 We're going to do philosophy in 45 minutes, believe it or not. I'm Mary Ann Talbott, as you probably guessed, and I've been asked to say something quickly about lifelong learning. I'm very happy to do that because I was thrown out of school at 15, some of you possibly know that, but others don't. I was thrown out of school at 15 for truancy and disruption. I didn't come back into full-time education until I was 26. I wnaeth am 26 ydym wedi bod yn y meddwl y university gyda'u defnyddio, fel hynny'r cyflwynt yma, sy'n cymorth o'r ffordd o'r pethau ym Ynwu Cymru, ac yn ddiddorol i'r ffordd. Byddwyd wedi gweld i'r ddisgu'r gwaith, ac yn ddiddorol er mwyn i'r gwaith, yn fawr o'r lelaf, ac yn ymwneud, ac mae'n ganddo i'r ffordd yma. It was the hardest thing I had ever done although I sat up all night trying to do this assignment, whatever it was. Ener Occultwn I thought, Wow, Wow, I really really enjoyed that. I just fell in love with philosophy. I went on, I did a year at the open University. I went on to Bedford College at the University of London. I was just walking on air. I absolutely adored it, and that's what lifelong learning is. It's never too late, and to illustrate that, my mum, in the year of her 50th wedding anniversary, the year she was 70, she got herself a 2-1 from the University of Manchester. Less in philosophy, she tried philosophy and she hated it. Probably the desires on the phone to her saying, are you sure you've done this, are you sure you've done that, that she really was not into that. But she absolutely loved studying later in life and she got herself a 2-1, as I say, in the year of her 70th birthday. I'm so proud of her. In English, which she continued to love. I mean, she should always love that. So that's something about lifelong learning. So if any of you are thinking of coming back to lifelong learning, I can only say, do please, you'll love it. If you choose the right subject, and of course we all know what the right subject is, don't we? I've also been asked to say something about the department, and to do that, I'm going to tell you about Eileen. Eileen, who won't thank me, I didn't tell her I was going to talk about her and she'll see us on the podcast and she'll be horrified. But she started coming here, actually I didn't know how long ago, it must have been about 15 years ago, maybe not quite as long as that, to start weekly classes in philosophy and she got hooked on philosophy rather than I did. And she did weekly classes, then she did the philosophy certificate course, which sadly is now defunct, but I'm hoping to get going again. Then she went on to Reading to do a master's degree and she's just submitted her PhD in philosophy at Reading University, so to Eileen, and I'm sure she'll get it because she's a very, very good philosopher. And that's coming to classes here, but many years later, it doesn't take, it takes longer than five minutes to get a PhD. OK, but we're really here to talk about philosophy. So, the word means love of wisdom, and what's more important is the first philosophers were the first people to search for natural as opposed to supernatural explanations. So, most people were happy to just think that God did something, is a perfectly good explanation, but the first philosophers, the Presocratics, were not happy with that sort of explanation. They would appeal to God in the final analysis if they really couldn't find any other explanation that would do, but first they would look for a natural explanation. Which is why the first philosophers were also the first scientists, and many sciences started off being philosophy, and then as they became empirical, as you could actually test things, they hithered off into their own discipline. Didn't mean that philosophy became irrelevant, as we'll see. So the subject matter of philosophy is everything. That's why it's so brilliant. OK, it's everything, because if a human being can think about it, there is a philosophy of it. So there's a philosophy of minds, there's a philosophy of language, philosophy of science, philosophy of politics, philosophy of religion, and I could have carried on forever, but I ran out of PowerPoint slide. So I've just got those on there. So let's have a look at some of these. Just in mind, for example, well, it's a mental epiphenomenal. So the mental to be epiphenomenal would be for it to have no causal power at all. You might think, well, nonsense. It's what I believe that causes me to do what I do. So it's because I believe that this person has very luminous grubs at the bottom of her feet that I'm going to say, would you pass me one? So she's covered in books and things. So she's passed me one, and I'm now showing you this is indeed very luminous. So it was my desire to show you that and my belief that I could do that by asking this person to give me a laugh that caused me to do that. My actions are the result of my beliefs, and that's why we attribute, thank you, beliefs to each other all the time. What we're trying to do is understand each other's behaviors, understand what we're