Searle: Philosophy of Mind, lecture 1

to buy and start reading and this syllabus I'm always a bit nervous about these making these solos because it looks like I'm promising you that on such on March 22nd I'll be lecturing on some damn-fool subject and maybe I will maybe not but anyway it gives people feel more secure if they have this and you can kind of keep up with a reading by looking at this all right now other requirements there are four very short papers and those kind of big chunk of your grade 50 or 60% and then there's a required final exam and that counts for the rest of your grade and your performance I say that's approximate your performance in the section will be taken into consideration in other words if you're a marginal case between an a-minus and an A but you've been absolutely terrific in the section then we'll take that into consideration in assigning the grades okay but those are the requirements you have to show up for a lecturer in section I you have to hand in the papers and you have to do the final exam now is there anything else I've forgotten to announce my general feeling about the waiting list is that if you get admitted to Berkeley you ought to be able to take the courses you want to take so I will try to accommodate everybody who really wants to take this course and the way I'll do that is i if it's pretty clear that that I'm I mean business in the first couple of lectures and with a reading assignment then I think we'll get some dropouts and I can take people on the waiting list that's been my experience in the past the the general principle is if you really want to take the course hang in there and I'm pretty confident this is a prediction I'm not a promise I'm pretty confident that you'll get admitted you'll be able to take the course for credit okay now after all that I'd like to go to work and start talking philosophy that's I always forget some bureaucratic stuff did I we get we get everything anybody have any pratik type questions to repeat the sections will start next week you'll have a discussion sections beginning next week and that's kind of the it's pedagogically essential for the course that you should be able to talk about the material in the lectures and the readings okay let's go to work then any questions any bureaucratic type stuff before we start doing philosophy all right well it's a course called the philosophy of mind and I have to situate that both intellectually and historically intellectually there's a single overriding question in contemporary philosophy and the question is this how do we fit our conception of ourselves how do we fit the human reality the reality of consciousness intentionality freewill aesthetics ethics politics rationality fiction great literature art how do we fit that reality in in with what we know about how the world is at the most fundamental level at the most fundamental level the world consists entirely in physical particles and fields of force that's it everything consists of physical particles and they're in fields of force other word particle may be the wrong word maybe there are strings or points of mass energy and I'm paying those guys down the hill to get a final answer to that and frankly I like physics better when there were electrons protons and neutrons yeah you guys don't remember that Golden Age when you learned that in high school then you can forget about the basic structure of reality but anyway I'm paying other people to figure out the basic structure the point we're taking for here for granted is to put it in technical terms now big things are made out of real little things and and the behavior the big things has to be explained by the behavior the little things now that's gives us a universe consisting entire of mindless meaningless physical particles but how doing in that universe do we fit in for example consciousness how do we forget fit in free well society rationality ethics aesthetics how do those fit in and it isn't just a question how they fit in but we have to be able to show how they're a natural consequence of the organization of the physical particles it isn't just that somehow other we can have both consciousness I and electrons but we've got to show how once you've got electrons and all the rest of it you're bound to have consciousness and indeed you can't have consciousness without having electrons and all the rest of it so that's the overriding question and the the central part of that question I think is the philosophy of mind that we can't really do subjects like ethics aesthetics political philosophy social philosophy philosophy of language until we get clear about the nature of the mind because all of those are derivative of and dependent on mental operations I now there's a slight calendar problem I have I teach three courses all devoted to different aspects of this and they the one that the department likes the schedule last is the fundamental the foundational one that's this one the philosophy of mind they make me teach that at the end of the year instead of the beginning of the year and that's a very scheduling reason saying like a guy from anyone who teaches an overlapping course and they don't want his course in my course that both be in the fall so this were not really to be in the fall but it is it's now it's gonna be in the spring and this is it so that's that's the overall intellectual situation is that we need an account of the human reality that is consistent with the basic reality and derivative from the basic reality the two central facts of intellectual life are the atomic theory of matter and the evolutionary theory of biology and we need to show how we already know how consistent with physics we can show how humans and other species evolved you have big carbon-based molecules with lots of hydrogen nitrogen and oxygen and somehow or other life began here's a scandal we don't know in our how life began on earth but we know it did begin and once you got it going if you got three to five billion years to operate with you got enough room for evolution to work and it did work and here we are we are the products of the fast three billion years or so of evolution of big carbon-based molecules in life-forms and now we're going to talk about certain crucial aspects of life namely those having to do with our minds okay that's the intellectual context in which we're operating now let me tell you the historical context in in the end there's no way to do philosophy intelligently without saying at least something about the history of the subject it's a tremendous burden and it's a pain in the neck but what you really ideally like to do it just tell your students the truth and send them home but they turn out to be very superficial philosophers if they never heard of Descartes and Plato and lightness and all those guys so I have to situate our problems historically and ideally if we had years and if I knew more we'd go back to the Greeks and I talked about Plato's theory of the mind but we don't have that kind of time so we're going to start with a big turning point namely the 17th century with a Descartes who was born at the end of the 16th century and died in the middle of the 17th century and there's a sense in which our problems today the problems about the nature of the mind and a relation of mind and body are inherited from Descartes and Descartes articulated a crucial distinction he didn't invent it it does go back to the Greeks but it has so much a part of intellectual culture and so much indeed a part of popular culture that the view in question is referred