#589: Reflections on Detection – The Knox Decalogue: An Introduction

Decalogue header

It may surprise you to learn that I think about the Knox Decalogue a lot.  But, like, a lot a lot, “maybe I should write a lecture on the Knox Decalogue and tout it round the various crime conventions” a lot.  Instead, because I work full time and am nowhere near famous enough for that to be an option, I’m going to go through the rules one at a time and share some thoughts on here.

Yes, that’s ten rules and four or five Tuesdays in a month; I don’t know how to resolve that.  Hopefully some of them will be two-parters.  For bookmarking purposes, here’s where the links will go:

Rule 1: The Criminal
Rule 2: The Supernatural
Rule 3: Secret Passages
Rule 4: Undiscovered Poisons
Rule 5: No Chinamen
Rule 6: No Accidents
Rule 7: The Detective-as-Criminal
Rule 8: Declaration of Clues
Rule 9: The Stupid Friend
Rule 10: Twins

And, yes, I have already spoken about this in a podcast episode.  But, dude, I didn’t even scratch the surface.  Said surface shall, alas, be rendered unrecognisable with all the scratching that I intend to do in these posts.  It is an itch I’ve been carrying around for a long time.

This was going to be a post about the first rule, but by the time I had explained my motivation and intent it already seemed long enough, so I guess we’ll actually start the rules next week.  See, my intent is not so much to provide some new historical context or interpretation — see above, I work full-time — largely since I’d hate to give the impression that I’m anywhere close enough to an expert to make those sorts of surmises, you’d need a John Curran, a John Norris, a Curtis Evans for that sort of historical and contextual piece.  Instead, I feel there’s a perspective on the Decalogue overall which has gone missing, and which overlooks the by-no-means-an-inevitability of GAD that we now get to treat as inevitable and closed but which, at the time, was a fairly revolutionary phenomenon worthy of observation.

To illustrate the misunderstanding that has developed, I draw your attention to this panel discussion at the Edinburgh Festival in 2016, featuring Val McDermid, Abir Mukherjee, and Lucy Ribchester, and chaired by Mariella Frostrup.  If you’re not in the UK you might have trouble listening to it, so I’ve transcribed the opening below:


The early crime critic Ronald Knox penned his ten rules of detective fiction back in 1929.  These included the illuminating ‘Not more than one secret passage or room’ and making sure the Watson sidekick was slightly less clever than the reader.  And perhaps most obvious, that the detective himself — it was only himself in those days — doesn’t commit the crime.  So after 30 novels, Val, do you have any such ‘golden rules’?


I don’t think so, no, I think everything’s up for grabs.  The Ronald Knox rules, we read them now and we laugh at them, but at the time they came out writers took them very seriously, and they contain such other gems as ‘There shall be no Chinaman in the story’ [laughter] and ‘There shall be no twins’ — identical twins are verboten.  And the solution mustn’t come to the detective in a dream.  Now, I have read crime novels that break all of those with gay abandon, so I think these days, because the genre has transformed itself, and continually reinvents itself, I think nothing is off-limits.  There are no rules, you find the way to tell your own story.


Abir Mukherjee, did you investigate the rules of the genre before you set out on your first novel?


I did, which was a shame because my first one was gonna be about dreaming Chinamen [laughter] so I had to start again.  But for me I think the only rule is “Forget Knox’s Rules”.  You follow your heart, you follow the story you want to tell, and your characters will tell it for you, I think.

Amusingly, at around the 23-minute mark, McDermid then goes on to criticise the “snobbery” of people who haven’t read the genre “properly” — amusing because, well, the four people involved in this discussion clearly haven’t read Knox’s rules properly (as in most cases, they’re referring to the pithier, shortened versions which strip out most of the detail and justification) and clearly lack any understanding of the context in which they were written and which informs their construction.  Ribchester even goes on to say that had she know there were rules for writing a crime novel then she probably wouldn’t have tried writing one to begin with…and, well, let’s unpick all of the above, shall we?


“Oh, let’s!”

It’s not that these people aren’t intelligent enough to understand what they’re criticising — McDermid is the only one of the three authors I’ve read, and she’s written some excellent books and expresses herself admirably in interviews — it’s that they’ve allowed a modern prejudice and preconception to colour their (yes, by no means deep) interpretation of the Decalogue.  The problems begin to an extent when Frostrup takes the time to assert both confidently and woefully incorrectly that “it was only himself in those days” where detectives were concerned — you can, I’m sure, provide plenty of your own examples to the contrary, and three minutes on Google will help you out if not — and so the old “No Chinaman” rule can also be trotted out to prove how damn woke we all are now and how much more insightful modern crime fiction is in comparison to this olde worlde stuff that only allowed men to detect and viewed all foreigners as suspicious like the bunch of racists and xenophobes everyone was back then.

