Pascal's Wager Read online

  He finally agreed to allow Jacqueline to keep a kind of faux cloister inside the Pascal home, never going out, except to Port-Royal for Mass, and receiving no visitors. Obediently, she took to her room and followed her vocation there until her father’s death.

  [1648] September 19

  The Great Experiment

  When men have realized that time has upset many fighting faiths, they may come to believe even more than they believe the very foundations of their own conduct that the ultimate good desired is better reached by free trade in ideas—that the best test of truth is the power of the thought to get itself accepted in the competition of the market, and that truth is the only ground upon which their wishes safely can be carried out. That at any rate is the theory of our Constitution. It is an experiment, as all life is an experiment.

  —OLIVER WENDELL HOLMES

  Every experiment is like a weapon, which must be used in its particular way—a spear to thrust, a club to strike. Experimenting requires that a man know when to thrust and when to strike, according to need and fashion.

  —PARACELSUS (PHILIPPUS AUREOLUS THEOPHRASTUS BOMBAST VON HOHENHEIM)

  Pascal fretted throughout the controversy. Even in his own mind, he had not proved the existence of the vacuum. His experiments, dramatic as they had been, could always be challenged as mistakes, as uncalculated effects, or just as sloppy workmanship. Since Pascal had always played the devil’s advocate in the debates with his father and Monsieur Petit, he could not get past the possibility that he had created only an apparent vacuum and no real vacuum at all. Père Noël and Descartes were right: the burden of proof was on him. Could there not at least be a limited horror of the vacuum, as Galileo suggested? It is one thing to break with two thousand years of intellectual tradition, but it is another to do so with ease. One other experiment remained to be done, an experiment that, Descartes said in a letter to Père Mersenne, he had already suggested to Monsieur Pascal. Someone would have to perform the Torricelli experiment several times in one day, at different altitudes, which would mean climbing a mountain. If, as Pascal suspected, and as Torricelli had first suggested, we are all living at the bottom of a sea of air, the pressure of that sea would grow less as one climbed higher. A reasonable assumption, but whom to get to do it? Climbing a mountain was impossible for Blaise because of his fragile health. With the weakness in his legs, he could barely walk across town.

  Pascal had someone in mind, however: his own cousin and brother-in-law, Florin Perier, who was a lawyer back at the old homestead in Clermont, but who was a physics buff on the side. And he had just the place, too—the Puy-de-Dôme, the mountain that loomed over the old city and was at least several thousand feet high. But would Florin do it? On November 15, 1647, Pascal wrote to Monsieur Perier, detailing the experiment and wheedling him into taking on the task. “I should not interrupt the continual work in which your duties engage you for the purpose of talking with you about meditations on physics, if I did not know that they serve to entertain you in your hours of relaxation and that whereas others might be embarrassed by them you will find them a diversion,” he writes with a little bit of humor, a little bit of flattery, a little bit of commiseration. Perier was a lawyer, just like Blaise’s father, and Blaise knew how much work went into such a life. Perier must have complained to him at one time about his workload, and Pascal knew that if was going to get the man to take on this experiment, it would be one more burden in his life.

  But he also knew that Perier was interested in Pascal’s experiments. He had seen the Paris experiments for himself, and he had tried them in Clermont on his own. If he was not a professional physicist, he was at least a fellow traveler. In his letter, Pascal tells Perier of his suspicions, that Torricelli had been correct, that the supposed horror of a vacuum had been the result of air pressure and not of some metaphysical principle, as if the insensate air could feel passions—horror, aversion, attraction—as if it were human and had a soul. But, he goes on to say, “for the lack of convincing experiments, I dared not then (and I dare not yet) give up the idea of the horror of a vacuum.”29 Pascal, for all his feistiness with Aristotelians and Jesuits, was a conservative man at heart and, unlike Galileo, did not joyfully leap into the new thinking, but plodded along until he was able to convince himself of the truth of the experiments.