to by the adjective adjective form of his name it's carte Cartesian dualism Cartesian dualism I those of you who care about morphology will recognize that his name when you spell it out in its pieces is Descartes meaning of the cards I and I think we should really have yeah it has to be an S there they kept I and that got shortened to one word and then the adjective you dropped the duh and you just get Cartesian so it's called Cartesian dualism Cartesian is the adjective for a Descartes it's not a consequence of the fact fact that people can't spell Descartes it's the fact that they drop the preposition of when they're using the adjective of form of its name anyway Cartesian dualism here's how it works according to Descartes there are two kinds of things in the universe mental things called minds and physical things called bodies and now Descartes has a real problem as to how exactly they relate to each other but he has certain general conceptions about the nature of each of the mind and the body and those general conceptions affect profoundly the way they're supposed to relate to each other so on Cartesian dualism there's the mental or mind half and then there's the body or physical half now each of these mind and body is called a substance and this jargon of substance and essence and accident that goes back to Aristotle Descartes thought he was breaking with the aristotelian past and in large measure he was but he the terminology of substance and essence he accepts so what he says is there are two kinds of substances in the in the universe there are mental substances or minds and physical substances or bodies now each substance has an essence and what is in essence an essence is what makes the substance the kind of thing that it is so the essence of mind he says is minds are always conscious and his terminology for that is to say they're always thinking by thinking he means any conscious state at all so being in pain would be a case of thinking and I'll just abbreviate that as CS following Freud here for consciousness minds are always conscious they're always in a state of consciousness it is of their essence to be conscious bodies on the other hand have as their essence extension and by extension he just means they are extended in space they have physical dimensions so this piece of chalk has a set of physical dimensions according to which it is extended in space but it has no mind it has no mental reality another word for mine in Descartes is soul or in French aspire the spirit I am Descartes treats the mind and the soul as the same thing now because of the essence there are various forms that the essence can take there are various modifications of the essence and those are the detailed properties that minds and bodies can have I don't remember actually if he used it the Aristotelian jargon of the essence and accident but in any case there are these features they're important minds are indivisible and hence they're indestructible you can't chop up a mind we're as bodies he tells us are infinitely divisible you can keep dividing a piece of matter up according to Descartes indefinitely you can keep chopping it up in the smaller bits furthermore the minds are free and that's why we have free will is that our mind are absolutely free we can will anything we like whereas bodies are entirely determined by the laws of physics they are determined now another feature that minds and bodies have is the way we have knowledge of them we have direct knowledge of our own minds just by reflecting we can't be mistaken if we think for example that we're in pain or that we're awake because we have direct awareness of the contents of our own minds whereas bodies if I look at my hand I don't strictly speaking see the hand I just see the effect that the hand has on my mind and so minds are known in directly okay now that in a nutshell is the Cartesian picture the universe divides into two kinds of entities minds and bodies soul and matter spirit and flesh and then these determine the nature of our existence because each of us is essentially a mind and we happen to be stuck onto this body and now Descartes has a hell of a problem how does the mind relate to the body see a guy hits my thumb with a hammer well that's just a physical transaction among two bodies all the same it hurts how come how can it hurt if the hurt is something going on entirely in my soul what's the connection between the body and the soul now Descartes had some ingenious and I think preposterous answers to that but with really smart guys dumb answers are always interesting so I'm going to get to that in a minute okay now the way I like to lecture is is I talk for a while and then I stop and take questions and then I'll talk some more okay now this is the part where we have questions and I take a drink of water just to summarize what I said so far there are the philosophy of mind is about aesthetic questions and they're situated historically in a in a in intellectual context where we're trying to give a consistent account of all of reality and it isn't clear how we can fit the mental part in with with what we know from the fundamental sciences historically we are the inheritors of a tradition the tradition is called dualism that says there are two kinds of things in the universe mental things and physical things I think this view hasn't got a chance I mean I think it's false but I think something like it is widely accepted the philosophy of mind is one of the areas where there's I asked with psychology and cognitive science where there's a big gulf between what the general public thinks and what the professionals think I I think most members of the general public if you ask them they probably say well you see I got a mind and I got a body and some people have even told me they have a mind and a body and a soul how why they need that extra thing God knows sorry about that but anyway yeah they do think that they got these these three things I now this is des cartes view is very comforting to religion because it turns out that God is the infinite mind and because minds are indivisible you can't destroy them your mind is going to last forever it's last eternally your soul is indestructible even though your body will be destroyed the soul cannot be divided up in a way the body can be divided up I and as I said I think something like Cartesian dualism is still part of popular culture you there are popular songs about how I don't know I love you body and soul or that body is willing but the flesh or no the soul is willing but the flesh is weak or maybe it's the other way around maybe the flesh is willing and the soul is weak but they're all it's sort of mind and body she's always saying things like well mentally I really like you a lot but physic well you can fill in the details yourself I saw that some kind of cartesianism seems to be part of popular culture people that think they have a mind and body I the problem is if you try to spell it out in detail you have real problems making it coherent and consistent I'm going to tell you some of de cartes problems in a minute okay questions about what I've said so far now I see a lot of late comers and there are seats around if you want to I mean here's one over here and another one here and one here so if you there was a period in Berkeley when in the 60s when students appeared they'll prefer to sit on the floor and it was hard to get him into seats that when I first came to Berkeley it seemed to me any you could tell who the professor's were anybody with a tie on was a professor we may be