In Our Time: Pascal

Blaise Pascal was a 17th Century Frenchman who was a scientist, mathematician & philosopher. Several of his ideas are still recognised today – either still in use (for instance some of his mathematical work) or recognised by the naming of modern things (like the programming language Pascal). Discussing him on In Our Time were David Wootton (University of York), Michael Moriarty (University of Cambridge) & Michela Massimi (University of Edinburgh).

Pascal was born in 1623, and died in 1662 age 39. David Wootton gave us some context for the France of the time which he called essentially the time of the Three Musketeers – so Richelieu is in charge in France, the country is allying with Protestants in the Thirty Years War but in terms of internal politics there is a big crackdown on Protestantism. In the wider world Galileo is active at this time – which took me by surprise as I think of Pascal as nearly-modern but Galileo as end-of-medieval and clearly that’s not a sensible distinction! Descartes is also still alive when Pascal is born.

Pascal was educated at home, his father had planned that the boy should be told about various subjects young but then not study them until later when he was ready for them. But the young Pascal had other ideas – for instance figuring out Euclidean geometry himself once he’d been told about it, rather than waiting till he was taught the subject. One of the people on the programme (I forget which one) said that Pascal was Mozart type levels of genius – just in maths, science & philosophy rather than music. One of Pascal’s first notable works was inventing a mechanical calculator while he was still in his teens – he did this to save his father time (his father was a banker and thus had lots of adding up to do).

Pascal’s work in physics was on one of the big questions of the day – could there be such a things as a vacuum or not. Aristotelian ideas said no, but an actual experiment suggested yes. Pascal repeated the experiment – taking a tube filled with mercury & closed at one end, then inverting it in a basin of mercury. The level of the mercury in the tube drops and a space opens up at the top of the tube, there’s nothing this space can be full of, so it must be a vacuum. Pascal also took these experiments further – looking at different liquids (like water), and testing the effects on the height of the mercury at different heights above sea level. He was one of the first to demonstrate that air had pressure, and that this pressure varied with altitude.

Pascal also had an influence on the future of science & the scientific method. He hadn’t been brought up reading Aristotle as the “answer” to all the questions about the natural world, and he didn’t believe that you required a metaphysical starting point to answer a physical question. So he said that in science there was no appeal to authority, nor was there Truth, just that you looked at the facts as they were and explained them as best you could. Then when more facts were known you might have to change your mind – you’d not have Truth, just have got as close as you could under the circumstances. One of the experts said that Pascal was one of the first people to actually demonstrate this way of having scientific progress – other writers before him had talked about how you could progress in science but he actually did it.

Pascal was also interested in mathematics & he corresponded with Fermat. One of his theorems to do with the geometry of conic sections is still used by mathematicians today. Pascal’s triangle was mentioned briefly on the programme as another example of his mathematical legacy. He was particularly interested in probability, and would work on gambling problems for French aristocrats he knew. He & Fermat worked on a particular problem to do with what the pay out should be for a game of Points that is interrupted before the end. In Points a coin is flipped multiple times, each time it’s heads player A gets a point, each time it’s tails player B does. First player to 10 points wins the pot. How the pot should be split if it’s terminated early depends on what the probabilities of each player winning from the state it’s in (rather than just splitting it according to how many points so far). Pascal & Fermat’s work has had far reaching implications in a lot of the business world, not just in gambling or the specific problem – like insurance for instance.

Later in life (if you can call it that for someone who dies so young) after some sort of intense religious experience Pascal turned away from science & towards religion & religious philosophy. Here he believed strongly in appeal to authority – he built on the work of earlier philosophers who said that human reason is too weak to comprehend the Truth of the world in a metaphysical sense. And so in contrast to his scientific ideas Pascal felt that religious Truth is revealed and is unchanging. Pascal had become a member of the Jasenists, a Catholic sect that built on the ideas of Augustine in the same sort of way that Protestants did – in particular believing that people cannot come to a state of grace through their own efforts, they must be chosen by God to receive God’s Grace and so only the chosen are saved. Mainstream Catholicism of the day believed that by doing good and repenting sin you could come closer to being saved, and so the Jesuits regarded the Jansenists as heretics just as much as Protestants were. One of Pascal’s later works was written to argue that the Jesuits & mainstream Catholicism were wrong, and it was partly arguing based on appealing to the authority of Augustine and saying that the Jesuits were diluting the true Christian morality to make it more palatable to the masses. This work is credited by some later Catholics as having damaged the reputation of the Jesuits enough to have been a contributing factor in their suppression in the late 18th Century.

Pascal’s Wager is one of his philosophical ideas that is still remembered today. Massimi pointed out that it was never intended to convert an atheist, but was aimed at sceptical Christians. In it Pascal says that given there are two states – either there is a God or there isn’t – then there two ways to wager: either bet for God or bet against God. Given this, how should you bet to maximise the chance of a good outcome? If you bet against God and you are wrong, then you will suffer eternal damnation after death, so the best thing to do is to avoid that – bet for God and even if you’re wrong you’ll suffer no consequences. This doesn’t work if you believe there is no God, you need to have doubt about that. It also doesn’t say anything about whether or not Christianity is the Truth – Massimi pointed out that one objection to Pascal’s Wager is that the same argument can be made for any religion. And if you enjoy this world’s pleasures then there is also a down side to betting for God, making it a less obvious choice (definitely no pleasure now as vs. possibly no pleasure later, a more complex situation to weigh up) – which was not a problem that Pascal had. He said once that life was like being chained in a dungeon in the dark, and every so often the guards come in and strangle someone. Cheerful fellow …!

In the summing up section of the programme they discussed how Pascal’s legacy lives on in science & mathematics but is most influential in religious thought. The three experts credited him with laying the foundations of modern Christianity – in that faith & religion now are seen as something that you choose to believe in without needing a rational argument. And that is a very Pascalian way to see it.