trying to do, why we're trying to do it, what our reasons are for doing what we do. So our mental states are implicated in our behaviors. But if I wave at you now, you can explain that by, I want to perform an action that I then say, well, how do you explain it? Okay, there's a desire and a belief there. But we all know that another explanation of my waving my hand is you'll. If somebody knew enough about my brain, they'd be able to say, well, there's that neural state there that's causing that behavioral behavior there. Well, this is why I needed the flipchart. So you've got one action, a hand waving, and two possible explanations, a neural explanation, and a mental explanation. Well, that's problematic, isn't it? Why should we need two causes for something? Surely one of those must be, and there are two possibilities you might think, either the neural state is the mental state, okay, so that in fact there are not two explanations here, there's just one explanation of the same thing. Or one of these explanations just isn't the right one, and surely it's going to be the mental one. And some people think that because we will eventually find a neural explanation for all our behavior, what that shows is that mental states are, either they don't exist at all, and that's metaphysics which we're going to do next slide, or if they exist, they're epithenominal, so it's rather like the shadow. So my shadow has no causes or effects, sorry, it has causes, it doesn't have effects. I have effects, but my shadow doesn't. And so the mental states would shadow neural states, but they don't themselves have effects. Now, philosophers won't say, well, okay, is that true, or is this true? Could it be that the mind is the very same thing as the brain? In that case, you've solved that problem. But there are big problems with that, and if anyone wants to see any more about those problems, they might look at my podcasts and there will be a reference to the podcast, a romp through the nature of mind at the end of this unit. And in that I look at whether the mind is the same thing as the body, and I look at all the problems for that because there are big problems for that. And it's not obviously a question that science will be able to answer. And I wish I could say something more about that now, but we haven't time, because we're going on to language. Okay, so that's just a feeling for what philosophy of mind is. If you ask me of language, now what's that? Okay, well, what is meaning? His, let's say, his word, mental. Okay, now you all know what that means, or if I write on here, James is tall. Okay, you all understand that, don't you? Okay, that has meaning. Well, how can that squiggle on the board? How can I just using a pen to squiggle those things? How does that have meaning for you? And what about my saying, James is tall? All that is is sounds crossing to your ear from my mouth, I suppose. How can that have meaning for you? And what is it to have meaning in the first place? What's the meaning of the word meaning? Here's why we might think that it's a bit difficult. If I say James is tall, you all understand that, don't you? Yep, okay. So it has meaning, doesn't it? Can you tell me whether it's true or not? Well done, exactly so. Not without knowing who James is. So you know what is tall is. You don't need to know any more about that, you can tell. But you need to know what the word James refers to, or the sounds James refers to. Okay, that's right. So there are two sorts of meaning, aren't there? One is weak meaning, which is what you had there. You had something that looked like meaning. But actually, if you can't tell the truth value of a sentence, do you really understand the sentence? Until you know who James is, do you really understand the sentence? If not, then there's another sort of meaning. There's also strong meaning. So weak meaning is meaning without a context, if you like. Strong meaning is meaning with a context. And there's another reason for thinking that that is important. So what's your name? Yes? Rupert. Rupert asks me, is he a good philosopher? And I say his handwriting is excellent. Okay, what is the meaning of what I've said there? Is it he's a good philosopher? Is it he's a bad philosopher? Isn't it? I'm implying that he's not a good philosopher, aren't I? And how do you know that? Because the meaning of the words that I used were completely irrelevant to the question I was asked, wasn't I? If I'm asked, is he a good philosopher and I say his handwriting is excellent, then it's the very fact that I used something with that weak meaning in a completely irrelevant context that alerts you to the fact that this has a different meaning from the meaning you're expecting, from the meaning it would normally have. Another one, I mean there are all sorts of things we can do with language. So, for example, if we think of this as the strict and literal truth conditions of a sentence, and then there's the force, whether it's used to ask a question or to make a command or to make a statement or something, and