In Our Time - Scepticism

Episode Date: July 5, 2012

Melvyn Bragg and his guests discuss Scepticism, the idea that it may be impossible to know anything with complete certainty. Scepticism was first outlined by ancient Greek philosophers: Socrates is reported to have said that the only thing he knew for certain was that he knew nothing. Later, Scepticism was taught at the Academy founded by Plato, and learnt by students who included the Roman statesman Cicero. The central ideas of Scepticism were taken up by later philosophers and came to the fore during the Renaissance, when thinkers including Rene Descartes and Michel de Montaigne took up its challenge. A central plank of the philosophical system of David Hume, Scepticism had a powerful influence on the religious and scientific debates of the Enlightenment.With:Peter Millican Professor of Philosophy at Hertford College, OxfordMelissa Lane Professor of Politics at Princeton UniversityJill Kraye Professor of the History of Renaissance Philosophy and Librarian at the Warburg Institute, University of London. Producer: Thomas Morris.

Thanks for downloading the In Our Time podcast. For more details about In Our Time and for our terms of use, please go to BBC.co.com.uk forward slash radio 4. I hope you enjoy the program. Hello, in one of his earliest works, The Ponce Philosophique of 1746, the French philosopher Denis Didaro wrote, A thing is not proved just because no one has ever questioned it.

Something that has never been examined dispassionately has never been properly examined. since, skepticism is the first step towards truth. Diderot was writing about a philosophical tradition which emerged in ancient Greece and which has been important ever since. Skepticism is the idea that it may be impossible to know anything with complete certainty.

One early Greek skeptic claimed that nothing can be known, not even this. Skepticism was rediscovered during the Middle Ages and it's been of key importance to scientific, religious and political thoughts since the Renaissance. With me to discuss the philosophy of skepticism are Melissa Lane, Professor of Politics at Princeton University. Jill Cray, Professor of the History of Renaissance Philosophy and librarian at the Warburg Institute University of London. And Peter Milliken, Gilbert Ryle Fellow and Professor of Philosophy at Hartford College, Oxford.

Peter Milliken, can you distinguish between everyday use of scepticism and scepticism as it is described in philosophy? Yes, I think in everyday use, a sceptic is often thought to be someone who deny, some orthodox view, so a skeptic in religion or a global warming skeptic or a skeptic about evolution, maybe someone who simply disagrees with the majority. But in philosophy, skepticism tends to be more about doubt than about negative assertion. So it's not so much denying some orthodox view as questioning it. And obviously there's quite a spectrum of possibilities there. Within philosophy, scepticism can be specific, so you can get scepticism, say, about the external world.

Do we really know that there's a world beyond our appearances? Skepticism about induction? Do we have any reason for believing that the future will resemble the past? And scepticism about things like morality and religion. But historically, scepticism's probably been most influential in philosophy as a general view. so not about one or two specific things, but rather an attitude of doubt towards just about everything. Can you just develop the ideas that's, give us a sort of, that was the rapid overview. Can you give us a rather longer overview of what we're going to be discussing?

What skepticism in the philosophical sense of the word? What areas it's led to in discussions? Right. Well, skepticism has been around for a long time. time and in the ancient world it took this global form and it was combined with a view of a certain ideal of form of life so the the thought was that by doubting everything by being undogmatic one could reach a kind of tranquility now when it came forward into the modern world it came through in a period where it was casting doubt on a lot of things

that were highly controversial, particularly in the context of religious debates and that sort of thing. So it had a very big effect in casting serious doubt on all sorts of things that people were very concerned about. And then it got developed by particular thinkers that we'll be talking about, particularly people like Descartes and Hume, came through into the contemporary world as a very living force because those arguments that they were providing seemed so. hard to challenge. And it got to the very essential nature of what is knowledge itself, and is there such

a thing as certain knowledge anywhere? Yes, exactly. I mean, it tends to suggest if you take the skeptical argument seriously, and some of them are very difficult indeed to defeat, that we can't know all sorts of things that we wish we did. Like, for example, proof of the external world turns out to be much more difficult than you might think, or proving that science has a solid base. that we can reliably glean laws about the universe from our observations.

