Metaphysics and Epistemology

Metaphysics and epistemology, metaphysics is the study of reality. It deals with questions like what is there or what exists, if that's actually a branch of metaphysics called ontology. I think you've probably heard me mention ontology for no ontology. Is your your ontology is your list of what exists. So who believes in ghosts? Couple of people. Okay, well, on your ontology, you have ghosts. If you believe in gods on your list of what exists, you have God.

If you don't believe in God, on your list of what exists, God doesn't feature. And if you don't believe in ghosts, ghosts won't feature on your list of what exists. But chairs probably would lecturer's probably would necklaces, things like that. Probably feature on your things list of things that exist. So metaphysics looks at what is there in the world and what is its nature.

Because once you've postulated the existence of something or decided on the existence of something, you have a further question to ask. Well, what's it like? So, for example, I told you that Heraclitus postulated atoms more than 500 years B.C. Well, he didn't know what they were like, except that by definition, they were the unknown splitter balls. Okay. Because an atom was as far as you can get, an atom of water is as far as you can go.

Sorry. No, I'll have the woolston here, please. I don't want them to drink it. That's it. Just stick it down on the floor. Are. Yeah, exactly. Look, here they are quite a few atoms of water on my finger. But at some point you'll get down to something such that if you go below that, it won't be water, it'll be CO2, it'll be a molecule, but it won't be water itself because you'll have gone too far for it to be water.

So you postulate the existence of atoms for whatever reason, it could be as a theoretical entity. So some people postulate God as a theoretical entity. How do we explain all this? We need something like this. Let's call it God. Okay, so how do we postulate this? We need something unstable. Let's call it an atom.

And of course, you might when you actually because once you've postulated the existence of something and you have some idea of what it's like, you then want to find out more about it and you want to say if you're right to think it exists. So, for example, the Higgs bows on. We have reason to think it exists. We have various ideas of what it's like, which I won't go into because I don't know enough about them.

We believe in its existence enough to spend millions on this Large Hadron Collider in Switzerland. But when we actually find it, if we actually find it, then we're going to know more about it. And that's what we're doing. We've postulated it. We said this is on our list of things that exist, at least as a hypothesis. Now we want to test that hypothesis and see whether it's true. So metaphysics ask questions like what is that and what is its nature?

Now, obviously, many of these questions are questions of science. So the Higgs goes on. Does it exist? What's it like? These are questions for science. But questions like causation. What is causation? Does causation exist? Causation, the relation between cause and effect? That's not a question for science. The scientists must assume that causation exists. Philosophers ask, does it? And what's the nature of causation?

Could causation go backwards? For example, could there be a cause that happens after its effect? Is causation a relation between events or between objects or between facts? Or what are the relator of the causal relation? So these are all questions of metaphysics and epistemology, on the other hand. Is the study of knowledge. So there's a big difference between what is the case and what we know or can know to be the case.

There may be things that are the case that we'll never know. And I've mentioned three consecutive sevens in the decimal expansion of PI before. So what do you know? And what is the case? You hope that's what two if you knows? Well, actually, if you know something, it must be the case. But what do you hope? Is that what you believe, you know, is actually the case? But the study of what is the case and what you know to be the case are two different questions.

One is to do with metaphysics, the others to do with epistemology. So epistemology looks at what can we know? Can we, for example, know that the sun will rise tomorrow? Do you remember when we were doing logic? We looked at induction. Can we know it? Well, we don't know for certain. Must knowledge be certain knowledge? Or could it be the case that we know something that we don't know we know. Do you see what I mean? What is knowledge like? So actually, I should put that here.

What is knowledge? What can we know? And how can we know it? So, for example, if there are moral values and we do not know it by sensory perception. I never see. Right and wrong. Certainly not through my eyes or through tactile sense or anything like that. So there must be some other way. How do we know that two plus two equals four? Again, you don't see that that's the case. How do you know that all swans are white?

I know they're not. Well, let's pretend for a minute. How do you know that all Ravens are black? That's a better one. Well, let's forget albino ones. I know what you're like. I could see you thinking that. How do we know that, given that if you if you're going to say that all Ravens are white, you're talking about all Ravens, even the ones that you've never seen, even the ones that nobody has ever seen, even the ones on Mars. If there are Ravens on Mars, you're saying all Ravens are black.

Includes those Ravens on Mars. Well, how can you know that? Do you see what I mean? So there are two different questions as what is. Knowledge in the first place. Must we know that we know something? Or can we know something that we don't know that we know? What's it got to do with justification? What's it got to do with belief, cetera? And how can we know these things? So that's the distinction between metaphysics. Metaphysics is to do with truth and what is the case and what's its nature.

Epistemology is to do with knowledge, justification, belief and how we can know whatever it is that we do know. So that's that's the main distinction, which is Paul myself, CMH to. What did I say? I said, remember that, right? I heard myself saying something false. Well, right, okay. Let's look at ontology. The study of what there is or what exists.

Okay. One question I said earlier that there are many things that questions of what is the case and what is its nature that ask questions for science. But questions like, does God exist in the God delusion if any of you have read it? Richard Dawkins claims that this is a scientific heighth hypothesis. Like any other. Well, if that's true, it must be possible to conduct experiments, observations in order to determine the existence of God.

I have no idea what experiments or observations he has in mind, but I actually don't think this is a question for science. I think Dawkins is wrong to think this is a straightforward scientific hypothesis. I think this question for philosophy, there are evidence are reasons for thinking God exists. Take the form of arguments rather than evidence or observations. So, for example, the most obvious argument is, is the one I used earlier.

God is a theoretical entity. He's postulated to explain the existence of the universe. Okay. That's the simplest arguments. It's the argument that people have used from the beginning of time. Other people use different arguments. For example, the moral argument. You don't need God to explain the existence of the physical world. But how come there exist people like us who are capable of rationality, who reason, who have freewill, who make choices, and in particular make moral choices.

People like us who value things, who see right and wrong, good and bad, beautiful and ugly and things like that. Physics can't see right and wrong, good or bad, etc. This is not the sort of thing that physics or any physical science can investigate. But you might think that God is the explanation for the existence of things like that. Or you might deny that. You might say, no, you don't need God to explain right and wrong. You can easily explain right and wrong by appeal to evolutionary biology.

So altruism is is a question of either kin's support or if I scratch your back, you'll scratch mine, etc. So if you look at Dawkins chapter, I think it's four, but I may be wrong about that. He offers four or five arguments for how you can explain morality without God. So does God exist. Lots of different arguments for the existence of God. Lots of different rejections of those arguments. Lots of different comebacks or those rejections.

And philosophers are going to have a job for at least a couple of hundred years. I think I think the God Delusion is far from the final word on it. But there are other questions like that. That's a biggie, obviously. But there are other beings. Do moral values exist? It's there right and wrong. Doug does. Right. It's a really a property of an actions being right or wrong. Or can we reduce the idea of being right to something? Some people would say natural like happiness.

