In Our Time - Pascal

Episode Date: September 19, 2013

Melvyn Bragg and his guests begin a new series of the programme with a discussion of the French polymath Blaise Pascal. Born in 1623, Pascal was a brilliant mathematician and scientist, inventing one of the first mechanical calculators and making important discoveries about fluids and vacuums while still a young man. In his thirties he experienced a religious conversion, after which he devoted most of his attention to philosophy and theology. Although he died in his late thirties, Pascal left a formidable legacy as a scientist and pioneer of probability theory, and as one of seventeenth century Europe's greatest writers. With:David Wootton Anniversary Professor of History at the University of YorkMichael Moriarty Drapers Professor of French at the University of CambridgeMichela Massimi Senior Lecturer in the Philosophy of Science at the University of Edinburgh.Producer: Thomas Morris.

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Thank you for downloading this episode of In Our Time. For more details about In Our Time and for our terms of use, please go to BBC.co.com.uk slash Radio 4. I hope you enjoy the program. Hello, the first practical calculating machine was invented in 1642 by the 19-year-old son of a tax inspector who wanted to find a way to make his father's job easier. His name was Bles Pascal. he's credited one of the major inventions of the 17th century, it's not his

most celebrated achievement. Pascal was one of history's great polymaths, a scholar who made significant contributions to mathematics, physics, philosophy and religious thought. Today, scientists measure pressure in Pascal's, a unit named after him in honour of his work on gases. He's also

remembered for Pascal's triangle, and for Pascal's wager, an argument for the existence of God which brings together religion and probability theory. And his most famous book, The Pornado, is celebrated as one of the best and most elegantly written works of French literature. He died in his late 30s. With me to discuss the life and work of Blaise Pascal are David Wooten,

Professor of History at the University of York. Michael Moriarty, Draper's Professor of French at the University of Cambridge. Mikala Massimi, Senior Lecture in Philosophy of Science at the University of Edinburgh. David Wooten, Blais Pascal was born in 1623. Would you give us some sense of what was going on in France at the time? Right. Well, in simple terms, this is the world of the three musketeers. France is at war with Spain and with the Habsburg Empire throughout the whole of Pascal's life effectively. Richelier comes to power in France when Pascal is one year old.

He's followed by Mazurin. They're both cardinals. And Mazarin dies the year before Pascal dies. So it's the world of Richelieu and Mazarin. Abroad, France is fighting an alliance with Protestants against Catholic powers. At home, the Cardinals in charge are crushing down Protestant. and trying to impose religious uniformity. What impact would that, would those events, Hamon, Pascal's family and Pascal himself?

Well, the extraordinary crisis of this long-drawn-out war struggle for hegemony in Europe. If you look at the 1630s, when Pascal's a young man, the prospect is one of defeat. In 1688, France effectively goes bankrupt. His father has put all his money into government bonds. The family's wiped out. So in that sense, he's living in a nation which is at war

and which is facing financial catastrophe. What were the major intellectual developments because nothing goes on singly. It wasn't just war that was going on, thinking was going on as well. What was happening in the intellectual world during that period? Pascal is 14, 13 or 14, when Descartes publishes his discourse on method. The year after that, Galileo publishes the founding text of modern physics, his two new sciences.

And Pascal, as a teenager, meets Mercer, and Mersenne is the great advocate of, he's a Minim Friar, he's the great advocate of Galilean science in Paris, and he's conducting the experiments that Galileo had conducted in order to check whether Galileo is right or not in his claims. So Pascal finds himself in the world of the new philosophy and the new science from his teenage years. Will, the listeners will know about Galileo and about Descartes,

but can you just bring rather more focus to bear on how that might have influenced the young Pascal, and I mean the young Pascal, because from an extraordinary early age, We're talking about a Mozart in precocity, aren't we? From an extraordinary early age, he was on the case. Yeah, and he's a genius mathematician from the earliest years. He more or less invents maths from scratch on his own. So in that sense, he's born to do the new science.

But Pascal's the first generation of people who've been brought up with outside the world of Aristotle. Right through the Middle Ages, philosophy is Aristotinian philosophy. The world is a finite world. Pascal is brought up where the whole Aristotelian sense of the order of the universe has been destroyed, and what you're going to replace that with is entirely up for grabs. It's a world of uncertainty that he's... Fundamentally, why is it destroyed?

