>> Hi. My name is Dr Suilin Lavelle. And today, I'd like to talk you through some of the core issues in philosophy of mind. Unfortunately, we're not going to be able to answer a lot of the questions that we pose because that's the nature of philosophy. We're looking at questions and we're trying to work out what good questions there are to ask. So, I'm going to point out some of the questions that philosophers have asked about the mind and some of the ways to which we've tried to answer those questions. In particular, I want to focus on why philosophers and psychologists often talk about the mind using the metaphor of a computer. Why has this so gripped the imagination? Well, first of all, what is it to have a mind? Okay. Well, one is the philosophical technique that people use when you're trying to find out more about a particular property, is that you look at something which definitely doesn't have that property. Here's a tennis ball. What happens to a tennis ball in an average day? Well, if it's my tennis ball, it gets thrown about, it gets bounced on the floor and it annoys the people in the flat below me. Then, I'll take it out in the garden and chuck it around a bit, leave it on the ground, the dog will come pick it up. Maybe it will get rained on, it will get slightly eroded, it will get soggy, maybe the rubber will contract and expand a bit. And that's it for the tennis ball. Tennis balls don't have a very interesting existence. They get beaten about, things happen to them, but they don't really instigate things happening in the world. The second example is a dog. Now, what kind of day does a dog have? Well, a dog gets up and the first thing it's usually thinking about is food. So, dogs think about food, they think about staying warm, they think about finding shelter. They think about belly rubs or try and find you and get your attention. Sometimes, dogs go out into the garden, find a tennis ball, play with that a bit, come back, and have a sleep. That's the day in the life of the average Scottish dog. Now, take me, in many ways, I'm like the dog. I woke up this morning, and the first thing I thought was, it's cold. Don't want to get out of bed. Like the dog, in my life, I seek warmth and shelter. The second thing I thought when I woke up was, hm, what's for breakfast? Like the dog, I think a lot about food. So, what I have in common with dogs allows certain traits such as wanting food, wanting warmth, wanting shelter. And I'm able to change my environment to bring those things about. Just like a dogs able to go inside if it wants to keep warm, I can go into my flat if I want to keep warm. Tennis balls, well, they don't have that same sort of desire to keep warm, they just stay where they're put. But while I'm very similar to the dog in some respects, I'm also quite different. Here's some ways in which my mind is different from the dogs. First of all, I can evaluate my own thoughts. So, maybe I'm thinking about the party I went to last night and I think, God I really didn't like that guy. I can't really put my finger on what it was about him that I didn't like. But, I didn't like him. And, then I catch myself thinking these thoughts and think hey, Suilin, you're being really prejudice. Why are you thinking this? And then, I like think back and think, oh, he has the mannerisms of someone I didn't like very much at school. And I shouldn't hold that against him. So, I'm wrong to think that this person isn't very nice. So then, I had a thought. Hm, I've got negative reactions to this person. But then, I can have a thought about a thought. I can think about why I have that thought and try and evaluate why I have it. And to be honest, a lot of human gossip is centered around thinking about our thoughts. It's one of our favorite things to do when we go for coffee with people is, I thought this, and I thought, why did I think that? The second thing about human minds which is interesting, is that we can think about things. So, I've just said that we can think about thoughts, but thoughts aren't the only things we can think about. We can make plans for the future. I can think about states of the world that don't actually exist yet. I can think about what I might be like when I'm 60 and whether I'm going to wear purple. I can think about, what it would like if I owned a 5-legged fire-breathing unicorn? 5-legged fire-breathing unicorns don't exist, as far as I'm aware, but that doesn't preclude me thinking about it. So, as humans, we're able to think about not only things that are immediate and around us in our environment that we can see. But we can also think about 5-legged fire-breathing unicorns that don't exist. And this is a very tricky aspect of human thought. It comes to us so naturally that we can think about things. I can think about a 5-legged fire-breathing unicorn. I could think about what I want for my lunch later on. I can think about non-actual things, or I can think about things here in the room, like the tennis ball that's on the floor. But what is it that makes thoughts about things? If we're going to give a description of a thought, how are we going to capture that aboutness, that this thought is about a tennis ball, that right now, I'm thinking about my holiday in Paris. How can we capture