#595: Reflections on Detection – The Knox Decalogue 2: The Supernatural

Decalogue header

Sometimes I regret saying I’ll do stuff; this week, I regret saying I’ll explore each of the rules of Ronald Knox’s Detective Fiction Decalogue in depth.  Mainly because I’m busy, and so I’m not going to do this as well as I otherwise might.  And that frustrates me doubly, because Rule 2 is the one that got me thinking about this in the first place.

If you’re interested, here’s how things stand:

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 Rule 2, concerning the supernatural, runs thus:

All supernatural or preternatural agencies are ruled out as a matter of course. To solve a detective problem by such means would be like winning a race on the river by the use of a concealed motor-engine. And here I venture to think there is a limitation about Mr. Chesterton’s Father Brown stories. He nearly always tries to put us off the scent by suggesting that the crime must have been done by magic; and we know that he is too good a sportsman to fall back upon such a solution. Consequently, although we seldom guess the answer to his riddles, we usually miss the thrill of having suspected the wrong person.

Now, let’s set some ground-rules.  As discussed last week, yes, it would be entirely possible to set a detective story in a world in which ghosts and other supernatural elements exist and are able to interact with its corporeal denizens.  Establish the rules of such a place clearly and fairly, and go about writing your detective story and you’ll have no complaints from anyone, least of all Monsignor Knox.  But, for the sake of ease and clarity, Knox was talking here — and I shall be talking similarly for however long this takes — about flesh-and-blood crimes committed by flesh-and-blood killers in a world where no ghostly intervention is possible.

Yes, there have been novels in which a ghost investigates its own murder — there was even a film starring Patrick Swayze, you may remember — and, again, while not dismissing that per se, what we’re not allowing is for any contact across the, er, veil of death: no seance in which a legitimate ghost actually tells those present who killed them, no manifestations of ghostly presences out of thin air to spur their son into a frenzy of bloody vengeance: ghosts, goblins, and associated happenings do not exist in Ronald Knox’s Detective Decalogue.  Equally, no psychic abilities to determine the thoughts of another (there’s enough dodgy psychology in GAD as it is…) — no tea leaves, no crystal balls, no monsters from the deep, no telekinesis, no special powers of any kind.


“Did somebody say ‘ball’?”

What I want to say is “these stories take place in our real, everyday world” but I know someone would crop up in the comments with “Well, how do you know there aren’t ghosts helping the police solve crimes?” and, honestly, I do not have the patience for that this week.  Kindly refrain.  If you want ghosty-wobbles and SF nonsense, there’s always The X-Files (good heavens, I did not appreciate how many callbacks I’d make to that post when I wrote it…) or Randall and Hopkirk (Deceased).

As before, I think there are two prongs to this.

The first is simply one of expectation, to be assured that we the reader is getting up front a rational tale which we can engage with, and hopefully solve, from a purely rational perspective.  Take the work of, say, William Hope Hodgson as an example: his Carnacki the Ghost-Finder stories are well-known and highly-regarded as a point in detective fiction where the irrational and the rational rubbed shoulders, knees, and toes: ‘The Thing Invisible’ (1912) remains oddly popular and widely anthologised for the way it rationally explains a way of stabbing a man who was alone in a building at the time.  And yet there’s another Carnacki story I read back when I first heard of Hodgson’s work in which a ghostly whistling is heard coming from an empty room, and upon further and deeper investigation Carnacki discovers — spoilers, but it has been over a hundred years — that the floorboards pucker like lips and physically whistle because the room is possessed by a, er, vengeful(?) spirit.

Now.  In the universe of Carnacki this is all well and fine — and, indeed, the lack of certainty as to whether we were getting a rational or a ghostly explanation is precisely the kind of thing I suggested would have done The X-Files some good in the post linked above — but for the detection fan, and the reader expecting a rational story, you can see the obvious disappointment that would result.  If you wonder how the killer vanished from a watched, snow-surrounded room in The Hollow Man (1935) and after 200 pages of logical, precise investigation it turned out that the killer was a floaty demon thing that could pass through walls…well, the book wouldn’t have the reputation it does.  If the murder in Mystery at Olympia (1935) was accomplished by psychic energy rather than the labyrinthine methods employed…again, we’d all dismiss it, wipe the book from the memory of history, and wonder what John Rhode put in his tea that week.  Remember, these are explanations coming about in the world those books already exist in, with not one detail changed beyond this sudden preternatural development at the end.

