The Nature of Arguments

hello there I'm Mary Ann Tolbert I'm director of studies in philosophy at Oxford University's Department of continuing education we're about to start a six-week course called critical reasoning for beginners and we're going to go through looking at how to recognize an argument what arguments are the different types of arguments that's deduction and induction and we'll be looking at how to set out arguments logic books style how to analyze them then we'll be looking at how to evaluate them and finally we'll look at fallacies which are arguments that look like good arguments but which are bad arguments okay so we're going to start off on the first week with how to recognize arguments and what the nature of an argument is right okay let's get started you're all here to do critical reasoning okay why why why do you want to do critical reasoning a couple you tell me what what you want to do it for what do you think you can't do now that you want to be able to do five into this course I'm going to sharp my sense of argumentation sharpen your set of argumentation is there anyone you want to argue with in particular asking why it won't work you know you've been married to God justjust turn speaking but particularly our political arguments and debate right okay so no man under here some detect the floors in other people's arguments you ought to be able to take the floors and other people's arguments okay what about your own arguments yeah that too because it that's very important so one of the things I'll talk first day is something called the principle of charity and you'll see where it well talk about that Donald I also and they were to get lost there's a valid point maker so to actually be able to have conviction of what I'm saying if I believe in it not let someone more intellectual and eloquent beat me down right okay a lot of one thing that will help I mean it won't do the trick completely to support that confidence has to come for you but it will help to feel that you know where you are in argument so when you try psychology yeah ha actually that's how I came to philosophy funny enough doing it something like that so I did an Open University course I was a mature student not very mature 26 and I said it was an open University cause they did logic in those days all symbolic logic and I tried to do this logic and I found it's so difficult really really difficult and I sat up all night and still trying to do it and in the morning I realized that I've had such a much nicer night much better night than I'd had with all sorts of other things you might stay up all night to do I've really enjoyed it and that's what got me into force to me in the first place I came out even thrown out of school at 50 and I came on here eventually eventually that took quite a long time but I have never lost my love of philosophy I've never lost my love of learning and that's all down to philosophy this confidence you have an argument because if you can learn how to argue properly you can nothing is hidden from you in principle it's always possible to tease out the arguments and to evaluate the arguments and to take yourself that step further and so I hope that after this series of six lectures of course you're not going to go away knowing all about logic and knowing all about how to reason properly but I hope what I'll have done by that time has given you more confidence and giving you a feeling for the fun it can be so that you'll go away and and start looking yourself and I'd be very happy to pass on some reading or give some other ideas of how you might do that right okay let me tell you about Monty Python I'm sure some of you know about it but what it's called the argument clinic and one man AFRICOM is name goes in and says John Cleese sitting there and he says is this the place for our arguments or something like that John teases one of it is well no you haven't yes I have no you haven't yes I have and this goes on in since you're not arguing you're contradicting me and John Polly says no not because you tomorrow no I'm not yes you are and so it goes on then presses a bell that's the end of the session he said but that wasn't five minutes yes this was I'm not arguing and so on and and that's supposed to be an amusing introduction but what I wanted to move on to is the idea that John Cleese had it wrong of course I'll give it isn't a set of contradictions it isn't a set of just you say one thing and I say another that doesn't get us anywhere part of the point of argument is to move us on from where we are to somewhere a bit further just imagine if the only way we'd find out about the world was through our senses if we see one thing and form one belief but not take that belief and move on to it to another belief so you would say that that's blue and the carpets blue but you couldn't say when two things are the same colour they match therefore the chair and the carpet match do you see whatever argument takes us from where we are to where we want to be or sometimes where we don't want to be we'll never get very far and without argument yes we're awash with technicians here okay so let's have a look at the definition of argument an argument is a set of sentences and I put sentences there after you wouldn't believe it's only half now wondering whether I should what statements propositions little expressions of statements or something but I'm looking sentences and anyone wants to quarrel with that's most welcome to do so a set of sentences starts at one of them's being said to be true and the others are being offered as reasons for believing the truth of the first okay that's all there is to an argument I put others with the F sin bracket here because of course it we might say that one thing is true on the basis of just one other sentence so here's an argument it's Friday Mary Ann always wears jeans on a Friday so Mary Ann will be wearing jeans today okay that's a set of sentences that is as a matter of fact an argument okay what are the sentences tell me what the sentences are this is an easy question to allow you into a false sense of security it's Friday that's one sentence okay it's um I've got a cholera Asterix I've gone straight on to the other sentence but that doesn't matter it is Friday as a sentence okay next one I told you these you Marianne always wears jeans on a Friday that's right so next one having a Merriam what we're going to use today okay those are the sentences that make up the argument exactly so and now here's a bit of tech technology terminology for you've got a technology focus on a conclusion is the sentence being said to be true and the premises are the sentences being offered as reasons for believing the other one okay remember that might be just one there might be just one premise that doesn't need to be - there could be 20 premises but but what makes something a premise and what makes something a conclusion is the role that they're playing in the argument the function that they're performing so here's the argument again what's the conclusion of the argument that's right yeah that's the conclusion because that's the one we're saying is true and what are the premises that's right so though there are