So the Utilitarians want to reduce happiness to the sorry that reduced right and wrong to the idea of the greatest happiness of the greatest number. So there's no more to right or wrong than how many people you make happy by an action that you do. Now, what you're doing there is you're reducing one thing to another thing. So here's something we don't understand right and wrong. And we think that it needs an explanation.

And we attempted to postulate God for it, maybe. But on the other hand, if if we can say, well, actually, we don't have an explanation for that, but there's actually no more to that than this in particular combinations. And we do have an explanation for this, or at least this is something for which we can think that there'd be a much easier explanation than God. So on the grounds of Ockham's Razor, given two explanations, both of which work you always go for the simpler one.

If you can explain happiness and you can reduce morality to happiness, then you haven't got a problem with morality. You don't need to postulate God. See what I mean? So you might I mean, some people try and reduce the idea of gods to. I mean, actually, Dawkins, again, does this. He thinks that God is the idea we all want for security for a. Father figure something to rely on. And so he's reducing gone to that the utilitarians try and reduce moral values to happiness.

Count, on the other hand, isn't a as he thinks right and wrong exist that the moral law exists in and of itself and that it's quite different from anything else. So if you remember last week, for Kant, a moral action is an action that's carried out because of reverence for the moral law. It can't be said to be anything else. It can't be said to be something that just as a matter of fact, produces the greatest happiness of the greatest number.

And reverence for the moral law, says Kant, is not something you can reduce to anything else, something easier to understand. Another example of this would be mental states. I thought I was going to come to mental states, but I say it's not on this or I'll put it in any way I do. Mental states exist. Well, what our mental states? Well, mental states divide into two. There are the so-called prophets propositional attitudes.

So attitudes to propositions, things like beliefs, you can't have a belief unless it's a belief about something, can you? So I believe that some is wearing sort in the room. Right. I believe and is wearing maroon. I believe when Ali's got a necklace on somebody who's got a lovely pink jumper on just in front Bhanot future sort of colour. Okay. All of those beliefs have a content. But there are other propositions, propositional attitudes.

So I can have a desire towards the same content. Desire is a different attitude. But I could have the desire that Anna's wearing a necklace or I could wish that Clark and is wearing is also named. That is wearing maroon. I could also intend that I was wearing maroon. I could set out to make sure she wears maroon today. So I want to use her as an example.

So these are lots of different attitudes to contents and you can get the same match tude and different contents and the same content and different attitudes. So that's one type of mental state. The so-called propositional attitudes. The other type is the so-called qualitative states. So when I looked at this lady's lovely future coloured cardigan, I have a certain experience. Okay, there's something that it's like for me to see that cardigan.

There's something that it's like for me to see these chairs. There's something it's like for me to be in pain or to feel a tickle or something like that. And these are qualitative states. There are states that have a quality to them. So I'm sure you can do your own rough and ready distinction now into states that have a certain raw feel to them. And states that are attitudes to propositions. Why do we think these exist?

Well, how could I possibly explain your behaviour without citing desires, beliefs, intentions, hopes, fears? You know, why did she suddenly get up and leave the room? Answer because she suddenly realised it was the wrong lecture. She suddenly realised it was the wrong lecture. So she had a belief about what the right lecture was. She suddenly came to believe that this was the wrong lecture. So she formed an intention to leave the room.

So in order to explain your behaviour, I postulate all sorts of beliefs and desires. But there is another little story woodlice. Why did woodlice congregate under rocks and things? Tell me it's dark. Why? Why do woodlice congregate where it's dark? Because they want to be safe. Or something like that. Okay. And they believe it's safe under rocks. Okay. You're a bit reluctant to attribute beliefs, so you don't give my story.

Yep, absolutely. Okay. When we first year last and certainly if we're speaking to a child or something like that, we would use belief, desire, psychology to explain woodlice behaviour because that's what comes very easily to us. So woodlice believe that it's safe under rocks and they want to be safe. So they intend to go under rocks.

As a matter of fact, the correct explanation of woodlice behaviour is that they embody a mechanism such that when it's dry around them, they move and they move in a speed that's determined by. How dry it is around them. And as it gets damper, they they come to a halt and instantly they move in whatever direction they happen to be pointed. They don't sort of turn around and make for that rock. If they're standing in that direction, there's rock over.

They'll they'll go for that one. Except they're not going for that one, are they? They're being pushed by the dryness. Now, once you know that explanation. I got it right. That's right. I wasn't going to use technical terminology, but they are. OK. So that's the proper explanation. Would last behaviour, once you know about Cannis, is like this. You can explain the behaviour of any woodlouse anywhere at all as long as it's a normal woodlouse, anywhere at all, at any time.

Once you know that belief desires have been made redundant, suddenly, you know, why should you postulate woodlice, beliefs? Now, woodlice, desires. In fact, all their behaviour is explicable in terms of things like like kinases. They're not all countries, but they're things like that. What about your behaviour? Can I explain your behaviour? Well, a lot of your behaviour, I can't explain. If I cheque my chalk at you. That shows how old I am. And if I cut my chalk, you're going to duck.

That's not a desire or belief driven behaviour. That's just a hardwired response to the fact you see something coming towards you. If you put your hands on a hot plate, do the same thing. So lots of your behaviour and that's just one. If you hear an ambulance coming, you'll move out of the way. That's a classically conditioned response. Lot of your behaviour doesn't need to be explained by appeal to beliefs and desires. But much of it does. And this is why we postulate beliefs and desires.

This is why we say that beliefs and desires exist. But perhaps ethologists, people who study animal behaviour are going to find out one day that we can explain all our behaviour in terms of brain states. And it might be that we can one time in the future will be able to soar off the skull of newborn babies and fitter perspex dome instead so that we don't have to go in for all this interpretation, which we're actually not very good at, is trying to find out what we're all going to do instead.

We can just look at somebodies brain and say, ha, okay, I know what you're going to do. Perhaps we'll all where woolly hats so we can surprise people or something like that. But do you see if we can explain all our behaviour without appealing to beliefs and desires? No more. Have reason to think you had a mind than we do to think woodlice do. So again, the question do mental state sexist is a huge question.

Lots of people try and reduce mental states to physical states and then explain physical states that it's much easier to explain physical states, the mental states. But if you don't want to be a reductionist, if you want to say you cannot reduce mental states to physical states, and there are all sorts of reasons to think you can't, then you're going to have to postulate mental states. You're going to have to postulate contents and qualia.

And the minute you do, you're going to have problems with with functionalism, with physics, being able ever to understand mental states. And, my goodness, you might end up having to postulate God or something again, or maybe not. We don't know. So, again, the question is, what is this? Does it exist at all? If it does exist, can we reduce it to something else? If we can't reduce it to something else? What is its nature? Here's another one.

