certain theory, and everything has to fit into that theory. If one little fact will not fit it, they throw it aside. But it is always the facts that will not fit in that are significant.”