two premises to this argument of one conclusion okay very simple stuff so there's the conclusion in red Marian will be wearing jeans today and the premises in green and it's very important to distinguish arguments from sets of sentences and let's see how to do that because an argument is a set of sentences but it's more than that there's more to an argument than a set of sentences question it back I'm very happy to take questions if I think they're going to go on too long I'll shut you up and put you on to the question time or if I think it's complicated or something but I was I'm classrooms to take yawn well the question is presumably premise depends on another because it's Friday's relevant until you know that Mary nanometers in that particular argument yes and that's good question let's go back to it and I actually I'm very happy for you to ask questions because if you do it might be a clarification clarification question like that one which is quite useful and if you look at that let's get to that one and if you take out that premise you might still have an argument you say it's Friday so mariann will be wearing jeans today but what have you done location as you describe it that's right you've left a suppressed premise haven't you because that wouldn't be a good argument it would still be an argument actually because you'd still be giving one sentence as a reason to believe another one and but it wouldn't be it wouldn't be an argument that could possibly be convincing were it not for that so we often leave premises suppressed in an argument but usually when because of the context or because of something that we can assume we assume that the person knows the other one so if we all knew if you knew that every time I ear well that every Friday I wear jeans if you all knew that that would be an argument without the second premise so thank you for that people that people didn't have that assumption is that what will return the non sequitur yes yeah well done and we'll say something more about maintenant sectors not today probably the later of course you could actually say whereas jeans on Friday she is wearing jeans today leave out then right yes you could you could I mean that would be a different argument but it would be a nod yes well Moo that would be a false argument hold that one we'll come back to that in a minute and you'll see what I meant to say about that but I just want to note that um okay I'm going to move on because yes you can make an argument out of it well let me just move on and show you exactly what I'm going to say there okay and it's important to to most arguments from sets of sentences sexy sentences that are not arguments might I have no relation at all between them or they may have between a really relation other than that characterizing an argument for example a set of sentences might be consistent ie such that they could all be true together without being an argument do you see what I mean or they could be related by all referring to what's really Mike and they could be related in that way without being an argument do you see what I mean lots of different ways sets of sentences can be related but the relation in order to be one of argument it's got to what it's awesome good in order to be an argument has got to be one sentence that's that you're putting forward as being true and the other sentences or sentence is a reason for believing that thing that's the relation that characterizes an arguments nothing else and here's a set of sentences that isn't an argument the sea is salt Melbourne is in Australia but it's very easy to make it an argument the sea is salt therefore Melbourne sin Australia now do you think I've made that an argument or not no why not you'll see why I'm saying this it's a what there's no link between so you think that my putting their foreign doesn't make it an argument okay let me tell you a little story okay we're we're doing a panel show okay we've got to find out things and and find out other things and then come back you will win a huge prize now we're particularly ignorant contestants here and we don't know whether the sea salt we don't know madam L burns in Australia but we do know that if one of these sentence is true so is the other okay that's all we know we know we know if one of these sentences is true so as the other so now we must find out whether one whether either of these censuses is true so half and half of us run off to see whether the sea salt the other half strong enough to find out Australia and the Melbourne since Australia sorry to see assault ones come back first they say the sea assault therefore Malcolm's in Australia hey is that an argument what do you know that's pretty good argument isn't it if what I'm doing there is I'm doing the reason I'm saying Melbourne is in Australia is true on time and I'm giving a reason for believing it namely the truth of the seas being salt fair enough is it an argument and what Servilia ok it was an argument before I gave you the context actually because arguing is something that we do with sentences ok it's we do them because of all sorts of things to do with our background what we've just found out our desires our hopes our fears our intentions things like that arguing is something we do and we can do it in any way this is why the idea of artificial intelligence and which was taught about a great deal a few years ago is getting frankly nowhere and the reason it's getting nowhere is human beings can see the relevance once the context is provided that a computer so far can't see I mean fingers crossed that we will be able to deal with this one but the fact is either the minute I give you the context you can see the argument are you some is this just content or is it only only implicit sentence that the fact that we have explicitly said those must be true one is true you're you're absolutely right that in fact though you might say no a lot of you could say there's a suppressed premise in there which is that if the see assault then Melbourne is in Australia there and I've given that by giving the context if you like so if we were gain contestants in that situation I wouldn't have to give that suppressed premise because we would all know it but but again well done so I think does the point at the back rest premise is the same as context no no it provides in the context I enabled us to see the suppressed premise if you like and because just at the moment there's no suppressed premise that we can see I mean we don't see why that's an argument you want denied it was an argument because you can't see the relevance between the two what I did was make one relevant to the other and in doing so I provided you with the premise that that was suppressed so there's a suppressed premise which is a sentence because premises are always sentences and that's what I provided by providing the context that's right that's I know this is a very interesting okay very interesting question what you're confusing I apologize is causation and entailment the premises the premises the premises of an argument do not cause the conclusion to be true okay if that's a person that's a premise do you think that what's caused me to wear jeans today is these