Conan Doyle wrote in such a way as to convince people that Holmes was exercising reasoning powers, not to showcase examples of such reasoning. By the power of plot, Holmes was correct, but it doesn’t follow that his stated reasoning was.
My favorite example of this is the story where Watson was lost in thought, heard Holmes say something, and realized to his shock that Holmes had commented on a thought he was thinking. Holmes then explained that he’d watched how Watson had looked around the room and followed his gaze and expressions as the doctor looked at the different things. Knowing this and Watson’s background, Holmes had figured out what thoughts those things had brought to Watson’s mind, so that when Watson was thinking what a shame people dying in wars was, Holmes could say “yes, it is quite a shame” (or something along those lines, it’s been years since I readthe story). Holmes proceeded to describe the exact train of thought that had been in Watson’s mind every moment, based on what he’d been looking and what his expressions were like at that moment.
Also there’s a lot of variation in how skilled people are at reading emotions. Also a lot of variation in how much attention people pay to small details, and how good a memory they have for them. I’ve heard anecdotes about Zen masters being able to do things similar to what Holmes did in the story—it’s not too far-fetched to think that that level of training combined with one in a million innate ability combined with a decent amount of prior knowledge about a person would give one something like legilimency.
Conan Doyle wrote in such a way as to convince people that Holmes was exercising reasoning powers, not to showcase examples of such reasoning. By the power of plot, Holmes was correct, but it doesn’t follow that his stated reasoning was.
My favorite example of this is the story where Watson was lost in thought, heard Holmes say something, and realized to his shock that Holmes had commented on a thought he was thinking. Holmes then explained that he’d watched how Watson had looked around the room and followed his gaze and expressions as the doctor looked at the different things. Knowing this and Watson’s background, Holmes had figured out what thoughts those things had brought to Watson’s mind, so that when Watson was thinking what a shame people dying in wars was, Holmes could say “yes, it is quite a shame” (or something along those lines, it’s been years since I readthe story). Holmes proceeded to describe the exact train of thought that had been in Watson’s mind every moment, based on what he’d been looking and what his expressions were like at that moment.
That was pretty clever writing, but… no. Just no.
Really? You have never guessed the thoughts of someone you have spent practically every day with for years?
Also there’s a lot of variation in how skilled people are at reading emotions. Also a lot of variation in how much attention people pay to small details, and how good a memory they have for them. I’ve heard anecdotes about Zen masters being able to do things similar to what Holmes did in the story—it’s not too far-fetched to think that that level of training combined with one in a million innate ability combined with a decent amount of prior knowledge about a person would give one something like legilimency.