Hercule Poirot is speaking, in The Mysterious Affair at Styles:
"No, no, you are on a wrong tack there. There is nothing weak-minded or degenerate about Miss Howard. She is an excellent specimen of well-balanced English beef and brawn. She is sanity itself."
Now, I'd like to think that I am "sanity itself." But if that comes at the price of being "beef and brawn"? Well, maybe not.