It's destroyed by the telescope, it's destroyed by the recognition that you cannot place limits upon the world in the world. The crystalline spheres that Aristotle had believed had shaped the world, no longer there. Plenty of what people call creative disruption. France almost wiped out, and Aristotle almost wiped out. Good. Michael Moriarty. Would you tell us something about Pascal's family in his background? Yes, his father was a member of the official class. I mean,

technically a nobleman, but not sort of three musketeers kind of nobleman, an official and financial administration. And that class was typically provided the royal servants. They were very loyal to the king, sometimes rather suspicious,

therefore, of forces outside France, hostile to international religious organisations, like the Society of Jesus, the Jesuits. So Pascal imbibes some of that from his upbringing. Basically, rather like Montaigne, low-level, low-sea conservative. Indeed, indeed, that's very true. From his father, he obtains a sort of remarkable education,

which is a kind of non-education. He never goes to school, whereas Descartes went to the best school available. Pascal was home-educated by his father. And that's one reason why, as David said, he was sort of, as it were, immune from the Aristotelian virus, as it were. He was never affected by it. Have you an idea what that education consisted of? Well, his father was a very advanced educational thinker who, instead of cramming him from his early years,

he thought, let him learn when he's ready to learn. So he told him about languages, and he told him about mathematics, before he actually taught him any languages and mathematics. And he was planning to teach him languages at the age of 11 to 15, and then go on to maths. His father was a very capable mathematician. And the family sort of legend is that Pascal is so excited by the maths he's been told about,

but forbidden to study, that he actually works out Euclid's geometry for himself. And his father discovers this and thinks, oh. How old is he then? Well, he's 11, according to the family story. And at that point, he's taken to Mayor Sen's sort of seminar, as it were, as David was talking about. So his father has an incredible,

strong intellectual and religious influence on his life as well. Because it's when his father has had an accident and has broken his leg, that his being treated by a couple of surgeons who were of the Jansenist wing of the Roman Catholic Church. And that's what leads to the family's sort of conversion to that particular spirit of Christianity or of Catholicism. So we're talking about... David's already mentioned Mersen. We're talking about an intellectual household that moved... His father moved to Paris,

that moved into an intellectual society as it was dominated by this amazing man who's a theologian and a scientist, Madame Monsen. Can you just tell us about that group society that he got involved in, again, as a boy, really? Well, the members of the society are other mathematicians like Hobel Val de Sard and so on, and there also, Moussen has a remarkable role as a sort of intellectual conduit.

He is the one who organises the publication of Descartes' meditations with the objections. And the people who publish objections to Descartes, like Hobbes and Gassendi, are people who've been sort of recruited by Moussen for that purpose. So he's in touch, as David says, with the latest, the most advanced. It's kind of light on religious, on the possibilities of religious intellectuals at the time. He's a great roving, Enlightenment intellectual across Europe. this man. Yeah, he is. That's right. And he's dealing with people like Hobbes,

whose religious belief is anything but orthodox, but he himself is a friar. Was there any sense a salon that he ran in the same? What we could call that? But not exactly, but Pascal in later life became more associated with sort of aristocratic salons. After his father died, he had a period

of socialising with aristocrats. He was just high enough born and well-bred to manage with that. And that also had an influence on him. This is when he's in his late 20s. and he becomes fascinated by sort of aristocratic sophistication, and it's in that media that he meets people who seemingly are not believers in religion and who are interested in gambling and who put problems in gambling to him. David Warton's told us about Descartes and Galileo.

Are there any other powerful influences on the way he thinks? If we're still talking about what we know is called a teenager. Yeah. Pascal, because he never went to school, isn't learned in the way that people would have been thought to be learned. But the reading that matter to him, apart from Descartes and Galileo, is certainly Montaigne. And from Montagne, he gets very much a sense of the weakness of human reason and the need to submit to authority. He doesn't like Montaigne's kind of ethics. He thinks Montaigne's a bit too relaxed and chilled out.