What about possibilities? OK. I might have been wearing jeans, mightn't I? OK, that's a possibility. But what's more, it's a possibility. That's actual, isn't it? It's an actual possibility. Well, what is a possibility? What's the nature of a possibility? It's not something that actually exists, is it? OK, so maybe we've got to postulate a different sort of existence.

Now, there are things that actually exist and there are things that possibly exist and there are things that don't even possibly exist. So there are square circles don't even possibly exist unicorns. Might they exist or not? Marianne's wearing jeans certainly is an existing possibility. Do you see what I mean? You're now getting layers of existence, different levels of existence. Well, in that little kitten on the floor down there, is it fat? You all looked you understood what my words were.

Do you need to postulate a little kitten down there in order to give meaning to my words? Some people have thought that if you do, then that little kitten exists. But it doesn't exist like. And does. So you need, again, another layer of existence. Well, some people have said that it's not really existence, let's call it persistence instead.

But but the thing is, you've got to say, if you say that every day in order for you to understand the meaning of that little kitten is fat, there needs to be a concept of a kitten or a kitten or some. You know, there's a kitten that gives meaning to the words, but it's not an existing kitten like the kitten that some of you may have at home. So it's a persisting kitten or a an imaginary kitten is another way of thinking about it. But do imaginary kittens exist? Well, do they in imagination.

There you are. There is another way of thinking of it. So its existence, different types of existence. There's existence in the real world and there's existence in your imagination. That's existence in novels. I mean, when when it comes to this little kitten down here, it could be black ginger or anything. Couldn't it? I haven't told you anything about what it's like, but we all know that Sherlock Holmes wore a door. I didn't mean to do something like that, wasn't it?

OK. So they've got, again, different levels of existence. We all know that unicorns have horns. Well, there aren't any unicorns. Well, how can unicorns have horns if there aren't any? Do you see any way? So do possibilities exist? It is a really difficult one. That's the sort of thing that leads people to postulate the existence of possible worlds. And I think I've mentioned possible worlds to before. Lots of people postulate possible worlds, but they're not realists about possible worlds.

Mathematicians, logicians, physicists, many of them all. All those disciplines postulate possible worlds. Not all people in those disciplines do. But if you postulate possible worlds, you can see possible worlds as reducing to possible situations in this world, or you can see possible worlds as real. And David Lewis, very famous philosopher, postulated the reality of possible worlds. And he said, well, I've never really had a very good argument against them.

I look at blank astonishment. Doesn't count as a as an argument. What about physical objects? Well, you might say, well, obviously they exist. You know, how can I deny that that exists? Okay, well, let's do a Cartesian thought experiment. In fact, let's do the Cartesian thought experiment. And I have some water. Descartes was interested in the facts that we know that some of our beliefs are false. But in the very nature of things, we don't know which those beliefs are.

You see what I mean? Would you like to tell me for sure that all your beliefs are true? Right. OK. What about you? Oh, no, it isn't. No, no. A lot of your beliefs are false. I guarantee if you believe it, you believe that it's true. That doesn't make it true, does it? No. I mean, you believe it's true.

Exactly. But this is the problem with beliefs. Every belief you have, you believe it's true because that sort of belief is to have the attitude of belief towards a particular content is is to assent to, as philosophers would say, that content. So in believing that this chair is blue, there's the content. That chair is blue. And I assent to it. I say, that is true. That's what a belief is. But of course, I may be wrong. I may be colour-blind or something like that.

Well, given the circumstances in this case, I probably would say I know. But the fact is, let's not bother about that. I was just offering that as a bit. But you have beliefs about a lot of things. The question is, you know that many of those beliefs are false. But you don't know which they are. And in the very nature of things, anything that you believe, you believe to be true, because that's what truth is.

You cannot have a belief that you don't believe to be true. But you do know that not all your beliefs are true. Well, Descartes became very interested in this. And he said, well, what I need to do is I'm going to take myself away from the world in the world. We have to assume that our beliefs are true because we have to act on them. So in believing that she has blue, if I'm looking for something to match it, I'll go and look for something blue.

OK. We have to act on our beliefs. He's going to put himself when think, OK, how do I know that my beliefs are true? What is it that justifies me in believing that my beliefs are true? And he thought the method I'm going to use to do this is to treat as if false, any belief I can entertain the slightest doubt about. So if the belief that I believe to be true could be false. I'm going to put it on one side as if it really is false. And by that means, hope to find something that I can.

That is absolutely certain. And from that, maybe I can build up the rest of my knowledge. So it's a bit like, you know, some of the apples in your baskets are rotten, but you don't know which they are. So you take each one out. And I need that's a little bruised. You put on one side as being maybe that's rotten. And you hope to be left with only the good apples in the basket.

So Descartes wanted to look at his beliefs and say, if there's any about which I can entertain the slightest doubt, I'm going to treat it as a false. OK. So he's not saying that his beliefs are false. He's saying it's as if they're false for this. So first, he went down three levels of doubt. The first one was the argument from illusion. OK. The argument from illusion tells us that while our senses of deceived us. I expect all of you have been deceived by your senses.

Sometimes you've got home that wonderful skirt that you thought would go so well with that blouse, and you've got the colour wrong. The lights in this shop were the wrong colour or something like that. We've all been deceived by our senses at some time. Well, if we've all been deceived by our senses at some sometime. Should we take all the beliefs that we base on our senses and put them in the doubting basket? Treat them as if they're false. Should we? If our senses has deceived us.

Should we treat all our sensory beliefs as false? OK. Put your hands up if you think. Yes. OK. Put your hand up and think. No. OK. Now tell me why you think no. Why must I be that possibility? Oh, no. Well, hang on, we've got two lots of Carns no's here. That's what we're suggesting, is that your sensitive sometimes deceived you. Does that mean you can never be sure that your senses are not deceiving you? Now. No, you can't be sure. So sometimes we do trust our senses, don't we?

I mean, as a matter of fact, how do you know that your senses have deceived you? Well, hang on, you experiment, you prove it, how how do you do this through your senses? Can you give me an example? Possibly not. Woo! Yes. Yes. Good one. Okay. So your belief that it was heavy. Although that's actually not a sensory belief properties. It is. No, no, but it's not. When your belief that the frying pan was heavy, you can't really look at a frying pan until it's going to be happy.

Maybe you can. Maybe. Let me give you Descartes own example, because I think it's a it's a good one. Day, Descartes said if you put a stick in water and it looks bent. Okay. You've got reason for thinking that stick is bent. You take it out of water, move it straight. You've got reason for thinking the stick straight. Well, okay, there are two possibilities. Maybe when you put the stick in water, it bends it. Or maybe it just appears bent. So how do you test this?

