As I sit here contemplating the curious relationship between knowledge and ignorance in Sherlock Holmes character, I realize that it is only the first hour of my 71 hour and 57 minute long journey listening to the soothing voice of Stephen Fry.

Like Watson, I myself cannot help but be struck when finding out that Sherlock was ignorant of some of the scientific facts “That any civilized human being in this nineteenth century should not be aware that the earth travelled round the sun appeared to be to me such an extraordinary fact that I could hardly realize it.”—and now for a brief moment just imagine Stephen fry articulating ’extraordinary fact’.

Surely this kind of example lets the kind of reader who enjoys Sherlock Holmes listen up immediately. I cannot help but be struck by the parallels between his thoughts and those of the great filmmaker Orson Welles. So much so that I had to do this writing to understand their similarities and to explore their shared perspectives.

Ignorance: Sherlock Holmes Key in His Philosophy of Selective Knowledge

In what I consider Sherlocks greatest declarations he says to Watson, that your brain is like an empty attic, and it is up to you to stock it out. Instead to furnish it with the first you come along at a yard sale, you should rather be on the lookout for these nuggets.

Don’t take in every piece of information that you come across. Only 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 they have a difficulty in laying their hands upon it. Now the skilled is very careful indeed as to what they take into their brain-attic.

Just like a skilled worker chooses only the tools that will help them in their work, Sherlock doesn’t allow useless facts to take up space and crowd out the useful ones. However, in this philosophy of selective knowledge, we must not confuse ignorance with a lack of curiosity or a disregard for scientific facts. Rather, it is the focus on the useful, and not the random, that guides him in his investigations.

Follow the conversation between Sherlock and Watson (or even better listen to Stephen Fry reading it to you exclusively on audible)

“You appear to be astonished,” Sherlock said, smiling at my expression of surprise. “Now that I do know it I shall do my best to forget it.”

“To forget it!”

“You see,” he explained, “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 that little room has elastic walls and can distend to any extent. Depend upon it there comes a time when for every 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.”

“But the Solar System!” I protested.

“What the deuce is it to me?” he interrupted impatiently; “you say that we go round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work.”

The parallels between his thoughts and those of the great filmmaker Orson are astonishing.

Ignorance: Orson Welles Key to Successful Decision Making

Interestingly, this view of ignorance as helpful is not unique to Sherlock Holmes, as I came across a similar sentiment in the words of the great filmmaker Orson Welles.

He famously said, “Sheer ignorance – you know, there's no confidence to equal it," when asked about how he was able to make his first film Citizen Kane, despite having no prior experience in filmmaking. He claimed that his ignorance allowed him to make bold creative choices without the fear of being constrained by the "rules" of filmmaking.

“Where did you get the confidence from, to make a movie…”

“Ignorance. Sheer ignorance – you know there's no confidence to equal it”, Orson replied, “It's only when you know something about a profession, that you're timid or careful.”

“How does ignorance show itself?”

“I thought you could do anything with a camera that the eye could do or the imagination could do. And if you come up from the bottom in the film business, you're taught all the things that the cameraman doesn't wanted to attempt for fear he will be criticized for having failed.”

“Yes.”

“And in this case I had a cameraman who didn't care if he was criticized if he failed. and i didn't know that there were things you couldn't do. So I anything I could think up in my dreams I attempted to photograph.

And of course I had a great advantage not only in the real genius of my cameraman, but in the fact that he, like all great men who are masters of a craft, told me right at the outset that there was nothing about camera work that I couldn't learn.”

“It's true an awful lot of things…”

“And I was lucky enough to be told that by the absolute best living cameraman.”

Interview edited for clarity.