But as far as religion goes, Montaigne is very useful because he destroys the kind of confidence in human reason that might inspire heretics and atheists and sort of encourages people. to accept what's there. So that's good. Religiously, as it comes later, the influence of St. Augustine is absolutely paramount. He reads Augustine very, very closely. And from him and from writers influenced by him, he imbibes a sense of religion, the power of God's grace, the demands of religion, the need not to compromise with the world. That is, as you say later. We'll certainly come to that, after a sister goes into. Mickham has a great religious conversion.

Michaela Massimi, his earliest work in mathematics have been referred to twice by two previous contributors. Can you tell us about the calculator that he made for his father who had a lot of adding up to do? It took him an enormous amount of time, and so this boy thought he'd help his father and invent something to help make it faster, and being long-winded here.

Invented the calculator. Can you tell us about it? Yes, at the age of 19, really, Pascal, manufactured one of the very first calculators of the time, and the only calculator of the 17th century, a machine that became known as the Pascaline. The Pascaline was able to perform additions, subtractions, multiplications and divisions.

It was obviously difficult to build and costly to build. It was also the first machine to receive a patent, a royal privilege by the then King of France, Louis 14th. and it's also the first machine that we find mentioned in Didero and Dalar and Syclypherd Encyclopedis. So it became really the prototype of later generations of calculators from Leibniz wheels to the arithmometers of the 19th century. And no wonder the name of Pascal is still given to a computer programming language precisely in memory of the great achievement of the time. If I may add something else to what... Please do.

David and Michael have just said. So we talked about Mersenne Academy and the importance that Pascal's father, Etienne, played in the education and the upbringing of the young child. And another area where the young Pascal made important contributions was geometry. Pascal was exposed at a very young age to some of the state of the art in geometry at the time,

which was precisely the Zargh, one of the members of Mersen. Academy. At the age of 16, he wrote an essay on conic sections where he found the so-called Pascal theorem that we still use today in geometry. And it's a generalization of an earlier theorem by Papus that basically says that the opposite sides of an hexagon inscribed into a conic intersect in three collinear points. Pascal didn't provide a proof for the theorem, but proofs were found later on, even some very recent ones in the 1990s and more

recently. So incredible achievements for a young boy at the age of 16 or 19 that shows really the versatility of Pascal and is a wide-ranging interest in pure mathematics, geometry as well as mechanics and building machines and calculators.

It's almost like a lyric purge, isn't it? But let's go back to the calculator. Did it work? Well, yes, it worked as far as I mean, did his father use it in save time, and have more time to teach his son, for instance? Well, as far as I know, it did work, given the limits of the technology of the time,

obviously, as I said, it was a very difficult enterprise to build, and Pascal built and sold the 50 of them, and some of them still survive in some museums around the world. So, yeah, it was an extraordinary achievement for the time. One of the serious intellectual arguments in the science of the time was the notion of whether there was or there was not a vacuum. Broadly, Aristotle said there wasn't, that there was something everywhere.

And Galileo and Dr. Shelley, and then over to Pascal, said there was nothing somewhere. So how did he arrive at that and what's the relevance of that? Can you just tell us that story, please? Sure. Well, the discovery of a vacuum, of a space bereft of matter was one of the greatest discovery of 17th century. The scientific orthodoxy at the time,

as we have heard from David and Michael, was really René Descartes physics. And for Descartes, that couldn't possibly be an empty space. Pascal believed that space was an infinite extension of matter, what he called in Latin Res Extensa. So, for example, Descartes believed that the universe and the space in between celestial bodies

was filled with a subtle, invisible ethereal mass. matter and that planetary motions could be explained as vortices in the ether. So the idea that there could be an empty space was an absurdity at the time. The first evidence for a vacuum came in 1644 where the Italian scientist, Evangelista Torricelli, observed an interesting new phenomenon. He observed that if you have a glass tube sealed on one end and filled with mercury and you invert the glass tube on a plate filled with mercury, the mercury in the column would assess.

because of atmospheric pressure, leaving a small space on the top of the tube. So the question was, what was the space? Was the empty space, as Torricelli speculated or not? And a debate began between the so-called planist and the vacuist. Plenist that there was four. That's right. So the planist were the defenders of the car that said that space couldn't possibly be an empty space, so it must have been filled with either rarefied...

