In Our Time - Bishop Berkeley

Episode Date: March 20, 2014

Melvyn Bragg and his guests discuss the work of George Berkeley, an Anglican bishop who was one of the most important philosophers of the eighteenth century. Bishop Berkeley believed that objects only truly exist in the mind of somebody who perceives them - an idea he called immaterialism. His interests and writing ranged widely, from the science of optics to religion and the medicinal benefits of tar water. His work on the nature of perception was a spur to many later thinkers, including David Hume and Immanuel Kant. The clarity of Berkeley's writing, and his ability to pose a profound problem in an easily understood form, has made him one of the most admired early modern thinkers.With:Peter Millican Gilbert Ryle Fellow and Professor of Philosophy at Hertford College, OxfordTom Stoneham Professor of Philosophy at the University of YorkMichela Massimi Senior Lecturer in Philosophy of Science at the University of Edinburgh.Producer: Thomas Morris.

This BBC podcast is supported by ads outside the UK. 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 programme. Hello. In his life of Samuel Johnson, James Boswell recalls a conversation the two men had about the work of the philosopher George Barclay and his theory that objects do not really exist except as ideas in our minds. Boswell observed to Dr. Johnson

that although Barclay's theory was obviously wrong, it was also impossible to refute. He later wrote, I never shall forget the alacrity with which Johnson answered, striking his foot with mighty force against a large stone till he rebounded from it. I refute it thus, he said. Berkeley was an Anglican bishop from Ireland

who became one of the most celebrated thinkers of the 18th century. In a series of philosophical works, he outlined a theory that he called immaterialism, which argued for the in existence of matter. Like John Locke and David Hume, Barclay is often described as a British empiricist, although his ideas differ from theirs in many important aspects. With me to discuss the life and work of Bishop Barclay are Peter Milliken, Gilbert Ryle Fellow and Professor of Philosophy at Hartford College Oxford,

Tom Stonham, Professor of Philosophy at the University of York, and Mikhaila Masimi, Senior Lecture in Philosophy in the Philosophy of Science at the University of Edinburgh. Peter Milliken, Barclay was born in 1685, 35 years after the death of Descartes, two years before Newton's masterpiece, Principia. Would you give us a sense of European thought at that time? Yes, certainly. He needs to be understood very much in the context of that scientific revolution

that started really with Galileo back in 609 and took up pace later on through Descartes and Newton and Boyle. and as you said Newton published his Principia in 1687. He also published his optics in 1704, another very influential and famous work. And Barclay was a talented mathematician and took a lot of interest in these developments. And in fact his first major publication was a new theory of vision on optics. So he was educated in Ireland at a college then he went to Trinity. Trinity College, definitely.

And so what would he be reading? Did he read classics as we all would expect? Was he reading contemporary philosophy? The biggest influence on Barclay, the biggest single influence, is John Locke, whose essay concerning human understanding was published in 1690. And that towered over the future, the generation. Locke, as you've said, was an empiricist. He thought that all our ideas are derived from experience. And Barclay followed in that tradition.

This theory has the implication that thought is seen as being very much like perception. The materials of our thought are copied from perception. So when we think it's something like replaying perception. Now, Barclay... Now, can you just say that again in different words? So we get it completely. Sure. Okay.

So Locke wanted to argue against particularly Descartes, who had thought that some of our ideas, like the idea of God, like the idea of extension, material extension, are innate. And Locke wanted to say, no, all of our ideas are taken from experience and in particular from sense experience. From the experience of the external world? Yeah. And that has the implication that if the ideas that are the materials of our thought

are like copies of our perceptions, then to think of red say is rather like seeing red, except it's less vivid. I'm with you, I'm just holding on here. Okay, so Locke is what's called a representative realist. He wants to say that the things of which we are directly aware in perception are these ideas in our minds. But we suppose that there are physical objects which cause those are. ideas in our minds. So Locke believes in matter in material substance. So he thinks that a tree is a tree out there? That's right. We receive an idea which is our perception of the tree,

but we suppose that there is a tree which in some way resembles our idea. But very importantly here, we need to distinguish between properties which the tree is supposed to have in itself, like its size and its shape, and properties which appear to us in a certain way, notably, for example, its colour or smell or taste and so forth. And Locke wanted to say that there is nothing resembling those ideas in the tree itself, but what there is in the tree is something we know not what, that causes those ideas in us.