going back to that era now but then there was a period in the 60s when anybody with shoes on was a professor but in any case if you don't want to sit on the floor there are places that are less uncomfortable okay questions about what I said so far everybody's up with us alright I'm gonna take a drink of water and then we'll go on terrific there's another seat here I I think we'll probably stay in this room I like the room are there more seats around yeah Oh question somebody had it quick yeah I have to talk louder yes I will yeah you bet I will I in fact I'm going to lecture on it in in more detail but let me say a little bit about it now I Descartes starts out by doubting everything and it's a very important part of his if this were a course in the history of philosophy I it's been a lot of time on this but he starts out by doubting everything and his purpose is to provide a secure foundation for knowledge but he finds this one thing he cannot doubt and that is the fact that he's doubting for if he doubts that he doubts then all the same he's still doubting so there's one thing that cannot be doubted is that he is doubting but if he's doubting he says he can't doubt his own existence whatever he doubts he can't doubt his own existence because the very fact of doubting is sufficient to guarantee his own existence so it turns out that he knows of his own existence in a way that is indubitable absolutely certain he can have no doubt about his own existence and there's a famous slogan in Latin it's koja tow ergo sum I think therefore I exist I in English I think therefore exist in French your calls don't just read I and this is probably a single most famous sentence in descartes and the idea is this come just called the Khajiit oh I think therefore I am and the idea is that in thinking I automatically am aware of my own existence and I cannot be mistaken about the I the fact of my own existence or the fact of what exists in my mind so I can if I think I'm in pain then I am in pain I can't be mistaken about the contents of my own mind they are known by the very certainty of the cogito the certainty of the cogeco guarantees that my self knowledge of my the existence of my mind and its contents is certain but when it comes to the real world with the external world I look and I see a hand in front of my face I can't have that kind of certainty about the existence of the hand because as Descartes I might be having a hallucination I might be deceived by an evil demon I the kind of direct knowledge that I have of the contents in my mind I cannot have of bodies well what is it that I'm aware of then when I see a body well that is a tricky question and we're going to spend a lot of time on it but the idea that he has is that when I see a material object strictly speaking I don't see the object itself I see an image in the mind that the object creates when it impacts on my nervous system and then the question arises well what's the relationship between the image that I see in my mind when I look at an object and the object itself and I cannot tell you what a disaster that question has been in the history of philosophy but you're going to hear more about it later in the course but the basic idea in Descartes is this you see a picture a mental picture of an object in the world but you can find out about the world because the object looks like the picture there's a resemblance rule between the picture in your visual system and the object itself by the way that the view is still common that you don't really see the real world you see only images in your brain that the real world creates I hope you had more sophisticated high school teachers than I did but that was the version we got in high school physics is you can't actually see objects what you see is the impact of the object on your nervous system and a lot of smart guys still believe that I reviewed a book by Francis Crick a very smart guy after all me the greatest biological discovery of the 20th century and the discovery of DNA along with Jim Watson Francis thought you can't ever see the real world all you can see is the impact that the world has on your nervous system and that's the view that goes right back to Descartes and Locke now I'm going to tell you in detail why that view is incoherent but that was his view de cartes view was you can't see the real world you only see the effect of the real world on your nervous system but you can be certain about your what the contents of your own mind because you have direct non inferential knowledge or the contents of your own mind okay now if you did that was a very good question if you didn't understand the answer don't worry because I'm gonna say a whole lot more about that you're going to hear an awful lot about the theory of perception and the question the problem for the theory of perception is what's the relationship between the perceptual experiences the conscious experiences we have in our perceptual system and the real world outside the perceptual system that is an essential question Descartes gave one famous answer to it it's called the representative theory of perception but it's not the only theory I'm going to tell you lots of other theories later okay any other questions that was a good one yes [Applause] yes Descartes got the mind and the soul are the same thing now I think people don't know what they think I I was astounded when I a student who told me that she thought she had a mind and a body and a soul now I thought you know maybe two ought to be enough a mine and a body but no I had some people think they got a third one but what's the relationship between the mind and the soul I would hesitate to ask cuz I doubt if there's a coherent answer to that I think if you're gonna postulate a mind then I don't see any reason to postulate another spiritual beast in there one ought to be enough a mind I and a soul ought to be the same thing incidentally there is a problem about translating from English to other languages there are two famous words in English which much English language philosophy is about their mind and meaning neither translates comfortably in the French or German so when a book that I gave you that I've assigned you to call intentionality an essay and the philosophy of mind was translated into French well they were very reluctant and translated as philosophy despite because place suggests a spirit you know the spirit is kind of gonna ooze out of your brain or something like that so they that translator was very cautious guy called it philosophy they say melt multo of mental states which sounds kind of foreign to me but I don't know and the same is true in German I mean one of the most ghastly words in German is Geist and that's without translation for mine because Geist also means spirit or ghost you know who wants the who wants to believe in the ghost well anyway if you think you got like if you think you got a mind in German you're in bed with a guys I don't know if you can get the guy's been anyway so there is a problem about these words and we're gonna hear more about them later okay any other questions all right now I'm gonna tell you some problems that Descartes had here is his picture I we have a body but we also have consciousness now the entity which is consciousness is a different entity from the body the entity which is conscious is a non material non extended entity it has no spatial dimensions at all and yet somehow or other it seems to be attached to the body so that's the first question for Descartes and I'm gonna tell you his questions and I might put the