air or spirits of mercury and the vacuist that claimed effectively that was an empty space so Pascal came along because he heard from Mersenne about Torricelli's experiment Mercerin witnessed Torricelli's experiment in Florence and so spread the news in France and in between 6046 and 47

he set on to repeat Torricelli's experiment with an eye to refuting the Cartesian orthodoxy and in terms of the time he did and Boyle because he was a sort of, as David Wooten has written, he was a transmitter, as we were Pascal, from the French Enlightenment to the British Enlightenment,

Boyle, the son of the Earl of Corfin, father of chemistry. He credited Pascal mightily for this vacuum and went on with his own experiments based on that. So we have that there as well. That's right, yeah. He's about seven programmes, Pascal, but we must move on. David, he took this order. Let's talk about Pascal now in terms of the area that Mikhail has been talking about.

Push this on into his study of gases. Yes. I mean, what Pascal did first. Let's stick with the vacuum from a moment. Pascal has three extraordinary experiments with a vacuum. First of all, he's the first person to repeat Torricelli's experiment and to show what happens when you do it. He does it in various forms.

He does it with mercury as Torricelli had done it, where you get a tube which has to be more than 27 inches high. He also does it with red wine, where you have to have a tube that's more than 32 foot high and you get the space at the top. And he does this in public. People gather around to see this extraordinary phenomenon because it's something that's supposed to be impossible to do.

And Galileo had said you ought to be able to do it. Here's Pascal doing it in public and showing it can be done. He then goes on to devise this extraordinary experiment where you take a tube of mercury and carry it up a mountain. And as you carry it up in the mountain, the level of the mercury in the tube falls. This is what we call a barometer. And what he's arguing here is that what's supporting the level of mercury in the tube is the weight of the air.

That effectively the barometer is a balance, a weighing machine. And as you go up, there's less air pressing down on the mercury and consequently the level drops. And this becomes a decisive evidence for the fact that we're all living under an ocean of air, which is pressing down on us all the time. No one had shown that before. So he not only proves existence of the vacuum, he claims he's proved the existence of the vacuum. Descartes's never convinced.

But still, he thinks he has. He also proves that we're living under the constant air pressure and this is what's being measured by the mercury. So there's a series brilliant experiments like that. Then what he also does is he works on water pressure. He thinks he's invented. Actually, Galileo had done this before, but Pascal doesn't know this.

He invents the hydraulic press where you take a pressure at one end and magnify it by passing it through liquids. And he shows what the theory of the theory of this is with what's called the barrel experiment where he takes a barrel of water and he puts a tall tube into it and fills the tube with water and the height of the tube is crucial in determining the pressure that feeds down into the barrel and if you have a tube that's 20 feet high and put very thin tube put water in it he'll burst the barrel through the pressure that it's

created so he's demonstrating the working of pressures in liquids so he opened up a develop went forward with an enormous field which had consequences which had rolled through the last two or three centuries. Absolutely. I mean, he's the first, people have done experiments before. Pascal is the first person to do experiments that get attention and that people think transform the nature of knowledge. Can I turn to you, Michael Moriarty on this? Because as David said, this is a transforming thing, and he didn't do it alone, but he did it most dramatically and most, for the purposes of this programme, most importantly. His approach to science, compared to the approach to science of thinkers had come before him, which was basically a priori and metaphysical, read the books.

if you want to know about medicine, read Galen, don't open anybody up, and so on. He was very, very firm, and it was radical at the time, and he was condemned for it, that that was not the way to do science. Exactly, and he cuts it off both from authoritative books. He says there are sciences that depend on authority, theology and law. You know, you've got to read the books there. But the sciences that develop through reasoning and experiment, authority is useless, and physics and mathematics are sciences like that.

So no authority in books And again, as you say, no a priori metaphysics. In fact, he cuts science off from metaphysics. He says there's no point like Aristotle in trying to define time and movement. We know what we mean. We can't define these basic terms. You just know what they mean.

So we can't know what ultimate reality is, but we can do science. We can get results in mathematics and in physics and so forth without an order of ultimate reality. And in that way, he separates himself. of course from Descartes, because Descartes' principles of philosophy begin with metaphysics and then go on to what we call physics.