All that sort of thing has a very real concern. And obviously also in areas like morality and religion, sceptical worries tend to be particularly strong where you've got a lot of real differences of opinion. And essentially what the sceptical arguments are doing is saying none of you have good reason for, what you're asserting. So it's a very troubling and upsetting sort of theme. And still two and a half thousand years on quite alive as a subject in philosophy. Very much so. Ms. Elaine, can you

go back now to the origins of skeptical thought? Skepsis in Greek means investigation and those investigations might lead you on the one hand to a kind of modesty about what you think you might know. and on the other hand, to a kind of relativism. And I think those were two of the key origins. So the modesty comes, especially from Socrates, who in Plato's apology is depicted as saying, what I do not know, I do not think I know, and that's sometimes lost as I know that I know nothing. So there's a kind of modesty about the limits of knowledge. True wisdom comes from the limits of knowledge. But then on the other hand, especially with regard to moral and religious ideas, the ancient Greeks, led in their investigations, if they looked at what people were doing around the world, they thought, well, maybe many of our moral and religious beliefs are just local conventions. So one pre-Socratic thinker said, well, the Ethiopians have gods that look Ethiopian and the Greeks have gods that look Greek. How do we know what the gods really look like? So that kind of investigation of customs and practices around the world also was a source of skepticism. And it went into how people dressed, the different civilized, dressed in...

Persians wear long gowns and things we don't do. that exactly, all those sorts of observations. When I say the origins of skeptical thought, would you be true to say this is really massive generalisation, so please knock it down, that up to about the 5th century BC or so,

thought had come out of or been associated strongly with religion, with the dogmas of religion and with revelations as some thought, with religion. And this moved away from it. This was one of the first big moves away from it. Well, I think

certainly the, I think that's right. I think that the Socratic view and the platonic view was in a way, not so much challenging religion, but reconstructing it on a rational basis. So casting doubt on some of the assertions. So for example, on the existence of all the multiple Olympic gods and saying actually God and its nature must be single, must be good. So skeptical arguments used in a way to rationalize religion, not necessarily to disprove it. Did skepticism lead to, to a release of thought? Yes, I think so. It's very strongly associated with freedom of thought in later thinkers, especially, as we'll talk about.

And Cicero describes it as a form of freedom of thought. Even Hegel says that's the skeptical moment, is the moment of free thinking. And you referred to Socrates and Plato's Academy, and it went through the Greek tradition there. There were two types of skepticism, as I understand it, the academic and the Pyrannist schools. Can you tell us the, can you distinguish between the two schools, please? Both schools trace their origins to the third century BC, so about 80 years after the death of Plato. And in a nutshell, the differences that the academics are still, they're within Plato's Academy. They're called academics. That's a movement that develops within the academy.

And they still hold to that Socratic view that the wise man is the person who knows the limits of knowledge. And in particular, the academics were in debate with the society. Stoics, who also had actually started within the academy and then split off from it, who said that to have knowledge, you have to have a criterion of certainty, that are certain cognitive impressions that are self-certifying. And the academics challenged that and said, there's no such thing as a self-certifying impression. So we can't have certain knowledge. And the other school were the Pyrannist school. And they, although they trace their origins to a couple of figures in the 3rd century BC, they only really take shape about 100 years either side of Christ. And they were

more radical because they held not that wisdom was still the path to tranquility, but wisdom was knowing the limits of our knowledge. That was the Socratic academic view. But instead the Pyrinists held that actually we could be happy and tranquil without having wisdom at all, that we could suspend what we should do, in fact, is try to suspend belief about any kind of dogmatic claim or appearance. So snow appears white, but is it really white? We suspend judgment about that. The gods appear Greek, but are they really Greek? We have to suspend judgment about that, and that it's that suspension of judgment, which will actually bring us tranquility. You use the word certain knowledge, and that played a part, and it has played a part in,