that aboutness? That's one of the big questions in philosophy of mind. The other way in which I'm slightly different from the dog, is that I have conscious awareness. Philosophers like to call this the what it is like, so there is something it is like when I sit down and I smell my beautiful bacon sandwich for breakfast in the morning. I start salivating. There's a distinctive experience, a distinctive awareness of that smell that I can experience. If you like, there's something that it's like for me to be sitting in a chair and thinking very hard about a particular problem. There's some kind of awareness or experience that accompanies that thought process. So, what is its likeness is the other tricky aspect in philosophy of mind. Philosophers of mind are trying to pin down, how do we characterize that what it's likeness to have a particular experience. Now, of course, I'm not saying that animals don't have experiences. I'm just saying that this is a very distinctive part of human thought and that if we want to characterize human thought, then this is something that we need to taken into account. So, any story of how the mind works is going to have to explain why we have this what it's likeness. And it's also going to explain how it is that we're able to think about things. Think about things that are here in our environment, that are non-existent, and even think about our own thoughts. So, those are the core issues in contemporary philosophy of mind. Perhaps, the most iconic philosopher of mind is the 17th century philosopher, Rene Descartes. Now, Descartes was very famous for putting forward a particular view of how the mind worked. Descartes believed that minds had to be made of fundamentally very different stuff from physical bodies. So, he thought that there were two types of substance in the world. There's physical stuff, stuff that our bodies are made out of, stuff that trees are made out of, irons, metals, things in the world. But then, there's this other fundamentally different substance which was immaterial, couldn't be studied by science. It couldn't be tracked by our best scientific instruments. It was an immaterial substance and that was what our minds were. So, Descartes thought that for every human being, there were two bits of stuff, if you like. Each human be, being has a physical form, which is your kind of average compounds of H2O, other chemicals, hormones that make up the human body. And in addition to this, there was this immaterial stuff. This immaterial stuff, and that was the mind. Now, this view is often known as substance dualism. Dual because it poses two things, and substance because it's posing two different substances. Material substances, which worldly things are made out of, including human bodies, and immaterial substances, which minds are made out of. It's also known as Certesian Dualism. Now, there are some significant problems with Descartes' view, including problems with the argument that he uses to argue for why minds and bodies have to be made out of fundamentally different things. And if you'd like to find more about that particular argument, you can look it up in the supplementary materials. However, the problem I'd like to draw your attention to, is the problem of causation. Now, the problem of causation was brought forward to Descartes by Elisabeth of Bohemia. Now, she was one of Descartes' pupils, and a very bright pupil she was as well. As she wrote to Descarste, asking, if we have this immaterial substance, then how doesn't it, how does it affect changes in the physical body? So, she says, look, in order to, for physical things to move, they have to be moved by another physical thing. So, for a rock to roll down the hill, someone has to push it, or perhaps, you need to have an earthquake if it shakes it. But it needs some impetus from another physical object to start its journey down the hill. And she says, look, human beings, they're exactly the same. In order for them to move, in order for them to affect changes in the world, there has to be some kind of physical impetus that changes the physical state of us, of our body, such that we can move. Princess Elisabeth of Bohemia said, look, if thoughts are made out of a material substance, then that substance isn't physical. But how can we then interact with the physical body so as to affect changes in the world? Because it's a fundamental feature of thoughts that the can cause our bodies to move. If I think I know the answer to a question in a test, I'll put my hand up. What caused me to put my hand up? Well, it was my thought I knew the answer to that particular question. If I want to buy some chocolate, then I'll set off, and I'll get my coat, and I'll walk out the door and go to the shops. What caused that particular behavior? Well, it was my desire for chocolate. It was my particular thought. So, thoughts, beliefs, and desires can cause particular behaviors. Behaviors happen in physical bodies. Princess Elizabeth of Bohemia wanted to know how on earth an immaterial substance which was so fundamentally different from the physical stuff, how this immaterial stuff could cause a physical thing to move? This is known as the problem of causation, and it's a very tricky one for Descartes and for substance dualism.