How (Not) to Think like Sherlock Holmes (Part Four)

The latest in my ongoing project to ruin Sherlock Holmes’ reputation: Holmes tries to think by himself, and this is a terrible idea.

The longer way of saying this is that Holmes’ reasoning skills are compromised by his epistemic isolation. This comes in two forms. The first is an extreme degree of specialisation, accompanied by a more general ignorance (which he deliberately chooses). The second, connected issue is the social isolation that arises from his ‘solitary genius’ status, which prevents him benefiting from full membership in an epistemic community.

Let’s start with the first issue. In A Study in Scarlet, Watson is shocked to discover that despite his extreme cleverness and comprehensive knowledge of some subjects, Holmes is remarkably ignorant about many others - and quite deliberately so.

His ignorance was as remarkable as his knowledge. Of contemporary literature, philosophy and politics he appeared to know next to nothing. Upon my quoting Thomas Carlyle, he inquired in the naivest way who he might be and what he had done. My surprise reached a climax, however, when I found incidentally that he was ignorant of the Copernican Theory and of the composition of the Solar System. That any civilized human being in this nineteenth century should not be aware that the earth traveled round the sun appeared to me to be such an extraordinary fact that I could hardly realize it.

Far from being ashamed of this ignorance of general knowledge, Holmes defends it as necessary in order to ensure that he becomes (and remains) knowledgeable about the stuff that is actually pertinent to his vocation:

“I consider that a man’s brain originally is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the lumber of every sort that he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things, so that he has a difficulty in laying his hands upon it. Now the skillful workman is very careful indeed as to what he takes into his brain-attic. He will have nothing but the tools which may help him in doing his work, but of these he has a large assortment, and all in the most perfect order. It is a mistake to think that this little room has elastic walls and can distend to any extent. Depend upon it, there comes a time when for any addition of knowledge, you forget something that you knew before. It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones.”

This extreme devotion to specialisation is problematic in that it requires that you know ahead of time whether something will be pertinent to your investigation or not - without learning it for yourself. Now admittedly, this isn’t altogether impossible. We can find out that developing a particular skill or area of knowledge isn’t very helpful for our interests, and decide not to bother with it. But we find this out by asking other people (perhaps those in our profession) if they have found it useful to learn that skill, and then following their advice. This in turn requires (a) that we are on friendly terms with a number of other people in our profession whose opinions we respect; (b) that those people have taken it upon themselves to learn about that topic without already knowing whether it would be helpful. It requires others to have taken on a particular epistemic responsibility which you are not taking on yourself. A sort of epistemic division of labour therefore seems appropriate: you learn about A, I’ll learn about B, we’ll regroup and report on whether either A or B are useful.

But this whole line of possibility requires that you have peers whom you respect. This doesn’t appear to be the case for Holmes, as Watson learns in The Sign of the Four:

I abhor the dull routine of existence. I crave for mental exaltation. That is why I have chosen my own particular profession,—or rather created it, for I am the only one in the world.”

“The only unofficial detective?” I said, raising my eyebrows.

“The only unofficial consulting detective,” he answered. “I am the last and highest court of appeal in detection. When Gregson or Lestrade or Athelney Jones are out of their depths—which, by the way, is their normal state—the matter is laid before me. I examine the data, as an expert, and pronounce a specialist’s opinion.

Sherlock’s high opinion of himself and low opinion of the police force in general ensures that he is unlikely to engage in any significant division of epistemic labour with (what he would never call) his colleagues. Whilst the police force may bring pertinent data to his attention, the interpretation of this data - its transformation into actual insights - is something that he entrusts to himself and himself alone.

In the Study in Scarlet, Lestrade proudly announces that he has found a note, written in blood, of the single word Rache. His interpretation of this is:

…”it means that the writer was going to put the female name Rachel, but was disturbed before he or she had time to finish. You mark my words, when this case comes to be cleared up you will find that a woman named Rachel has something to do with it. It’s all very well for you to laugh, Mr. Sherlock Holmes. You may be very smart and clever, but the old hound is the best, when all is said and done.”

After having mocked Lestrade with manner and tone of voice, and examined the room in detail, Holmes reels off a list of details about the murderer and then as a parting shot issues this:

“One other thing, Lestrade,” he added, turning round at the door: “‘Rache,’ is the German for ‘revenge;’ so don’t lose your time looking for Miss Rachel.” With which Parthian shot he walked away, leaving the two rivals open-mouthed behind him.

BBC’s Sherlock offers a rather elegant reversal of this exchange in A Study in Pink. As Sherlock and John are ushered into the crime scene by Lestrade, Anderson proudly delivers his insight: “She’s German! Rache, German for revenge. She might be trying to tell us something…” and is interrupted by Sherlock’s brusque “Yes, thank you for your input” and a door slammed in his face. Later, when Sherlock suggests they start inquiries about a woman named Rachel, and Lestrade asks for confirmation “She was writing Rachel, then?” Sherlock replies sarcastically “No, she was writing an angry note in German… Of course she was writing Rachel, no other word it can be!”

No other word it can be.

In the version of this where Sherlock Holmes alone is familiar with German, knowledge of German is esteemed, and interpretations of evidence which rely on this knowledge are therefore elevated. (After all, German must be relevant to the investigative process, right? Sherlock would have jettisoned it from his brain-attic, otherwise). But in the version where Anderson also knows German, knowledge of German is devalued, and so too are potential interpretations which rely upon it.

What I find particularly interesting in this respect is that a lot of Sherlock’s ‘deductions’ about that scene are based on a forensic analysis of the victim’s wedding ring. I learnt from a German-speaking student of mine that if the victim is German, it’s not actually a wedding ring. It’s on the wrong hand: in Germany, the wedding ring is worn on the right. The (possibly false) assumption that it is a wedding ring underpins a lot of Sherlock’s reasoning here, so it would clearly be helpful if the possibility that she might be German is left on the table.

Of course, Sherlock turns out to be right. He has the writers on his side, after all. But Doylist explanations aside, he does have a sharper mind and a better track record than Anderson, so the temptation to defer to Sherlock and ignore Anderson is tempting - not only to Sherlock, but to the observers, too.

In the Conduct of the Understanding, John Locke articulates why this is a bad idea. There are, he says:

those who readily and sincerely follow reason, but for want of having that which one may call large sound roundabout sense, have not a full view of all that relates to the question and may be of moment to decide it. We are all shortsighted, and very often see but one side of a matter; our views are not extended to all that has a connexion with it. From this defect I think no man is free. We see but in part, and we know but in part, and therefore it is no wonder we conclude not right from our partial views. This might instruct the proudest esteemer of his own parts how useful it is to talk and consult with others, even such as come short of him in capacity quickness and penetration, for since no one sees all, and we generally have different prospects of the same thing according to our different as I may say positions to it, it is not incongruous to think nor beneath any man to try whether another may not have Notions of things Which have escaped him, and which his reason would make use of if they came into his Mind.

Notice that my initial criticism of Sherlock was that he tries to think ‘by himself’. This is not the same as thinking ‘for himself’. Thinking for yourself is to be commended: I take this to mean engaging with the evidence and evaluating it, and putting forward original ideas. Thinking by yourself, however, involves deliberately excluding the intellectual input of others. This makes your beliefs less justified than they could be, even if they happen to be true. This applies even though Anderson ‘comes short’ of Sherlock in ‘quickness and penetration’; because whilst intelligence might be a property of individuals, knowledge isn’t.