This post has been wrought out of many ponderings over the eternal question of “what is a mystery” and “what categories mysteries have”. It is an attempt to refine my previous discussions by introducing a wider definition while salvaging the previous one, by introducing a dichotomy of categories.
The inspiration came from scottkratner in the comments here, who wisely pointed out the importance of pinpointing the quality of “sudden retrospective illumination” as a form of reader’s enjoyment.
But I was also pondering a very important dichotomy Amara of Solving the Mystery of Murder has introduced in On A Defense of the Impossible Alibi Problem and “Doylist” Impossibilities. Now it seems to me that it can be fruitfully extended beyond delineating which crimes in mystery are impossible and can be applied to the structural features of mysteries in general.
On one side, there are the “Watsonian”, or internal, plot points, which make sense from the limited point of view of the characters within the story. Other plot points are “Doylean”, or external, requiring the whole picture available ot the omniscient narrator to resolve. Any internal point is also external by definition, but not necessarily otherwise.
We may postulate:
Definition 1. A mystery is a situation with an unknown fact. Such as: a crime has been committed, hence there must be a perpetrator. However, their identity is unknown.
Definition 2. A contradiction is a seeming logical mismatch in the known facts. Such as: a crime has been committed in a room apparently locked from the inside and devoid of persons.
A puzzle is either is a situation that is either a mystery, or a contradiction.
Definition 3. The perpetrator is the person or persons responsible for creating the puzzle by making effort to have some facts hidden or creating a seeming logical mismatch.
The sleuth is the person who searches for a solution to the puzzle within the plotline based only on the facts available to characters and not to the omniscient narrator or the perpetrator (= available internally).
Definition 4. A solution to a puzzle is called logical if it fulfills the following two conditions:
- fits to both the stated problem and the rules of the world without mismatch;
- is completely findable based on the facts given without employing any other tools but logical reasoning over them.
A logical solution is external if findable based on the facts given to the reader; internal if findable based on the facts given to the characters.
Definition 5. The property of fair play is the provision to the reader of any data available to the sleuth.
Primary Notion 1.
A Doylean story (or, a story of reasoning, or an external mystery) is a story featuring a puzzle which in the climax and as the main element of plot resolution is given a logical solution.
Primary Notion 2. A Watsonian story, (or, as I still insist, a deductive story, or an internal mystery) is a story where the puzzle is internalized. Namely, it is a story featuring a puzzle which in the climax and as the main element of plot resolution is given a logical solution internally, by the sleuth employing only logical inference.
Corollary 1. In a Doylean story, all the data sufficient to reach the solution are provided to the reader. In a Watsonian story, all the data sufficient to reach the solution are provided to the sleuth.
Proof. As the climax of a Doylean story, a solution must be provided logically. By definition of a logical solution, it is completely findable based on the facts already given to the reader. The second case resolves analogically.
Corollary 2. A fair play Watsonian story is a Doylean story.
Proof. In the climax of a Watsonian story, a logical solution is established by a sleuth. Hence, all the data required to reach the solution had been available to the sleuth. But, by fair play, the same facts are then available to the reader.
Note. The theses of “What Is Vital in Deductive Story” are spread as follows:
World-consistent (by Definition 4.1), prepared, conveyed, explicated are properties of both a Doylean and a Watsonian story. Internally soluble, logically reachable (as stated), internally derived are properties of a Watsonian (deductive) story proper. Unique is, strictly saying, not demanded, though welcome.
Note that it is possible for a story to be Watsonian but not Doylean; a story with the super-sleuth giving final reasoning based on the facts found by them but not revealed to the reader beforehand would qualify.
And Then There Were None, Trent’s Last Case, Boileau-Narcejac are all Doylean stories (external), yet not Watsonian (internal). The internal definition generally agrees with my previous definition of a deductive story.
The Detection Collection 