The Chain of Chance

advanced rheumatism. Therefore the ones who were exposed to the greatest danger were those who had already crossed the shadow line. In retrospect, the more closely one examined the facts, the more interrelated they became. For example, the chemical poisonings all took place during the blooming season, when drivers were more apt to use Plimasine, and since patients with acute asthma were physically unable to drive, they would have had no need for a drag intended for drivers.

Barth was gracious enough to keep me company during my stay in the hospital, so I decided to pay him a farewell visit before flying back to the States. Pierre was keeping a lookout by the stairs but ducked out of sight the moment he saw me coming. I knew what was on his mind and promised him I wouldn’t forget about his helmet. Barth had another visitor, Dr. Saussure, now wearing a shirt with frilled cuffs instead of a frock coat, with a pocket watch dangling from his neck instead of a calculator. While he browsed through some books in the library, Barth spoke to me about one of the supreme ironies of the case: even though it had been inoperative and unprogrammed the whole time, the computer had proved enormously beneficial to the investigation. Because if I hadn’t flown to Paris with the idea of using the computer, I never would have stayed at Barth’s place, never would have aroused the sympathy of his grandmother, and little Pierre never would have come to my rescue with the flowers of sulfur after my fall on the stairs… In short, the computer played an undisputed role in unraveling the mystery, though in a purely abstract sort of way. With a laugh I commented that the whole combination of fortuitous events leading up to the solving of the mystery now seemed to me more amazing than the mystery itself.

“Now you’re committing the egocentrist fallacy!” Saussure exclaimed as he turned around to face us from the bookcase. “This series of yours is not as much a sign of the times as a portent of tomorrow. A vague premonition of things to come…”

“Do you understand it?”

“I see only the warning signs. Mankind has multiplied to such an extent that it’s now starting to be governed by atomic laws. The movement of gas atoms is chaotic, but out of this chaos are born such things as stable pressure, temperature, specific gravity, and so on. Your accidental success looks like a long series of extraordinary coincidences. But it only seems that way to you. You will probably argue that besides your falling down Barth’s stairs and accidentally inhaling sulfur, a number of other factors were necessary to trigger the chain reaction: your scouting trip to Rue Amelie, your sneezing fit, the decision to buy some almonds for your nephews, the flight cancellation, the crowded hotel, the barber, and even the fact that the barber was a Gascon…”

“Oh, why stop there,” I intruded. “If I hadn’t broken my tail bone in the liberation of France, I wouldn’t have had a relapse on the escalator in Rome, or here, either, for that matter. And if I hadn’t wound up in front of the assassin on the escalator, my picture wouldn’t have landed on the cover of Paris-Match. And if it hadn’t been for the picture, I would have spent the night in Paris instead of fighting for a room at the Hotel Air France, and that would have been the end of it. The chances of my being there at all during the explosion were astronomically small. I could have booked another flight; I could have been standing on another step… Not to mention all the other astronomical improbabilities that came before and after! For instance, if I hadn’t heard about the Proque affair, I wouldn’t have decided to fly back to Rome just when the flights were being canceled… and in a way that was the purest coincidence of all.”

“You mean your finding out about the Proque affair? I don’t believe it was a coincidence. The doctor and I were just talking about it before you came in. You were briefed because of the political infighting going on between Surete and Defense. Someone was out to discredit a certain military official who was playing politics to promote Dr. Dunant. You were caught in a billiard game.”

“Was I supposed to be a ball or a cue?”

“Our guess is that they were using you to get the Proque case reopened so they could damage Dunant’s reputation…”

“But I still don’t see what my coming to Paris had to do with all this political infighting.”

“It had absolutely nothing to do with it. That’s why the large number of coincidences strikes you as being contrary to common sense. But I say to hell with common sense! By itself each segment of your experience is plausible enough, but the trajectory resulting from the aggregate of these segments borders on being a miracle. That’s what you thought, wasn’t it?”

“Yes.”

“But meanwhile the very thing I was telling you about three weeks ago has happened. Imagine a firing range where a postage stamp is set up as a target a half mile away. Let’s make it a ten-centime stamp, with a picture of Marianne on it. Along comes a fly and leaves a speck the size of a dot. Now let several sharpshooters start firing away at the dot. They will surely miss it, because at that distance they won’t even be able to see it. But now suppose a hundred mediocre marksmen were to start firing for weeks on end. You can bet that one of their bullets will eventually hit its target. Not because the man who fired it was a phenomenal marksman, but because of the sheer density of fire. Wouldn’t you agree?”

“Yes, but that still doesn’t explain—”

“Wait, I’m not finished yet. It’s summer now, and the range is crawling with flies. The probability of hitting the dot was extremely small. But the probability of simultaneously hitting both the dot and a fly that happens to wander into the bullet’s path is even smaller. The probability of hitting the dot and three flies with the same bullet would be—to use your words—astronomically small. And yet I assure you that such a coincidence would come to pass as long as the firing was kept up long enough.”

“Excuse me, but you’re talking about a whole barrage, while I was just one of a series…”

“That’s an illusion. At the precise moment the bullet hits both the dot and the three flies, then it, too, is only one of a series. The lucky marksman will be just as amazed as you were, even though there would be nothing so terribly miraculous or unusual about the fact that he hit it, because, you see, somebody would have had to hit it. See what I mean? Common sense isn’t worth a damn here. My prediction came true. The Naples mystery was the result of a random causality, and it was the same random causality that solved it. The law of probability applies to both members of the proposition. Needless to say, if only one of the set of necessary conditions had gone unfulfilled, you never would have been drugged, but sooner or later someone would have met all the conditions. One, three, five years from now. And that is so because we now live in such a dense world of random chance, in a molecular and chaotic gas whose ‘improbabilities’ are amazing only to the individual human atoms. It’s a world where yesterday’s rarity becomes today’s cliche, and where today’s exception becomes tomorrow’s rule.”

“O.K., but I was the one—”

He didn’t let me finish. Barth, who knew Saussure, looked at both of us with twinkling eyes, as if trying his best not to laugh.

“Excuse me, but if it hadn’t been you, it would have been someone else.”

“Who? Some other detective?”

“I don’t know and I don’t care. Someone, that’s all. By the way, is it true you’re planning to write a book about the case?”

“As a matter of fact, I am. I even have a publisher… but why do you ask?”

“Because that’s also related. Just as some bullet is bound to hit its target, someone was bound to crack the case. And if that’s so, then regardless of the publisher or author, the publication of this book was also a mathematical certainty.”

November 1975

Also by Stanislaw Lem

Solaris

The Star Diaries

The Cyberiad: Fables for the Cybernitic Age

The Futurological Congress

The Investigation

The Invincible