And Descartes' theory is you can't do proper physics unless you've got an accurate metaphysical grounding. But Pascal, that doesn't matter at all. So in that sense, he's very modern in the sense of separating the practice of the investigation of nature away from the quest for an ultimate reality, which he thinks, like Montaigne, we can't ever access. Yes, and that's at the centre of a great deal that it does

he's going to come to his writings. But one of the things he's saying is that there is no such, seeing as truth, what you can do is deliver the best with the best available facts, but should more facts turn up, this will change. And therefore, he opens the way for constant progress. Yes, that's right.

Truth belongs in a different realm. Revelation gives you truth, but science is a progressive accumulation of truth. Of that sort, yes. And was that resisted at the time? Was that over the time? Was it in the air? It's picked up by so many other people,

I think, as my colleagues could explain, I think in Britain and France later on, that notion of science as a gradual... I mean, Newton says rather similar things about science as accumulation. Well, they start doing it in the beginnings of the Royal Society in Oxford. And Wilkins are doing experiments in the college ground,

Wren and people every day of the week, haven't they? Indeed, yeah. Indeed. Francis Bacon, whom everybody in France has read, Descartes read and Pascal presumably read, had argued that science could progress, but Bacon doesn't give a good example of actually progressing anything. What Pascal does is actually show progress in action and declare this is what science is going to be like from now on.

Michaela Massimi, we talked about maths in the 1650s, and around that time he moved on. I mean, we are talking about a man of many minds. He went towards philosophy. Can you talk about his major contributions to that period? Can we get to probability theory and so on? Sure. Pascal is rightly considered one of the father of modern probability theory

and at the around 1645, we began a correspondence with the mathematician Pierre Fermat on a very famous gambling problem. The Fermat theorem, yeah. Which is, well, the problem that we're working on is called the problem of points. So it's a gambling problem. Imagine you have two players, player one and two,

playing with a coin. So if the coin comes up head, one gets one point. If the coin comes up tail, player two gets a point. And whoever gets 10 points win the game. And imagine there is a price pot of, say, 10 pounds that each of them are contributed to. So the problem is, imagine the game doesn't reach the end because of some unexpected reason. And we need to calculate how to divide the stakes between player one and two in a fair way. How do we go about doing that? This is the problem of points that Fermat and Pascal were working on around 1645.

Now Pascal and Fermat gave a different solution to the problem, but the key intuition was that a fair distribution of the stakes shouldn't take into account how many points have been accumulated up to that point when the game was interrupted, but should take into account the many possible ways in which the game could have finished if it had not been interrupted. So it is in that context that Pascal introduce a key concept that we still use today, which is the concept of the expected value of a game.

So we need to look at the returns of the game, namely we need to look at whether Player 1 is going to win the 10 pounds or is going to get zero in each of the possible outcomes for the next tosses of the coin if the game had not been interrupted, and calculate they weighted some of those returns using the probability of each outcome, Player 1 winning or losing at the next toss, as the weight for that returns. So it's a brand new notion, still using probability theory. And the validity and importance extends well beyond casino and gambling to any areas where calculating returns and risks and uncertainty of future events matter. So from project management to insurance to business forecasting is a very important contribution. So the theory of probability has developed and runs right through our society now today.

Yeah, that's right. I mean, he made that important step. obviously other people came along after him like Christian Oiggins and others that laid the proper foundation of probability theory but that correspondence with Fermat played an important role in introducing some of the key concepts

in probability. We all think of Pascal and Fermat corresponding with each other, isn't we? I'm working on the same thing. Right, David Woodham, we now turn to the religious side of this extraordinary man, he's still only in his 20th, early 30s. He joined a Catholic sect called the Jansenists

who became increasingly important to him. Can you tell us what they were first and why they're important to him second? Cornelius Janssen died in 1638 and he left behind him a manuscript called the Augustinus, a book about Augustine. And this is published

in 1640 and it immediately causes a storm. Jansen is a good Catholic but he believes that Augustine has understood the relationship between human beings and God and that salvation depends upon God choosing to save you. We have no capacity to choose our

salvation and we have no capacity to do good. We are fundamentally utterly sinful because of the fall. Everything we do is corrupt and if we do good it's because God is working in us. This as far as Jansen was concerned is Orthodox Augustinian teaching and this is taken up in the followers of Janssen in France. The Jesuits turn on this and say this is heresy because it's exactly the same as what the Protestants say and the Protestants are heretics. There's a large group of Catholics that are who've always said some things rather like this, but who don't want to get caught in this fight and decide that they're going to effectively side with the Jesuits.

