G. K. Chesterton: The Wisdom of Father Brown

11. The Strange Crime of John Boulnois (continued)

Father Brown looked honestly embarrassed, and passed his hand across his forehead. "Two very little things," he said. "At least, one's very trivial and the other very vague. But such as they are, they don't fit in with Mr Boulnois being the murderer."

He turned his blank, round face up to the stars and continued absentmindedly: "To take the vague idea first. I attach a good deal of importance to vague ideas. All those things that `aren't evidence' are what convince me. I think a moral impossibility the biggest of all impossibilities. I know your husband only slightly, but I think this crime of his, as generally conceived, something very like a moral impossibility. Please do not think I mean that Boulnois could not be so wicked. Anybody can be wicked--as wicked as he chooses. We can direct our moral wills; but we can't generally change our instinctive tastes and ways of doing things. Boulnois might commit a murder, but not this murder. He would not snatch Romeo's sword from its romantic scabbard; or slay his foe on the sundial as on a kind of altar; or leave his body among the roses, or fling the sword away among the pines. If Boulnois killed anyone he'd do it quietly and heavily, as he'd do any other doubtful thing-- take a tenth glass of port, or read a loose Greek poet. No, the romantic setting is not like Boulnois. It's more like Champion."

"Ah!" she said, and looked at him with eyes like diamonds.

"And the trivial thing was this," said Brown. "There were finger-prints on that sword; finger-prints can be detected quite a time after they are made if they're on some polished surface like glass or steel. These were on a polished surface. They were half-way down the blade of the sword. Whose prints they were I have no earthly clue; but why should anybody hold a sword half-way down? It was a long sword, but length is an advantage in lunging at an enemy. At least, at most enemies. At all enemies except one."

"Except one," she repeated.

"There is only one enemy," said Father Brown, "whom it is easier to kill with a dagger than a sword."