You put your hands in the water. You feel sick. When it's under water and low, it's straight. Okay, so you've now got two reasons for thinking the stick straight and only one. But the thing is, you couldn't even know that your senses were deceiving you unless you rely on your senses. So all we got to hear from the argument from illusion is that we know that not all our sensory beliefs are true. Not all our sensory beliefs are true.

Sometimes usually in an unusual psycho optimal conditions or maybe not unusual, but not perfect. Psycho physical conditions or sensory beliefs deceive us. But you can't go from the universal possibility of illusion to the possibility of universal illusion. If you want me to say that again. No. Oh, I might say that. What did not you say? It's gone. Thank you. Thank you. You cannot go from the universal possibility of illusion to the possibility of universal illusion.

You with me. Okay. So all those who said no, you're right. We do know that our senses sometimes deceive us. But that doesn't tell us that we. We can put all our sensory beliefs into the doubting basket because we would never know that our senses deceive us unless we rely on our senses. So that's the first and second argument. Descartes went to lose the arguments from the demon, the demon argument, rather the argument from the dean.

The dean, sorry, a dream. And anyone who knows what they're talking about will know that I'm talking rubbish. Second one was the dream, the argument from dreaming. Okay, so you're sitting here, you're in the fire, you're the lights are on. Everything's fine. You're looking at your hands in front of you. How can you doubt that your senses aren't deceiving you now, are they?

But on the other hand, says Descartes. Have you ever been in a situation where everything seems to you to be a certain way and then you've suddenly woken up and found it wasn't that way at all? So it looks as if all the sensory evidence is in. And yet you're still wrong. Your belief is false. So you believe that the hand is in front of you. It's exactly with you as it would be if your hand was in front of you, but your hands not in front of you.

It's a matter of fact, you're dreaming. Okay. Does that mean we should put all our sensory beliefs in the doubting basket? Put your hands up if you think. Yes. Put your hand up if you think. No. You're beginning to get this now. You don't mean like some you sort of jump. Sorry, I've picked on you and you don't have to. OK. Would anyone else like to answer what? Why can we not put all of sensory beliefs in the doubting basket now?

Because we wake up and what does that tell us? That we're not always asleep. Exactly. That sometimes our beliefs are true sometimes. And I've got my hand in front of me like that and I'm thinking my hands in front of me. I am awake. And the reason I know that is because if I didn't wake up, I couldn't know I was dreaming. So it's exactly the same structure of arguments as in the first one. But what if we got rid of all sensory beliefs that are formed in optimal psycho physical conditions here?

Here we've got rid of a lot more, haven't we? Why do you got to. Well, it's a contrast, isn't it? Yeah, right. But but in order to know that they are like that, they must have woken up. Well, OK, but but with you, I'm quite sure you've had lucid dream once where you've had the dream and suddenly you're broken up and you thought, wow, you know, who could have believed that I was dreaming? Sometimes you can know your dream, but it's the lucid dream.

That's that's good for this one. But what have we lost here? What's in the doubting basket now? Instantly. There's nothing I want you to notice that lots of people think. I mean, it's hell sheer hell. Being a philosopher is a party because when people find out you're a philosopher, they're going for little games like, oh, good. Tell me that this exists. Does this exist? What? And you say something and they say, oh, no, it doesn't.

Tell me how. Tell me how. And they're playing a sort of sceptic's game that's extremely irritating. I hope none of you ever played. Descartes found reasons for doubting everything. He didn't just doubt. He took beliefs he believed to be true. And he looked for a reason to doubt them. And it's only when he found a reason to doubt them that he put them on one side. So he wasn't just doubting. He wasn't playing the skip the sceptics game.

He was actually looking for reasons to doubt. So what have we lost here? What's in the doubting basket? Once you've got the argument from dreaming. Well, no, because when you are, you know that sometimes your belief that a hand in front of you is correct is true. So you don't you don't lose that. You do sometimes see your hands in front of me. But what do you lose? No, no, no, we're looking for certainty, we're wanting to know what isn't certain as a result of this, some things are left certain.

I mean, it's left certain, for example. Well, okay, I'm asking you that. What is left certain? That's when you are awake. Your jury, your beliefs, your sensory beliefs, if they're formed in an optimal psycho physical conditions, are true. You still got no reason to doubt that. It's just that you can say that unless I know I'm awake, I cannot know for sure that there is a hand in front of me. Okay. Do I know that I'm really awake? Answer no, I do.

Because I could be having a lucid dream, but I do know that hands exist and that I can see them and that chair's existence, that I can't see them. Or if you do not like that. Because I can. In our dreams, we sometimes put together things in strange ways. I can know that blue exists. So you can go to simple things horses, horns, whiteness, things like that. The simple things from which we build up complex things.

I know that they exist. So we're losing something of the world here, but we haven't lost the whole world yet. There's still an awful lot that we know. I don't know anything to be true. Now that I do have reason to believe that it is true.

If it is true, sometimes I went either way and I have these reasons to believe things, but that we get down to the demon argument and that the demon argument, Descartes says, okay, well, I'm assuming on time that these experiences that I have as of my hands and of blueness and so on, I'm assuming that these experiences are actually caused by something outside myself and that the experience that I have is is a guide to the nature of the cause of these experiences.

So my experience of blueness as of a blue chair is causing me to think that that experience is being caused by a chair that's blue. And you've got a problem here because. In order to know that A causes B, you've got to be here, haven't you? You've got to see a correlation between A and B in the same way to know that A resembles B. You've got to be able see both A and B. But are we ever in this position with result? With respect to our experiences and the causes of our experience?

Never. We're always here, aren't we? Leave enough room for my arrow. We experience the world, if you like, through our experiences. We can get outside experiences to see what the world is like, to see what's causing these experiences. So it could be that our experiences are caused by something completely other than we take them to be caused by. So here's the demon or I know it looks like a cat, but it's a demon.

Okay. A demon opens up a gap between our experiences themselves and the causes of those experiences. And it's actually says, how do we even know these experiences are cause? Why aren't there just experiences, one following the other, following the other, following the other? And there's nothing out there at all. And actually, Descartes at that point says, I can't do this. I'm going to put the demon there because I can't. I find it impossible to believe there's nothing other than my experiences.

But I can think that there's some cause of my experiences, which is completely other than I take it to be. And some people have tried putting evil scientists in here. But that doesn't work because an evil scientist isn't magic. What you're trying to do, the demon is just there because it's impossible to imagine that your experiences don't have causes at all. So you're putting something there so that there is a cause, but the cause is completely other than you take it to be.

