"Life itself is an unsolved mystery", said the clergyman gravely. - Agatha Christie

There is no telling what a human character is. Until the test comes. To most of us the test comes early in life. A man is confronted quite soon with the necessity to stand on his own feet, to face dangers and difficulties and to take his own line of dealing with them. It may be the straight way, it may be the crooked way — - whichever it is, a man usually learns early just what he is made of.

Quite absurd, because Caleb has absolutely no taste for fornication. He never has had. So lucky, being a clergyman.

Every murderer is probably somebody’s old friend,” observed Poirot philosophically. “You cannot mix up sentiment and reason.