questions on this board if everybody can see it so the question the first question for cartesianism is what is the relation of M&B and that has got a famous name in philosophy that is called the mind-body problem and for most courses in the philosophy of mind I think most people spend most of their time on that issue what's the relation of mind and body but it's a serious problem for Descartes because as I told you if somebody hits my hammer with a thumb hits my thumb with a hammer that would be hard the other way it hits my thumb with a hammer there isn't any question that I feel a pain but how is that possible because after all the hammer is just a material object like any other and the thumb is just a material object like any other now how can there be a causal relation because the soul is not a material object it's not even it hasn't even got spatial dimensions it's not even spread space so how is it that my soul can feel a pain when there's just this ordinary physical transaction when a hammer hits one material object hits another how is it that I can feel pain okay that's problem number one for Descartes is they causal relation between the mind and the body it gets worse the other way in my soul I decide to raise my arm that's a transaction in the soul but then an amazing thing happens that damn thing goes up now how can it because after all all I did was make a transaction in the soul I made a purely mental movement in my soul I decided let the arm go up and Damned it went up now it only works in oddball cases if I here's an arm it looks much nicer than mine if I decide well that one go up too okay got nothing works it doesn't happen or let the chair go up doesn't happen but I do seem to have a special relationship to these chunks of matter that are attached to me I in that I can it some extent control them at will now I can't do everything I can't control my digestion well some Buddhists tell me they can I'm not sure I believe but anyway I can't okay so that's the first question for Descartes is what exactly is the relation of mind and body but it gets worse a second question is I know that I have a mind by the coach at oh by immediate inspection of my own mind I'm aware of heaven but when I look at you all I see is a body so how do I know that you have a mind after all for all I know you might be just a cleverly constructed machine and this has also got a name this is called the problem of other minds how do I know that other people have minds when all they all I can ever observe is their bodies in my own case I know that I have a mind and mental states by the khajit oh by just directly experiencing the contents of my own mind but when it comes to other people all I can ever observe is not the contents of their own mind but just the behavior of their bodies I have no reason for supposing that other people have mental states at all if all as I can observe is their body and you might say no no we do have scientific reason for supposing that they have mental states because just as in my own case so when I hit my thumb with a hammer I observe a physical transaction hammer hits thumb and I observe another physical event I cry out in pain but I know I cry out because between the impact of hammer on thumb and the cry of pain there was a sensation a sensation of pain so in my own case I observed a physical event followed by a physical event because as a mental event in between so in your case I observe a physical event followed by a physical event and by analogy I can postulate that there is this mental event in between that argument also has a name that is called the argument from analogy but that won't work we can try it out scientifically treat it as if it were a scientific experiment like any other I want to know whether or not I thumbs that are hit by a hammer I'm sorry to make such a painful example but anyway I'm sort of stuck with it for the moment I so I'm going to test it out so everybody we to bigger room but we get a bunch of us and everybody puts their thumb on the table scientific experiment here and I go around and bang each thumb with a hammer guess what this is the only one that hurts I can bang that thumb all day long and I don't feel a thing so I've got a scientific proof this thumb hurts other thumbs do not work the argument from analogy looks like it doesn't work because I can't make the analogy work since when I bang this thumb over here I can't feel a thing now there's a formal property that is wrong with the argument from analogy and that's this whenever you know something in this way by inference there has to be some non inferential way of [Applause] checking the inference if I know by inference that I have a wallet in my pocket because I can kind of feel the pressure of it well all the same there's a non inferential way I can haul a damn thing out and have a look at it but in your case how do I check the inference if I infer that you have a pain how do I ever check to see that the inference is valid now there's an extreme view that says well I am the only person that has consciousness and has any mental life and it's called solid system solipsism is the view that my mental states are the only mental states that exist now solecism is interesting in the history of philosophy in the Majestic crazy view you can imagine has been held by some famous philosopher or other but I don't know of any famous philosophers who were solipsistic told me well Viktor was a solipsistic I mean you have all that you go I look up the fic HDE but I have never found any any honest to Jon philosopher that I know who said of himself or herself I am a Sol obsessed I am the only person who exists in the universe my mental states are the only mental states that exist now you can say well that's because if somebody's a solid cyst what's the point of trying to tell us since we don't exist I mean I if I were a Sol abscissa there aren't any other people but that leads to another problem about solipsistic again it is peculiar in the history of philosophy I in that your solipsistic refuted by me if you come to me and say I am a solipsistic xizt you don't have any thoughts and feelings I don't think oh my gosh maybe she's right maybe I don't I don't think that at all I think well ok hi nutty philosophical views are everywhere and she happens to hold one of them so I that is the first odd asymmetry about salep system is that your solecism is instantly refuted by me I don't when somebody tells me there are solid cysts I don't think well maybe they're right maybe solid system is right way to go I know they're mistaken on the other hand this is the flip side of that my salep system is not refutable by any of the standard means my uncle Chet was reliable about a very large number of things I could call him about cars income tax who to vote for in the election he had rather extreme Republican views but in any case very reliable guy but I can't call him up and say uncle Chet do I really exist because of course any answer that he gives is consistent with my solipsism that is the illusion that I have that he is expressing his own psychological opinion is just an illusion if indeed Halep sysm is true so my sight your solids ISM is you stantly refutable by me but my salafism isn't refutable by any of the standard tests now there are different degrees of solecism the most extreme version of soloff's is nobody has any mental states except me indeed maybe the only thing that exists in the universe are my mental states that's that's the strongest version of salt system there's a weaker version that says well