The novel of detection is a game — the rules are clear, the author shows the reader what is needed, and the reader is able to pick up what they believe to be the salient points and thus turn in a solution, correct or otherwise.  Without that clear delineation in responsibility on both sides, the whole (ahem) spirit and intent of the enterprise goes out of the window.  We, as a reader, do not appreciate the intelligence of a plot device that we could not anticipate, and the ghost leaning over the barrier twixt life and death to lend a hand or point a finger comes from so far outside the acceptable as to be genre-destroying.  Where is the magnificence of the detective’s achievement if someone else — corporeal or otherwise — is simply able to relay what they saw and so solve the case?  A detective who was able to enter the mind of witnesses would essentially be using an invisibility cloak to insert themself into a scene they did not need to detect the truth behind: simply go from person to person until you “see” them committing the murder, end credits.  That’s certainly something, but it’s not detection.


“About that ball, though…”

It’s not a problem if you know you’re getting a genre-straddling story, but what if you don’t?  There has, in the last year or two, been a novel published by a popular novelist in which the following situation presents itself: a man seen in two places at once, one of which is the location of a terrible murder, the fingerprints of the suspect being found at the scene when he was also definitely miles away.  The talent involved in providing a rational explanation here is immense, witness Through a Glass Darkly (1932/1950) by Helen McCloy, which goes to hugely creative lengths to stitch such a seemingly wondrous possibility into the achievable world.  In this recent novel, a huge amount of time is spent breaking down the various testimonies, examining possibilities, trying permutations, and in the end it turns out that the murder was committed by…a sort of demon-thing that can mimic people.  And the book to get to this answer is 600 pages (and, yeah, that sort of spoils who the author is — but, c’mon). Wow.  How inventive.  Form here, why not Mr. Ratchett’s murderer being a imp that scampered away over the snow too quickly to leave a footprint, or Betty Kane being able to accuse Marion Sharpe and her mother of kidnap and ill treatment because she’s psychic, floats through walls, can stop time, and is able to wipe memories at will?  Robert Blair wouldn’t stand a chance then.

Yes, I’m labouring a point, and yes I’m preaching to the choir, and yes the same thing goes for a detective who is able to enter a special trance or have lucid dreams and thus stumble upon the key moment of realisation that still dogs the genre even to this day under a different name: the moment of sudden intuitive inspiration.  Detection requires the detective to amass information, and usually requires them to look at it in a particular way, but the beauty of seeing your protagonist succeed is is knowing that they’ve done so by their own talent, their own doggedness, and not simply having the answer handed to them by an obsequious man-of-all-work who lives in their head.  Make Papa Poirot into a slightly objectionable foreigner who has convenient dreams and he’s far less compelling a presence.  If Joseph French is led to the killer’s door by the vengeful spirit of the victim, you rob that character of everything that makes him him.  Your detective becomes a passive presence in their own story, and the reader a passive witness to something they wish to actively engage with.

Along with Hodgson, a number of authors wrote both rational and irrational solutions to their mysteries; Walter S. Masterman started out with a very good debut impossible crime, but as Robert Adey notes, “then moved on to the more sinister worlds of giant toads and other misshapen monsters”, and part of the difficulty in reading more Masterman is knowing which of his novels fall into which camp.  We read detection for the retrospective realisation of how thoroughly we have been (hopefully fairly) hoodwinked, and being unsure up front if that’s what’s going to happen makes us less likely to want to risk the time and money that could be put towards something which will do that.  I’d wager this, as much as his until-recent unavailability, has contributed to Masterman’s obscurity.