  Pascal had no doubt that Perier would perform the experiment. The only problem was his busy schedule. He was so certain of Perier’s participation that in his letter he related how he had already told many of his Parisian friends, including Père Mersenne, all about the coming experiment, and that Père Mersenne had immediately sent letters to his correspondents around Europe. Within a few weeks, Pascal assumed, practitioners of physics in Italy, Holland, Poland, and Sweden would have heard about what Pascal was up to. More than a little bit of pressure on dear Cousin Florin.

  But the experiment may indeed have been an imposition on the already overburdened Perier, because he was not able to get it done for another ten months, all the way into the next September. He traveled a great deal in his work, and there were weather problems, and this, that, and the other—which must have sparked some anxiety in Pascal, since Mersenne himself had written to others encouraging them to try the experiment for themselves, and to tell them of his plan to try it himself, if only he could get some decent glass tubes. Through much of the time, the weather had been bad on the Puy-de-Dôme, first snow, then rain. Finally, on September 19,1648, Perier carried out the experiment, and wrote this account of it:

  The weather was chancy last Saturday, the nineteenth of the month. At around five o’clock that morning, though, it seemed to be clear enough; the Puy-de-Dôme was visible at that time, so I decided to give it a try. Several important people in this city of Clermont had asked me to let them know when I would make the ascent, and so I informed them. Some of these people were clergymen, while others were laymen. All of these men were leaders of the community, not only professionally, but intellectually. I was delighted to have them with me in this great work.

  That day at eight o’clock, we met in the garden of the Minim Fathers, which has the lowest elevation in town, and began the experiment in this way: First, I poured sixteen pounds of quicksilver that I had purified during the preceding three days into a vessel, and then took several glass tubes of the same length, each four feet long and hermetically sealed at one end and open at the other, and placed them in the vessel and performed the experiment in the usual way. I found that the quicksilver stood at twenty-six inches and three and a half lines above the quicksilver in the vessel, for all the tubes. I then repeated the experiment two more times while standing at the same spot, and found that the experiments produced the same results each time—same horizontal level, same height.

  After that, I attached one of the tubes to the vessel and marked the height of the quicksilver, and left it there. I asked Father Chastin, one of the Minim brothers, and a man as pious as he is reliable, a man who reasons well in these matters, to be so kind as to watch if any changes should occur during the day. Taking the other tube and a portion of the quicksilver, and accompanied by a small crowd of gentlemen, I walked to the top of the Puy-de-Dôme, around 500 fathoms higher than the monastery, where upon doing the experiment, we found that the quicksilver reached a height of only twenty-three inches and two lines, a difference of three inches, one and one half lines. We were ecstatic with wonder and delight, and to fulfill our own curiosity, we decided to repeat the experiment. So I repeated it five times with great care, each at different points on the summit, one time in the shelter of a little chapel standing there, once in the open air, and once more in the rain and fog, which came and went. Each time, I carefully evacuated any air that might be in the tube, and in each case, we found the same height of quicksilver, which satisfied us completely.30

  They had done it. On the way down the mountain, Perier performed the experiment two more times, and then once they returned to the convent of the Minims, they checked with Père
Chastin, who said that the level had not budged, “although the weather had been disturbed, sometimes clear and still, sometimes rainy, sometimes foggy, sometimes windy.” They did the experiment with the other tubes one more time, and found the same result they had that morning—twenty-six inches and three lines of mercury. They felt that they had proved it, that the horror vacui lessened as they climbed the mountain, which meant that it was merely the result of pressure from the sea of air, which grew less as they climbed the mountain. This was proof even Pascal could accept.

  Pascal was delighted, and upon receiving his brother-in-law’s letter, he repeated the experiment in Paris, climbing to the top of the bell tower in the church of Saint-Jacques-de-la-Boucherie, about fifty meters from the ground, where the mercury level dropped two lines on the glass. He tried it once more in a private home, climbing some ninety steps, and the mercury dropped by half a line. It was done. It was proved. Everyone could see it.31 Even Descartes—not that he would have admitted it too publicly.