as I understand it, in the development of skepticism ever since. Have you any way of telling listeners what is meant at that time in the third century received by human knowledge? By certain knowledge, So that does derive from this, particularly from the stoic approach, from the stoic claim, that there has to be a criterion so that anything that appears to me, I can't just go on appearance. I have to have a criterion to determine is that appearance really valid? Is it actually the way that things are in reality? And some of the disciples, particularly of the pyrrhenists suggested, well, actually, well, both the academics and the pyrrionists suggested, we just can't have such a criterion. And any appearance that might say, seem to be certain is actually indistinguishable from another appearance that wouldn't have that certain origin. And so we just don't have that criterion. And Jill Crow, let's continue the talk about the Pyrrheny School, name after this person called Piero. Would you tell us a bit more about him and more specifically what he believed? He's, as Melissa said, he's from the third century and we don't really know much about him.

He didn't write anything, and all we have are a bunch of legends and rumors which grew up about him and were reported, and they didn't really actually, in the form that we know them, they were written down in the third century AD, so that's about six centuries after he lived. So it's very hard to sift out what he actually believed from what the legends that developed. but he had the view that nothing was either in itself good or bad, honorable, or dishonorable, that nothing was either more this than that. And he apparently, according to some stories, he took this to such an extreme that he would not pay any attention to what was going on around him. So if he was walking across the street and there was a carriage, he wouldn't get out of the way.

If he was walking by a cliff and in order to prevent him, himself, he would have to turn, he wouldn't do that. So his friends would follow him around and keep him out of harm's way. And then Diogenes says, but he lived to 90, so they must have done a good job. And we have another story, one of these very helpful friends who was saving his life, fell in a ditch. And Piro just walked by and paid no attention to him. And some people criticized him, but the friend said, no, that shows that he's not paying more attention to his emotions, that he doesn't think anything is more this than that.

We have stories that he had this completely even demeanor. So when he was talking and somebody went away, he would just continue talking because that's what he was doing. We have stories that he went against the conventions of the day. There are a lot of them involving pigs. He would wash pigs. He would take them to market. He was on a boat once when there was a storm and everyone was getting upset. And he said, no, be calm.

Look at that pig over there. And that's sitting there eating. that pig has the tranquility and he uses the technical term that the skeptics use for that, that the wise man should follow. But we also have evidence in

the life of Piro that I said from the third century, Diogenes Laertesius that the people in the Pyreneist revival that Melissa mentioned from the first century BC said no, he didn't actually try and live his philosophy. He only suspended judgment in thought and in his

own life he actually behaved like everyone else. So you pay your money and you takes your chances. I mean, the stories are just contradictory and we have to still sort them out and people in the Renaissance were trying to sort them out and in the 19th century.

One of the people who tried to sort them out was Nietzsche, who his first two articles were actually on the sources of Diogenes Leerschis. Well, that's vivid enough then. I mean, so we've got, we've nailed him, I think. No, no. Can you tell us what he

stood for that was important enough for people to follow it and for it to enter into the mainstream of the philosophical discussion of skepticism? I think it's this idea the central idea is that nothing is either

this nor that, more this than that. In other words, the sense of complete indifference and therefore this indifference will lead you to the suspension of judgment, the suspension of judgment will then lead you to this peace of mind. And there's a nice story which actually comes from another source of the painter of Pellys, who was trying to paint the foam. A horse had a little bit of saliva on his mouth and he was trying to paint that and he couldn't do it and he couldn't do

it. And finally, he just took the sponge that he was cleaning his brushes with and threw it at the painting and it produced the effect that he wanted. He threw in the sponge and he got the effect. And that's what suspension of judgment is throwing in the sponge the effect is you get this tranquility and peace of mind, which people in the Hellenistic era seem to be very interested in achieving.