So the mind turns the thing into an idea, and the idea matches the thing. The thing has a causal impact on our sense organs which generates an idea in the mind and we suppose that there is something real out there which in some ways at least resembles our idea of it. Tom Stoner, he was born in Ireland, as has been mentioned, Berkeley, and in his late 30s became a bishop

so most of the time he was known as, it was a nobleman son, known as a scholar. Can you give us some idea, a little more idea of his life, his background? Yes, of course. I think it's best to think of his life in kind of four main periods. The first period is the Dublin period. He enrols at Trinity College Dublin in 1700, takes his degree in 1704, becomes a fellow in 1707. And then we get the period, the big boom of publication. The first major work, the New Theory of Vision in 1709, the Principles of Human Knowledge in 1710.

working on the second part of the principles and the three dialogues in 17, after 1710, and working as a fellow in the college. And then in 1712, he takes leave of absence and goes to London. And this kind of is the second phase in his life. He's still to publish the three dialogues. His plan is to publish that in London once he's made a reputation for himself. So he starts moving in literary circles in London, trying to build up a reputation,

and spends about five months doing this, writing for popular papers, especially the Guardian, Richard Steele's Guardian, and then publishes the three dialogues to much more acclaim than the principles. Then he goes travelling. He becomes chaplain to the Earl of Peterborough, who is sent as a special ambassador to the coronation of the King of Sicily. So this takes him to Italy. He travels with the Earl of Peterborough for a few years, then becomes tutor to George Ash, carries on travelling in Europe until about 1720. When he comes back to Britain, via London, he goes back to Dublin. He goes back to his fellowship briefly, but mainly to seek a job in the church.

He gets appointed Dean of Derry, which is very lucrative, and uses this as a platform for his big project, which is to found a college in Bermuda. Goes to America in 1728, comes back having failed to found the college in 1731, and we get the fourth final stage, which is when in 1734 he becomes Bishop of Cloin and he becomes dedicated to his church work. Well, thank you. That's very comprehensive and very admirably brief.

We talked about Locke, or rather Peter Milliken, has given an introduction to Locke. Were there any of them thinkers as important to Barclay as Locke was? I think there were definitely. Locke's the one he mentions most. But in his notebooks, which we do have, we're very lucky to have, we see that he's discussing reading and discussing Descartes, Malabranch, Hobbes, Spinoza, Sergeant, who's a critic of Locke's.

And he's also, through most of his life, completely obsessed with a group of thinkers he calls the free thinkers, who are largely materialists, largely arguing against revealed religion and against the Christian mysteries. He rarely mentions them by name. He doesn't want to advertise them, but he treats them as a group. And these are all very important influences on him, especially perhaps Descartes and Malabranch as positive influences,

though he's critical, Hobbs and Spinoza as archetypal enemies. So he's drawing in an immense part of the Western tradition of the last two or three hundred years. Oh, absolutely. And as a fellow Trinity, he was teaching Greek and teaching Plato. He's an excellent Plato scholar. Michaela, his first major work, as has been mentioned by Tom, was an essay towards the new theory of vision. What was he attempting to do in this work?

The new theory of vision was published in 1709. Barclay at the time was only age 24, and it was regarded at the time of one of his really best work. We know for sure Thomas Reed, one of the key figures of the Scottish Enlightenment, was a great admirer of Barclay's work on New Theory of Vision. There were two goals in that book. The first one was to discuss how we learn to distinguish the distance, shape and magnitudes of objects

and to examine the difference between different kinds of sensory ideas, such as ideas of sight and ideas of touch, following pretty much the empiricist lines that Peter has already mentioned. So the target of the book is really Descartes, and Descartes, optical geometry. So Descartes believed that human beings are born hardwired to perceive a distance and magnitudes of objects. So I can tell the distance between the glasses sitting in front of me and the bottle sitting over there

just by looking at the different angles that those objects and the ray of light form on my retina. And Barclay was pretty much objecting against that form of innate optical geometry. So Barclay believed that we learn by experience and by perception to recognize the distance, shape and magnitudes of objects. And in particular, we learn to combine different kinds of sensory ideas, ideas that we may get by touching objects or by seeing objects. So there is an obvious problem there because the visual field is two-dimensional, and obviously by touching we may get the three-dimensional of the object. So in new theory of vision, Barclay refers to a very famous problem at the time,

called the Molinot Problem. This was a problem that William Molinot raised in 1688 to Locke. And it's the following problem. Imagine a human being born blind, that by touching is able to recognize the difference between a cube and a sphere. Imagine that person can regain sight later on in his life. Will the person be able to tell just by seeing the difference between a cube and a sphere? So how do visual ideas combine with ideas of?