“I’m sorry to interrupt, but–“

But there is a flip-side to this, as Knox acknowledges.  The gods of reason such genre adherence invokes demand a certain sacrifice: namely that the reader knows automatically that any such spirit-world shenanigans can be dismissed without compunction.  The eldritch phantasms may carouse as freely and loudly as they wish through the pages of a novel of detection, but come the end they’ll always be so many wires, so much cheesecloth.  And as such the supernatural trappings are little more than set-dressing on an otherwise mundane story to disguise the “growing difficulty, for the author, of finding ways in which he can deceive his reader without either breaking the rules, or using gambits which have been used ad nauseam before”.  Hence, as Knox so kindly puts it, we often “miss the thrill of suspecting the wrong person”, i.e., it’s bloody obvious whodunnit.

And so the preternatural — prophetic dreams, bilocation, seances, demonic possession — tends to lends itself more to the howdunnit than the whodunnit (though Arthur Conan Doyle crafted a fine whydunnit from supernatural origins) and as such limit its usefulness in the genre.  And so the argument against phantasmagoria is strengthened in part even further, given that the howdunnit — the impossible crime — proved to be a difficult beast to tame (though it’s telling that a sizeable portion of the people reading this are itching to point out Rim of the Pit (1944) by Hake Talbot or The Reader is Warned (1939) by Carter Dickson in defence of the other side, showing how damn arresting the concept is when used well).  And yet we, like gamblers, tend to remember the wins rather than the losses.  Through a Glass Darkly, mentioned above, does good work, but never really convincing work in misguiding you to believe that bilocation is possible.  Norman Berrow’s giant killer thumb is wildly enjoyable, but does anyone ever really buy into it?  I think not.

Detective fiction — classic detective fiction — never shied away from doing the difficult thing, but equally the desire is to see the genre do what it does to the best of its abilities as regularly as possible.  No-one becomes a fan of a genre that hits the mark one book in ten, and since we know that the magical elements of any detective novel as Knox sees them can be dismissed, there’s an argument that the supernatural should be banished from the genre altogether.  Ether that, or we give up our pious belief in genre as a construct and accept that sometimes the answer is simply going to be “Yup, it was aliens”.  Of the two options, I think I like the second one least.

Pom with ball


15 thoughts on “#595: Reflections on Detection – The Knox Decalogue 2: The Supernatural

  1. Inspired by your explorations, I’ve ordered a second hand copy of Sins for Father Knox by Josef Skvorecky. This is mentioned in Adey’s Locked Room Murders.
    The Amazon blurb is below:
    “Each story violates one of the rules of the Detective Story Decalogue by Father Ronald Knox. The reader must decide which rule has been broken and identify the murderer.”


    • Ah, I had not realised that the Skvorecky tales were unresolved — makes them sound a bit more interesting. Hadn’t thought they were my kind of thing if they were just stories that broke a rule each, but if you have to figure out which one then that makes it a bit more interesting. Thanks for letting me know, I might just start to keep an eye out for it in this case…


  2. …since we know that the magical elements of any detective novel as Knox sees them can be dismissed, there’s an argument that the supernatural should be banished from the genre altogether.

    This may surprise some of you, coming from a purist like myself, but only certain writers should have been banned from using the supernatural in their detective stories. There are writers who can use genuine supernatural elements without corrupting the integrity of detective story. Carr’s The Burning Court immediately comes to mind, but my personal favorite will always be A.C. Baantjer’s De dertien katten (The Thirteen Cats), which deals with reincarnation and has an ending that kicked open the door to the Great Beyond. However, Baantjer leaves the interpretation of that ending up to the reader. He used a similar, supernatural-tinged ending in De Cock en de moord in seance (translated as DeKok and the Murder in Seance) to good effect.

    On the other hand, you have hackwork like T.C.H. Jacobs’ Appointment with the Hangman, which is mostly filled with second-rate parlor tricks and the levitation-trick was explained away as the only true supernatural phenomena in the story!

    This is not only disappointing and plain cheating, but destroyed the flimsy internal logic of the story. Why would a cult-like leader who can use the power of his mind to levitate fake a mid-air vanishing and a talking cat? Just being able to actually levitate is enough to astonish even the most devout skeptic. Yeah, depending on who’s writing the story, this rule can be either discarded or should be enforced with a cast-iron fist.