It's a very odd thing. One of the students of Plato's Academy, a long time after Plato's death, was the Roman statesman and writer Cicero. How did skepticism influence his work? You can't think of anybody further away from the Piro, can you? But how did it affect

his work? Well, he studied in Athens with the academic skeptics and he was a member of that sect and he is a very important source for us because almost all the philosophers that he writes about we have no works by them so he is the person who transmits them and his idea was that he wanted to transplant Greek philosophy to Rome and the thing about the Romans as we all know they were very practical people

They fought wars, they conquered people, they built aqueducts and roads. They weren't very interested in philosophy. That was something for the Greeks who were intellectual but ineffectual, and they'd been conquered by the Romans. So he wanted to bring philosophy to Rome, and to do that, you had to write in Latin, you had to explain these ideas, and this is what he did, particularly we know about,

he wrote about the Epicureans whom he didn't like, and the Stoics he was sympathetic to, but with the skeptics, they're his group. He's a card-carrying member, and we get an inside account. Peter Milliken, there's an important surviving work of ancient skepticism by a philosopher called Sextus Empiricus. He's anti-scepticism, but in the process of being anti, as I understand, he says a lot about it.

No, I don't think of him as being anti-sceptical. Well, in somebody's notes, they were very keen on him being anti-I. I'm... I don't know. He's the man. Yeah, sextus is... extremely important because, I mean, a couple of the works that survived have already been mentioned. We've got Cicero's works, in particular, a work called Academica, and we've got Diogenes-Laeuxes, who wrote Lives of the Eminent Philosophers, which really has lots of snippets.

But Sextus Empiricus was the third, and possibly the most important, in terms of future influence, of the works that actually survived to tell us about ancient skepticism. he flourished around the end of the second century AD. He was a physician, possibly in Alexandria, we're not sure, but he collected together all sorts of teachings of the Pyranist school. So he wrote a work called Outlines of Pyranism, which was particularly famous and various other works as well, with arguments against all sorts of people, logicians, physicists, ethicists, and various dogmatists. But what was so important about Sextus is that he was a systematic collector of these. He codified a lot of the ways of arguing the reasons for doubt. And his manuscript survived pretty much intact until the early

modern period and had a huge effect then. So he emphasized things like the problem of the criterion. That's already been mentioned by Melissa, the idea that you want a criterion of truth. How do you know what's true. And the problem of the criterion is that in order to recognise the criterion of truth, it seems that you need a criterion for choosing your criterion. So you get a kind of circular problem. Or it regresses. Yeah, exactly. Yes. And so he also... So he, I just go straight, because I think I'm slightly going mad here. So he actually accepted the philosopher, the philosophy of skepticism and put it forward. I must be cross-eyed in our that bit. Okay, fine.

And as we've heard, the idea of the Pyrinist scepticism was to suspend judgment. So what he did was codify a whole load of ways of arguing so that on more or less any question you could see reasons for arguing either side. And the idea of this was to bring you to a position of suspension where you're neither affirming nor denying anything. Incidentally, the Pyranists typically said of the academic skeptics that they were dogmatists for denying that you could have knowledge.

So you shouldn't even assert that we can't have knowledge. Yes. Manuselaine, skepticism touched on religion in the Middle Ages. Let's begin way deep in the Middle Ages, almost before it. Augustine of Hippo, who was a skeptic and then a Platonist and then a Christian. Did he set the course for the discussion between these two systems? Augustine engages very directly. with Cicero, whom Joe was talking

about earlier, and it is, as you say, a phase in his philosophical and religious evolution. So actually it comes after his Manichaean phase. He starts to think of the Manichaeans as dogmatists. And so in the early 380s... The people believe the world was divided

into... Good and evil. And exactly that these are two forces sort of battling it out. And in the early 380s, reading the skeptics, Augustine entertains the thought, well, maybe they're wiser to suggest that we should doubt everything and we can't actually have any certain knowledge. And so he's following Cicero, and Cicero is

his source. But then when he goes into his Platonist and Christian phase, he then writes a work contra-academico's so against Cicero's skeptical work. And it's very interesting. He brings a number of different arguments against it. So on the one hand, he's been thought to anticipate Descartes by saying there are some necessary truths. And Augustine says, I err, therefore, I am. So I make mistakes, but even in making mistakes, I must exist to make the mistakes. He also says, well, against the skeptics, there are some subjective truths. So he says, I know that this feels cold to me. So the skeptics would have said, well, it feels cold, but you don't know whether it's really cold or not. And Augustine says, that may be so, but I know that it feels cold. So that's something