then there's the tone we use. So, how about, I'm not angry! I mean, what I've said, the strict and literal truth conditions of what I've said are contradicted by the tone in which I've said this, aren't they? And then there's the context. So, what would happen if, what's your name? Gordon. Gordon. Say we'd been having a class every six weeks for a while and he turns up every time Gordon's been late. OK, so 10 minutes into this class the door crashes, Gordon comes in and I say, hello Gordon, early again. What have I said? You're late. Haven't I? So the context has reversed what I've said. So many things that we can do with language. So many things we can do with meaning. So, I mean these are just, in each case I put just a few of the questions that philosophers want to know. How can we do this? How can we get this meaning? So, it's the job of a linguist to study how language works empirically. But of course as a linguist must work with the idea of meaning that must be assumed by a linguist and again with the idea of reference. But it's the job of a philosopher to say, well what is meaning? What's the meaning of the word meaning? What is reference? How does a name, what's your name? George. George, how does the name George get attached to him? And probably is there anyone else called George in this room? No, so it's George. And this is where I say, is anyone called John thinking everybody around my age who's male is called John, is there? No, look at that, there isn't. Oh yes, there's one person. Okay, but let's move to science. Okay, one question that a philosopher might ask. Okay, the question of how science and philosophy differ is a very important one because you have heard Stephen Hawking's, for example, said recently that philosophy is dead, he said, philosophers haven't kept up, philosophy is dead. Now logic is something that philosophers study and of course logic, one type of argument in logic is arguments that come from authority. So Stephen Hawking says P, therefore P. Is that a good argument? No, why not? Just sometimes isn't it? I mean if Stephen Hawking tells me that time travel is possible, I'm going to think well maybe time travel is possible, but if Stephen Hawking says philosophy is dead, am I going to believe him? Answer not necessarily because of course he is an authority on physics but not an authority on philosophy. Let's have a look at, okay, the paradoxes of confirmation. This is going to be good. If I have a generalisation like all ravens are black, all ravens are black, that will have come to that by saying one black raven and another black raven and another black raven, so we've seen so many black ravens. We think okay, we'll extrapolate here, all ravens are black. Now I see a black raven. Does that confirm or a little bit confirm all ravens are black? You say no, why not? Okay, yes but that's why I said a little bit. I mean it's not a falsification is it? A right raven would be a falsification but another black raven is just a tiny bit of confirmation because once you've got to the point that all ravens are black, every black raven you see is further confirmation of that theory, which is uninteresting frankly. Who would think, well it is isn't it? I mean if you've got to a stage where you make this generalisation in the first place you've seen so many black ravens that seeing another is uninteresting. So confirming a generalisation is nice but not interesting. Actually it's not nice because we're a much rather false fan. But what about a white gymshw? Once seeing a white gymshw confirm all ravens are black, who thinks yes? You're all wrong. Cos a white gymshw does confirm all ravens are black and this is why. I'll tell you what, let me get the arguments out then it disagrees with me. All ravens are black is logically equivalent to all non black things are non ravens. Is that right? What logical equivalence means is there's no situation where that's true, where that's not true and there's no situation where that's true, where that's not true. OK? So who thinks that this isn't a logical equivalence? Come on, there's several of you. I'm dying to know why you think that's not a logical equivalence. Now you've all gone quiet. The only situation I can think that it wouldn't be is if you're using all ravens are black as a definition of what a raven is. Well even then it would still be true wouldn't it that all non black things are non ravens. Yeah, I mean even that wouldn't. Yes, do you see what it means? You could say that by definition if it's not black it's not a raven. We usually think of discovering that ravens are black as something extra we learn about ravens rather than something that's part of the definition of ravens mainly because of albino ravens which of course... We're ignoring the odd white ravens. Yes, we're ignoring the odd white ravens. Okay, does anyone want to disagree with me that this is a logical equivalence? Yes, that's true, my boots are black. But are they a non black, non raven? No, because they're black. They are a non raven. But we're not saying all black