Watson observes.............

 "What a very attractive woman!" I exclaimed, turning to my companion.

He had lit his pipe again and was leaning back with drooping eyelids.  "Is she?" he said languidly; "I did not observe."

"You really are an automaton—a calculating machine," I cried. "There is something positively inhuman in you at times."

He smiled gently.  "It is of the first importance," he said, "not to allow your judgment to be biased by personal qualities.  A client is to me a mere unit, a factor in a problem.  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 repellent man of my acquaintance is a philanthropist who has spent nearly a quarter of a million upon the London poor."

-Arthur Conan Doyle, channeling his inner Holmes in The Sign of Four