"Naturally," Vance replied, "—since it's an irrelevant factor in most crimes. Every one of us, my dear chap, has just as good a motive for killing at least a score of men, as the motives which actuate ninety-nine crimes out of a hundred. And, when anyone is murdered, there are dozens of innocent people who had just as strong a motive for doing it as had the actual murderer. Really, y' know, the fact that a man has a motive is no evidence whatever that he's guilty,—such motives are too universal a possession of the human race. Suspecting a man of murder because he has a motive is like suspecting a man of running away with another man's wife because he has two legs. The reason that some people kill and others don't, is a matter of temp'rament—of individual psychology. It all comes back to that. . . . And another thing: when a person does possess a real motive—something tremendous and overpowering—he's pretty apt to keep it to himself, to hide it and guard it carefully—eh, what? He may even have disguised the motive through years of preparation; or the motive may have been born within five minutes of the crime through the unexpected discovery of facts a decade old. . . . So, d' ye see, the absence of any apparent motive in a crime might be regarded as more incriminating than the presence of one."
"You are going to have some difficulty in eliminating the idea of cui bono from the consideration of crime."
"I dare say," agreed Vance. "The idea of cui bono is just silly enough to be impregnable. And