Now, this callout culture of pointing out what someone did wrong as a form of self-embiggening isn’t going anywhere any time soon, but the shame of it is that it is fraught with a wilful blindness that conveniently ignores what came before that makes what’s possible now actually, y’know, possible.  If you choose to dismiss the Knox Decalogue because it seems a bit racist and Noachian, and if you balk at the idea of “rules” being a bad thing where detective fiction is concerned, then you don’t really understand that whereof you speak.  “[A]t the time they came out writers took them very seriously” McDermid says, managing to entirely overlook the entire point of them being taken seriously in the first place.  Nobody went to write a detective novel in 1930, read Knox’s list, and thought “Hmm, I better take that Chinaman out of the narrative”…only to replace him with a Dutchman or a Serbian: by not appreciating what The Chinaman per se represents, and we’ll get to that in week 412, I suggest that you overlook one of the key facets of detective fiction, which — as McDermid correctly suggests — has been slowly and steadily reinvented as the crime fiction of today.

Equally, Ribchester shuddering at the idea of rules, of everyone being hidebound and so boxed in writing on dilapidated, rusty rails, misses the point by an almost Olympic record distance.  Of course there are rules, there are always rules in any universe you create in genre fiction, and you’ve only written a crime novel because you’ve adhered to expectations like a crime, a detective, a solution that works in the setting and milieu provided…if your solution relies on aliens coming down with 55 pages left, what you’ve written is SF, if your book is about two people bonding over the aftermath of a crime whose commission and solution has no bearing beyond bringing them together to overcome differences and difficulties to find love, you’ve written a Romance.  If everyone’s on horseback and living in the 1800s, you’ve written a Western — someone writing inside of a genre and then poo-pooing the concept of “rules” as a limiting, square, moribund, Bad Thing does not understand genre fiction (and Knox is ahead of you there, too: “Rules so numerous and so stringent cannot fail to cramp the style of the author, and make the practice of the art not difficult only, but progressively more difficult.”)

If Mukherjee’s only rule really is “Forget Knox’s rules” then he has no detective, no crime that the reader can follow, no need to describe the crime scene as the opening passage of his book (which he reads at a later point) does, there’s no sense of scale or suitability where motive is concerned, there’s no clever misdirection or utilisation of intelligent plotting…so what’s he writing?  Isaac Newton famously said “If I have seen further it is by standing on the shoulders of Giants,” whereas this lot seem to say “Well, there might have been giants once, but I heard a giant tried to kill that beanstalk guy so we should probably ignore anything they did”.  It’s especially cloth-eared because of how proud Mukherjee seems to be when he starts talking about his novel looking at the difference between truth and justice — how one can be found but not necessarily always the other.  Which, like, is a core concept of GAD.  Shoulders of giants?  This entire conversation is taking place in the footprints of giants, thoroughly unaware that there’s anything beyond the walls they’re hemmed in by.


“I’m a Libra!”

Now, the above isn’t my sole motivation, but it does help exemplify the ignorance and dismissal that has cropped up around the formation of GAD.  And, sure, those authors probably aren’t as enmeshed in the 1930s era of the genre as I am, but I also feel there’s a tendency even among we enthusiasts to overlook, to take for granted, what happened when GAD became a going concern.

So my plan with this series, however long it runs for, is to unpick piecemeal what the Knox Decalogue means to me — how I see it informing, enriching, enlivening, enabling the precepts of GAD, and how the formalisation of observations, never with the intent of prescribing what should and shouldn’t be written.  You’re more than welcome to disagree with what I say, I never claimed to be an expert on any of this, I just happen to write about it a lot, and I hope that I’ll gradually encourage some re-examination of the Knox Decalogue and idea of what it meant when Knox sat down to codify what he was observing happening in the genre.  It’s going to be a mighty fine pedagogical time, and I look forward to three of you having the patience to stick with me through it all.

The full text of Knox’s introduction and each of the rules can be found here at the GADetection wiki if anyone wishes to read long at home, and I’ll see you next week to discuss why the criminal must be someone mentioned in the early part of the story…

28 thoughts on “#589: Reflections on Detection – The Knox Decalogue: An Introduction

    • Ha; the smugness of that conversation and the way the GAD writers are sort of brushed aside did vex me immensely…but thankfully I’m not off on another jeremiad. And I have a feeling that you may be one of only maybe six people actually interested enough to read these wanderings…but what’s the point of having a blog if I don’t get to write about what interests me?? 🙂

      Liked by 1 person

  1. My gripe with the decalogue is that Knox’ rules don’t necessarily lead to what he himself writes in the introduction about the detective story, that it “must have as its main interest the unravelling of a mystery; a mystery whose elements are clearly presented to the reader at an early stage in the proceedings, and whose nature is such as to arouse curiosity, a curiosity which is gratified at the end.”