So Pascal, when he adopts this position and writes about it, always says, I'm teaching and believing exactly what Augustine said, and now you're accusing me of being a heretic. Everything I say derives from Augustine is indistinguishable from Augustine. This is actually a political fight, not a religious fight, because my religious thinking is traditional. We're at an extraordinary cusp in European thinking, aren't we? And he is emblematic of it.

He's a powerful scientist, extraordinary. At the same time, when he addresses religion, it's with the same power of intellect and passion. Do you know anything? Can he tell us why he was drawn to it in such a way that he abandoned most of his other studies? Yes, he completely abandons his other studies. He has a religious experience in 1654,

where we don't know exactly what happens. He writes down some notes on it afterwards, which he carries everywhere with him and eventually sews into his clothes and are found in his clothes when he dies. We don't know if he hears voices or if he sees things, but something extraordinary happens to him.

And this is the culminating event in a long period of religious thinking, and his sister has gone into a nunnery, the nunnery run by the Jansans. This is Por Royale. So he's surrounding. and there's an enormous religious fervent around him. But I think it's also worth...

One of the ways of thinking about this is that what Augustinianism does is tell you that human beings act out of their passions. And their passions are about pleasure and interest. They are, as it were, predictable. There's a very close relationship between a social-scientific understanding of human behavior, which is that we act out of our desire

to maximize our pleasures. and an Augustinian view of God. So one of the things you can then do is adopt a view that God is all-powerful, and at the same time human beings in their normal behavior are comprehensible in terms of social motivations. He's also Michael Moriarty firmly of the opinion that you can't prove, and there's no point in trying to prove by reason that God exists. This is pointless.

That's right. And then he writes that inside this very provocative work called Provincial Letters, which is an attack on the Jesuits, which was like attacking Stalin in the 1950s. He could go undercover. It was eventually put on the index. Can you give us the drive of provincial letters? Yeah.

Basically, the issues keep on coming back to this. Is religion inclusive or exclusive? And that theme one's right through it. So at the beginning, the first few letters are about grace. The Jesuits teach grace is given to everyone. We decide whether we accept it or not. Pascal, following Augustine, says it's not given to everyone, and it works.

if you have it. Okay, so it's a more exclusive kind of thing. It's given. Similarly, he accuses the Jesuits of diluting Christian morality so as to keep everybody on board. So if you've killed a man in a duel and you go to a confessor who's a sort of Jansenist, he'll say, well, that's murder. You go to a Jesuit and you say, well, I suppose you were doing it to defend your honour. Well, to defend your honour is itself perfectly legitimate, so it's not actually murder that you've done. That's a sort of... That's casuistry. That's casuistry. It's the analysis of concrete moral problems and some people think Pascal's treatment of his unfair but the point is that he's constantly insisting that that Christianity is a demanding morality founded on the love of God

and the Jesuits have reduced it to a series of tick boxes of the most of the sort of most mechanical kind and they've diluted it so that sort of more or less everybody passes and the third dimension to it he says that they're doing this because they want to be modern he has his Jesuit character saying, well, the fathers of the church like St Augustine, they were all very well, but they lived a long time ago. We need people for the modern age. And Pascal, of course, thinks that this approach is appalling. Religious truth is eternal, unlike scientific truth which develops. Religious truth doesn't develop. And if Augustine said it, that's authoritative. It was thought at the time to damage the Jesuits severely, and they tried to take their revenge

on him by banning him and hounding him. Yeah, they did. But I think the impact on it was pretty damning. I mean, a hundred years later, the Jesuits were actually abolished by the Roman Catholic Church. And I think in some ways that that's why some Roman Catholics are hostile to Pascal, because they think of the damage

he did to the church. Michaela Massimi, after the publication of provincial letters, he embarked on his what people, a lot of people think on most ambitious work, which he didn't finish, he worked for years, it's been put together since an enormous work called. Ponce, supposed to be one of the most elegant works ever written in French, by the three of you to start with.