He didn't panic for that reason. No, he just literally couldn't wrap his mind around the idea that there's nothing outside causing your experiences. You try it. It's really very difficult to to get yourself to the point where you understand that there might be no physical world at all. Your experiences could be exactly as there are as they are, even though nothing else else exists. So all there is is Anne's experiences as of Marianne giving a lecture in philosophy.

There's no Marianne, there's no philosophy, there's no lecture. There's no blue chair. It's it is a frightening experience. Yeah, but it's nothing to do with God. It's. Yeah. Yes. Okay. But but this is a different thing because it's it's not worrying about that sort of thing. But it is a worrying thought. I mean, we want our beliefs about the external world to be true, don't we?

And yet what's happening is that we're discovering that what Descartes said was that actually once you've done this thought experiment, you realise that there's the world. And there's your picture of the world. OK. All your beliefs that you've formed about the world and you go through the world updating your beliefs all the time. But once you've retreated into your picture of your picture of the world, which should be here, run out of room.

The world actually becomes unnecessary because if all there was was this, you couldn't ever get outside to see whether this is there or not. So once you've pushed yourself back into a reflective position, you see that the world that you picture is quite different from your picture of the world and that your picture of the world could be exactly as it is. Even though the world was completely different. And that's the Cartesian thought experiment. That's hyperbolic. All doubt at this point. You.

You've started the question of how could we know? I mean, we do take ourselves to know that there's an external world, a physical world out there. But what sort what possible justification could we have for this, given that all we can do is go and look for more experiences? And our experiences are exactly what we are asking. Are they caused by something? And if so, what? I can't step outside my thoughts. It's of course, no scientific experiment is going to tell you the answer.

Between all my experiences caused by an external world or are they caused by an evil demon? There's no I can't go down and say, oh, is it a chair? But yes, here we are. It's a chair. Why can't I do that? All I'm doing is giving myself more experiences on time. I'm now having a tactile experience as well as a visual experience, and there's an auditory one there as well. But I mean, they're only more experienced, aren't they? You.

On. I'm having another experience at this moment. It's an auditory one, as you know. It's as all someone what they do. But no, no, hang on. You haven't got yourself into hyperbolic all doubt, Hashi. Why hasn't she got into hyperbolic out? Yes. She said no. She still thinks that I should think that she exists. I have not. I have very good reason to think I am having experiences as of a female wearing maroon sitting in front of me who is speaking to me.

But these are just more of my experiences, aren't I? I can no more get outside my experiences to cheque whether ands really there and whether she's really telling me what I think she's telling me that I can to see whether the chair is there. All I've got is more experiences. So all I've got it is more of this here. And I still haven't got this. Which is what I need. So there's no point in looking for corroboration, which is why there can't be any scientific way of testing.

Which hypothesis is true. So here I have my experience, the external world of those I can be certain. Okay, I aps I'm absolutely sure now that I am having experiences as of a lecture theatre, etc. What I want to know is all those experiences causing me to form beliefs that are true. I there is a lecture theatre. Now notice the difference between I believe there's a lecture theatre and there is a lecture theatre. The latter is metaphysics, isn't it. The former is this symbology.

I can be certain of the former. I can be certain of my own beliefs, but I can't be certain that these beliefs are true. Can I? And it's at this level of hyperbolic all doubt, at the third level of doubt that you start to wonder. Do physical objects exist at all? Interestingly, Descartes thought that you could show that they did. Descartes wasn't a sceptic. Lots of people think he was. But in fact, he wasn't. He did this sceptical thought experiment in order to pre-empt scepticism.

He ended up believing in the existence of a physical world, but he thought it was necessary to believe in God first. He did. That's right. Coquito ergo sum. And the reason he did that. Can anyone think why he did that? Thinking of what I told you.

What's that? Oh, yes, that's right. Once you've got yourself back into your picture of your picture of the world and your inability to determine the existence of the world that you picture, the only thing of which you can be certain is that your thinking, isn't it? So here's my belief. And that's the content. And my belief is. The chair is blue. I've got the attitude, a belief towards that. I've now got another attitude, which is that a doubt towards that belief?

Do you see what I mean? You can't doubt your own beliefs without seeing that you have these beliefs. And that's what Descartes says. He said, the very act of doubting makes me see that I believe and if I believe I exist, I don't know what I am like, but I exist because I exist as a thinking thing, as a thing that thinks so. I think, therefore, I am is because that once you've been hyperbolic comes out, that is the only certainty you have.

You actually have a few more about what you think. But but you don't need to. I think therefore it just encapsulates it rather neatly, I think. But you see, you cannot doubt your own beliefs without seeing that you do believe something or other. All you don't know is whether that belief is true. Just so let's do the rounds of Wednesday talking about all sex predators, sometimes to figure out. How sometimes sizeable foreign firms are true or or can you believe it? Evidence for this nature.

Hey, way about what might for that kind of stuff. What we see is extremely distorted view of our perception of our great country needs to be more concerned about what's happening right now. So actually, you know what theory? I'm afraid that what you're saying, you'll make it clear that you haven't got into hyperbolic doubt either. Well, in that case, I'm going to pass on several decades. Personally, I don't think it is what you say. Well, we could, but we can agree with all that and unaccept.

I mean, all day Kosofsky is can we be certain that our experiences of being caused by anything? Secondly, can we be certain that our experiences are a good guide to what there is? Now, what you're saying is that the second we know empirically that the answer to the second question is no. But of course, for him, the most important question is the first one, not the second one about the nature of consciousness, which is what we may see that actually again.

Yes, sure. But I mean, this is more grist to Descartes. Well, I mean, it's either irrelevant scuse me. Or it's grist to Descartes smell. I mean, you can say you can add these in if you like, to the argument from illusion. But the argument for evolution is only the first step of Descartes argument. And the steps that really matters is this one. And that's the one that takes us to hyperbolic doubt. And that's very definitely a philosophical or metaphysical question, not her, an empirical one.

There's no way science can show us that we might. Well, there still is. But the empiricism is nothing more than me testing out one experience against another, which is a bit like testing out one newspaper against another. It's not going to get you very far. Why? Well, dieting is a form of thinking. Well, you know, you can't bring in on the people, say you no, you can't you can't bring in other people at all.

The doubting is not what you're certain of by doubting is that you believe because in order to doubt the thing that you doubt is a belief of your own. Well, exactly. A belief is a thought. It's a type of thought. So your your doubting that your thinking and interest, you try and doubt whether your thinking and you will become completely certain that your thinking. And so Descartes says, isn't it strange?

Because I would have thought that the world was far more presence to me than my own thoughts. In fact, my own thoughts have always seemed to be rather shadowy. We know things that I'm not really certain of at all that, you know, I can't hold them or see them or touch them or song. But having done this, I now see that my thoughts are far more certain to me the next in the world, which could be nothing.