I know. So that was an interesting move. But I think one of the most interesting moves about Augustine, with Augustine, that's unusual, actually, is that he also thinks skepticism is morally and religiously dangerous. So he says, what if you have a young man who becomes a skeptic and then lays siege to the chastity of another man's wife, that skepticism could lead to a kind of immorality? And that's an unusual charge, because actually most of the concern about skepticism was that it would lead to paralysis of the kind that Jill was describing with Piro, that the skeptic just wouldn't be able to act. Whereas Augustine actually sees it. as a danger to religion and one that needs to be overcome.

Moving on a bit quickly here, but just to take another bite at it from a different period of history, skepticism was rediscovered in the Renaissance, partly through Cicero's works and partly through the spread of these works in Latin and the invention of the printing press, which distributed knowledge much more widely and so on. Can you tell us how it was discovered and what impact it had? Well, Cicero's Academica was read not very much in the Middle Ages, but we find evidence in the 14th and 15th century of more people reading it, more copies being made. But it's not really till the 16th century that it takes off and people start writing commentaries and treatises. We get with the Greek skeptical works, Diogenes Laertesius, which this bit of it was not known in the Middle Ages, is translated into Latin in 1433 in Florence. and interestingly, that is where we get the word skeptic

because the translator, instead of translating the Greek skepticos as an inquirer and investigator, just chooses to transliterate it, and then from that Latin word it gets into the vernacular languages. That work was very popular. It was circulated in manuscript. It was printed frequently. And it's a very large work, so we don't know that people were particularly interested in the life of Piro, but it was available to them. Sextus Empiricus also, we start seeing manuscripts circulating in the 15th century.

It remained in manuscript in Greek until late in the 16th century, so only a very few people could read it because Greek was a very unusual skill, particularly in the 15th century. But we have a handful of people who we know read it and exerted it, usually leaving out the philosophical bits and just taking the arguments that Sextus was imposing opposing. It gets into Latin in the 1560s.

The outlines is translated by a Protestant and against the professors is translated by a Catholic. They're published and they're put together with the life of Piro from Diogenes

Laertes and a very interesting little work by Galen which is called The Best Method of Teaching which is a small little work where he attacks skepticism, but rather like Augustine, in attacking it, he provides information. And that work was translated by Erasmus. What were these views that Sextus was opposing? He was opposing everything, as Peter said. He wrote against the logicians, against the ethicists, he wrote against the physicians, he wrote against grammarians, astrologers, geometers, musicians,

everything. What he wanted to show always was that for every argument there is, is a counter-argument of equal force. That was the kind of central idea. And the various arguments are all to show you that. And if you then see that for every dogmatic argument, there's an equally powerful and valid counter-argument, you will suspend judgment because you can't make a decision. Peter Milliken, so why do you think skeptical thought

had such an appeal to humanist scholars? Erasmus has been mentioned. Yeah, well, I think the reason it had such impact at the time, it's important to see the context. As you mentioned, you've got the invention of printing, which is spreading these things around much more than they've ever been spread before. You've got the translation into Latin, which is making them much more available. But also, it's coming into a world which is full of doubt.

Perhaps most important, Luther and the Reformation, starting around 1517, population is growing, there's a lot of trade with new places, the new world is being discovered. And suddenly people are aware. where the Bible and Aristotle, which have been pretty much the oracles up till now, actually don't say anything about this new world. There's cultural relativity, new lands being found, people with strange beliefs. All these things naturally raise the question,

how confident can we be in our own beliefs, given that there are all these people, some of them our neighbours with different religious views, some of them far away with all sorts of exotic beliefs, how confident can we be in our own beliefs? And so it was from that starting point really and the fact that the America wasn't in the Old Testament and so on. That sort of thing. I mean, I think another thing is that with Galileo and his discoveries,