    I’d assume there’s an underlying notion that a detective story must also be fair, the idea that there’s a satisfying pay-off when the curious mystery is revolved, because there was a genuine mystery despite all the elements being presented clearly to the reader.

    Yet, Knox’ rules do not inherently lead to a better or more fair detective story. All of us can think of fantastic stories that violate either the specific rule, or even only the spirit of the rule, and those examples are really not *despite* the rule or *the exeption*. The “unless we have been duly prepared for them” part of the final rule is in fact the only thing that is truly important: any of the specific examples of Knox can work easily in mystery fiction as defined by himself, as long as the reader is duly prepared for them because that makes the curious mystery satisfying. And this requires work on the part of the writer. But I don’t think it really helped Knox’ argument by formulating 10 specific commandments that don’t necessarily connect to his main point anyway.

    Liked by 2 people

    • Ah, see, but my thesis isn’t going to be so much “this is why everything should conform to Knox’s rules” — it’s more a sort of “well, this is where I see this coming from and what it means to GAD”.

      Knox acknowledges that too many rules are a bad thing, and that rules in general don’t necessarily have to be followed for a story to be good. What’s interesting for me is the context and the motivation behind them; he could have stopped at six, probably, and done just as well, but he wanted ten because a) the religious parallel and b) there’s some merit in each of them if taken in context.

      However, more on that in the weeks and months ahead…

      Liked by 1 person

      • Ah, I did get that you’re going a different direction with your series, and while I agree there’s something interesting to find if you look at *where* each idea sprung from/the inspiration/direct context for each rule, I think that ultimately as a whole, Knox’ own main point and the (spirit of his) rules don’t actually mesh well. Fewer rules that would actually touch closer upon the underlying notion would’ve worked better, instead of splitting it in Chinaman/twins/secret passages/etc. even though you could make a more direct point by gathering them together. So I always have trouble taking the decalogue really serious.

        Though it’ll be interesting to see how deep you can dive into each rule 😀 Looking forward to the series proper!

        Liked by 1 person

        • I wonder how much he intended them to still be a topic of discussion 90 years later 😆 He seemed in a pretty unforgiving mood when writing that introduction, given what he says about the stories in the collection, and I feel it was possibly just a bit of venting after seeing repeated failures of other authors to observe what he felt detection should be,

          But that doesn’t mean there aren’t some good points in there, though I’m not pretending they’re the last word in What GAD Should Be.

          As to how deep…well, time will tell.


  2. JJ, looking forward to your Knox series a lot. I’ve always imagined that Knox’s rules were partly tongue-in-cheek, partly serious. I suspect he is enumerating some of the already overused plot improbabilities of Victorian (and following) ‘sensation’ fiction, and by making fun of these–which were presumably still easily recognized by his 1929 audience–pointing the way for GAD. I guess I’ll be finding out over the coming weeks and months whether my supposition has any merit. Thanks for taking this on!

    Liked by 1 person

    • Thanks, Ken — and, yeah, we’re in agreement, I feel. Hopefully this will be borne out by what I write in the weeks ahead, but I think the tnedrils of sensation fiction were pretty tightly wrapped around detection even in 1929. So that will form part of the discussion, certainly.

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  3. I can’t wait to read these and look forward to the discussions that they spawn. There’s the outward facing interpretation of each rule in short form, which when strictly interpreted probably leads to the “what a dumb rule” reaction. Then you have the actual intent of the rule and why it was relevant at the time (and perhaps even still is today). And of course, the well executed violations of the rule and why they worked. Each of these three cases is worth dissecting, and it’s interesting to consider tangible examples.

    Liked by 1 person

    • I’m…hopeful that I’ll be able to do all this, but I’m not pretending or a second that I’ll be offering up the final word on any aspect — so, yes, please do dive in with further interpretations and points. Mainly this is to get the ever-circling self-conversation out of my head, so conversing with others will certainly form a huge part of that 😆


  4. I’m more of a fan of Van Dine’s rules than of Knox’s decalouge. I’ve always felt that a lot of GAD authors, Brand especially, would have been much better off if they had followed Van Dine’s rules of ‘No love interest’ and ‘Detective is not a detective unless he detects’.


    • Van Dine, I feel, took it rather more to heart than Knox — witness the way his final rule is actually another list of ten — and as such I’ve always found that list more of a menial exercise than something done in the spirit of the genre. Tastes differ, eh?