two things not necessarily I mean it might be or it might be then actually I wear jeans on a Friday because to commemorate the first pair of jeans that my mum ever bought me or something I can't think of a good reason for my invited I might wear jeans every day yes exactly so so and the fact that a and B together entails EE doesn't mean that a and B cause see okay and when you say that the C is salt doesn't cause Melbourne to be in Australia you're quite right but saying that the sea is salt therefore Melbourne in Australia isn't implying causation of any kinds okay ah you ignore them and what again that's a very good question I'm glad you asked it and let's give some sea salt one loose well actually we could do it with a Mary Ann one as well because there are lots of people called Mary on other than meat in the world and all that it means is if Mary Ann is there any Wells called Mary Ann in this room all right put up your hand if you're called John this is Titus is happy okay there are no John's in this room that's just me you're like is there anyone else called Mike Mike - Mike's in this room if I have if I say Mike is tall okay at the moment that time vigorous isn't it it has two meanings I could be referred to that Michael that Mike and one of you may be short in which case would be false as one and true of the other but what I've actually got here is two sentences and how complicated I'm going to get here there's a type of sentence I have no opinions believe it or not that was another thing that fell off the list would you mind that you can't see this yes you can imagine it okay Mike is tall is what it says now if I could actually look forget Mike let what John is tall there now if I thought John is tall out there that has no meaning doesn't live it in the context of this room in the sense that there's nobody to whom John refers as we know okay but I could use that sentence John is tall to say something from type in the same way here is a sentence type that could be used to say things and I could use this type of sentence to say Mike is tall or I could use the same sentence to say Mike is tall but those are two different tokens of the same type of sentence see what I mean so just as that's one token of the type chair and that's another one and this is one token of the time being and that's another one Mike is tall is one token of that type of sentence and Mike is tall is another token of that type of sentence so actually if you have to Melbourne you can have two arguments that that could be it could either be the C assault there for Melbourne which is in the Northern Territory is in Australia or Melbourne which is in thank you Victoria is in Australia for a dollar or one no not in Derbyshire because that would falsify that moment unless there's a Derbyshire in Australia until it yep I'm going to hold over that question and I'm going to take it together with with your claims that beyond that's false okay and I'll come back to it shortly okay so and arguing is something that we do with sentences weaker any sentences could form parts of an argument there's no such thing as a sentence that couldn't be part of an argument and what makes it an argument is the fact that we are making an argument claim we're putting forward one sentence and we're offering the other sentences as reasons to believe that sentence so you cannot recognize arguments by recognizing the sentences that are in arguments you've got to recognize the relation between the sentences okay that's a look at these which of these sentences are arguments right who thinks that this is an argument okay no one else okay why do you think that's an argument he's making the assumption the storm clouds formed in the sky and the storm broke because the clouds formed the side bracket does that make it an argument because that word because is very difficult because distinguish closes and reasons for something okay there can be a causal relation between two events so a causal relation between two events and there can be a rational relation between two sentences or two beliefs okay and we tend to use because after both of these types of relation but these are causes and these are reasons and you were making them and you shouldn't be worried about making a seraph as it was a very very common one you were thinking of the causal relation as a rational relation but it's not is it okay so that's not an argument because always saying is that actually three events happen don't we Percy clouds formed then the sky blackens then the storm broke and there may be a causal relation between them but we're not saying that these two are reason for believing the other are we with me this one is this an argument but yeah I don't you think yes yes okay which is the conclusion and the premises that's right Manchester's North Oxford Edinburgh is North Oxford sorry forgot anyone's north of Manchester and it was North Oxford is the conclusion okay so this one is since Manchester in North Oxford and Edinburgh is north of Manchester Edinburgh is north of Oxford Edinburgh is north of Oxford is the conclusion the other two of the premises that's definitely an argument okay which is floats because witches are made of wood and wood floats is that an argument or not put your hand up if you think it is an argument okay that's not good you're quite right what's the conclusion which is float okay and then the premises are wood boats that's right notice that the conclusion is that the front here doesn't make any difference does it because what makes the sentence of conclusion evolved in order to compromise no because it might not follow from the other two premises it might be a bad argument what makes something a conclusion nope I wanted that in sense as well well even if you had it in prep in argument what it wouldn't have done come on somebody it's the one you're saying is true that's right your so you're saying this is true because of the others and whether because is a rational because not a causal because okay and let me tell you again the only thing that makes a sentence a conclusion or a premise is the role that it's playing in the argument okay if it's playing the role of being the the sentence for which you're arguing then it's a conclusion and if it's playing the role of a sentence for which the story which you're offering is a reason for believing the other one then it's a premise okay that's the only thing that makes sense it's a premise or a conclusion well we'll come to drouth in a minute - truth is you're quite right stick the truths very important but not just yet and notice incidentally that there's no there's no reason why a sentence has claimed the role of a conclusion in one arguments can't play the role of a premise in another argument do you see what I mean that's why it's very important that what makes them a premise or a conclusion is the function they're playing the role they're playing not anything intrinsic to the sentence music it was intrinsic to the sentence you'd have a sentence that could only be a conclusion which should be rather order wouldn't it I'm now sure there are some I think thinking one that I fell off the top of my head so what makes the sentence of conclusion is that