things are ravens. We're saying all ravens are black. Got to get your van diagrams the right way around. The fact that our gym shoe happens... We haven't got onto the gym shoe yet. Well this is a non black thing. Yeah, you're right. And it's a non raven. You're absolutely right. It does not prove that all ravens are black. Now let me continue because Gordon's got there first. Okay, if all ravens are black is logically equivalent to all non black things are non ravens then the sighting of a white gym shoe which is, as Gordon says, a non black non raven if it confirms that and this is logically equivalent to that it ought to confirm that as well. So logic tells us that a white gym shoe does confirm all ravens are black. Now this is nonsense, isn't it? Well we all know that the sighting of a white gym shoe does not confirm all ravens are black. So what's gone wrong here? Can anyone tell me what's gone wrong? You're trying to reverse the argument. No, the logic, believe me, really does work. If you believe that that is logically equivalent to that and you should because it is. No, we're in charge. There are certain things you ought to take on a farce here and if we had longer I would have convinced you but I can, yeah. But actually you don't need my authority to tell you that that and that are logically equivalent. You can see they are. Hang on, I've got to draw it. Okay, I need somebody with arms. George, come up on stage. That's what you get for sitting in the front. Okay, all ravens are black. Here are all black things and here are ravens. Right, what was your objection? So Marianne's boots are here. No, and here are... Do you know nobody else's wearing boots? Yes, you are. What's your name? Oh, they're black. Okay, what's your name? Emily's boots are brown. They're not black. So have I convinced you yet or not? Why not? I mean, what's the problem? Actually you're going to have to move a bit over that way because you've got the... That's it. There are other things, all of which are black. Cole, okay? Cole is here. Okay, this is the class of non-black things. Okay, so it's separate from the class of black things. Emily's boots are in here. Sorry, I've run out of room to do my circles as I should, but you can see Emily's boots belong here. Okay, and white gymshoos belong here, don't they? But all ravens are black. So in the class of all black things, you get all ravens. Are you convinced? Yes, okay. Right, now I've got what I was saying. Thank you. Ah, yes, I remember. Okay, so now this... Now do that. Okay, so this is the logical equivalence of that. For logic tells us that the sighting of a white gymshoo confirms all ravens are black. We all won't say nonsense. No chances, no way of sighting of a gymshoo. So what I asked you was why not, what went wrong. And I'll tell you what went wrong. Well, actually, you tell me. Was that a hands going up? Is it because one white gymshoo is not all non-black things? So it's just a point toward... No, no, because that's... No, because if it was a white raven, it would be just one white thing and it would completely go to smithereens, wouldn't it? If it was a white raven. Is it the logic... Can you cash that out a little more? Well, I'm thinking of such a vast number of things in the world. The implication of one of those things being a particular colour, that we just know isn't going to imply that all... That's... OK, I can see you're getting tied up in your words, but you're absolutely on the right track. I can't argue from the individual to the... an assumption from one to all the general... No, because you're not making an assumption from one. You're seeing a white gymshoo, so you're seeing a non-black, non-raven. This is the sighting of one black raven would confirm this, so the sighting of one white gymshoo would confirm this, and therefore logically confirm that. But there's one more and then we'll move on. Is it because there are more things in the world than just ravens and gymshoos? So, you know, if something is a gymshoo, it doesn't mean it's like the inverse of a raven. It could be... OK, you're also going in the right direction. What it shows us... So, you're all shouting out now. Good. What it shows us is that in order to decide what would confirm all ravens are black, you are bringing to bear background knowledge of the world in which we live. OK, if you were using only logic, you would agree that a white gymshoo would confirm all ravens are black. But you're not using only logic. You're also bringing to bear your background knowledge of the world. And what your background knowledge tells you is that there are too many non-black, non-ravens... I don't know why I'm writing this. You can't read it. I can't either. There are too many non-black, non-ravens in the world for it to be interesting. There are ten things in the world, apart from me, that is. And nine of them are black and nine of them are ravens. If I was in that world, the sighting of a white gymshoo would make it quite conclusive that all ravens are black, wouldn't it? You're saying no. No, not if