The vulgar definition, "a Whodunit," is correct. The basic formula is this: a murder occurs; many are suspected; all but one suspect, who is the murderer, are eliminated; the murderer is arrested or dies.
This definition excludes:
1 ) Studies of murderers whose guilt is known, e.g., Malice Aforethought. There are borderline cases in which the murderer is known and there are no false suspects, but the proof is lacking, e.g., many of the stories of Freeman Wills Crofts. Most of these are permissible.
2,) Thrillers, spy stories, stories of master crooks, etc., when the identification of the criminal is subordinate to the defeat of his criminal designs.
The interest in the thriller is the ethical and characteristic conflict between good and evil, between Us and Them. The interest in the study of a murderer is the observation, by the innocent many, of the sufferings of the guilty one. The interest in the detective story is the dialectic of innocence and guilt.
As in the Aristotelian description of tragedy, there is Concealment (the innocent seem guilty and the guilty seem innocent) and Manifestation (the real guilt is brought to consciousness). There is also peripeteia, in this case not a reversal of fortune but a double reversal from apparent guilt to innocence and from apparent innocence to guilt. The formula may be diagrammed as follows:
Peaceful state before murder
False clues, secondary murder, etc.
Solution
Arrest of murderer
Peaceful state after arrest
In Greek tragedy the audience knows the truth; the actors do not, but discover or bring to pass the inevitable. In modern, e.g., Elizabethan, tragedy the audience knows neither less nor more than the most knowing of the actors. In the detective story the audience does not know the truth at all; one of the actors—the murderer—does; and the detective, of his own free will, discovers and reveals what the murderer, of his own free will, tries to conceal.
False innocence
Revelation of presence of guilt
False location of guilt Location of real guilt Catharsis True Innocence
Greek tragedy and the detective story have one characteristic in common in which they both differ from modern tragedy, namely, the characters are not changed in or by their actions: in Greek tragedy because their actions are fated, in the detective story because the decisive event, the murder, has already occurred. Time and space therefore are simply the when and where of revealing either what has to happen or what has actually happened. In consequence, the detective story probably should, and usually does, obey the classical unities, whereas modern tragedy, in which the characters develop with time, can only do so by a technical tourde force; and the thriller, like the picaresque novel, even demands frequent changes of time and place.
Why Murder?
There are three classes of crime: (A) offenses against God and one's neighbor or neighbors; (B) offenses against God and society; (C) offenses against God. (All crimes, of course, are offenses against oneself.)
Murder is a member and the only member of Class B. The character common to all crimes in Class A is that it is possible, at least theoretically, either that restitution can be made to the injured party (e.g., stolen goods can be returned), or that the injured party can forgive the criminal (e.g., in the case of rape). Consequendy, society as a whole is only in- direcdy involved; its representatives (the police, etc.) act in the interests of the injured party.
Murder is unique in that it abolishes the party it injures, so that society has to take the place of the victim and on his behalf demand restitution or grant forgiveness; it is the one crime in which society has a direct interest.
Many detective stories begin with a death that appears to be suicide and is later discovered to have been murder. Suicide is a crime belonging to Class C in which neither the criminal's neighbors nor society has any interest, direct or indirect. As long as a death is believed to be suicide, even private curiosity is improper; as soon as it is proved to be murder, public inquiry becomes a duty.
The detective story has five elements—the milieu, the victim, the murderer, the suspects, the detectives.
The Milieu (Human)
The detective story requires:
i) A closed society so that the possibility of an outside murderer (and hence of the society being totally innocent) is excluded; and a closely related society so that all its members are potentially suspect (cf. the thriller, which requires an open society in which any stranger may be a friend or enemy in disguise).
Such conditions are met by: a) the group of blood relatives (the Christmas dinner in the country house); b) the closely knit geographical group (the old world village); c) the occupational group (the theatrical company); d) the group isolated by the neutral place (the Pullman car).
In this last type the concealment-manifestation formula applies not only to the murder but also to the relations between the members of the group who first appear to be strangers to each other, but are later found to be related.
2) It must appear to be an innocent society in a state of grace, i.e., a society where there is no need of the law, no contradiction between the aesthetic individual and the ethical universal, and where murder, therefore, is the unheard-of act which precipitates a crisis (for it reveals that some member has fallen and is no longer in a state of grace). The law becomes a reality and for a time all must live in its shadow, till the fallen one is identified. With his arrest, innocence is restored, and the law retires forever.
The characters in a detective story should, therefore, be eccentric (aesthetically interesting individuals) and good (instinctively ethical)—good, that is, either in appearance, later shown to be false, or in reality, first concealed by an appearance of bad.
It is a sound instinct that has made so many detective story writers choose a college as a setting. The ruling passion of the ideal professor is the pursuit of knowledge for its own sake so that he is related to other human beings only in- direcdy through their common relation to the truth; and those passions, like lust and avarice and envy, which relate individuals directly and may lead to murder are, in his case, ideally excluded. If a murder occurs in a college, therefore, it is a sign that some colleague is not only a bad man but also a bad professor. Further, as the basic premise of academic life is that truth is universal and to be shared with all, the gnosis of a concrete crime and the gnosis of abstract ideas nicely parallel and parody each other.
(The even more ideal contradiction of a murder in a monastery is excluded by the fact that monks go regularly to confession and, while the murderer might well not confess
his crime, the suspects who are innocent of murder but guilty of lesser sins cannot be supposed to conceal them without making the monastery absurd. Incidentally, is it an accident that the detective story has flourished most in predominantly Protestant countries?)
The detective story writer is also wise to choose a society with an elaborate ritual and to describe this in detail. A ritual is a sign of harmony between the aesthetic and the ethical in which body and mind, individual will and general laws, are not in conflict. The murderer uses his knowledge of the ritual to commit the crime and can be caught only by someone who acquires an equal or superior familiarity with it.
The Milieu (Natural)
In the detective story, as in its mirror image, the Quest for the Grail, maps (the ritual of space) and timetables (the ritual of time) are desirable. Nature should reflect its human inhabitants, i.e., it should be the Great Good Place; for the more Eden-like it is, the greater the contradiction of murder. The country is preferable to the town, a well-to-do neighborhood (but not too well-to-do—or there will be a suspicion of ill-gotten gains) better than a slum. The corpse must shock not only because it is a corpse but also because, even for a corpse, it is shockingly out of place, as when a dog makes a mess on a drawing room carpet.