    By the way, I probably should have said this in one of your earlier blog-posts, but you have to keep in mind Van Dine and Knox compiled their list of rules in the late 1920s. So they were probably written in an attempt to bring a little order to the genre, because the genre pre-1930 wasn’t always what we imagine when we think of the Golden Age. Unless it was by one of the well-known writers of the period.


    • The notion of bringing order to the genre is very much what I have in mind that Knox, er, had in mind — the timing is interesting, and I think we tend to take for granted that it was universally understood what GAD was just because some “big names” who are still discussed to this day were doing it.

      And, yes it’s very difficult to ever say that something should be entirely taken out of a genre, since there will inevitably be examples of someone doing it brilliantly (provided the genre has been appropriately explored, that is). This is what is so vexing about the prevailing modern attitude to this list: it’s easy to assume that a) it was all so freakin’ obvious at the time and b) this was seen as a sort of definitive and authoritarian attempt to limit what was permissible in the genre. Neither could be further from the truth.


  3. I’m a sucker for a story with some supernatural flair. The Plague Court Murders, Hag’s Nook, The Red Widow Murders, Rim of the Pit, The Burning Court, The Reader is Warned – each of these is elevated by that somewhat pulpy sense of horror and adventure. And yet it’s key while reading that we know the solution isn’t going to be supernatural. It would be a very different experience to be reading, say, The Crooked Hinge and thinking that it really was a story about a cursed automaton. In fact, I wouldn’t be reading it at all, because “people dealing with killer ghost” isn’t really the type of thing I’m into reading at the moment.

    And maybe that’s partly the point – if I want to read a mystery, I need to know that it’s a mystery and likely to deliver that “aha, I didn’t see that coming” moment in the end. If I wanted to read horror, I’d read horror. That isn’t to say that horror can’t provide that “aha” moment at the end (I can think of some excellent or even mediocre horror movies that do this), it’s just that I don’t walk into a horror movie expecting that sort of conclusion – it’s just as acceptable that the final girl slays the axe wielding maniac in the end (with requisite twist that the killer is really still alive).


    • I’m with you in loving the supernatural, and with TomCat in feeling that the element of faux-supernaturalism should probably have been the purview of only a handful of authors. Because. yes, the entire purpose of reading a mystery — a classic one, at least — is in knowing that we’ll get a solution we could anticipate, and there are some authors and some books which throw in the supernatural merely as a sort of “Meh, will this do?” attempt to stir the pot. The titles you quote above are exemplary points on the graph of The Supernatural in Rational Detective Fiction, and I’d add Murder on the Way! to the list, too, but man, is it ever a diluted pool thanks to people who just wanted a comedy seance (and I say this as a lover of the comedy seance).

      That Isaac Asimov “locked room” with the man turned into a demon that I mentioned last week is a prime example of the sort of genre-straddling that never goes down well — his SF fans dislike it, the impossible crime fans dislike it, no-one wants to give it a home…and it’s actually not a bad conceit, it’;s just not what anyone signed up for. Imagine if M.R. James had finished ‘The Mezzotint’ with the revelation of hundreds of subtly-different carvings in the attic, or ‘Lost Hearts’ with the revelation that the protagonist had been drugged and so was hallucinating. There’s a time and a place to challenge genre conventions, no doubt, but the old bait-and-switch rarely goes down well.


  4. As I see it, the rules of Knox (as well as those of Van Dine, Carr, and the others) are largely tautological listings of illustrations (of varying scope) of a very small number of tacit expectations, namely:

    1. The puzzle shall indicate the solution.
    2. The solution shall account for the puzzle.
    3. The solution shall surprise.

    (Of course, there remains precise delineation of such questions as “to what degree must the puzzle indicate the solution?” and “what level of detail can exist in the puzzle which is not accounted for by (i.e. pertinent to) the solution?”— questions which I believe make the issue of “fairness” immeasurable. But that’s for a different discussion).