      I’m no fan of intrusive love stories, but there have been a few that work amazingly in the book, and I’m not entirely sure that it needs to be a rule to ban them…I think the majority of the bad ones were just crammed in by writers to provide “human interest” when it wasn’t their chief interest. Or, in some cases, to pad the page count of a novella so it could be published as a novel. So while I agree they were often not the best thing for the genre, that’s also not quite the tack I’m going to be taking with these Knox rules — however, I’ll leave the Van Dine list to anyone else who is similalrly obsessed with it!

      Liked by 1 person

  5. Well, Jasper Jerome, you’re at it again: embarking on another multi-part series that weill bring the readers in by droves and generate a mile-long comments section, while those of us who are carefully planning to post the 750th review of The Mystery of the Peacock’s Eye will be woefully ignored. I refuse to “like” this post, do you hear me? I absolutely refuse . . .
    Oh well, I guess if I’m going to play fair when taking part in this series, I need to focus my comments here on the case in hand– namely, the introduction and rationale for the Decalogue – and save my thoughts on the rules themselves for the appropriate post.

    If I have been following the historians correctly, the Golden Age of Detection ran for approximately twenty years, from 1920 to 1940. Of course certain antecedents were laid for decades before this, and the basic GAD pattern appeared – often with excellent results – for decades afterward, even as the “Modern Psychological Writer” began to view it as antique.

    But the fact is that by 1929, when Knox published his Decalogue, GAD fiction was thriving; it was popular enough to spawn The Detection Club a year later. Knox certainly didn’t invent the rules of the game, not like the makers of Monopoly invented that game, since these rules were already in evidence in hundreds or thousands of novels and stories. He was commenting on them from the heights, where one who dabbles in a highly popular form of literature can enthrone himself. Clearly he knows his peers aren’t going to abide by these rules: as early as #1 he is giving Christie an out because she broke that one so well. (More about this next week!)

    As for the conversation between MacDermid and her cronies . . . well, it’s amusing and ironic that they dismiss something so antique, since some of Knox’ rules did the same thing. If one takes from their words that modern crime fiction doesn’t abide by rules in this way, they are correct. Few of them write puzzle-centric tales; many, like Kate Atkinson, lean more toward general fiction with crime elements. A canny author/commentator could still come up with “rules” about what is written today. (Somebody – anybody – write a rule forbidding unreliable narrators . . . please!) It doesn’t matter because Knox – and S.S. Van Dine, who needed twice as many rules to make his point – are seeking to entertain us and, willingly or not, to provide a fascinating historical perspective on what hundreds of authors wrote and millions of readers read for much of the twentieth century.

    This is what I’m sure you’ll be covering over the next 71 weeks, meaning that my review of The Mystery of the Peacock’s Eye will be posted on Friday, March 19, 2021. (Perhaps by then I will be finished with the damn thing . . . )

    Liked by 1 person

    • I think the culture of Knox’s Decalogue was more open to the idea of a list of rules not being a series of strictures or an implicit criticism…these days, the sheer quantity of bristling that results when anything regards “rules” and fiction is mentioned would, I feel, end up generating more conflict than insight.

      I suppose, when you’re on the vanguard of an exciting time like GAD you’re willing to accept a multitude of perspectives; now that so much crime fiction is just a damp, cold reheat of ideas already done better and to death a century ago…well, you’d get a bit insecure at implied criticism, hey?

      Although, yes, I’m aware that the above is a straw man argument with no citations. This is just a warm-up for the speculation to come…

      Liked by 1 person

  6. I’ll be looking forward to this – there’s a lot of interesting things to unpick in the Decalogue.
    My take on Knox’s list is that it’s really more about what detective fiction isn’t than what it is. I think it’s key that this comes just a year before the formation of the Detection Club, which admitted you only after consideration of your merits as a writer of detective fiction – in particular excluding the writers of thrillers. If I remember rightly, apart from the “Watson” rule, all of the rules are calling out common tropes from thrillers, and challenging writers to write something better. I guess you could call it snobbery of a sort… and so, nearly a century later, we come to snobbery towards GAD itself. I guess it’s like saying you’ll never get old like your parents did. :p

    Liked by 1 person

    • Well, I hope the forthcoming discussions are encouraging, then — we’re coming from similar perspectives, I can see, so we’ll probably fall out over a tiny point of no consequence 🙂

      I guess it’s like saying you’ll never get old like your parents did

      Ha! you sound just like my father…


  7. An excellent post JJ.

    And Brad is right, GAD was a big deal by 1929. Van Dine was one of the biggest sellers of the 1920s, Christie was a huge hit, Marsh and Queen were publishing, and several early talkies were mysteries.

    I’d say more, but with you and Brad both being right I figure it’s time for that skiing trip in Hell.

    Liked by 1 person

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