Can you just give us some idea of the drive in de Ponce? Right. So Pascal's last project was an apology for the Christian religion. That was the title. And the goal was to defend the truth of Christianity against what we call the libertines and the skeptics. Pascal began to work on it around 1657, but because of the frail health conditions, and the untimely death in 1662, the work remained incomplete. So after Pascal death, what was found were hundreds and hundreds of fragments and pieces of paper. Some of them contained reference to the provincial letters. Others were religious meditations on the nature of miracles and prophecies,

yet others were reflections on Cartesian philosophy and ancient skeptics, as well as the nature of laws and social institutions. Pascal didn't leave a table of content. I didn't leave any idea about the plan and the project for this big work. So the challenge was to gather all that scattered material together, and the task was done by a small committee of people, including Etienne Perrier, who was the nephew of Pascal, and some of the Port Royal Theologians, such as the Arnaud and Nicole,

the former little committee that made a selection of fragments leaving behind the more polemical one, because in the meantime, there have been a rapprochement between the Jansenist and the church, thanks to Pope Clement the 9th. They heavily edited some of those fragments and put them together in what became the Port Royal edition

of the Penseu de Monsieur Pascal in 6070, which became the first edition and the basis of any subsequent edition of the Pense. And since then, people have dug the treasures out of them that they wanted to dig out of them. What for you is the most important thing that's come out of them, David Woodman? There's so many, I suppose two things. First of all, there's the issue of how do we live in a world that we cannot fully understand.

And the answer for Pascal is that we have to make the best choices we can under conditions of uncertainty. And this is the foundation of his religious thinking, which leads to the wager. The second thing that he wants to think about is how can we be, how can we make sense of a life where we are such inadequate, defective creatures and where we know that our lives are going to end without us achieving anything worth achieving? He compares human existence to being chained in a dungeon and having the guards come in every now and again and strangle someone. Right?

Just awful. Just terrible. And this is what we're stuck with. How can we make that seem worthwhile? And Pascal's answer to that, of course, is only religion can make that worthwhile. The problem about religion is that he has no proof of God's existence. Philosophers before had always claimed they could prove that God existed.

Pascal says we can't prove God exists. So Michael Moriarty, what do you think is coming out of the point? Do you agree? Obviously, I would guess you go along with David? Would you like to develop that in any way? Yes. You can't prove the existence of God because the proofs aren't convincing.

They're not going to convince atheists even if they happen to be valid. So what you have to do is to think about the human condition. And the world, David has described very correctly how Pascal sees the human condition as one of wretchedness and an inability to obtain happiness, knowledge, wisdom, health, whatever. Pascal makes a move at this point that goes somewhat in the opposite direction where he says, our consciousness of these things means we kind of transcend them. In many ways our lives are like those of animals,

but we're unhappy animals because we can imagine something better. How did we ever come to imagine something better? So that's the element of the greatness of the human condition. Imagination is very important for him. It is, yes, and it kind of is partly delusive, but it's also partly a sign that we're maladjusted to reality. We're not just part of the world, although we seem to be. So how do we solve this idea that we're at one level totally part of a natural world

and another level we seem to transcend it? And at that point he suggests, well, Christianity explains this. There's the doctrine of the fall. We once did know happiness, truth, justice, virtue. We've still got memories of that and that's why we can never be happy. Sorry, to interrupt your mind. Did he believe this literally or is a metaphor? No, no, he believed it literally.

Right, yeah. That we actually do inherit guilt from Adam and Eve. And so at that point, the person who's not interested in Christianity, I think maybe there is something in this after all. And Pascal analyzes the quest for happiness, mostly as kind of escapism from the pain of the present. But here's a religion that promises you true happiness. So his argument then is on the simple calculation of probability,

you've got to investigate it, you've got to see whether it may be true. So this is Pascal's wager? Yes, that's right. And what that means is investigating the history. If you look at the facts of history, you'll see there's something special about Christianity. and that's sort of the kind of way it goes. Michaela, do you like to tell us about Pascal's Wager?