maybe other people have mental states but we can never know all we can ever know all we can never be certain about is our own mental states we can't be sure that other people have a mental states and there's a still weaker version that I think is tempting to that is more tempting to people and that is the view that well other people do exist and they do have mental states but we can't really be sure that they're like ours so I have a certain experience that I call seeing Ren when I bought this damn thing in Shanghai is starting to look the worse for wear that I call seeing red but for all I know when you see it you might have an experience which if I could have that experience I would call seeing green that is I don't know what the character of your experience is just by the words that you use notice that we would still make the same discriminations you'd point to that and say yeah that's red and I point to it and say it's red we both stopped when the light turns red and go when it turns green but how do we know that the inner experience isn't different it might be the case that unknown to us there's a section of the population that has the experience of green that other people would call seeing red and the people that call their experience seeing red the other people would call seeing green notice none the behavioral tests will identify this because what the behavioral tasks ask you to do is discriminate you have to tell the green patch from the red patch but they did the color test the airforce color blindness test don't tell you what the character of the experience is like so there's a kind of solid system it's a weaker version that's still left over and that's the one that says yes other people do have experiences but we can't really know what they're like maybe they're different from our experiences in the course of the semester we're going to consider a lot of different versions of scepticism there are lots of kinds of scepticism little rise but I think main skepticism about the external world can they ever really know that you're seeing object skepticism about the future can never know that the Sun will rise in the east tomorrow but there's the kind of scepticism that I think has the most grip is skepticism about other minds even people you're very close to you always feel well there's in it there's a part of them that you're never really know that you're never really feel completely confident about and this comes out when they do something that's utterly surprising and what we do in those cases is we cheat we tell a narrative that makes the surprising event makes sense so I she ran off with a circus after she had was in a successful I graduate student career then you cheat you tell a story they said well really we should have been able to guess all along that she was gonna run off with a circus or worse yet I hope this never happens to you but when I was an undergraduate a couple of friends of mine committed suicide and in both cases it was a terrible shock but I noticed that what I and my friends did was then retell and narrative so that it made sense well of course you could expect that that was going to happen or of course he was always she was I had this possibility and I think that's cheating in a way if you can't make the prediction now then it shows there is something with your awareness with your understanding of the other person so I mentioned this in passing I don't think salep system is a is a serious possible view but I haven't argued against it I'm just telling you that it's a problem for Descartes how do we know that other people have mental states but I think of forms of philosophical skepticism this one has a kind of grip that say skepticism about induction or skepticism about the external world don't anyway I'm gonna go through with some of these my cards got a whole lot of problems and we're gonna hear more about him okay now besides the question of the mind-body problem how can there be a causal relation there is a problem about other minds but that leads into a third problem for Descartes and that is skepticism in general and skepticism in general how do we know anything about the world other than the contents of our own mind and that is very much related to the problem of perception what is de cartes account of perception now somebody asked me a question about known directly and indirectly and I'm now going to go into some detail here is the puzzle if all that I can know with certainty are the contents of my own mind then how is it that I can claim to know a whole lot of things that are not about the contents of my own I know right now I that in the eastern part of the United States there's a city called Washington DC and that there is there a government and that in the government as a president Barack Obama and so on I know all these things all of that goes beyond the contents of my own mind how can I claim to know that now the basic means that we have finding out about things is perception so any philosopher who cares about knowledge has to have a theory of perception and I'm now going to sketch the leading theories of perception how are we doing for time let's take questions about I've covered an awful lot of philosophy so let's take question about what I've said yes yeah yeah okay no they said III like this kind of answer here's I may repeat it for people in the back I we we have other methods of finding out about what's going on in your minds other than just asking you we could put a scanning device on your brain and now there's a sort of magic bullet that a lot of people use in cognitive science it's called magnetic resonance imaging MRI and the most fun part is called functional they use a small F functional magnetic resonance imaging aware I not had this I've had MRI it's boring because I had one heavy-duty MRI where I had a lie there in this cigar tube for two hours and I'm not a patient guy I lie motionless for two hours anyway but you can see what's going on in the brain usually it's pretty boring but anyway and there are all sorts of interesting things you can discover one of the things is nice is you get different parts of people's brains to light up when they're thinking about different things and you give them different problems and they're all the stuff this stuff is terrifically exciting a friend of mine did some experiments in San Francisco at UCSF and she found different parts of men's brains light up when they're solving the certain problem Tower of Hanoi problem from women's brains women use a different part of their brain for certain types of problems I don't know what the feminists are going to make of this but in any case this is Louann Brizendine who is a a neurobiologist at ucf did this research okay now her question was well if we found that the pain centers of the brain light up when I hit the thumb doesn't that solve our problem right okay what Descartes is gonna say is that's a physical event like any other C among physical events in the world there are increased neuronal activity in your brain so what what we want to know is how does that connect to the soul C pair is it let me put the extreme a problem for Descartes and I haven't mentioned it yet but it's it's it's on my list it's a solar speaking the next one and that is what is Descartes gonna tell us about this is problem number five animals each of us has an immortal soul and the soul is somehow attached to the body but what about animals do they do have an immortal soul now Descartes has a problem if you say no no animals don't have an immortal soul then it's gonna turn