  [1647]

  A Skirmish with the Devil

  Heresy is the lifeblood of religions. It is faith that begets heretics. There are no heresies in a dead religion.

  —ANDRÉ SUARÈS

  If there were an art to overcoming heresy with fire, the executioners would be the most learned men on earth.

  —MARTIN LUTHER

  Saint-Cyran had been dead for four years. He had died in 1643, the same year that his disciple Antoine Arnauld published De la fréquente communion, the little tract that started a theological war. It was also the year that Louis XIII died of tuberculosis and the year after the death of Cardinal Richelieu, Saint-Cyran’s great enemy. Blaise Pascal received a copy of Arnauld’s pamphlet soon after it was published, and admired it greatly. It seemed to connect beautifully with the Augustinian tradition that Guillebert had been teaching him, in harmony with the music of his faith. For Pascal, the universe was becoming ever more strange, intensely mathematical and yet beyond all logic. The packed world of Descartes had given way to a world where empty spaces could be created without much struggle, where the emptiness of the cosmos seemed to go on infinitely. God, therefore, had to be equally strange, and the human powers of reason, for all their greatness, were powerless to plumb his divine depths.

  Suddenly, as if by God’s will, his new fervor was put to the test. Pascal was still living in Rouen, in his father’s house, and would not return to Paris for four more years. There came to the nearby town of Crosville-sur-Cie a forty-five-year-old cleric, a former Capuchin turned diocesan priest, by the name of Jacques Forton, sieur de Saint-Ange, a minor noble who had studied theology and held a post teaching at the University of Bourges. He taught a “new philosophy,” as Gilberte Perier put it, “that attracted all the curious.” In fact, Saint-Ange had become quite fashionable in his way, having gathered the notice of Cardinal Richelieu’s nephew, who had secured the parish for him.

  Two young friends of Pascal’s, both fervent admirers of Saint-Cyran and of Antoine Arnauld, alarmed by this man’s new ideas, came to the Pascal home in Rouen and asked Blaise to accompany them to speak with the man. It didn’t take long, however, once their conversation with Saint-Ange had begun, before they decided that the man was a rampant heretic. He was in fact a blatant Pelagian who, according to Gilberte, believed “that the body of Jesus Christ was not formed out of the blood of the Blessed Virgin Mary.” Apparently, Jesus’s body was made of some special substance created just for that purpose.32 Moreover, he taught that reason could demonstrate the existence of the Holy Trinity, and that faith was necessary only for those incapable of rational thought. The implications of this were outrageous to any pious young Jansenist, Augustinian to the core. What need was there for revelation? Where were the mysteries of the faith? Was he saying that people could be saved without divine grace? God in heaven! It could not be borne!

  The three young men swore to bring this heretic, this devil, to heel. Following the advice of St. Paul, they first privately admonished him, holding long conversations with him and, of course, keeping meticulous records of the conversations as evidence. But he would not budge, so they referred his case to the coadjutor archbishop, who was an administrator—a church bureaucrat and not a fire-eating theologian—and he promptly delayed taking action. Frustrated, the three sent the case to the archbishop himself, an old man ready for retirement, who was not particularly interested in theological controversies on his doorstep. The three pushed and pushed, however, until they got a judgment against the priest, a judgment that pleased no one. The archbishop refused to name Saint-Ange a heretic, but he also refused to allow him to serve as a priest in Crosville-sur-Cie, which meant that the priest had to move on, which he did, and found another parish fairly quickly.