touch. And Berkeley answered to the problem was that the two ideas are very different in nature, etheregenious, and it's only via process of trial and error that we are able to combine those ideas and form a kind of fully-fledged view about the distance and shape of objects. He's probably best known for his work treaties concerning the principles of human knowledge the following. Does this take on the argument that you've developed? Pretty much. So the principles of human knowledge was published just one year after the new theory of vision in 1710. And it continues exactly the same empiricist lines.

So the goal of the principles of human knowledge is to spell out in a systematic way Barclay's view about how we come to know the world. And Barclay believed that we come to know the world by perception and what we perceive are ideas, different kinds of ideas. So by touch, I get the ideas of rough or smooth, by seeing I get ideas of colors, red and blue, smelling gives me odors, and by hearing I get different sounds and different tones, and by combining those different kinds of sensory ideas,

and by labeling them, we come to know what objects are. So an apple is nothing but a collection or a bundle of the idea of red that I may have by seeing the apple, the idea of sweet that I may have, by smelling the apple, the idea of crunchness I may have, by tasting the apple, This is the view that came to be known as idealism. It's the view that came to be known as idealism because it says the world is not a world of material objects, as Peter was saying. But for all we know and for all we can say, the world that consists in bundles of sensory ideas that we form by combining those different kinds of sensory impressions that we get. So most of the principles was dedicated to spelling out the arguments

in support of such a bold, radical philosophical view that Barclay was putting forward. Could we take, thank you, could you take that up, Peter Milliken? And can you bring back Locke's philosophy and if you choose to so that we see the way he's opposing himself to Locke and how Locke is generating his, Barclay's ideas? Yes, certainly. Barclay presents his arguments in the principles very vigorously, because the whole battery of arguments directly against Locke.

Now, as Michaela said, he takes the view that objects are collections of perceptions. He gives the example of an apple. And now remember, Locke thought that the direct object of perception, the thing that we directly perceive is the idea itself. But Locke thought that there's some material object that's causing the ideas in us. Now, what Barclay wants to say is, we directly perceive the object itself, it just is the bundle of ideas. Now, one way of, as I've said, he gives a battery of arguments, he wants to say that it's

quite impossible for an idea or anything that resembles an idea to exist outside a mind. Now, I think one way of making this vivid is to think of something like a smell. Take the smell of lavender, say. And you imagine not the chemical that causes it in the air. but the actual sensation, we sniff and we get a characteristic idea in our mind. Could that idea possibly exist in anything other than a mind? And Barclay wants to say no. It is intrinsically sensory.

It requires the awareness of it. So nothing that even resembles such an idea could possibly exist outside a mind. We can't even conceive of something like that. Let's just pause for a second. So this cannot exist outside a mind. The smell of lavender can only exist in the mind. Yeah. It doesn't go on smelling if the mind isn't turning it into an idea.

But the point is that the idea is itself intrinsically something that requires a mind to perceive it. Whatever there might be in the outside world, there's no way that that could resemble the... the sensation of lavender, except by actually being sensed. And the same goes for the colour of red. And Barclay wants to say that the same goes also for the primary qualities, the shape and size and so forth,

because he wants to argue that we can't actually conceive of those without giving them sensory qualities. We can't conceive of something round without thinking of it as coloured or having some other sensory quality, such as the qualities of touch. Could you want to take that on, Tom Stoneham, because he summed up much of his thinking in the Latin phrase, if I hope I'm a bit rusty, essay est percipi, meaning to exist is to be perceived.

Actually, Melvin, I hope you don't mind if I contradict you there. Chease me up no end, it means I'll learn of it. He didn't ever actually write that. He didn't. Oh, well. In that case. It's a standard misquotation. What he wrote was of these ideas that we perceive that their essay is Poughkepe.