the Aristotelian worldview was being overthrown. There was a new science being developed by people like him and Descartes. And they saw skepticism also as a useful tool. So Descartes uses it in order to clear away the Aristotelian orthodoxy. Jill Craig, can we move to the French writer Michel de Montagne, who took up skepticism with a great deal of enthusiasm? Can you tell us about that? He got access to Sextus Empiricus from the Latin translation that I was speaking of in 1562,

and it really had a fantastic impact on him. We know in his library, which he retreated to to write his essays, he carved little mottos on the beams, and many of them come directly from Sextus Empiricus. I suspend judgment. I examine. I don't lean this way more than that way. And in one of his most famous essays which deals with skepticism, he talks about his own personal device, his logo. And that is a pair of scales which are evenly balanced. And this is the argument for every proposition. There's a counter proposition. And under it, he says he has the motto in French, French, Cassege, what do I know? And this is probably the most famous of his quotation. And we do actually have a medal of Montaigne which survives, and it does have the scales, but instead of the French motto, it has the Greek for I suspend judgment. So it was really quite important to him.

And I think the fact that he was living through very brutal wars of religion in France, which he tried to stay out of. I mean, he was a Catholic, but he tried to be very tolerant. But he saw around him people killing each other, killing their neighbors, over things that they believed. and he really thought that this was a result of dogmatism. He says dogmatism does not allow us not to know what we do not know. In other words, it polarizes things.

It forces us to change, to take sides. And therefore, skepticism can diffuse this. There seems to be this battle on Melissa Lane, which is growing through and now growing between schools, skepticism we're saying we don't know anything or we know little or we're uncertain of most things, and the search for certainty, which comes back again emphatically with Descartes,

moving the story forward. Can you discuss Descartes? Yes, so exactly. That contrast between skepticism itself being the solution, as it were, the therapy, the way of life that will bring us tranquility, which is what it was for the ancient skeptics and for Montaigne. But in Descartes, it becomes a tool in the search for certainty.

So skepticism becomes a moment to be overcome. rather than actually the path to tranquility. And one mark of this, I think, is that whereas in Cicero and Augustine, we get dialogues. Their works about skepticism are in dialogical form. In Descartes we have a kind of monologue. We have a single mind inquiring within his own head rather than opposing arguments from the outside one to the other. And so Descartes really introduces this thought of searching for the foundations of knowledge. and he very explicitly uses this architectural metaphor from the rediscovery of Vitruvius

that what we're trying to do is to build solid foundations. If you're an architect, you don't want to build on sand. And so you have to question all your beliefs, subject them all to a radical doubt, so that you can reconstruct some foundational beliefs that can then serve as the basis for science and philosophy. And rather like Montaigne, his foundational belief came up with a phrase that's still with us, isn't it? Yes. So actually his earliest formulation was in French. I think, therefore, I am. But of course, we now think of it from a later version that he used in Latin, the Cogito ergo sum. I think, therefore I am. Was that received with any approbation or did approval or did people question that?

It was very controversial. I mean, it set the agenda for science for some decades to come. And it was challenged, on the one hand, by some religious Christians, a bishop. Bishop attacks Descartes saying, actually, he's undermining the foundations of faith. Descartes himself had thought that he was firming up the foundations of faith, because at the bottom of his foundations for knowledge was actually the existence of God. But not everyone accepted that that was the way you should go thinking about God. Peter Milligan, what was the next stage for it? Are we talking about the influence that Pierre Baile had on it,

just taking it through after Descartes? Yeah, well, Descartes had a big anti-sceptical influence. and he had a lot of followers because he seemed to be pointing the way towards a new way of thinking about the world, a new physics as well as a new metaphysics. And so he was extremely influential, but the sceptical theme did get carried forward, probably mostly by Pierre Bale. Pierre Bale, like Montaigne, was influenced a lot by the wars of religion in France. and for similar sorts of reasons, though from the other side,