So he's, you know, he thinks he's gone from something or he's found something really surprising. Once you move from the perspective of picturing your world. So I'm I'm thinking of the world that I picture, not my picture of the world. Usually the only time I'm thinking of my picture of the world is when something's gone wrong. You know, I thought I had I hung my coat here, okay. I believed I hung my coat here. I now have reason to believe it isn't there.

What's gone wrong? So I've been pushed back into my picture of my picture of the world in order to question whether my belief is true or false. But of course, usually I come back almost immediately. Oh, there it is. And so I immediately move back into my picture of the world, looking at the world. But what Descartes did is he forced himself to stay here, where what he was reflecting on was his picture of the world rather than the world that he pictured.

So he's looking at his beliefs and thinking of a true or false. Are they justified or are they not? Instead of looking at the chair and think he. Is it blue? Is it hard? Is it okay? Do you see why people are out here? Not in here and isn't a belief. My belief about art is a belief and is here. And Marion's belief about heaven is what I am certain of. But I'm certain of it. Until I doubt it. And the minutes. I doubt it. I can be certain of that belief, but I can't be certain that it's true.

So whatever I says is just more of my experiences. I can say that's right. I believe that and says it's blue. And I know that my belief that answers it's true does not make it true. That and says it's true. And as I can tell you, to be able to do this when you become philosophers. Do you see what I mean? Once you understand what you're saying, it becomes easy to set. Although I can't say it again. But I'll have to get the flow of it back.

Okay. Do you see why people are outside? Well, I hope my cat thinks we have two houses and she has adaptively. Oh, definitely. Well, there's a very interesting between three and five children actually acquire the context, the contest concept of a belief. And until that point, there is evidence to think that they do not properly form beliefs of their own.

But this is a an experiment that goes Maxcy, the puppet, whoever it is who's looking after Maxcy, I can't remember, puts a chocolate in a box and then Maxcy goes out to play and the children are watching this. And Max's mum comes and takes the chocolate from the box and puts it into a cupboard or something like that. Then Maxey comes in from playing and the children are asked, where is Maxcy going to look for the chocolate?

Now, all the three year olds say in the cupboard because that's where they believe the chocolate is. They know the chocolate is in the cupboard. Okay, so that's where they think maxilla, the five year olds will all say she'll look in the drawer because they've understood that the difference between appearance and reality. Okay. The world can appear to you to be other than the way the world is and what your daughter did, she she linked up her to beliefs and saw, oh, that house.

Is that house. How old was she? Yeah, she she probably wasn't really. Yeah, I mean, beliefs at that point. Yeah. The thought is you don't really have a belief until you have the concept of belief, because once it's only when you've got the concept of belief that you have the difference between appearance and reality and you see that beliefs can be either true or false. So you can grasp the content concept of conditions of truth and falsehood.

And at that point, you can really actually believe something, whereas up until then it's just that you're just responding to a world because the world is you don't make any distinction between the worlds being one way and its appearing one way. You don't see that those can come apart. No. No. Except, I mean, we'd call it one. When we're speaking loosely, but no. Okay. Right. Let's move on a bit because, I mean, we've we've been doing a lot of epistemology here under the heading of metaphysics.

But, of course, actually, there's the metaphysics of epistemology just to confuse you, because, of course, if you want to know the truth about knowledge, then you're doing the metaphysics of knowledge and therefore the metaphysics of epistemology. So we were looking at ontology before we got onto scepticism. But so we asked ourselves whether these things exist. But we can then go on and ask, well, what are they like?

You know, if we believe that God exists. Is he all these things? How can he be all these things? Because surely there's contradiction here, isn't there? If he's on the evidence, he can do anything at all. If he's omniscient, he knows everything at all. And if he's benevolent or good, then how can he see the suffering in the world and not do something about it? So can God be all those things? What about moral values? If they exist, are they absolute or relative?

Do we all have our own moral values or is there a moral law that's objective and that exists for all of us? Are there different possible worlds or any different possible states of this world? And what's the difference between those two? And what about physical objects? Are they independent of us or bundles of our ideas?

Barclay Bishop Berkeley thoughts that scepticism was so threatening the idea that we couldn't be sure we had knowledge of the external world that what he thought is we had to build the external world from what we could be sure about. So the only thing we can be sure about is our own experiences. So what is the external world other than bundles of our own experiences? Now, this may sound daft, you know, I mean, there's more to and than my experience.

If I touch her, she'll say outport scuse me or something like that. But actually, there again, what if I got other than my own experiences, auditory experiences, etc. So what Berkely was saying was actually, if you think of all your experiences, Morial counterfactual experiences, in other words, if I came into this room at midnight, that blue chair would still be there. Do you see that's a counterfactual experience. I would still see that blue chair.

There is no more to an object than our experience or counterfactual experiences. And actually, you try and convince me that you have any reason to believe that the physical world exists. That doesn't appeal to either an experience of yours or a counterfactual experience of yours. And you'll fail counterfactual. Yes, it is. If I came into this room last night at midnight, that's that's not true. I didn't come into this room at midnight. I was forced to sleep in bed.

But had I come into this room at midnight last night, I would have seen that blue chair. And that's part of my reason for thinking that that blue chair exists independently of me. Is that it was here all the time. It would still be here if I came back tomorrow, but it might. Well, exactly. And so what is saying is, is that there is no reason I can give. For believing that that chair exists. That doesn't depend on either an actual experience of mine here.

It exists, you know. And you're having experiences of this chair now as well. If you exist or counterfactual ones, if I came in tonight, it would still be here. I would still see it. That's true. But I would still. Okay. But that's if I had come in last night, it would have been there. Yeah, but I should be able to answer that. And I can't because I'm tired. If somebody had moved it, I wouldn't see. Have seen it. Okay. I might not be able to follow.

But it's certainly true that I have reason to believe that this chair would have been here simply because it's tied to the floor. I mean, that's not conclusive. And that's not a very good response to what you're saying. I've no reason to think it won't be a lie. What's more important to you? You try. This is a thought experiment for yourself. Try and give yourself reason to believe that something that you believe exists exists.

Okay. So you believe this exists. What are your reasons for believing it exists? And see if you can find one that doesn't depend upon your own experiences, either, your actual experiences, I can see it, feel it, touch it, hear it, or your counterfactual experiences. If I was there, then if I did this, then if you see what I mean, then I would. So you won't be able to do it. Markley was much cleverer than people think.

People tend to think that he thought the external world as a ghostly sort of thing. But he's just offering another explanation for our experiences and the fact that we go from these experiences to thinking this next to the world. We do that immediately. Why do we do this? Okay, so. So this is that's metaphysics then moving to epistemology. What is knowledge? Okay. Do we have knowledge? We've looked at that in some depth already. Do we have knowledge?