And what he was trying to say, he was referring back there to the scholastic doctrine of being or essay, that their nature, their very essence, is to be perceived. And he wasn't trying to... So can we start at the beginning, because I kind of foster that up. What mess that up? What is he saying that's useful for how we're trying to drive this through? So if we kind of take the two thoughts that Michaela

and Peter have put forward there. So Michaela was talking about how he describes the object, the apple, as this collection of qualities, colour, taste, smell. And Peter was pointing out how he thinks that each of those individual qualities is something that is essentially perceived. It's its very nature to be an object of perception. It's not something that could have any other kind of existence. And then what he needs to do is to say, that's enough.

That means we have apples. As he said later, I'm not for turning things into ideas, rather ideas into things. So he wants to say these ideas that Peter's been describing, these sensory experiences, they are what make up the real world because they're all that matter to us. They're all that we experience. So an apple just is tastes, smells, feels, and those are things which are essentially perceived by someone. And so what did you say to people who said, hold on, these things are existing, you know what I'm about to say, without you having a central reception of Samuel Johnson. Yeah.

Clicking the boulder and saying, look, that's an object. Well, of course, the Johnson point, that's just another sensory experience. Johnson bruises his toe and he has another sensory experience. He hasn't proved anything beyond sensory experience there. But the people who say, well, they must have some existence when no one's perceiving them. He has lots of responses. he thinks that it's very unlikely no one is perceiving them,

including no animals or God, but he also thinks that if something really, really was unperceived by any mind at all, it wouldn't matter. It wouldn't matter whether it existed or not. It would have no practical purpose. It would make no practical difference. So if it's a consequence

of his philosophy that things really don't exist entirely unperceived, that's not a bad consequence. No one's going to be worried about that. Do you want to take that up, Peter? No, that's fine. I mean, I can add more arguments that he uses against Locke. I mean, there is a well-known parody of Barclay,

which suggests that he brings in God in order to ensure the continued existence of things when they're not perceived. But it's rather dubious this interpretation of Barclay, but it's perhaps worth reciting it. It comes from 1924 from Ronald Knox. I'm ready for the trial, but read it again. The once was a man who said,

God must think it exceedingly odd, if he finds that this tree still continues to be when there's no one about in the quad. How can the tree continue to exist in the quad if nobody's perceiving it? And then the answer is, Dear sir, your astonishment's odd. I am always about in the quad.

And that's why the tree will continue to be, since observed by yours faithfully God. Now, there are some hints in Berkeley that he is using the continuity of things when unperceived as an argument for God, but they're not very strong hints, and it's very debatable whether that's a major plank of his theory. And I told him to Macalah to Masimi to take this forward.

He was ordained in his 20s, and he became a bishop in his late 30s, so God played a part in his life. How did it play a part Peter's begun to hinted it, or begin to talk about, in his philosophy? Yeah, there is no doubt that God plays a central role within Berkeley's system in two different ways. First of all, idealism was proposed as the best antidotes

against the spread of atheism that is so at work in Descartes-mechanical philosophy in the materialism of the time, in the attempt to reduce the physical world to a world of material objects consisting of corpuscles, matter in motions, and nothing but matter in motion.

But he saw the threat of atheism, surprisingly also in Newton, in Newton physics. He was a great admirer of Newton Principia and in several places he refers with great esteem and admiration to Newton. But it was also the one that, in a way, saw Newton's theories about, for example,

absolute space and time as being potentially dangerous in spreading this idea that God is, God, eternity and God omnipresence is nothing but absolute space and absolute time. So idealism was the best antidotes against the spread of atheism, and moreover, idealism was the best argument for the existence of God. So Barclay provided an argument for the existence of God, granted the premise, which is a big concession to make, that we accept idealism. So if we accept that the physical world consists of objects,

and those objects are not material objects, they're not corpuscles or matter emotions, but they are bundles or collections of ideas, then the obvious question to ask is where does idea come from? So they cannot come from material objects, because we just said the whole point of idealism is to deny that there are material objects as the causes of our sensory ideas. Because they don't have thoughts. Yeah, because it basically claimed that matter cannot impart ideas on our mind. That matter belongs to a kind of different realm.