he was a Huguenot, a French Protestant, he was very keen to emphasise the importance of toleration. So he saw scepticism in the form of argument. Again, as Melissa was saying, where Descartes has got this monologue, the skeptics often tend to put things in terms of dialogue. So Bale writes this historical and critical dictionary in which he puts lots of,

views from all over the place, lots of contrasting discussions, most of it's actually in footnotes with all sorts of imagined conversations, giving different sides of different stories, and all of them with the intention of promoting tolerance and the realisation that there's lots to be said on all different sides. Melissa, religious belief and skepticism are intertwined and opposed, and underpinning each other and undermining each other right throughout the 17th century, in many cases, from then on. Can you give us a specific example that would help us on this?

It's interesting because in a way it goes back actually to antiquity, that on the one hand there were people who were using skeptical arguments to shore up Christianity, saying, well, if we can disprove all the dogmatic claims of reason, that leaves room for faith. And then on the other hand, you have people saying skepticism is a kind of danger to religion because it undermines our certainty and our own beliefs. And so that goes right through into the early modern period. And one interesting example is from the early 16th century, the nephew of the famous Pico della Mirandola,

this is the nephew Gianfranchesco. And he uses, he's our only actually known reader of sextus in Greek before it was translated into Latin. and he uses skeptical arguments to attack all the vain doctrines of the nations or of the Gentiles and leave room for a Christian faith. So that's a kind of interesting example of skepticism being used to defend Christianity, even though others thought that it was a danger to it. He was in fact a follower of Savonarola, and Savonarola is famous, of course, for the bonfire of the vanities,

and the treatise that John Francesco wrote is called the Vanity of Pagan Learning. So it's another thing to put on the... on the bonfire, that we must get rid of pagan learning because if we demolish it, then people will turn to the authority of the Bible and the Catholic Church and the papacy. And that is a position that Montaigne takes as well. He says that after the reason why the Pyrinists are so valuable is they show man naked without any power. He loses faith in his reason.

And that allows him or encourages him to take, his inspiration from on high. And he refers, he says, after skepticism, man is like a blank tablet on which the finger of God can carve whatever word he wants. Peter Milliken, can you take us to the Scottish Enlightenment, particularly David Hume, who played a, has a big part to play here. So let's concentrate a bit on David Hume.

What did he bring to the table? Well, David Hume actually was influenced quite a lot by Bail. And just following up something that Jill said there, In both Bale and Hume, we have this issue that sceptical arguments are presented, and then we get the thought that the scepticism makes room for faith. And it can be quite difficult to work out what the real view of the writer is. I mean, my suspicion is that Bale really was a believer. He really was what we call a fideast.

That's someone who believes on the basis of faith, with the skepticism having undermined mere human reason in the way that St. Paul or Calvin would have approved of. Whereas David Hume, I think, is in fact pretty much what we would call an atheist. And for him, I think, when he says skepticism has made room for faith, I think he's being disingenuous for very good reasons. But Hume was born in 1711. He wrote one of the greatest works of philosophy,

absolutely full of skepticism, the Treatise of Human Nature, in 1739 and 1740. His later work is much more mitigated. He moved towards what he called. called academic skepticism. It's not quite clear that his understanding of it was exactly the same as that of the ancients, but generally a mitigated skepticism in which skeptical arguments make us aware of how little justification we've got for dogmatism and going towards a very reasonable kind of spirit of inquiry.

Again, going back really to the original thought of skeptics. so in fact Hume's ultimate view is not very different from that of a modern scientist He does rather graphically say I struggled with this particular problem of induction if you can bring that to the attention of militants

and then I went out one night and then I came back and looked at it and said what am I bothering with this for you can say it rather better than that yes well he actually says this most famously with regard to the problem of the external world

where he grapples with this in the treatise in book one and comes to the conclusion that our belief in the external world is completely incoherent. Not only can you not give any good arguments for it, when you actually examine the belief, you find it really doesn't make sense to think of an object persisting through time. So there aren't any continuing objects distinct from us.