Descartes would say we can't claim to have knowledge of the external world unless we can get over his thought experiment, which he thinks we can. What is knowledge, though? Some people believe that it's okay. Let me ask you this. What what is knowledge? We've been talking about knowledge for the last hour and a half or something. What is it? That's very optimistic. I'll be launching out like that. Good for you.

Go on. See you. Yeah. What do you mean my gathered? But we have knowledge of things that don't involve sensors, don't we? Two plus two equals four is not sensory knowledge. So what is knowledge? We collect it and put it in our brains. How do you put something in your brain? Well, actually, you don't. I'm not sure you intentionally acquire knowledge anyway. Most of the time the knowledge you acquire isn't acquired intentionally just so it's somebody else's.

It's certainly a Quad's, but what is it we acquire? Memory is involved, but there's a difference between memory and knowledge, isn't there? I mean that in order to remember something, that something has to have happened. So you only have so much memory is important, but memory is different from knowledge is not the same thing. Memory is essentially time related, whereas knowledge isn't essentially time related. It can be time related. But it's not essentially so in the way that memory is.

Yep, well, and I mean, they're different sorts of knowledge, aren't there, as well. I mean, I know how to ride a bike. Well, I do. I remember it well. It's not propositional knowledge. OK, let me tell you what one answer the classical answer to the question of what knowledge is, is that it's justified. True belief. OK, if you're going to have knowledge, you must have a belief that belief must be justified and that belief must be true.

So you believe of you you know that I'm wearing an aubergine dress, don't you? You will know that. Very good colour concepts. You have a belief that I'm wearing an aubergine dress. Do you? Yeah. Okay. Is that belief justified how you can see it. Yeah. Okay. You're justified in believing that. And let me tell you that it's true. Okay. So, you know, I'm wearing an aubergine dress. So that's the idea. That is. So if a student comes to me and says, well, I Descartes said such and such.

And I say, why do you think that? And he says, the I don't know. And I said, okay, well, what what follows from that belief? And he says, I don't know. And I said, well, why do you think that? And he says, no, he doesn't know. It does. It does. He may have a belief about that, but it's. And what's what may be a true belief, but it's not justified. Therefore, it doesn't count as knowledge. He doesn't know it at all. If you don't have a belief about something, you certainly can't know it.

But the other one is the one that most people get more worried about is that you cannot know something false. If you cannot know that I'm wearing a yellow dress, for example, you couldn't believe that you know something false. But your belief that you know it is itself false. Are you with me? So if you actually know something, that thing must be true. So Maxi comes in from playing and she does. She knows that the chocolate is in the drawer.

No, she believes she knows the chocolate is in the drawer. But what she doesn't know is that her mum took it out and put it somewhere else. So if she has what she thinks is knowledge, but it's not knowledge because it's not true, she's got the belief she's justified in the belief, but the belief isn't true. Therefore, it cannot be counted as knowledge.

So you've got to, again, make that distinction between what you believe to be the case and what actually is the case, because you can believe, you know, something that's false, but you cannot actually know something false. The more data you have in your house, those things which you need to be useful, which you know. Yes. I'm not sure it's the crux of that, but it certainly comes into it. Absolutely. Yeah. Okay. So but here's a little problem for you.

Getting a came up with this little problem. It's called and it's been called ever since. Get your problems. You have seen me driving a golf DTI around Oxford. You've come to believe that I own a golf GDI. As a matter of fact, there is a golf GDI that I own. But it's in my garage. And the one that you've seen me driving around belongs to a friend. Okay. Do you know that I own a golf GCI, I believe. No, sorry. You believe that. You know. But do you know. No, you don't.

No. Why not? Well, is this justified? No. You've seen me driving around in it. You're perfectly justified. It is true. I've got one in the garage. No, you don't do that. You don't know. But you don't know. That's not the point. Why not? Because we haven't seen or. Oh. Happened to you all. There's no reason. But we do usually claim about claim to have knowledge without having certainty.

Don't we? I mean, you've seen me driving this car often. So, you know, you think you're justified in claiming to know that. I know. I'll tell you what's happened here is the conditions that make your belief true, i.e., the car that's sitting in my garage that you've never seen me in.

Apart from the conditions that justify your belief, the Gulf TTR, you've seen me driving around it, and it's only if the conditions that make true your belief are the same as the conditions that justify your belief that you can have knowledge that what you have counsel's knowledge so well getting showed is that it cannot be the case that knowledge is justified, true belief justified. True belief may be necessary for knowledge, but it is not sufficient.

You need some other claim that makes it impossible for the truth conditions to come apart from the conditions of justification. What is that other thing? Well, it's a very big question and it's one that we're still looking at and lots of answers, but no consensus on on what the answer is. Do we have knowledge of all the things that we think we have knowledge of? What was I thinking of here? Well, I mean, the example of the external world, again, the example of other mines is another one here.

How do I know that you have a mines and you might be just an automaton? I do. I think that, you know, I've got a mind. You will like me in all sorts of ways. Therefore, you have a mind. Is it some sort of argument from analogy or is there more to it than that? Is there is this instead that your mind is a theoretical entity? That I'm postulating an explanation of your behaviour? I suggested something like that earlier. And of course, are there different sorts of knowledge?

I mean, I mentioned earlier the type my knowledge of how to ride a bike is propositional knowledge. It isn't knowledge that I can explicate in any way. I have no idea how to ride a bike, but I still know how to ride one. So this is knowledge how rather than knowledge that I'm not quite sure a lot about tacit knowledge. You've probably heard of Chomsky and his tacit knowledge of grammar.

Some people think there's no such thing as tacit knowledge because it is that far down in your psyche that it doesn't count as knowledge because knowledge is a mental state, not a physical structure in the brain, which is what people think tacit knowledge is. So lots of different questions in epistemology, including the sceptical one that we were looking at earlier. Hugely easy to confuse metaphysics and possible epistemology in the first year of an undergraduates philosophical life.

There are two things I find really hard. One is to get him or her behind the veil of perception down into hyperbolic all doubt. That takes me about the whole of the first term. And then I spend the rest of his his undergraduate existence trying to get him out behind out from there again. And the other one other thing that's most difficult is, is to get them to distinguish between epistemology and metaphysics.

People say things like there's no evidence for the truth of homoeopathy. Therefore, home homoeopathy must be false. Well, if you're doing science, that's probably a very reasonable claim. If you do philosophy, it's not really because something can be true, even though there's no evidence for it and it's not entirely true inside. But if there's absolutely no evidence for something, the fact is no evidence for something doesn't mean that that something isn't true.

Of course. Good. Well, I'm glad to hear it. Yeah. Because that's. But on the other hand, if you tried everything to produce evidence and there's still no evidence, so no, it would be a rush. Scientists, though, who claimed that something was the case, even though. Right. But scientists presumably. Yeah. Yeah. But I mean, I don't I often hear scientists saying things like homeopathy is is not scientifically respectable because there's no evidence for it. And it's not the case.