out animals can't have any mental states the animal cannot literally be in pain and indeed that's what the Cartesian said now Descartes was a little bit embarrassed by saying this and he said well you know maybe I'm wrong about this but as far as we can tell animals do not have mental states and his followers malleable and grillings and I'll tell you no spell our names later I said definitely animals do not have mental states if you see a dog hit by a car or this is 17th century you see a dog hit by carriage and the dog is in terrible pain screaming and howling in pain don't feel any pity at all it doesn't feel a thing it couldn't feel anything now I any dog I'm a dog owner I'll bring Gilbert you want to see a conscious dark gilbert is a conscious dog any dog owners gonna be outraged at that but it's given their assumptions it's perfectly reasonable think about it when I am hit by a car my body doesn't feel anything my body's just a material object like any other feeling started my body we like feeling it would be like feeling sorry for another car car a hits car B you don't think what car B must be in terrible pain look at that fender now similarly with a guy if the guy is hit by a car and his fender in the form of his thigh is mashed up the guy doesn't feel anything the thigh is just a material object the point the the entity that feels the pain is the sole all right humans can feel pains not because they have pains in their bodies but because they have a pain in the sole how does the body connect to the soul well we'll get to that that's one of de cartes chief problems but animals can have pains because they haven't got souls now who knows maybe we're wrong maybe they do have souls but that's pretty tough to say that because if every flea has a soul well think of the number of insects in the universe heaven is going to be very overpopulated with I with species of souls that you may not want to hang out with simply well I won't go through the details but Descartes has a real problem here how if the body can't feel anything the body can't feel anything because it's just a material object a body won't no longer feel no more feels things in a car or a chair can feel something then if the if the body can't feel anything and animals have only bodies and not souls then it follows animals can't feel anything okay what is the nature of perception this is a crucial question how much time have I got how are we doing let me look at my water oh we're not we got a lot of time okay terrific I am now going to give you a five minute sketch of theories of perception then I'll stop four more questions I think that the pre theoretical a pre philosophical pre scientific notion of perception is that typically when we see something we just literally see the damn thing here is this cup I look at it it's in broad more or less broad daylight light waves are reflected off of the cup they strike my eye visual system a series of transactions are set up and an event takes place that's called me seeing the company and I think in very simple pictures so here's how it works here's the cup here's me and I see the cup I this I represent the arrow going outside of me in fact if it's a visual experience it's all literally in my head but the point about the visual experience is it reaches up to the object itself there's a name for that and we're gonna say a great deal about it it's called intentionality the press the feature of the mind by which it's directed at or about other things and I represent the arrow there because I want to mark the intentionality of the conscious visual experience it reaches right up to the company now this view that says you really see objects in the real world it's called realism about perception or in the version that I just gave you it's called naive realism and it's called naive realism by people who don't like it because they think people like me will believe it are naive to believe so that's naive realism now here I think naive realism is right and you should watch out because I I'm gonna be telling you other views and you want to make sure I don't cheat and make them sound dumber than they are but anyway here are the other and here's an embarrassing thing about the history philosophy none of the great philosophers were naive realists at least nobody that I know since a Descartes revolutionized philosophy in the 17th century there are no great knife Descartes Locke Berkeley Hume can't I mean it's one catastrophe after another and it gets worse when we get into the h's Hegel and all those other Germans whose names start with H I can't even tell you their names but in any case nobody's a naive realist and a naive realist raise their hand I raise my hand but nobody else hardly anybody else's in my realist and none of the great philosophers are naive realism why not well there are two classes of arguments to refute naive realism one is called the argument from illusion that says the naive realist cannot account for things like hallucinations the illusions a supply said confidently and smugly I see a cup but suppose it's all elucidation what do I see then well I see something even if it's only a hallucination of a copy but now what is it that I see when I see a hallucination of a cop well you might say I see my own experience I see my own sensation and philosophers have evolved a term for that they call it a sense datum the plural is sensed data but now if in the hallucination case all that I see is a sense date and the hallucination case is indistinguishable from the non illumination case from the so called vertical case then I should see in all cases what I see is a sense datum and then the question arises what's the relationship between sense data that I do see and real objects that I don't see now I'll tell you in advance I think this move is the greatest single disaster in philosophy over the past four centuries Cartesian dualism was a disaster because it left us with skepticism but the argument for sense data makes the problem of scepticism impossible to solve for reasons that I'm going to tell you in detail but in any case at this point we can say what happens when you get the argument from illusion is that this line gets driven out of the horizontal where it reaches up to the object and becomes itself the object of perception all you ever see our sense data here's the object out here here's the sense data that you see what's the relationship between the sense data you do see any object you don't see de cartes answer and Locke's answer was the sense data are like pictures or representations of the object they resemble the object and the reason they can resemble the object is that the object causes the sense data okay now that's the conception that you get in Descartes and Locke that's called the representative theory of perception I'm giving you sort of the names of numbers and the players here and the representative theory sometimes called representative realism because it says there's a real world the representative theory says you can have knowledge of objects in the world on the basis of perception even though you don't actually see the object all you see are your own sense later because the sense data is a kind of picture of the object the sense data can enable you to get information you infer the features of the object from the features of the sense data okay now Berkeley and Hume looked at that picture and said it doesn't make any sense why well we're told that the sense data that I do see resembles the cup that I don't see can't see but how can something that's invisible look