nine of them are ravens and nine of them are black. If you see one white... Nine of the things that exist are ravens and nine of the things that exist are black. Nine of them are black and nine of them are ravens. So the sighting of a white gymshoo in this world would make it absolutely conclusive that all ravens are black. But the reason this is important, and I do this often with scientists, so they get just as irritated with me as you did, because what knows is this, what is white gymshoo you've got to do with it. What it's got to do with this is it draws our attention to the fact that actually we're always beginning to bear assumptions that we don't even notice when we decide what we'll confirm, what theory to... postulate, what theory to test, how to test it, et cetera. And so what this does is it brings out the fact that we rely on all sorts of assumptions that we don't even notice. And it's perfectly reasonable to rely on that assumption here, but isn't it interesting we don't even notice it? And of course sometimes the assumptions on which we rely are very important and they turn out to be false. Okay, that's thought of in science. I knew that would take ages. Politics, okay. Which principles should ground society? I mean, John Rawls, who's a very important philosopher of politics, asks us to imagine what he calls the original position. And the original position is a position where none of us know who we are. Our task is to choose the principles by which society should be run, whether it should be equality, whether it should be utilitarianism, whether it should be deontology, et cetera, et cetera. Okay, you may not know what these things are, but just bear with me for the moment. But in the original position, what we don't know is who we are or indeed anything about ourselves. So we don't know whether we're male or female. We don't know whether we're old or young. We don't know whether we're rich or poor. We don't know whether we're tall or short. You get the idea. So we're behind what he calls the veil of ignorance. And what we do have, we do have some knowledge. We have the thin theory of good. And the thin theory of good tells us some physiological, psychological, political facts about human beings. So, for example, we know that it's human females who have babies, not human males. We know that the gestation period is nine months. We know things like that, but we don't know whether we ourselves are female or male. Now, why would that be a good position from which to decide on the principles of justice? Can anyone tell me? You can't load the dice in your favour. That's so nicely put. You can't load the dice in your favour. You can't say, well, I'm a man. All women should be at home by nine o'clock at night cooking a meal. Six o'clock at night. What do I mean nine o'clock at night? Because I'm male, I think that. Actually, I might be female. Would I want that? No, I wouldn't want that, therefore. So we can't load the dice in our favour. That's exactly what the veil of ignorance and the thin theory of good and the original position of four. All sorts of problems with that, and it would be lovely to tell you about them, but we haven't got time. So what about the conflict between justice and equality? This was a thought experiment done by a chap called Robert Nozick, who's another very important political philosopher. He asked us to think about a chap called Waltz... Or was it Waltz? Chamberlain. Waltz Chamberlain. Partly it was a basketball player. Is that right? You're Canadian, you ought to know. Okay, so Waltz Chamberlain is a brilliant basketball player. We all love to see... I mean, we may hate sport the rest of the time, but we really want to see Waltz Chamberlain play, and we're prepared to each of us give him 25 cents to play. As a result, for him to play rather, as a result, Waltz gets extremely rich. We're all quite poor, but Waltz gets extremely rich. Now, the only way we can make us equal again is by restricting freedom in some way. So we can either restrict your freedom to give Waltz 25 cents of your money to see him play, but you might think, well, hang on, that's a bit annoying. I want to see him play. I think he's worth 25 cents. Or we can say to Waltz, okay, you can take all this money, but you've got to give quite a lot of it back. So redistributing wealth. But that's to restrict Waltz freedom to spend the money he has earned as he chooses. And the only way we can get equality is by restricting freedom. And the only way we can get freedom is by allowing inequality. That's what the Waltz Chamberlain argument is supposed to do. So those of us who want both freedom and equality within a society have immediately got a problem. And what are we going to do with that problem? Sadly, we don't have time to think about it right now, but this is what you would do if you were thinking about philosophy. Okay, religion, the big one. Okay, this is... If God exists, why is there so much evil in the world? You have heard of this, the problem of free will. Problem free will is God is omnipotent. He