always nervous, and acts more like a guilty one than the criminal himself, even his insides. They forget that these machines are operated by the most catankerous one of all, the human machine. And your psychological detective wants to pick out the kind of man who committed a crime; after which he hunts around till he finds one and says, ‘Behold the murderer,’ whether the evidence supports him or not. I hope you'll permit me to say damned nonsense. There is no man who is incapable of a crime under any circumstances; to say that a daring crime was necessarily committed by a daring person is to argue that a drunken author can write on the subject of nothing but liquor, or that an atheistical artist could not paint the Crucifixion. It is frequently the tippler who writes the best temperance essay, and the atheist who finds the most convincing arguments for religion.
“And your so-called ‘reason,’ in an intricate crime, convinces you of exactly what is untrue. It reduces the thing to the silly restricted rules of mathematics. In this Mercier murder, for example, reason said to me, Mercier was alive when the train started, because he was seen sitting by the window, and the guard took his ticket; also, somebody must have been in the compartment with him, since no man could have strangled him from outside while the train was in motion. This was perfectly elementary logic, and quite false. Imagination asked me these questions: Why did not Mercier make an outcry when somebody attacked him? Why did he not struggle; does a person sit quiet and unmoving when he is assailed? Why no resistance, then? Because Mercier did not see the murderer, a thing impossible if anybody were in the compartment. What does it suggest? Hands through the window, obviously; confirmed by the fact that, though Mercier’s wallet was robbed, his pockets were not rifled—the murderer’s