But then at the end of that, he just says, well, the only solution to this is, carelessness and inattention. I won't pay any attention to the skeptical arguments. And in a very famous passage, he says, I dine, I play a game of backgammon, I converse with my friends, and all of these skeptical worries just disappear.

And I go back and look at what I've written and think it's strained. You must finish a good day. Yes, that's right. But as I say, the Hume's ultimate view seems to be quite different from that. It's much more calm and relaxed. the sort of extreme skepticism that you get in the treatise where these fundamental beliefs are portrayed as completely incoherent,

that disappears. And what we get instead is an appreciation of what Hume calls the whimsical condition of mankind. We have faculties which tell us about the world. We can reasonably expect, say, that stones will fall when we drop them, or billiard balls will move when other bulls bash into them. But famously, although we don't.

know what will happen in the future. If we use the working model that it would be much the same as happened today or in the past, then it'll be okay. That's the reasonable thing to do, but we're just in this whimsical condition that we can't justify our own faculties. Of course we use them, but we can't ultimately justify them. So the

dogmatic philosopher who wants to take everything down to certain principles is simply going after the impossible. Did skepticism, Jill cry, did skepticism have a profound effect on the scientific in light? Yes, it did. In the 17th century, you have the one line of inquiry, which is Descartes, who says you really can't do science, you can't go on and make progress in science unless we have absolute metaphysical certainty, unless we know that we have absolutely infallible information, which comes from the Cogato. And then there's another school of thought. You get some French priest, Marant, Mersen, and Pierre Gassendi, who say, no, we can't get that kind of sense.

certainty. Only God has that certainty, but it doesn't really matter because we can get a second level of certainty, which only deals with appearances. We're not making any claims about reality, but that is actually sufficient to be getting on with scientific progress. There's an interesting political dimension to that as well. So if we think of Thomas Hobbs, who's part of that scientific revolution in the mid-17th century, he starts his political philosophy, not from something we know, but from something he thinks people can't reasonably deny, which is the claim that I have the right to try to preserve myself. And so you see the mark of skepticism there.

We have to build up science again and build up political science, but not on the basis of a knowledge claim, but outside that. They develop this theory of limited certitude, which means that we know less than the dogmatists think, but rather more than the skeptics think. So we can have a fairly certain knowledge about mass and about physical events. We can have knowledge that will allow us to get through our lives by applying the principle of reasonable doubt.

We shouldn't doubt everything that's possible. We should only doubt it when we have a good reason. And I think you can draw a distinction between kinds of doubt. So we tend to think of doubt as opposite to belief. But actually it needn't be. Doubt can be just the spirit of inquiry about one's beliefs, what the grounds are for them. So it's perfectly possible,

Hume is the most famous example here, to carry on believing things and yet at the same time have an attitude of skepticism towards those beliefs, an attitude of constant inquiry, wondering what the basis for them is, appreciation that the basis isn't as firm as some people might like. But it's enough for life. And we don't have to always be looking for certainty. Probability is most of the time good enough.

And particularly in science, the group around the Royal Society took this more or less as their principle, that they would find the best hypothesis they could that would explain appearances, and that would allow them to make scientific progress. And even a great scientist like Robert Boyle wrote a work called the Skeptical Chemist. So we can go forward with science

on the basis of this limited certitude, and we can get on with our lives. Finally, Ms. Lane, how influential is skepticism today, do you think? It still sets the basic problem of epistemology. So whenever you take epistemology, 101, you're taught, well, how can we refute the skeptic? That still remains one of the fundamental questions in philosophy,

although some people have tried to get away from the foundationalist paradigm. How can we know what we know? How can we know what we know, exactly? Some people have tried to get away from that foundationalist paradigm and come up with another way forward. If you've got a sentence, Peter, fine. And we've heard how actually the spirit of modern science is absolutely infused with skepticism.

Well, thank you very much, Jill Cray, Melissa Lane, Peter, Ehrlich. Next week, Haydrian's Wall. Thank you for listening. If you've enjoyed this BBC podcast, why not try others such as The Forum, the discussion programme about global ideas? To find out more, visit BBCworldservis.com slash forum.