The Sign of the Four (Sherlock Holmes #2)

by Arthur Conan Doyle

Detection is, or ought to be, an exact science, and should be treated in the same cold and unemotional manner. You have attempted to tinge it with romanticism, which produces much the same effect as if you worked a love-story or an elopement into the fifth proposition of Euclid."

The emotional qualities are antagonistic to clear reasoning. I assure you that the most winning woman I ever knew was hanged for poisoning three little children for their insurance-money, and the most repellant man of my acquaintance is a philanthropist who has spent nearly a quarter of a million upon the London poor."

I could not but think what a terrible criminal he would have made had he turned his energy and sagacity against the law, instead of exerting them in its defense.