And here Tom and me contradict me. That matter belongs to a different realm from the realm of the mind. So matter can affect other matter, but matter cannot affect the human mind. So ideas can originate. it from material objects, they cannot come from our own mind. They're not figments of our imagination. Our mind doesn't have the causal power to produce those kind of ideas. In a way, they come to us, sensory ideas, ideas of smell or touch, or as Peter would say, the smell of a lavender, they just appear to us. So it's not something that we are produced or constructed in our mind.

So the question is, okay, where do they come from? If they don't come from the lavender, they don't come from our mind, they should come from somewhere. And the answer is, in a way, there has to be a benevolent God that imparts ideas on us. And it is also the guarantor that those ideas are regular, they are ordered, they follow laws of nature, they are not erratic as the ideas that we may have in hallucinations or dreams. So, Berkeley in a way, needed God as the ultimate cause of, the reality of the ideas that we do form. So idealism is the best argument for the existence of God.

Do you want to take that? I know Peter. Would you like to take that on Tom? Tom, Senator, for a moment. I mean, I think that's a very nice expression of the argument. For Berkeley, the beauty of this argument is that the real world consists of these ideas, of the senses, and those are directly caused by God. So we're directly in contact with God.

And you talked about Newton's absolute space and time as Berkeley seeing this as a threat to religion. And it was partly because it distanced God from humanity. And for him, the great attraction of the idealist route to God is that it brings God into our everyday lives. And we have this direct awareness, even though most people aren't aware that that's what it is, of God. Peter.

It's one important point here as well is that that Barclay doesn't think that there's a way out in Locke's direction, saying, oh, the explanation for all this uniformity in nature, for all the systematic patterns of things, is that there are material objects. Because he wants to say that minds are quite unlike anything that we perceive. Minds are active, spirits are active, and that is us, of course, and God. Whereas ideas, the things we perceive, and therefore the objects that we perceive,

we see them to be clearly and visibly passive. They cannot do anything. And it was a slight embarrassment for Locke that he couldn't explain how physical objects cause ideas in the mind. He accepted that it's completely mysterious. Why, say, light bouncing off a particular surface texture should produce in our minds the idea of red. So it's a complete mystery for the materialists,

whereas Barclay can appeal to the active mind of God, directly generating that and because our experience shows us that minds are active he wants to say that it's a much more satisfactory explanation so basically you've got a world which consists entirely of spirits and ideas and the ideas

these passive ideas exist only by being in the minds of spirits briefly Tom yes I just want to add to that point that it's not merely that he thinks a material world couldn't cause ideas in our own minds he challenges that competence of physics to explain how matter causes effects in matter as well. So he doesn't really

think that science and physics have explained the causal relation between material objects. So matter is inert for him as well. He moves from religion, philosophy, to science quite easily and seamlessly in his work. So, Michaela, I'm obviously interested in science and he read a major work, a work entitled On Motion. And he's, as it were, can we get to the cut to the chase as to what he objects to in what, let's stick with Newton. I know it's a Leibniz as well, but I'm afraid it's a bit easier for me. If we stick to Newton, can we stick to Newton? What is he objecting to?

Right. So the text called Demoto was published in 1721 and was originally designed for the Paris Academy of Sciences that was running an essay competition for the best essay on motion. It offers a systematic critique of the two main denies, theories of motion of the time, precisely Newton and Leibniz. And in particular, it offers a criticism of what some scholars like Lisa Downing as called dynamic realism.

So dynamic realism is the view that the world is a world populated by forces, and forces are real causal agents to explain motion, different kinds of motion. So take Newton and Newton mechanics, take Newton's second law, equal I may. In that case, the metaphysical assumption is that there are forces in nature, impressed forces that are the causes of acceleration. If you impress the force on a body, the body will change motion into an accelerated motion. Even more evident, Newton's gravity as an example of a universal force that is the cause of a variety of phenomena from the apple falling from the tree to planetary motions and tides and so forth.

So it was pretty much part of a tradition that really probably stretches back to Aristotle in thinking that it is the job of scientists and is the job of philosophers to investigate the causes of motion. And those causes can be identified with the scientific revolution into forces, into dynamics. Leibniz in Germany made exactly the same point. I published a short essay called the Specumen Dynamicum. And in Specimen Dynamics, Leibniz defended a... elasticity or repulsive force as a fundamental force of nature

and defended the view that in elastic collisions between bodies, say, two billion balls colliding, forces have to be conserved. So the amount of force at the beginning has to be the same as the amount of force at the end of the process. So Barclan deMote is reacting against that view that says there are forces, they are real causal agents in nature that can explain a variety of motion from non-inertial motion to every other kinds of motion like elastic collisions.