    In the case of the supernatural and preternatural, I feel the issue is covered by expectation #1 and, as you suggest, is more clearly stated “unless supernatural elements are defined and explained prior to the revelation of the solution, it is assumed that the universe of the fiction operates as ours does.” No solution which is dependent upon people walking through walls could be said to be indicated by a puzzle which does not explain that it takes place in a world in which people can walk through walls; thus, all elements which lie outside our default (natural) physical universe fall into the same categories as plot elements which are un-clued and only introduced after the “equals sign” of the denouement (I don’t the game analogy of detective fiction holds, but I think the equation analogy is pretty good). And again, though I’m entirely convinced the concept of “fairness” is logically inapplicable to the genre, the initial introduction of essential plot elements at the denouement certainly falls under the category of what strikes most readers as intuitively “unfair.”


    • Scott, you have as usual condensed my blatherings into a far more swallowable pill: “the initial introduction of essential plot elements at the denouement” is the perfect way to summarise that moment of frustration we mystery fans have all together too much experience with. The fact that it’s a broad panoply of possibility — I was having a conversation this week about whether knowing the uses for certain medicines was sufficient for the presence of medication to count as declaration — is what makes it difficult, but if something is mentioned in the summary chapter which we did not know before, then the jig is up.

      Expect a series of posts on the Ratner Triumvirate 100 years from now…


    • I write a puzzle whose only possible solution is telekinesis. The solution is telekinesis. You are surprised at how awful this is.

      I have passed your three tests.


  5. I, too, love the use of the supernatural in a mystery provided that it is explained away by natural means. The spooky seances in The Sittaford Mystery and Dumb Witness actually help solve those mysteries, while the caaa-raaaaazy one in Rim of the Pit establishes the bona fides of the detective before the real hilarity ensues.

    That said, if a mystery can combine the two satisfactorily, I might go along for the ride. I suppose The Burning Court divides readers, but I’m on the “pro” side and I figure that if it didn’t end that way, it wouldn’t be quite the classic it is. Sadly, this is the only example I can think of. I don’t hear much love in the blogosphere for Caroline Graham, but I loved her books . . . UNTIL the end when she tried to mix up the genres a bit for a surprise that fell flat. So, yeah, don’t mess with this stuff unless you’ve got the moxie to do it big and the skills to do it well.

    Meanwhile, in the Biting Off More Than We Can Chew Dept. . . . I have to laugh at your suffering over the fact that you set this WEEKLY task before you and now find that life intrudes. When I conceived my Carter Dickson Celebration, I started with the idea that I would cover a book a month. Fortunately, a saner head prevailed, and I now expect to finish in the summer of 2036. It only means that my reader (some guy named Joe in Biloxi, Mississippi) and I will get to savor the experience a lot longer.


    • For all the attention inevitably paid to The Burning Court in the wake of such a discussion, my favourite use of the supernatural in Carr’s work is still, I think, the time he used it with no explanation at all: The Devil in Velvet (and, to a certain extent, Fire, Burn). I like to think that he became so well-known for his rational impossibilities that he opted out of going “full ghost” in most of his setups, since the readers would be unlikely to buy it anyway (The Reader is Waned being a notable exception — but there you know whodunnit and not how).

      John Sladek did it reasonably well in Black Aura, and I’m sure there are other cases that elude me at present. But, as we keep saying, they’re in the minority. And I hear Joe is very excited to get to Night at the Mocking Widow — apparently it’s his fave. So ya gotta keep going, Brad. For Joe’s sake.


    • I think a lot of the missing of Knox’s point is done not on account of the humour but instead by people who don’t really appreciate the purpose of his undertaing. It’s, at heart, an intellectual proposition to see if the limits and nature of the detective story can be codified — not to restrict what’s allowable, but just to see if it can be. And then he admits at the end that it’s probably not an exhaustive list anyway and that too many rules would give the impression of trying to enforce a particular form of practice on the genre and be a bad thing…essentially admitting the folly of his undertaking.

      but that doesn’t mean there isn’t some validity to what he says (and he’s doubtless having more fun than Van Dine, whose list is tedium personified — Now there is someone trying to impose their own perspectives on the genre overall, and yet it’s Knox who gets castigated on account of The Chinaman, as it happens purely on the basis of a hugely ironic misunderstanding. But we’ll get to that).


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