Sure. Pascal Wager marks the beginning of modern decision theory, so it's a very simple argument that says, imagine there are two possible states of affairs, either there is God or the reason God, and there are two possible courses of action, wager for God or wager against God. The argument is designed to persuade the libertines and the skeptics, not the atheists,

because we need to assume that the two states of affairs, there isn't God, the reason God have a non-zero probability. So if we are atheist, we would assign zero probability to the hypothesis that there is God. So we are trying to persuade the undecided, the skeptic. And the argument goes that, well, if there is no God, and in that case we're not going to lose anything if we wager for or against God,

but if there is God and we wager against God, then we risk eternal damnation. So we should wager for God because the expected utility is higher in their case. There are a series of problems with the argument, which obviously depends on whether you accept the premises. So some may dispute that there are only two possible states of affair. There is God or there isn't God. One may say, well, there could be a third state. You can claim that there is God, but we will never come to know God. via life of religious devotion, as Pascal claimed.

So in that case, the argument wouldn't go through. Others have claimed that Pascal's wager doesn't really establish that Christianity is the only real possibility because you can apply Pascal Wager to gods of other religion. This is what the French philosopher did the role said. This has an imam could reason just as well. There is no way to establish the validity of Christianity using Pascal's Wager.

There's a third kind of problem. one may say that the libertine is actually giving up something when she decides to go for a life of religious devotion because if there is no God, the libertine has given up a life of worldly pleasure, so it's missing out something. So whether or not the argument goes through depends on whether the agent

may count a future event as more valuable than present events. So if the rational agent discounts the future, then obviously the argument with an apply. David, how did the Pascal's Wager feed into the island of the time? Was it as it were the last gasp

of a Christian philosophy or one of the last gasps, or was it the breathing a bit of life into Christian philosophy? Well, in many ways it seems to me it's the founding of modern Christianity. Modern Christianity takes

its start, one might think, from the notion that religious faith is a an act of decision-making where you commit yourself to something that goes beyond reason. And in emphasizing that you're going beyond reason in this commitment, Pascal is changing the nature of Christianity. Traditional medieval Christianity insisted, but fundamentally all the basic principles of difficulties about explaining the Trinity and miracles and so on. But fundamentally, Christianity was a rational religion. Pascal wants to say it's not a rational religion.

It's a decision you make under conditions of uncertainty where you don't know what the truth is but you commit yourself to it. It's an existential decision. It's an existential decision. And it leads to a whole, I mean, Kierkegaard and the whole of modern existential Christianity comes straight out of this.

We've been talking, Michael Morale, by the most extraordinary man who died in his 30s and did so much and there's so much more to say. But what was his chief legacy, would you say? What is his chief legacy? I think probably two religious thought in the way that David has experienced. blamed. There are some other remarkable things to his legacy, like he has an argument about the way that

the imagination works in societies, which is a strange anticipation of certain aspects of Marxism. But that's a byproduct in a way. His crucial thing is that he's changed the nature of Christian belief. You think that's more important than the calculating machine than all the other stuff? No, I mean, I suppose... You can't weigh them in the balance. You can't weigh them in the balance. I suppose his scientific method has probably been a greater legacy, but his really is very important. religious legacies is very powerful one. Gaila, what would you say? Well, I would just say that

there are really two areas where the legacy is obviously evident, so we mentioned already a series of those areas. So probability theory and decision theory with Pascal wagers are important areas to which it significantly contributed to. In geometry, we still use Pascal's theorem.

We didn't mention this, but there is also Pascal's triangle in mathematics that we still use today to calculate the coefficients of binomial expansions used in combinatorics and statistics. Pascal is the name given to, as we said, the computer programming language in memory of his calculator. So there has wide-ranging areas in science where Pascal made important contributions. And finally, David, put him from you. Let me point to something else. Voltaire hated Pascal insofar as he presented a picture of human beings as corrupt and inadequate. Voltaire wanted to say, we can be happy in this world.

But Voltaire read Pascal all the time in order to learn how to fight intellectually, to write brilliantly, to be unfair and win. Thank you very much. Thank you, Michaela Masimi, David Wharton, Michael Moriarty. Next week we'll be talking to the Mamlux, the slaves who ruled Egypt and Syria for about 250 years in the Middle Ages. Thank you very much for listening.

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