Yeah, well, it certainly is true that because the fact is, truth outstrips evidence. Truth is independent of us. Or is it? I mean, that's another one thing. The second thing I've got here, truth is something different for each of us. We've got to be a bit careful of this because it's saying that. Here's a I can't remember whether I did this with you last week and believes Marianne is wearing O'Bagy. OK, I notice that there's one belief here and another belief here.

Is that right? Okay, so there's one sorry, one sentence. Marianne is wearing aubergine invented in another sentence and believes Marianne is wearing aubergine. Can that be true and not be false? Yeah, and it was a false belief. Can they both be false? Yes. Yes. It is so maybe false, Marianne's wearing aubergine and false that and believes it. Maybe she wouldn't believe it if I wasn't. Could they both be true? Yes. And could that be false and not true?

Yes, it could be because I might be wearing aubergine, but I didn't come today, she hasn't formed any belief about what I'm wearing. OK. Or maybe she's colour-blind or something like that. Maybe she doesn't cut colours as finally as aubergine. So she's never formed that belief. The fact is that the facts that make true, the belief that unbelieve something is a quite different fact from the facts. That makes true the belief, the thing that she believes, isn't it?

People don't realise that. I mean, if I've got Freds believes that mugging the elderly is okay. Some people think that therefore mugging the elderly is okay for Fred and moral relativism must be true. But of course, actually, all that means is that Fred believes that mugging the elderly is OK. Doesn't mean that mugging the elderly is okay for Fred. Okay. It just means Fred believes that it's just a way we have speaking.

So usually here's the world that we picture and here's each of us picturing the world. So it's true that each of you has a different belief about my wearing aubergine, but there is the fact of my wearing aubergine in addition to your beliefs about it. At least that's what we usually think. Truth is, I mean, as you've seen, there are there are big questions about whether that's true.

But what we shouldn't do is, is say, you know, truth is something different for each of us when actually all we mean is that our beliefs are different. Each of us has different beliefs. You see, that's confusing claims about people's beliefs or understanding or knowledge from claims about how the world is. You cannot go from each of us believes something different about truth to truth is different for each of us.

And in the same way, you can't go from Freds beliefs P to therefore P is true for Fred or anyone else, because all it means is Fred believes it. So it's very, very easy to confuse metaphysics and epistemology. And and I think in your first year of studying philosophy, it's almost always the case that when you're stumbling, it's because of a confusion of this kind. A very common confusion, very easy to to make. And it takes quite a while to get out of it.

Very important to distinguish three levels. The level of the world, the level of thought and the level of language. So here you've got redness, the property, here you've got redness, the concept. And here you've got red. The word. And if you confuse those three, you're going to have great difficulty sorting out your thoughts and you will confuse those three for you, because everyone does that one or that one redness the property.

Well, you understood it, didn't you? You all did. Whereas if you'd all gone. I mean, when I said aubergine, you went out of line. I think we might be talking about this next week. I'm not sure. But the question of whether it's absolutely, definitely true that we might all look at that chair and see something completely different. So you might look at this chair and see the colours that I see when I look at your cardigan.

That doesn't matter because you call it blue. And so do I. So actually, blue does not mean the private experience you have when you look at that chair. Blue means the colour of that chair. No, because we may not have a common experience. I can't get at your experience. If if I if in order to teach my child the word blue, I had to get my child to look at my experience and make sure she was having the same one.

It would be impossible and I wouldn't ever be able to test whether she was having the same one. Exactly. I point to the chair and other things that are blue and she whatever she experiences, she learns to call those things blue. So even if what she experiences is the future of your lovely cardigan, there she is. She will call it blue. Demi Moore. But that's that's a red is the colour that normal people see.

Well, red is the colour that red objects appear to normal people under normal circumstances. That's a circular definition because actually you can't get closer than that. But that's another topic. Let me just say, I think we've come to the end. Let's see. Oh, yes. I just wanted to ask. We will have a couple of minutes for questions, but I just. Next week is the last week. Would anyone be interested in a short demonstration off to the lecture?

So the lecture will be from two to three, 30, as usual. But then I if you like, I'll stay on for half an hour and give you a short romp through the online courses. Put your hands up if you're interested. Quite a few of you. OK. So I'll do that. So the rest of you can go on for coffee if you're not interested in that. But I'll do a short thing on the online courses afterwards. OK. We've got a couple of minutes for questions if anyone wants one. So.

Yeah. This language fought in the world, so I can be talking about the property of redness or I can be talking about the concept, which a constituent of your thoughts? Content. Or I could be talking about the word red notice. I need quotes if I'm talking about that, because if he was speaking French, it would be a different word, but the same meaning. I don't know any more than you do. I mean, that's what philosophers have spent there.

But you used it all the time. There's a sense in which you know the meaning of that word. You know, for example, the truth is a property of sentences or beliefs. You know, you'll talk about corresponds to the facts. Maybe you'll talk about coherence. But what what truth is and therefore what's truth is. And therefore, the definition of true or the explication of our concept true is a huge mystery. So very difficult to define. I don't know the answer. If I knew the answer would arise together.

Make a fortune on a couple of other questions. Just as for the world. All our beliefs about the external world, by the time you got to the demon one, the external world is gone completely. All your beliefs about the external world may be false standee beliefs that you can be sure of or your beliefs, but your own mind. That was the demon. You lose all your beliefs. Well, I mean, you can do this for yourself under if you just think about what would be false if you were dreaming.

So if I'm dreaming, Bluenose exists, that's still true. But if I'm dreaming, that's blue chairs in front of me. It's probably false. Do you see what I mean? Whatever it is that you could be dreaming it destroy. That would be false. If you were dreaming. Goes into the dark thousand basket. And one final question here. Well, that I mean, then philosophy and science merge into each other. I mean, a lot of scientists must use logic, for example, so they must use philosophical techniques.

And any scientist, sorry, any philosopher who is completely uninterested in what's going on in science is probably a bad philosopher as well. So they do overlap, but but they are completely different. They're interested in completely different questions, really. So scientists must assume causation, for example. He wouldn't want to waste his time spending it on the causation unless he was half a philosopher as well.

But a philosopher is interested in causation. Well, it's the same worlds that we're interested in. So it's not surprising that there is a lot of overlap. Yeah. Oh, no. Oh, yeah. Yes, they do. Yeah. Yeah. Yeah. Well, I just think they do it on the somewhat philosophise. Yeah. If they. Well I don't go to study their subjects. Why should they study. But like I said, I did go to study their subject. Why should they come and study mine. I mean some people are interested in philosophy.

Other people don't. And you can dissuade some. But there are some people who are not the world's philosophers. Anyway, I'm sorry I can't come to coffee today because I'm going straight off to London. So.