you are arguing for it what makes it a premise is that you are using it to argue for something else okay is this an argument hands up if you think it is yeah it's a more difficult one isn't it but it were conclusion which would of suffer if it were an argument which would be the conclusion okay so then the premise would be Jesse James left town and Jesse James took his gang with him yeah so we could say Jesse James left town Jesse James took his gang with him therefore things have been a lot quieter there's an implied premises that Jesse James and his gang we can make anything yes I don't think that's an argument myself I think it's just a concatenation of sentences are you several sentences strung together and it but there might problem in fact there probably is a causal relationship too isn't it why are things quieter because Jesse James left annotate nice painless gang with him as well to some explanation ah now explanations reasons and causes now you're really getting into the interesting stuff explanations can be both causal and rational can't they so I can give an explanation of your behavior that's rational or I can get an explanation of your behavior that's causal so what's your name Paul Paul okay so the reason Paul did that was whatever or Paul did that because what's your name Jenny pushed him you know Jen's question pulled fell over okay all Paul fell over because he was trying to make the children laugh juicy ones a rational explanation and the others a causal explanation causes reasons and explanations are intimately tied together and we'll talk about probably quite often in these sessions but the important thing is that it might mean that not all causes are reasons it may be as all reasons of causes but it's not the case that all causes the reasons because some causes are non rational they have no reasons involved in them to any way this is getting complicated you don't need to worry about this the important thing is that a set of sentences is only an argument if you're putting one forward is true and putting the others forward as reasons for believing the one that's what an argument is so if the set of sentences doesn't have that relation between them it isn't an argument so it may be just fine students yes you may not be same as even a causal relationship here you know actually since Jesse James left town taking is gang with him things have been a lot quieter because it's not been necessary to do this that or the other yes yeah but you could very easy to that context and with that was in our well as I said you can no supplier context in which anything is an argument so that's true yeah here's a set of senses movement subjective or objective home is it a matter of opinion well is it I mean if we go back to I mean you can answer this question yourself if we go back to that one is it a matter of opinion that that's an argument or did I somehow make it an argument I mean did I make it appear to be an argument or did I make it an argument I might have made it appear to be an argument by making an argument and therefore it became an argument or rather you started to see that it was an argument is that right so um objective and subjective when I used to teach undergraduates I used to say that I wouldn't let them use those words until their third year and because they're very difficult words and the reason they're very different difficult words is because there are objective facts about subjective things if you think of a subjective state as the state of a subject state happiness or something like that then there are objective facts about such states and happy no you're not that's a bad example actually happiness anyway you can see what I mean I guess I won't reject an argument because they say ah I don't think it's not or do you mean is not a valid argument I would that's I was just going to make that distinction okay two questions you might ask that isn't an argument or that isn't a good argument clearly you can make that distinction and that claim whether the person making it that's an interesting one if you mind leave that on one side because I'll think about what I think about that I'm I'm not sure I've a feeling you say yes it is but then you'd have to provide the context which would make it clear to the other person that it's an argument okay let's move on to John Cleese What did he say oh that's not an argument indeed he did say that that's right that's not an argument and what he meant by that is that's just a contradiction yeah you have just two sentences one is politics the other stats lawton arguments and that's an argument against but it's also I'm going to get to the truth of it is is it's the argument gets the truth of that's an argument Oh clarity of thoughts it's wonderful right let's move on um okay there are often words that suggest that a set of sentences is an argument and we when we looked at these and we saw that you sir wanted a because in there because that would have convinced you it was an argument should it have done no not necessarily because thus sometimes into this argument but not always and okay where's the argument word in this one oh okay what about that one so yeah okay can you give me any more ah if there is a difficult one um the answer is the world agile I'll talk about that in a minute I will put if on one side because you've got to system English between implication and entailments but we'll do that in a minute okay hence it's a good one yeah even given there then yeah then is another one that's a bit iffy actually therefore is very definitely an argument word yeah and notice incidentally that there are words that aren't we consequently yeah okay let's leave that so it's in firstly we've we've said what an argument is and we said how to distinguish an argument from a set of sentences and but we've also got to distinguish an argument from an assertion just a straightforward assertion okay an argument is a set of sentences just one of which is being asserted okay an assertion is a single sentence possibly a complex sentence so it might be Mary Ann's wearing jeans and it's Friday so that's one sentence with a sentence conjunction the end that's being expressed in at its esoteric moves so which of these sentences are or could be assertions only number one exactly so I say it could be because of course it could be said I could say the room is hot in that Australian intonation that makes it a question do you see what I mean so so I could ask a question in in a form of words that would usually be used for a Satori so again remember that language is something we use and we can use it in all sorts of different ways but this is this sentences interrogative force doesn't it is the room hot and this has imperative force turn the heat up that one is you've been used asset Oracle II not the others some assertions and this will pick up the point to you and making there look very like arguments if it's snowing the mail will be late okay so you might think that this is an argument because it's an if-then sentence why isn't it that's an argument can anyone tell me well done yes it is it's assertion okay I'm good okay I'll be asserting it is snowing no are we asserting the male will be late