Read Pascal's Wager for Free Online Page A

of Paris, the French equivalent of the Royal Society, would likely have met in his monastic cell sitting on hard, straight-backed chairs without much padding, in a circle or around a table. Some may have smoked tobacco in long clay pipes, since smoking was not forbidden—because, after all, better to tax it than forbid it, and because even Catherine de Médicis, the great queen of France from the century before, often took snuff as a cure for migraines. They would drink wine, not coffee (for coffee was a Calvinist drink, a Huguenot drink for the rising bourgeoisie, promoted by the Protestants as a way to awaken humanity from its Catholic alcoholic stupor to a new world of activity and industry). A bit of bread, a bit of onion, a bit of cheese, a bit of wine, and along the way they discussed matters of scientific merit, from methods of identifying prime numbers to new ways of marrying algebra with geometry to the failures and weaknesses of alchemy. Salacious, even radical, conversation they left to the libertines, those scoffers and doubters, those Deists, who were not welcome at Père Mersenne’s table. They would leave such libertine conversation to the insidious salon of Madame Sainctot, the retired courtesan with the notorious past who was another friend of Étienne Pascal’s.
    This little group gathering in Père Mersenne’s monastic cell made quite a splash. Some of the best minds in Europe were there. Descartes was a member. Mersenne himself had been the leading investigator into prime numbers. His formula n = 2 p - 1 (where p is a prime number) was not perfect for identifying primes, but it came close, and it is in fact still being used to help identify large primes. As a scholar, he was so connected, through letter and personal contact, with the leading thinkers of the time that many said that telling Père Mersenne about a new idea was the same as publishing it.
    Pierre de Fermat, Blaise’s future correspondent on probability, was also a member, and it was in Mersenne’s monastic cell that Blaise first met him. Fermat is famous even today for his last theorem, and for his work on spirals and falling bodies. 7 He first came to Mersenne’s groupby writing to the priest and by correcting some of Galileo’s titanic mistakes in geometry. He also developed new ways of determining the maxima and minima in an equation’s curve, methods that conflicted with Descartes’ own ideas, already published in his La géométrie , where he set forth his view of algebraic geometry. Needless to say, this set off a feud. Descartes wrote, expressing his dislike for Fermat’s method for determining maxima, minima, and tangents, and Fermat fired back. Étienne Pascal entered the war on the side of Fermat, as did Gilles Roberval, a royal professor of mathematics and another of Mersenne’s group. Descartes asked Girard Desargues, yet another member, to referee, and soon after he was proved wrong. Descartes had the good grace to admit it in a letter, though grudgingly. Nevertheless, those who had sided with Fermat were from that point on in a bad odor with René Descartes.
    It was about this time that Desargues, a man known to both Pascals, published a book on conic sections that would be a strong influence on the young Blaise, leading to his first published work. Desargues’ book had the unlovely title of Brouillon projet d’une atteinte aux événements des rencontres du cône avec un plan , or Rough Draft for an Essay on the Results of Taking Plane Sections of a Cone. Inside it, however, was an entirely new type of geometry, a projective geometry, with a new way of looking at conic sections as having properties that are invariant under projection. That is, if you draw lines through points on conic sections, those lines form projections out into the space around the conic section, and those projections will act in regular ways. In this way, Desargues invented a unified theory of conic sections, something that had not been done in