like something that's visible then as I'm told the sense data looks a lot like a cup oh yeah but the cups invisible I mean if a guy says I got two cars in my garage they look exactly alike but the one on the right is invisible well that doesn't make any sense and that's what these guys seem to be telling us is that yes you can't see the object but you can know about it because the sense data you do see looks like or resembles the object you don't see but the object can't look like anything it's totally invisible all right now then occurred one of the great disasters again in the history of philosophy Berkeley looked at that picture and instead of going back to naive realism which is what I wish he had done what he did said is this let's get rid of all that crap and then the only things that exist are minds and ideas and that's Barclays view and that view is called idealism or more commonly called phenomenalism and the phenomena theory of perception says all you can ever perceive are your own experiences and that's what objects are objects just are collections of actual and possible experiences all right let me tell you the names of some of the players here Descartes and Locke our representative theorists Berkeley and Hume are phenomenal and Humes thought that naive realism is so obviously false that no serious philosopher could believe it but in contentiously says if you're tempted to naive realism he doesn't use that jargon but that's what he's talking about he says if you're tempted the naive realism just push one eyeball and if you push I don't do this habitually you'll get a headache but but if you push one eyeball you'll notice that you see apparently twice as many things as used to see before because you've got eye binocular vision and by unfocused I won't tell you the whole story but now Hume says the naive realist would have to say everything doubled the population the class doubled if naive realism were true but I didn't double so naive realism is false okay so that's one argument against naive realism is the argument from the illusion and that certainly influenced Locke and Descartes I'm actually asking all these guys accepting a human Berkeley and Conte and everybody else there is an argument that's more influential in the 20th and the 21st century and that is called the argument from science so the argument from illusion says there's no way that naive realism can count for illusions the argument from science says we know scientifically that naive realism is false why if you do a study of the physiology and the physics of perception what do you find well light waves a strike I the eye both eye they pass through the lens and they stimulate the famous rods and cones in the retina there is a series of electrical impulses set up in the optic nerve that passes over the optic chiasma it goes to the lateral geniculate nucleus the signal does then it goes from the LVN which is kind of in the middle of things back here to the back of the brain to the visual cortex which is back in this area and then there's a whole lot of feedback back to the LGN and then there's a whole lot of feed forward into forward parts of the brain until an amazing thing happens you seen something see when you actually see this what actually is happening is a series of training action that begin with the stimulation of the photoreceptor cells those are the famous rods and cones and then it goes to the other of the five layers of the cells now let's see if I can remember them the horizontal of bipolar the amacrine yeah but I can remember it even at 9:00 in the morning and he and the ganglion cells and then the ganglion the eyeball really is a kind of extension your brain the ganglion cells kind of ooze into the optic nerve and the whole thing gets to the LGN what's going on in the LGN I asked the famous neurobiologist we got a Nobel Prize for this kind of crap what's going on in the algae and he said don't ask and only rather than tell me oh hi anyway hi then it goes back to the object now but then I there's an amazing thing it happens at the end of this whole process just see something okay now what do you actually see what you see it's not a cop for God's sake what you say is the thing going on in your brain the thing going on in the frontal lobes which is the actual visual experience now this creates a problem of its own this view because it what you see is what is going on in the frontal lobe then who's looking at it well it looks like you are going to commit something called the homunculus fallacy homunculus just means little person little guides and the homunculus fallacy I says well what happens when you see something here is a object what happens when you see something is that the object sets up a series of stimulations of the kind that I described and they go back and then back there you see in the brain itself there's a little television set and there's a guy sitting on a chair watching television and he's got the remote and so he sees the little guy sitting back there is that what actually sees the object but he does it by seeing a picture on the TV screen now you'd be so that's such a ridiculous fallacy you can't imagine anybody making it but a lot of people do make it implicitly or explicitly the problem with it immediately is well if the little guy sees the television screen and this is how seeing works there must be another little guy inside his head with a real little television screen and then if you've ever had a philosophy course you know that's an infinite regress so the homunculus fallacy is a fallacy however it's still with us and indeed again one of my favorite scientist Francis Crick said well there's no way that we can account for the operation of brain without supposing that there is a homunculus in there I he thinks they can avoid the infinite regress however I this is the the second argument for the sense data theory is I think more convincing at this phase of intellectual history than the argument from illusion the second argument is the argument from science and the second argument says we know from science that naive realism is false because we know from science that you can't see the world as it really is all you could ever see is the impact of the world on your nervous system but when the world has an impact on your nervous system what it creates is an entity that you can actually see and that otherwise perceive the same story would work for touch or hearing or anything else is just vision as everybody's favorite because we learned so much more envision what you actually see is not the real world you see the effect of the real world on your nervous system and we might as well have a name for those effects call them sense data then the question arises what's the relationship between the sense data that we do see and material objects that we don't see Bertrand Russell put this very as his usual way very elegantly he said look when we do science we have to presuppose naive realism because we got to suppose when we look at these laboratory eye objects the test tubes and the and the meters and the gauges that we're really seeing something so it looks like you can't do science without presupposing naive realism so says Russell physics presupposes naive realism but physics biophysics we mean science in general physics shows that naive realism is false therefore if naive realism is true it's false therefore it's false in general if you can show that any proposition implies its own falsehood then you can show that that proposition is false so in Russell it goes as follows physics