no are we asserting in its no the male will be late yes so there's only one sentence there isn't that it happens to be complex it's a it's a sentence that the sub sentential parts are themselves sentential and but it's not an argument because it doesn't satisfy the description does it it doesn't satisfy the the claim that there must be a sentence that's being put forward is true and other sentences that are being put forward to support the claim that that one sentence is true so that's an int a love sorry that's an earth and implication not an entailment okay so that it's no you ply to male we'll be late it doesn't entail that the male will be late customer back one of the making ungrammatical actually therefore it is snowing the male will be later that would make it an argument because they're there for signals entailment and then can signal entailment but but doesn't automatically but therefore we're going to say something very rash there but therefore always does and i may be right about that okay so we need to distinguish things like that from arguments and now we get on to the bit that's been worrying around this end of the room here okay thing about assertions is they're either true or false okay now this is an interesting thing there are only two sorts of things that can be true or false in this world one of them is beliefs beliefs are either true or false and the other is the sentences that we use to express beliefs okay so if I believe that the chair is blue I can express that belief in the sentence the chair is blue and both the belief and the sentence used to express it can be either true or false are you with me can you think of anything else that can be true or false no facts are what make sentences true or false they are not themselves true or false they just exists or don't exist so the fact that that chair is blue makes true the sentence that chair is blue you with me okay her hair is blonde when you say that are you saying what about that fact or that sentence that sentence well that's either true or false isn't it and if you I mean let me just point out an ambiguity what's your link yeah Yona sense what about what did you say her hair is blond her hair is blonde if I put it like that I'm talking about the fact on type whereas if I took it do that I'm now talking about the sentence right if I take those out again that's not the sort of thing that can be true because the fact that someone's hair is blonde that her hair is blonde makes true the sentence her hair is blonde with difficult stuff philosophy isn't it but but the really nice thing is that if you persevere with logic you too will like be able to do things like this you know these distinctions are there to be made you just need the clarity of thought to be able to make them fact are true at all that fact are what make sentences true but that's either it's a fact if you like in combinations of things or events or things or properties and events so if you think of something like her hair is blonde that's a fact okay her hair's being blonde her jackets being is agree whether that's the fact or not we're not really sure if extreme and there's a fact of matter which is that story believe it Diana's Japanese dream and these are facts which either exist or not I mean a bit and some people might say that that's not a fact that Dinah's dragons dream the sentence that expresses that the belief that that's a fact is false sorry I lost myself in the beginning that sentence refers to a fact if you like even though in that context CPR I see it referred to a potential factor putative fact yes that's right yes of course I know that's it thank you that's very good point to make because if I say something false and what makes it false is a fact but but it's not the fact so if I say that chairs black the fact of the chairs not being black is what makes that true it gets difficult as you can see but but the thing to remember is this there are three different levels that we very importantly have to keep separate in thinking clearly and of course all critical reasoning involves clarity of thought but these levels are the level of language fort and the thing I always call reality but that's it that's wrong because of course language and thoughts are real so so that's completely wrong but I'm using it that way and so if I put down red okay and I put quotes around so that you make it clear that make it clear that it is a word okay it's a linguistic item then there's the concept red okay it's when I think that is red okay I'm using the concept red and then there's redness the property so these three things are quite different from each other aren't they so if I say and this pen has the property of being red okay I'm talking about this and if I'm thinking about this pen as being red that I'm next using my concept of red and if I see listen hell is red then i'm using the word red notice in french it would be different what it wouldn't it but the same concept and the same property so there's an arbitrary element in language isn't there in the other tunes so what's the French sir okay I'm glad I use red not something else I'm sorry could you take them this is metaphysics 101 it's all true right okay let's unpack what you're talking about here in terms of facts and truths and so on um okay what you're suggesting is that what I see is red Mike might see is green or something up okay so what we say is why isn't anyone wearing red will somebody please come next time wearing red maybe ion and it makes it much easier there's a lady that working on middle there so when I look at stat ladies what's your name Hildegard right okay when I look at Hildegard Stafford ICP I see it looks like that and when my clips is it it looks thick okay appears differently to mine so I would say that jacket is pink and of course Mike would also say it's pink okay the pink is different for the Mike that is for me that's what your what are you that's what you're saying okay you might have to put it read a lot of producers at colors it's nothing yeah shall we not get into that well let's let's make a very important distinction between epistemology and metaphysics here there's one person which is if something effect and there's another question do we know it's a fact okay so let's talk about it is pink as a fact okay rather than do we know it's a fact Vic and shine showed us that actually the question could we see it differently is actually an on question the answer is if there are no this is getting too complicated it's going to take us too far away from I'm sorry I don't want to teasing with this but I've just realized what I was about I believe some believe it oh right okay you're using beliefs in a world in a way that lots of people do so actually I'm very glad you brought this up people think of beliefs as things that you can't prove so you have either belief or you have knowledge well that's not how we use the word belief in philosophy a belief is something you postulate an explanation of someone's behavior or is something you've put forward as true or as false and it's certainly not the case that it's something you can't prove I mean there are many beliefs that we can prove I mean just a his I believe