And it was defending some in line with this idealism, was defending the view that, well, because motions are just appearances, again, bundles of ideas, forces similarly should be regarded as such. So they are useful tools or instruments that we can use in our natural science, but they should not be regarded as real causal agents in nature. And it was, sorry, and it was raising these two different arguments, one against Newton, gravity was basically unfairly accusing Newton of resorting to, again, occult qualities. This was a classic charge against Newton, and the poor Newton was a pain to defend himself from this accusation.

And against Leibniz, he was branding anti-vitalist arguments. So it was attacking Leibniz view about what is called the now living force, which is the ancestor of our concept of kinetic energy and claiming that we shouldn't really regard matters and doubt with some sort of living forces. Peter Milliken, he was taking on the Great Beasts, wasn't he? I mean, Locke and Newton and sailing in with his own ideas, which at the time, and particularly in America later,

for a while, obtained quite strongly. He had also the theory of the human mind itself. Can you tell us what that was? his theory of the human mind. Okay, so Barclay, remember, thinks that everything that we perceive out in the world consists of ideas. But then there is a question, how can we know about the existence of our own minds? We can't actually form a full-blooded idea of our minds because we don't perceive our minds in the way that we perceive ideas. But rather what he wanted to say was we can form something called an understanding.

notion of our mind. So by experiencing the operations of our mind, for example, willing, perceiving, and thinking, we are aware that there is in us a power to do these things. And that gives us knowledge of ourselves. And one can argue about exactly what kind of knowledge he thinks this is, whether it's a matter of inference, that I see various ideas coming, I'm aware of those ideas, and therefore I infer that there is something that is aware of them, or whether he thinks there's some kind of intuitive awareness of myself. And that's not absolutely clear in the text, but he thinks we know about ourselves in a very different way

from the way we know about external things. Does he think that mind is matter in a way that a tree is matter? Well, he doesn't actually believe that there is... Such a thing as a tree? No. Or such a thing as matter? Can we start again? So we've got this...

I think the easiest way to think of this is he thinks there's this absolute divide between spirits, i.e. minds, and the contents of minds. And the contents of minds are ideas. And they're purely passive, whereas minds are active. And we are aware of the existence of minds by being one, but not in the way that we are aware of external objects. So he doesn't have a... That's as clear as you can get about what he thought the mind was like. Tom Sturman's wagging an index finger, so maybe this is the US cavalry coming here. Well, we can't get that clear because the book that he was going to explain this in was never written.

But... It just gets more intriguing. It does. It does. But I think as Peter's making clear, he's a kind of dualist. He thinks that there is a deep divide in the world between minds and things. The things are tables, trees, and they're composed of the sensory qualities that we experience, the colours, the shapes, the smells, the tastes.

And then there's the experiencing mind. And they're completely different categories of item in the world. It's not a Cartesian dualism. The things that the mind is a substance, not a material substance, a mental substance, but the ideas and the objects that they compose aren't substances. They're just bundles or collections of qualities. like colours, taste, smells, again. So it is a kind of dualism.

Michael, his last major work was a book called Siris, which started off as an advertisement for the medicinal properties of diluted tar. We will pause here, and then it went into religion, understanding and philosophy. Outside the properties of diluted tar to improve your health, I'm sure all our listeners are rushing out. Anyway, never mind that.

What's the after in the world? that book that's important. Right. So this was Barclay last book in 1743 and he was probably one of the most popular at the time. He went through six edition in six months. It was published at the end of an epidemic in Ireland where tar water was obviously in need and Berkeley himself as far as understand was able to produce some and to provide it to his own parishioners. So the goal of the A book is really a chain of philosophical reflections about the therapeutic properties of tar water in treating a variety of diseases such as asthma as smallpox up to lifting the mind and the soul to God. Now, what's the link between those two, very kind of heterogeneous topics that it covers?