can do everything. If he's omniscient, he knows everything. And if he's omnibenevolent, he wants everything to be good for us all, then how come there is so much evil in the world? I mean, God could stop it. He's omnipotent. He knows about it. It's not that it's gone past his radar. He knows about it. He's omniscient for goodness sake. And it's not that he doesn't want to do anything about it because he's omnipotent. So how come there is evil in the world? The traditional answer is that's why we've got free will. Because it's better that we have free will and evil because we choose to do evil than it is to not have free will, in which case there wouldn't be any bad in the world, nor would there be any good in the world. And one of the things I like to do as students here is ask them to engage in a thought experiment. If you were God, you couldn't create a world in which there's only good or only evil. If you create good, you have to create the possibility of evil. Because you have to create free will, you have to create choice. Would you choose not to create a world at all just perhaps to create a world with no good or evil? Or would you choose to create a world in which there's both good and evil? I'm going to leave you with that one. You can stay awake tonight worrying about that one. There's a what? There's a course about it. There's a course about all the things I'm talking about, often by me. Okay, so just going back to that, what I've said is that the subject matter of philosophy is everything. There's nothing a human being can think about that a philosopher isn't interested in thinking about the thinking about it. That's what we do. I've given you some examples there. But if there's any subject matter that can be said to be peculiarly the province of philosophy, it's these four. Logic, ethics, metaphysics and epistemology. When I say logic is peculiarly the province of philosophy, of course it's not. It's also the province of maths. But maths and philosophers are now computer scientists who I suppose I'm counting as mathematicians in a way. Possibly unfairly. Actually study logic. It's only in philosophy and maths in universities and computer science that logic is studied. What we study is what is an argument. Which arguments are good? Which arguments are bad? Are there different types of argument? Or laws of logic? I can ask you a question about that. One thing that's assumed for many, many years has been assumed to be a law of logic is the law of excluded middle, which says either P is true or not P is true. So P or not P is always and everywhere true. Quantum mechanics has called that into question over the last century. Which of course is interesting. Could there be an empirical objection to a law of logic? That's a very interesting one. But here's a rather easier example. Your jacket there, let me take it, is a fame at last says, actually it's not quite going to work for me. It's not, not red is it? Unfortunately it is not red, you're quite right. Do you see if it will have a different colour? I could say it's not, not red. And isn't that already, thank you, a counter example to the law of excluded middle? If something's not, not red, then it's neither P nor not P, isn't it? Do you see? So we didn't need to wait for quantum mechanics. Surely we could just say. And here's another example. That little kitten on the floor there, is it black? Mouse? You can't answer that, but what I've said, the little kitten on the floor is black, is neither true nor false, is it? Do you think it's straight forwardly false that the little kitten is black? Not really, because if you say it's false, you're sort of implying there is a kitten there, but it's ginger. So the laws, what the laws of logic are, is still a live issue. There are lots of different types of logic, and classical logic, which is the one that says the law of excluded middle is a law of logic, is only one type of logic. Ethics, of course, is a very big one. Is moral truth absolute or relative? Well, lots of people think it's relative. Anyone here think that moral truth is relative? Anyone tell me why? Okay, different generations have different moral beliefs. Okay, and different cultures have different moral beliefs. Okay, so moral truth is relative to a culture at the back, and moral truth is relative to a generation, or time perhaps at the front here. Okay, or you could say moral truth is relative to an individual. You believe that abortion is right, and I think it's wrong or something like that. Surely the fact that different people have different beliefs is reason to believe that moral truth is relative. Who is it? If I have two genetically identical seeds, and I put one of them in John Innes' number three compost, water it nicely, talk to it, give it a pat every now and again, put it somewhere where it's going to get the sun, and the other one I put in nasty garden soil and I stick it in the airing cupboard and forget about it. I give it enough water to keep it alive, but that's all. Are they going to look similar after six weeks? They're