that two plus two is four and I dare say that you wouldn't want me to even attempt to prove that because you believe it too is that reasonable okay so here's a belief that we can that we believe is conclusive true so so we don't mean believed to mean religious belief or or something like that and look this is part in if we go back to this and let's use chair concept of chair and chair here so the chair is something I can draw okay I can't draw the concept of a chair can i I can only entertain it and I can say chair has five letters see what I mean okay chairs exist now that's a fact which I can think about do chairs exist Berkeley said that didn't exist acceptors perceptions in my mind and of course I can then talk about what I'm thinking about so the fact that chairs exist if indeed it is a fact is something we can think about and talk about do you do you see the distinction you may not feel confident in using it at the moment that's just a matter of practice it's if we confuse these three levels we will not think clearly as you might end up thinking like the concept chair has five letters or concepts those how many letters actually or you might think chairs have five letters well actually chairs don't have any letters doesn't make sense the thing the chair is having letters see what I mean heat these so go back to this one and if I said this jug is loud what would you think this jug is loud I would wonder if you're near in a different context or so well and you'd be perfectly reasonable for you to be is to think that because actually that doesn't make any sense that sense and does it because jugs aren't the sort of thing that can be loud okay that it's just not it would have to be metaphorical I'd have to be being poetic or something like that or I would just not I would be displaying my misunderstandings were loud all the misunderstanding the word jug is that right when you say that argument is false you display the fact that you don't understand either the words are an argument or false this arguments can't be true or false okay and arguments can only be good or there can be valid or invalid they can't be true or false and that's because it's the only things that are true or false our beliefs or sentences the sentences that express beliefs now in general everyday talk we do talk about arguments being true or false you know everybody does that but but if you want to learn how to reason if you want to learn how to think clearly about argument you must stop doing that because arguments can't be false what is it for a belief to be false if I if I talk about what if I took vote Mike is tall okay what is it for that belief to be false it's the thing that I mean by Mike to not be in the in the class of things that at all is that right and arguments are sets of sentences you can't evaluate them in that way can you let them know that there's a form of argument that is sound the truth preserving um all arguments truth preserve or lease all good arguments of truth preserving because the truth of the premises is preserved in the truth of the conclusion so it's studied to say as an army the truth and we'll talk about that later on we're all sorry but we're not saying the unrest wrong we say it's truth preserving Charlie yeah okay do we understand this this is crucially important because to understand what truth is it's to see that it's predicated only of sentences and beliefs not of arguments and to understand what an argument is is to see that it can't be true or false you can see what that it can't be right the truth is only contained to that argument nobody would say that which is made of wood unless you bought at the store but in terms of the way the argument is constructed yeah and I I'm not sure how to unpack what you're saying here except to say that and that's a key oh yes that was an argument and it's not humor because we're saying that that is true and we're offering us reasons for believing its truth the truth of that and the truth of that okay so the argument itself is a good one and you use the word valid and we'll get on to valid at some point next week I think but term that's that's the argument itself can't be true or false but the sentences that constitute the arguments can of course be either true or false ah yeah well that that's a very important one we'll come to that later so does that sentence actually contain three assertions it contains three sentences each of which could be used as an assertion and in order for a sentence to be an assertion it's got to be asserted and I'm not really asserting this I'm just talking about it but yeah so we have three potential assertions each of which is either true or false and together they make up the arguments because two are being offered as reasons for believing the truth of the other right okay a good argument this is coming on to your point now a tooth that a good argument must have at least two characteristics actually it needs many more than two characteristics but there are two that we're really interested in these are the two the conclusion was followed from the premises okay and the premises must all be true okay if both of those things are true you've got a good argument if one of these things if the conclusion doesn't follow then even if the premises are true you haven't got a convincing arguments or if the premises are not true and the cano the conclusion follows then you haven't got a good argument in that way because the premises are false but having said that and we're interested only in argument in this session we're not actually interested in the truth of the premises at all we're interested only in the whether the arguments follow from sorry when the conclusion follows from the premises so as magicians generally and when most in the business of going out of the world to see where the premises are true or false we're only in the business of seeing whether the relation between the the premises and the conclusion is such that the art the conclusion follows from the premises and as we'll see next week there are loads of different ways in which conclusions can follow from premises and but so I I would often talk about an arguments being good even though the premises I mean let's take this one okay is that a good argument or not it's good in the logician sense isn't it I mean actually the premises are all false are they they're both false there are only two premises of this argument they're both false it's not Friday it's Monday and Mary Ann always wears jeans on Friday it's also false you'll have to take it for me so that's not a good argument from the point of view of the premises but as far as a magician is concerned that is a good argument because the conclusion follows from the premises okay so if we were actually using that argument to say anything we'd want the premises to be true as well but as we're just talking about the arguments in order to say what's a good argument isn't a good argument that will do if that's if that's a conclusive argument isn't it if the premises are true there the conclusion would have to be true and so it's a very good argument so let's no biggest if the premises are true here the conclusion have to be true winter which is