The link is the ether, and this is where things get really interesting. This is where Barclay's engagement with the sciences of his own time becomes all the more. important. Barclay believed that both the therapeutic virtue of Tarwater and the general goal of explaining how we can lift our mind up to God had something to do with this substance, subtle, imponderable substance called the ether that was the matter of light but also the matter of fire. And in that sense, it borrows elements from Newton once again, in particular from Newton's optics. So Peter mentioned the optics was one of the most important text of the time. And probably some historians have rightly said that more than the Principia, the optics really

shaped the natural philosophy, both in Britain and in the continent in the first half of the 18th century. And in the queries added to the Latin edition of the optics and the second English edition of the optics, Newton went back to a topic that he speculated about before the principia, namely the existence of this imponderable ether, diffused through all space, being the medium of light, but also the medium of electrical phenomena, thermal phenomenon, and so forth. The view was picked up by several people, both in Britain and the continent, in particular Herman Borraven Leiden, who in 1732 wrote a text called Elementa Chemie, and in that text, Borave believed in the ether as the matter of light and the matter of fire. So we find exactly

that kind of tradition, the speculative experimental tradition of Newton and Borave in Sari's as a way of explaining both God's presence in nature and the medical virtue of tar water. Peter Milken, what other impacts did, and how great was the impact of Berkeley in his own time? Well, one point that has briefly been mentioned earlier

is that Barclay's ideas were rather in the air. You had other immaterialists as well, a chap called Arthur Collier, for example, wrote an immaterialist treatise shortly after Barclays. And there were philosophers like Malabrash and his followers who were occasionalists, their view in many ways rather similar. So Barclay, I think his most distinctive influence during his lifetime, because he was often seen as an object of ridicule in Britain,

as we saw with Samuel Johnson. I think his biggest influence was on David Hume. David Hume used quite a number of Barclay's arguments, in particular the argument against abstraction. He wanted to say it's not possible to abstract away from your experience of, say, a red rectangle. It's not possible to think of the rectangularity without the redness. And therefore, since the redness is acknowledged on all hands to be something in the mind, not in the object, therefore the rectangularity can't be in the object either. Now, Hume uses this argument quite a lot,

but his reaction to it is rather interesting. And there's an amusing thing in one of his indexes where he has an index reference to Bishop Barclay, a sceptic, which Barclay, of course, would have hated. And he says, Barclay's arguments admit of no answer but produce no conviction. So his attitude towards Barclay's argument, seems to be rather ambivalent,

but he was clearly impressed by the logical force of Barclay. Tom Sturton, was it thought at the time that his, with the increasingly non-religious nature of philosophy, and that his religion, Barclay's religion was getting in the way of his thinking? I don't think so at the time. I think most of the respect he had in his own time was for his religious writings and his defence of Christianity. I think later, as philosophy became more secularised,

people have struggled to find ways of interpreting the philosophy with less religion in it. And in particular, we mentioned earlier the arguments for the existence of God, whether those really get you to a Christian god or something more deistic. But I think his legacy as a philosopher is the clarity and beauty of his arguments and the incisiveness of the critic.

of the materialist views that he's attacking. His work on vision continued to be influential and was influential in the Scottish Enlightenment with Thomas Reed and the other Scottish Enlightenment philosophers. So there was a continuing influence. And by another route, which you haven't got time to go into, he gave his name to one of the great universities in America, of course. Of course, and endowed quite a large endowment to Yale.

Yes. Why, briefly Michaela, I'm sorry, why did he fall so much out of favour? Peters used the word ridicule. Why did he fall so much out of favour? I think it's fair to say that the reception of his work was really twofold. So as we just heard, the reception of his scientific work was actually very positive. But the first reviews of the principles of human knowledge were scathing.

And in the journal de Savan and journal literary people accused the Berkeley of sliding into some dangerous form of panty. and believing that everything exists in God's mind or that somehow the world reduces to some sort of spiritual entity. In 1733, Andrew Baxter wrote an essay where he basically said that if God is the source of our sensory ideas, therefore God should be also the source of our sins and wrongdoings. So there were some serious allegations being brought forward to his view. At the same time, I think it's probably fair to say

that unwittingly Barclay put on the table a view called the idea, that was bound to stay for philosophy. And 70 years later, one of the greatest philosophers of his time, Emmanuel Kant, brought the text called the Critic of Pure Reason, where he proposed a view that he called the transcendental idealism. Transcendental ideas is very different from Berkeley's idealism, but it's just to say that it's thanks to Berkeley that the word idealism became common currency in the early modern period.

