Tzvetan Todorov, from “An Introduction to Verisimilitude,” in The Poetics of Prose (Cornell, 1977)

Verisimilitude is the theme of the murder mystery; its law is the antagonism between truth and verisimilitude. But by establishing this law, we are once again confronted by verisimilitude. By relying on antiverisimilitude, the murder mystery has come under the sway of another verisimilitude, that of its own genre. No matter how much it contests ordinary verisimilitudes, it will always remain subject to some verisimilitude. And this fact represents a serious threat to the life of the murder mystery, for the discovery of this law involves the death of the riddle. We have no need to follow the detective's ingenious logic to discover the killer--we need merely refer to the much simpler law of the author of murder mysteries. The culprit will not be one of the suspects; he will not be brought to light at any point in the narrative; he will always be linked in a certain way with the events of the crime, but some reason--apparently quite important, actually secondary--keeps us from regarding him as a potential culprit. Hence it is not difficult to discover the killer in a murder mystery: we need merely follow the verisimilitude of the text and not the truth of the world evoked.

There is something tragic in the fate of the murder-mystery writer; his goal is to contest verisimilitudes, yet the better he succeeds, the more powerfully he establishes a new verisimilitude, one linking his text to the genre to which it belongs. Hence the murder mystery affords our purest image of the impossibility of escaping verisimilitude: the more we condemn verisimilitude, the more we are enslaved by it.

The murder-mystery writer is not alone in suffering this fate; all of us do, and all the time. From the very first we find ourselves in a situation less favorable than his: he can contest the laws of verisimilitude, and even make antiverisimilitude his law. Though we may discover the laws and conventions of the life around us, it is not within our power to change them--we shall always be obliged to obey them, though such obedience is twice as difficult after this discovery. It comes as a bitter surprise when we realize that our life is governed by the same laws we discovered in our morning paper and that we cannot change them. To know that justice obeys the laws of verisimilitude, not of truth, will keep no one from being sentenced.

But independent of this serious and immutable character of the laws of verisimilitude, with which we are concerned here, verisimilitude lies in wait for us at every turn, and we cannot escape it-any more than the murder-mystery writer can. The 'constitutive law of our discourse binds us to it. If I speak, my utterance will obey a certain law and participate in a verisimilitude I cannot make explicit and reject without thereby utilizing another utterance whose law will be implicit. Being an act and not only an utterance, my discourse will always participate in some verisimilitude; a speech-act cannot, by definition, be made altogether explicit: if I speak of it, I am no longer speaking of it but of its utterance, which is an act in its turn and one which I cannot utter.