Pierre Bayard, Who Killed Roger Ackroyd

Editions de Minuit 1998 / The New Press 2000, pp. 19-21

from Part 1, Chapter 3, The Van Dine Principle

All theoretical literature on the detective mystery is dominated by a principle of disguise that Agatha Christie seems to have perfected, a principle summarized in two rules.

The first is that the truth must be hidden throughout the book. The detective novel has meaning only if the truth is not revealed until the end of the book, and, if possible, not until the last few pages. This game-playing dimension is essential to the construction of blindness, which is all the more powerful when the veil is lifted at the last possible moment.

The second rule of the disguise principle: While being hid­den, this truth must be accessible to the reader, even in plain view. It would be out of keeping with the genre for the truth to be connected to elements unavailable to the reader; such as an unknown character, a hidden clue, or the like. This second rule distinguishes this type of novel from other detec­tive stories in which the main emphasis is less on solving a mystery than on describing a milieu or evoking an atmosphere. This fundamental principle of the detective mystery was es­tablished most clearly by S. S. Van Dine in an article published in the September 1928 issue of the American Magazine (a work that is of course contemporary with Agatha Christie's The Murder of Roger Ackroyd). In it, Van Dine (pseudonym of the American writer Willard H. Wright, creator of the charac­ter Philo Vance) tries to formalize what he considered the twenty rules of the detective genre.

The seventh rule - on which we shall not insist while still endorsing it - requires the minimal necessity of one corpse per book: "There simply must be a corpse in a detective novel, and the deader the corpse, the better. . . . Three hundred pages is far too much bother for a crime other than murder. After all, the reader's trouble and expenditure of energy must be re­warded." Other rules, more original, concern the identity of the culprit. Thus, according to Van Dine, it could never be a policeman or a detective ("This is bald trickery, on a par with offering someone a bright penny for a five-dollar gold piece") or a servant ("The culprit must be a decidedly worth-while person"). He has to have played an important role in the story - he cannot be a marginal character appearing in the final pages - and he must be unique: "The entire indignation of the reader must be permitted to concentrate on a single black nature."

But the chief rule, listed as number fifteen, concerns the method of concealing the truth:

The truth of the problem must at all times be apparent - provided the reader is shrewd enough to see it. By this I mean that if the reader; after learning the explanation for the crime, should reread the book, he would see that the solution had, in a sense, been staring him in the face - that all clues really pointed to the culprit - and that, if he had been as clever as the detective, he could have solved the mystery himself without going on to the final chap­ter.

We could read Agatha Christie's entire corpus as the rigorous and systematic application of the Van Dine principle. When we study her novels together; we realize that they involve experi­menting in great detail with all the possible combinations al­lowing the application of this two-sided principle that prevents the reader from grasping the truth even while it is exposed in full view.