  The skirmish was over, and yet Pascal, seemingly the victor, paid a price. His health declined precipitously, and his energy flagged. He had been in the midst of his debates over the vacuum, fresh from his public experiments, and the battle for orthodoxy pushed him over the edge. But the struggle was typical of Blaise Pascal, and spoke eloquently about his version of the faith. He was a theological pit bull. His Jansenism was a thing to be defended, like the vacuum. It was a set of principles, like science, and those who accepted took responsibility for the defense of those principles. In the war with Saint-Ange, Blaise took the offensive, attacking the priest’s position vigorously, as if he were a champion blowing a horn for battle. As Saint-Ange quickly learned, those who disagreed with Blaise had better move aside.

  [1608]

  Port-Royal and the Clan Arnauld

  The brethren asked the abbot Poemen about a certain brother who fasted for six days out of seven with perfect abstinence, but was extremely choleric. Why should he suffer so? And the old man answered, “He that has taught himself to fast for six days and still cannot control his temper should bring more zeal to less toil.”

  —THE DESERT FATHERS

  Like the Pascals, the family Arnauld came out of the Auvergne and landed in Paris, where they became lawyers at once. The father, Antoine Arnauld (1560–1619), achieved membership in the Assembly of Paris and later became a counselor of state under the soon to be assassinated Henri IV. His anti-Jesuit feelings appeared early on, in some of his short political writing, especially Le franc et veritable discourse du roi sur le rétablissement qui lui est démandé des jésuites, which he wrote in 1602. He also represented the Sorbonne in a lawsuit against the Society of Jesus, and pounded out a career-making speech that had them expelled from France for a short time. Years later, after the Jesuits had returned to Paris and Antoine’s children were bloodied by their theological battles with the society, the wits of the city referred to Antoine’s lawsuit as the “original sin.”33

  The Jesuits were not just any order of Catholic priests. Unlike Benedictines and Cistercians, they did not retreat from the world but lived in it, determined to inject Christianity into the bloodstream of modern life. They wanted to change the world. In the eyes of many, they were suspect because they were connected to the pope by ties of a special vow. They were ultramontanists, who supported the church on the other side of the mountains rather than the church in France, and many nationalists saw them as Papists only and not truly French in their hearts. They were the great opponents of Protestantism and of Augustinianism in almost any form, though they honored St. Augustine, the man and the tradition. Where Thomas Aquinas hedged his bets about predestination, the Jesuits did not. They were against it and any form of Calvinist extremism that it implied.

  For his own part, Antoine Arnauld the elder was good at two things—arguing before the bar and procreating. He and his wife, Catherine Marion, had a total of twenty children, half of whom died young while the other half lived longer than their father, who died in 1619, seven years after his youngest son, Antoine, eventually nicknamed “The Great,” was born. They had six children who achieved notoriety, while three of these six gathered lasting fame. The first was Jacqueline Marie-Angélique Arnauld, the t
hird child of twenty. Like all the Arnaulds, she crackled with wit and intelligence, but also like them, her greatest gifts were also her greatest flaws. Some people possess beauty—she had that, a little at least—and some possess intelligence—she had that as well—but her defining characteristic was her will. She was the kind of woman who, once set upon a path, pursued it to the end, and would not turn back. This strength of will would bring her honor, and in the end destroy her and everything she built.

  As the third child of the vast Arnauld clan, a family of courtiers on the rise, she had few choices in life. She could be married to a likely man, not for love but for family gain, or she could enter the convent. Virginia Woolf had not yet been born, and the independent woman of means was still two centuries away. Jacqueline’s grandfather Marion had decided that she was meant for the convent when she was still a child, and when presented with the idea, she agreed, but added the condition that they find a way to make her an abbess. She was eight years old in 1599 when she entered the Benedictine abbey of Saint Antoine in Paris. A year later, she moved to the abbey of Maubuisson, whose abbess was Angélique d’Estrées. Typical of the times, the abbess’s sister Gabrielle was a mistress of Henri IV and a beauty at court, a woman of great charm and grace, with a touch of infamy. She had l’esprit, as the ladies of the court called it, in spades. It was also typical of the times that no one thought it odd that the royal mistress had a sister who was an abbess.