presupposes naive realism but physics proves that naive realism is false therefore if naive realism is I underlying physics I then I realism is false therefore naive realism is false and that's then you got a problem well how do you account for perception if naive realism is false okay now just to summarize what I've said and this is essential is it's going to be very important for other material in the course how does the mind relate to objects in the world the standard answer is by way of perception but then what is the correct analysis of perception well there are three theories of perception or at least three that I can draw diagram so I can't draw Conte I'll tell you about Conte but I can't draw a picture of it the three theories are naive realism that says you directly see objects naive realism is refuted by two arguments the argument from the illusion and the argument from science if naive realism is false then you're left with a problem what's the relation between the sense-data you do see and objects you don't see and there are two answers to that the sense-data are pictures or representations of objects that's called a representative theory of perception and the other extreme answer is all the object is is a collection of sense data actual sense data and possible sense data when you buy a piece of real estate what you're buying is an infinite amount of possible sense data as mill said an object is just a permanent possibility of sensation okay now I've covered a lot of philosophies so I want to catch our breath and take questions about that I've now we're now going through the questions that Descartes had and these two questions I'm lumping together what's the relation of skepticism in general how can we know about objects and states of affairs in the world and the answer is we know by perception but then the question is what's the analysis of perception and Descartes gave us a version of a representative theory questions about all of that or about anything else I've said let's I'm going to take another drink with and catch your breath catch your breath and think of the questions well I got a little bit of time okay well I want to get through some more material yeah what yeah physics according to Russell proves that you don't really see objects you just see the effect that the object has on your nervous system and I the best a book on this I reviewed it for the New York Review and it's called the quest for consciousness by Christoph Kok a Kaos eh and what Christoph does is described in great detail we actually know more about this than we knew when I first got interested in the brain it described the actual path that the visual stimulus takes until it produces an experience in the brain and then the crucial question is well if you have this conscious event in your brain which we can identify with MRI I then isn't that what you see what you actually see is the impact of the external world on your nervous system now I don't believe that but I'm telling you what these other guys believe I think that's perfectly consistent with naive realism to say yes when you see an object there is a series of neurobiological processes that begin with the stimulation of the photoreceptor cells and and when you actually have the visual experience but it doesn't follow that all you see is the visual experience what you see is the object itself but now the naive realist has got a question well what about these problems from what do you see then when you're having a hallucination what do you see by the way philosophers talk about hallucination as if they're the most common thing in the world never had a hallucination you know I've never I've never seen pink elephants maybe I didn't have enough to drink but I've never had the standard hallucinations but on the naive realist view when you have a hallucination that's what it looks like you have the experience but there's no object on the end that's the correct drawing what you're gonna hear more about this stuff but I wanted to give a picture of Descartes and his problems okay other questions yes at the back now don't stop your notebooks yet we got a lot of time yes how do i account for things that exist that we can't perceive that is another problem for anybody's theory of perception is that we want to postulate the existence of entities that you can actually perceive and the way that we normally do it is that we get them to produce effects the electron will produce an effect in in the cloud chamber or in the bubble chamber and it's the it is the causal effect of the electron that enables us to infer the presence of the electron so there are unobservable entities but notice the postulations of the unobservable entities rests on the fact that we can actually perceive observable entities and the unobservable entities have effects on the entities that we can perceive now there's another question and that is well what about entities that don't have any effects like numbers if you think well there's only one even prime number the number two how do you know about it if you can't see it well one philosophical problem at a time okay today I'm talking about de cartes problems about his mind-body and remind me later in the course moment when I give you a full blown theory of perception what I want to say about the inference to the existence of unperceived entities no question we do that and indeed we couldn't do science without the assumption we can establish the existence of unperceived entities okay now let me tell you where we are I am gonna keep going with this as a sort of the introductory as the way of getting into the philosophy of mind I think des cartes dualism is a good way to get into it because everybody has a feel for it you all are brought up in a culture where a talk of the mind and the body is perfectly you feel perfectly at home with that if I use the Aristotelian jargon of substantial forms you wouldn't know what the hell I was talking about but the idea that everybody's got a mind and a body that fits in with our tradition there are lots of religions that are at home with that so I'm gonna continue going with that roughly speaking the course will divide into two parts there's a part where I'm gonna do mainstream philosophy of mind what other philosophers think the philosophy of mind is really about I and I'm going to spend about half of the course on that because you ought to know it then I'm going to tell you what I really think we ought to be studying and that is about how the mind works and that's the theory of consciousness and intentionality but in order I to get to what I think is the really important stuff I have to get you have to have a complete feel I want you to feel completely comfortable with the history of the subject and with and with mainstream philosophy of mind which i think is a series of horrendous mistakes and if you want to look ahead and look at that little book I wrote called mind a brief introduction one guy said to me boy the lectures are pretty close to the book you bet they are I wrote the book on the basis of the lectures so if you want to know the kind of stuff I want to be saying look at that little book mine and and I hope those who think who think you know it's not all that interesting drop the course I need to get everybody in the course and wants to get in okay I'll see you on Thursday

Channel: SocioPhilosophy

Views: 147,658

Rating: 4.8871121 out of 5

Keywords: John, Searle, Philosophy, of, Mind, University, California, Berkeley

Id: zi7Va_4ekko

Length: 76min 27sec (4587 seconds)

Published: Sun Oct 09 2011