something or but not visionary for a very well then it wouldn't be true that some Mary always wears jeans or I did say I always wore jeans on the Friday maybe go what are you leaving I'm not sure dead people wear jeans at all a premise is true if if there's actually I see a huge for the software person in there but let me just say yes if there's a fact that makes the sentence true then it's true yeah Oh can't believe I said that Felicity that's awful but that might happen do well I tried easy this is your - Viking we're going to be out next week which is the inductive argument so the inductive arguments always take us further than we can actually go by claiming something like swans are always white Maryanne always wears jeans on the Friday but but you would still say that we're not going to get into knowledge the philosophy of knowledge is definitely not on this curriculum and okay going back to what I saying there okay so you understand the difference between the truth of the premise and the conclusions following from the the premises that that's the important thing and it's because what makes an argument good is that the conclusion follows from the premises that you've got to distinguish the goodness of an argument from the truth of the premises truth just because truth is a good thing and validity say is a good thing doesn't make them the same thing and that's the important thing we mustn't just take validity as a sort of general Pro word and in the same way truth isn't just a general Pro word okay let's have a look at these arguments okay one of them is good one of them is bad don't pull out but just have a look at them yourselves and decide which is the good one and which is the bad one who's decided alright bit more time okay who's decided okay his that's a good argument it's that's a good argument well done yeah absolutely so you don't need counselors class no you're absolutely right this is a deductive argument it gives us absolute certainty in the following sense if these premises and I'll read out the premises if it's Monday the lecture will finish at 3:30 it is Monday therefore the lecture will finish at 3:30 if these premises are both true this conclusion would have to be true wouldn't it it couldn't be false if those two premises are both true and so the truth of the premises is preserved in the truth of the conclusion there you couldn't have those two premises true and that conclusion not so if you believe those two premises rationally speaking you must believe that conclusion okay that's what it is to be a rational animal and instantly I say you're wasting your time coming to these lectures if you knew that of course that's nonsense because you're all rational animals you have to be rational animals in you wouldn't be here if you were because you sort of the leaf little whatever you saw and you thought that sounds interesting I would like to go to that lecture that lecture starts at two o'clock on Monday need whatever date this is therefore I will go to that lecture hall did you not you had loads of reasons so we're talking theoretical arguments here but of course actually arguments the most active practical thing in the world you're bitter practical reasoning led you here so each one of you is rational what we're doing in these lectures is learning how to explicate our capacity for reason okay you know whether conclusion follows from premises or not yet that's why when you argue in the pub with your sons daughters wives or whoever and you know whether what you're hearing is a good argument or not you can there's something wrong with that argument you say as you read the reader in the newspaper as you prepare the personal television or something like that something wrong with that argument your intuitions or your rational intuitions are telling you what you need to know but what you're doing these classes is learning how to make explicit your intuitions what your intuitions are telling you okay so your intuitions tell you quite categorically that that's good or that's a bad one what's wrong with this one yes okay everything I've heard there is it's good the fact is that okay let me ask you a question could it be the case that these two premises are true and yet this conclusion false okay can anyone give me a counter example to this argument let me read them out again because the people who can't hear if it's Monday the lecture will finish at 3:30 the lecture will finish at 3:30 therefore it's Monday okay can anyone give me a counter example to that argument a situation in which both those premises are true and that conclusion is false a situation in which both those premises are true and that we've Lucien is false good well done Oh - Oh Thursday Friday exactly and this says if it's mundane electoral finish at 3:30 this merely says the lecture will finish at 3:30 it could be Monday but it might not be okay so there is a situation in which both these premises are true and this conclusion is false therefore this is a bad argument it's an invalid argument it's actually a instance of the fallacy of affirming the consequent because you see that the at the lecture the lectures the argument whatever they are they look very similar but of course they're not because this one's taken me antecedent as the second premise and this one's taking the consequence that's the second premise and we'll be learning a lot more about fallacies later on in the course but that's it for today next week we're going to look at the all the different sorts of argument their arguments there are and how to distinguish them from each other and then we're going to get on to learning how to set them out properly and how to evaluate them okay we've got quarter and alpha for questions that's easy you could try really hazeled she might be able to tell you but I doubt it who is this party before the ten-year concept he didn't think of chairs only a concept it was Bishop Berkeley George Berkeley who lived I don't know any lived I'm sorry I couldn't remember dates and he believed that our only reason for believing that something exists is because we can either see it now or that we could see it under some other circumstances so if I claim okay what makes it true that this lectern exists so we can see it and hear it we can touch it all sorts of things what's more we also believe that were we to come back tonight at midnight and nobody had moved it and so on all other things being equal it would still be here okay so there we have an appeal to actual perceptions okay we can see it now and we've got an appeal to counterfactual perceptions if we came at 12 o'clock we would be able to see it and Berkeley says you can be a reason for thinking that anything exists that doesn't depend upon actual or counterfactual perceptions sorry let me rephrase that you will not be able to give me a reason for thinking that anything is this that doesn't appeal to one or other of those two therefore if something is unconceivable then you have no reason for this what weak spirits concepts all the time that we you wouldn't be thinking of a concept is a constituent of a thought so as long as you think you think then you will think in concepts and we have recent thinking concepts