Well, thank you very much, Michaela Massimi, Peter Milliken, and Tom Sternman. Next term, next week we were talking about the Protestant work ethic as proposed by Max Weber and thank you very much for listening The In Our Time podcast gets some extra time now with a few minutes of bonus material from Melvin and his guests What do you think we missed in that? It's all right.

It's a bit more of Newton and also I think we missed abstraction and why you might think he's not an empiricist. Yes, but we probably wouldn't have had time for that. No. I know the problem is we've got 43 minutes, not the problem is sometimes. But do you think the missing of Newton was a... You would have liked to talk more about Newton?

But you had a chance. There were a couple of questions in there where you could have got... I said something about Newton, but there was a lot more to be said about his criticism of Newton. So, for example, the philosopher of science, Karl Popper, so Berkeley as a precursor of Ernst Mac. And Harris Mac wrote a text at the end of the 19th century that is regarded as anticipating somehow Einstein-relathinge,

in some key ideas. So there's a famous criticism of Mac. The Mac launches against Newton in a bucket experiment that you can find actually already in a way with suitable caveats and qualification in Berkeley. So it's all reaction against

Newton absolute space and absolute time has been read by someone like Popper as important for the history of physics. So the other side is what do you think we got over? Are you got over? You three? Got over. what did you manage to say that you thought was important to say?

Most of it. The radical nature of the view, I think. I think, and some of your puzzlement, Melvin, was because of the radical nature of the view. It's very difficult to get your head around this. Because it looks like he's saying, which kind of trapped in our minds, this jump, if you see him as,

he starts as a criticism of Locke, who says material objects cause these experiences, He drops out the material objects. It looks like we're just trapped in the subjective. And it's trying to see that he's got a bolder view than that, that he wants to say, actually those things that Locke thinks of as merely subjective experiences are actually the elements of the real world. I'd have liked this of a description of what you three think of is an idea.

How would you describe an idea? I'd have felt an a bit more solid ground if I'd know what you meant by idea. It's a famously ambiguous term. Yeah. And Locke is... We didn't even get to ambiguity. We just get to me feeling, where am I with this notion of the idea of the idealist? But bear in mind that if you're an empiricist, again, you are going to equate thinking with perception.

It's going to be like a kind of weaker, less vivid perception. And that means that it's not so inappropriate to use the same term for perception. that you use for thinking. It's very controversial, of course. Most people now probably would not have much truck with that, but at the time it was absolutely a standard view. I mean, I think there's a good question, and Barclay does appear occasionally to reflect on this,

why he uses the word idea at all. And I think as a young man, he did it because it engaged with a tradition, that everyone had been writing about the objects of experience as ideas, and he wanted to tap into that tradition of thought. So you think the big thing was not... Because he's saying about gravity, as I understand it, that gravity is... Marvel, all the superlatives you want.

System of mathematics, but to imbue it with further meaning is not on. It's an instrument for understanding the world, not the understanding of the way the world works. Yes. But does he not... Is he not a religious objection, or does it come out of what you've been talking about,

of his idealist objection, which not is it? Right. I'd say it's actually just pure philosophy of science. He's thinking, what is the purpose and function of all this scientific inquiry? And why do we build scientific theories? We build scientific theories, like the theory of universal gravitation, in order to help us do things, to make things, to predict things. And so that's where all the reality lies in those experiences we predict, in those objects we make.

and the rest is just a theory to get us then. One interesting point here with gravity. Gravity was considered a real problem in the early modern period because you had philosophers, going back to Galileo, Descartes, and Boyle, very notably, who thought that mechanical interaction, one thing bashing into another and making it move, was uniquely intelligible to us.

And then along comes Newton and postulates this gravitational force, and everybody says, well, that's mysterious, that's not intelligible, that looks occult, the term that harks back to Aristotelian theories. If the moon is attracted towards the earth, then the moon would have to know where the earth is, and that's spooky. So we don't like that. Now, the interesting thing is that Newton's reaction to this was to say, well, the equations work, it produces useful results, I'm not going to worry about what the cause

I'm going to use it as a theory to do my science. And in a way, Barclay is exactly in that spirit, except he applies it to all of science. There are many more Radio 4 arts and discussion programs to download for free. Find these on the website at BBC.co.uk slash radio 4.