the river curved away. To Bencolin, every house held a quiet mysterious beauty, every street-stone was a shining miracle. He leaned on the balustrade and sniffed the sharp wind.
“A pretty enough chess-board, isn’t it?” he remarked after a while. “A chess game can be a terrible and enthralling thing, when you play it backwards and blindfolded. Your adversary starts out with his king in check, and tries to move his pieces back to where they were at first; that’s why you can’t apply rules or mathematical laws to crime. The great chess player is the one who can visualize the board as it will be after his move. The great detective is the one who can visualize the board as it has been when he finds the pieces jumbled. He must have the imagination to see the opportunities that the criminal saw, and act as the criminal would act. It’s a great, ugly, terrific play of opposite imaginations. Nobody is more apt than a detective to say a lot of windy, fancy things about reasoning, and deduction, and logic. He too frequently says ‘reason’ when he means ‘imagination.’ I object to having a cheap, strait-laced pedantry like reason confused with a far greater thing.”
“But, look here,” said Sir John, “suppose you take this business tonight. You gave a reconstruction of that crime, all right, and perhaps that was imagination. But you didn’t tell us how you knew that was the way it happened. Reason told you that. Didn’t it?—how did you get on to the murder, anyhow?”
“It’s an example of what I was trying to say. There is so much elaborate hocus-pocus around the whole matter of criminal detection that it makes a detective wonder why people think he acts that way. The fiction writers want to call it a science, and attach blood-pressure instruments to people’s arms, and give them Freud tests—they forget that your innocent man is