exist sorry is that the same sort of thing as perfect collapsing in the middle of some forest someone would never be here yes yes I mean the practice if you were in the forest you would hear it yeah is another happy me that they would make inaudible no that's I mean your reason for thinking that noise exists is that you would hear it if you were there so that's a counterfactual perception that you're basing that's on I mean what Berkeley is very important and he's a fascinating philosopher actually he thinks that physical objects are made up of ideas of ours he's one of the first idealists and he doesn't mean that you know you can put your hand through this because it's an idea he just means that my idea of this lectern is an idea made up of partly of solidity the idea that if I do that I won't be able to push any further that's a perception notice that's a perception that it's a bundle of perceptions accounts of because what would this idea that so what we see is actually the result of a reaction in the brain to something that comes through the retina and gets translated into a particular way so there's economy there $0.00 data perhaps so so that we never see the object directly we just see the data there's a kind of dark rum you know yeah by the screen there are two ways of thinking about sense state one way is now very old-fashioned we don't think that's the way the muscle and BIC and style people like that part of it which is we never see the thing itself yeah we only ever see it an idea in our mind so and why would you think that answer because you can never be sure that I mean are you really sure that I'm here I mean your reasons for being for believing that I'm here as you can see me carrying some but couldn't it leave with you exactly as it is now and yet it not to be true that I'm here whenever when you say no have you never had a lucid drink with you said you said you said so so you don't think that you could have an experience as if I were here doing what I'm doing and yet I'm not here you'll probably have one of those tonight Jeannie would be one but but here's another one I mean were what making what you think at the moment is that you're having perceptions as of me and what's causing those perceptions is me and what's more your perceptions are a good guide to what I like but look if we talk about the causal relation if we think that a must cause B or sorry a causes B we have to know about both a and B don't we we have to see that they're constantly conjoined they're correlated something like that and we can't so we've got to be sanding here if you like to see the day and beer correlated but if you're thinking of B is a chair and a is your idea of a chair and you can't get outside your ideas and here is where you stand with respect to your perceptions isn't it how can you get outside your perceptions to see what causes them you see what I mean in a dream yeah well we don't talk about dreams you yep let me ask the question again if we talk about your idea of a chair your ideas of the chair concept to chair the song and chairs can you get outside your idea a chair in order to see that it's caused by a chair now if you can be with me exactly as it is now Here I am and look at this chair action without hearing the chair all sorts of things and yes it's possible that I might be asleep but then there being no chair here even if I'm asleep I might want to say something like well I mustn't experience chair before in order to be able to do this I could say well why should I think in the first place that there is something that's causing my perceptions all I've got is my perceptions I can't get outside my perceptions to adopt this perspective on them can I so are you saying you could create the idea maybe not be creative it may be an evil demon what I'm giving you here is the Cartesian four to experiment and yeah and the idea being that if you push what you know to the final degree you'll see that actually you're the only reason you believe in the physical universe and things outside yourself and that includes your own body is because you assume that your perceptions are caused by something outside yourself outside your mind and that your mind is a good guide to the nature of these things that if you question both those perceptions you're left with nothing because what makes you think that there's something outside causing your perceptions if all you can see is the perceptions themselves rather than the causal relation between your perceptions and whatever is causing them we get a pitch away from critical but all you're talking about is one experience after another aren't you I mean there are some perceptions of mine that obey my will and there are other perception to mind the don't that chair doesn't obey my will that that particular perception doesn't obey my will whereas others do I think perhaps I've introduced the parties in thought experiment with too little time to convince you I mean you can go away every first meditation it's very easy to really this some actually it doesn't take much longer to be Barclays Barclays I did I mean the Conte's in thought experiments to completely revolutionize philosophy because it realized revolutionized our belief that we could claim to have knowledge Berkeley attempted to get over that because if we okay here's the world and here's our mind and here's the evil demon if Dave Martin has shown that once this is in place and you see that could be exactly as it is whatever this is like you need to say that something about our knowledge of the external world and what Berkeley is doing is he's remaking the world in the mind so if there is nothing more to a physical object than of perceptions and it's the only thing of which we can have knowledge is our perceptions then there's no reason why we can't have knowledge of physical objects if they are perceptions so Berkeley was trying to show that we do have knowledge despite the Cartesian thought experiment anyway there is no way we can if you would like to know more about that you have to come to another set of lectures okay and I see oh there is time for one more question if anyone would like on just across the room there's one in fact this they do have cost money no what do you know what their but they're all goods on the rule they wouldn't be on reading this the short introduction to logic is very interesting and that's very easy to read very short so I haven't gave it that the Hackett book is on the little leaflet the winds I never read okay well if you look outside they'll find we'll find those leaflets on the thing and you should point sorry sentence again yes yes I know it sounds pretty very irritating you said you can get it on them Anderson you get out yeah it's the reason it's irritating is it's a very good report if you call it final sometimes and let me know I can't remember loops by sorry it's it's on the reasonless yeah okay I think we'll stop there Thank You Scully see you next week

Channel: University of Oxford

Views: 161,774

Rating: 4.8859935 out of 5

Keywords: yt:stretch=16:9, philosophy, arguments, critical reasoning, argument, reasoning

Id: kBlQj5uiOXc

Length: 79min 20sec (4760 seconds)

Published: Fri Oct 22 2010