not, are they? They're going to look very different. Okay, is the fact that the phenotype is different evidence for they're not having the same genotype? No, it isn't, is it? Because the environment counts as well. And might we not think that the same thing is true with morality in some cases? So, for example, we keep our elderly alive as long as possible. The inuit at least used to put them gently to death. Might that not be explained by the fact that we both respect the elderly, but in their environment respecting the elderly is to let them die, whereas in our environment it isn't. Alternatively, one of us could be wrong, and I wouldn't like to say who it is in this case, but one of us could be wrong. And so the fact that there are differences in moral beliefs amongst cultures or generations or even individuals is actually not in itself sufficient to say that morality is relative. Okay, metaphysics is to do with... This is the most general. Metaphysics means before physics. What exists? So all of you in this room have an ontology. Some of you believe in ghosts, some of you believe in fairies, and others don't. Those who believe in fairies have an ontology, a list of what exists, on which fairies feature. Some people say that moral values exist. Other people will say, well, what are they? They're the queer sort of things if they do exist. Perhaps they don't exist. But if we model everything on physical objects, things you can touch or kick or put into your pocket or something, then moral values do look very old, don't they? So metaphysics asks, well, what does exist? Do mental states exist? Does truth exist? And the second question that metaphysics asks is what is the nature of what exists? So if physical objects exist, what is their nature? Are they, as Barkley said, constituted of nothing more than actual or counterfactual perceptions? Or are they, as Locke thought, real mind independent three-dimensional solid things, which is what we all think until we read Barkley, then we don't know what to think. I haven't got time to ask you what truth is, which is a shame. So I'll send you home thinking, asking yourself what truth is. And epistemology is what can we know? What is knowledge? How can we justify claims to know something? Did you know that if you know something, there's something you know can't be false? We can't know something false. Does anyone disagree with that? Wait till someone disagrees with it, and I'll tell you. Can we not know that something is false? Oh, we can know something is false? Yes, that's right, because then it's true that it's false, isn't it? But we can't know something false. Okay, they tell you that they're 50, so you believe they're 50. But do you know that they're 50? You don't. We can believe that we know something false. We can't know something false. If it's false, we can't know it. Because knowledge is factive, which means nothing more than you can't know something false. Perceptions also factive. I can't perceive something that doesn't exist. When Beth thought that he could perceive the dagger in front of him, he was wrong. He was hallucinating the dagger in front of him. He believed he could see it. He couldn't see it because there wasn't a dagger. Perception is factive, knowledge is factive. Okay, so that's a romp through philosophy in 45 minutes. I hope I've convinced you this is the best subject in the world, because it is. That's just true. Where to go from here? OEDC, you know where we are now. I hope you come again. There are weekly classes in philosophy. There's this newspaper which will tell you all about it. We've got things on thought experiments in philosophy and introduction in philosophy of science, philosophy of maths for beginners, applied ethics, aesthetics, creativity, imagination and fiction. Just a few of the weekly classes we've got. We've also got weekend schools. I've been doing an introduction to critical reasoning, but that's finished sadly, but there will be a podcast. Anti-realism, what is it and should we believe it? Philosophical intelligence coming up. Philosophy in the weekend, I'm doing that with a chap called Nigel Warburton. Philosophy of the family. Told you we can think about everything. Language in its pragmatics, philosophy in literature and an introduction to the mind-body problem which I'm doing in Newbury in June. There are also summer schools and I forgot to bring a prospectus to have no idea what we're doing there. There are lots of online courses. We do our ethics, philosophy, introductions to philosophy, mind, bioethics, religion, theory of knowledge, introduction to metaphysics, philosophy of science. There are ten-week short courses and they're really good, I really recommend them. That's the philosophical society. We've got 284 members and you'd be most welcome to come. Oxford University philosophy podcasts including my podcasts and that's my website, that's my Twitter feed. Hope you're all going to follow me. That's my Facebook page. You can like it, which will be very kind of you. And that's it. Thank you very much.