Setting out Arguments Logic Book Style - Marianne Talbot

right now we're on to the third week now and this week we're going to learn how to identify and how to analyze arguments and how to set them out logic book style and the point of doing this is it enables you to get rid of all sorts of things that are irrelevant to the argument and you set up the argument so the structure of the argument is very clear that way it's much easier to evaluate okay let's get started okay and just a brief recap as usual on last week if you remember we looked at the fact that there are two basic types of arguments deductive and inductive and we saw that deductive arguments are such that come on tell me don't look at your handouts tell me what a deductive argument is how do you recognize it Oh aren't you good haven't you done well you're absolutely right that's right the truth of the premise makes the truth of conclusion certain or those of you who use the word guarantee the truth of the premises goin tease the truth of the conclusion well done that's absolutely right okay then inductive arguments are such that good okay I can hear that you've got it as well okay I've put it slightly differently this week because if you remember last week we got into trouble with the way I phrase this is more or less because we don't want promises making less probable the conclusion do we so I've said the truth of the premise makes the truth of the conclusion more likely and of course as you know it's either much more likely as in the case of the Sun has written in there every day in the whole history of the universe therefore it's likely it'll rise tomorrow and it's really pretty likely isn't it it's almost certain or slightly more likely so the fact that every time you've seen me I've been wearing earrings makes it slightly more likely that the next time you see me I'll be wearing earrings so the the whereas deduction is an either/or thing induction is a matter of degree an argument is more or less strong good we then looked at some examples of arguments that are deductively valid in virtue of their form and do you remember I was using the P's and Q's and so on to talk about things like modus ponens and modus tollens and so on so we've got if P then Q P therefore Q that's valid in virtue its form because it doesn't matter what you're talking about it doesn't matter what sentences you put in for P or Q if these if the structure of the argument is if P then Q P therefore Q it will be valid okay so then we looked at some arguments that is deductively valid in virtue of their content can you remember any of those this is a bit harder because there were only examples that we gave good uh not quite lying is wrong therefore we shouldn't lie exactly do you remember how that is if that's a deductively valid argument it's in virtue of the meaning of the word wrong isn't it lying is wrong therefore we shouldn't lie so thought is that if you understand the word wrong properly you'll see that if lying is wrong if you believe lying is wrong then you'll also believe that you shouldn't lie doesn't mean you won't lie but it does mean that if you do you'll feel guilty or whatever but that's in virtue of the meaning of the word wrong can you remember any other arguments that were valid in virtue of the content the meaning of particular words right I can't remember the particular example I used there I don't think that would have been one actually I might be wrong about that but I've a feeling that was an example that I used of one of ones that's valid in virtue of form ok no that came later temporal yes ok that was one can you remember how that went ok that's right it's raining today therefore tomorrow it will have rained today okay so and that that's because of the word tomorrow and our understanding of before and after and yesterday and today and so on okay good then we moved on to inductive arguments and we looked at several different examples of an inductive argument can you remember any of those you you mentioned one of minutes ago yes what was it about Einstein it was an argument from Authority good okay so this man's an authority on this therefore he said this therefore he's an authority on this that's a bad way of looking at it but but you can see it that assumes the principle of what what's behind every inductive argument a logic yes and continuity yes can anyone put it in the way I put it last week there's a principle that Hume is most famous for David Hume he said the principle of the uniformity of nature that's right so what's happened in the past will happen in the future if it was like that in the past it's going to be like that in the future and so on that's the principle of the uniformity of nature which underlies every inductive argument and which can't itself be argued for because arguing for it takes us in a circle why is the future like the past because it always has been well again we're relying on induction aren't we okay so we looked at some examples this week we're going to be learning how to identify and analyze arguments and how to set them out to logic books style so if you've got some arguments from this week that you had trouble analyzing or you had trouble recognizing you'll be able to use the arguments that you found this week to practice what we're going to learn today okay so let's start by seeing an argument set out logic book style you're getting sick of this argument aren't you I'm getting sick of this argument but here it is again set out logic book style okay you don't have to write up premise one in fall you can just put p1 or you don't even have to put that you can just assume that the premises come first then Bend the conclusion but that's an argument set out logic book style and you might ask well what's the point of setting out arguments logic what style has anyone got any idea why why do we bother setting out arguments logic book style yes absolutely yep it should make it stronger because what you're doing is setting out an argument logic book style is just identifying the argument you therefore you shouldn't you shouldn't be able to make it either stronger or weaker all you're doing is identifying what the argument is so we're not evaluating it at the moment we're just analyzing it just setting it out logic books style good absolutely that's that's right what we do in setting out an argument logic book style is we actually identify all the premises so if there's a suppressed premise or an assumption as Paul says we try and make it explicit if we can absolutely it's a set format so if you remember what was on there you've got premise premise conclusion so we know exactly what is being argued for because that's what the conclusion is isn't it and we know exactly what's being put forward as reasons for believing that thing which are the premises any other ideas on this one one two and then we'll move on that's right because if you remember I was asking you to identify the premises and the conclusion of course you have to be able to do that to set out an argument logic book style but once you've done it once you've set it out logic well then it's obvious yep one two would gentleman behind you is first yep it can do yes yes yes that might also come later again we'll have a look at that later on one more and Oh up to a point as we'll see Lord Kapur okay and I've put down though there's the one we mentioned it enables us to add suppressed premises it enables us to eliminate cross references irrelevant seized and inconsistent terms okay and and that makes it much easier to identify the arguments we'll go through all this so if you don't quite understand what I mean here don't worry about it we'll we'll cover it in a minute and it makes it much much easier to evaluate the argument as I hope you'll see today okay right on the surface of it it's easy to set out arguments logic book style let's try this one you've you're familiar with this you've seen this argument before first of all tell me what's the conclusion of this argument tell me what the couch is the conclusion good Edinburgh is north of Oxford so and premise one good and I'm glad you left out the words since because that's a logical word isn't it that doesn't act that's not actually part of the sentence that is the premise so you were absolutely right to leave that out okay premise one then so you're writing down premise one Manchester is north of Oxford premise two Edinburgh is north of Manchester good and the conclusion Eddie burrows north of Oxford and he left out since and and well done those two are the logical words they're the words on which the validity of the argument hangs as we'll see later but we leave them out of the identification of the premise and the conclusion okay um let's try this one what's the conclusion which is float yeah okay the conclusion is which float premise one which is are made of wood wood floats good and again you left out the logic words and that's right can I just give you a warning of this and is a logical word but and here is connecting which two parts of language and it two of the same parts of language what's it connecting here to two premises okay but what are premises their sentences so and here is a sentence connector okay and we can connect any sentences we want here is it here it is used again connecting these two sentences but what about this one and Oedipus is a black and white cat okay it's and working as a sentence connective there EDA Puss is a black and white cat what's it connecting their two adjectives or two predicates as we would say in logic so you've got to be a bit careful and when you see and in a sentence sometimes and will be part of the content if it's not combining two sentences but two predicates are you with me so just watch out for that keep keep an eye open for that right good well we've set those two out logic book stars okay now try this one yeah okay now I'm not serious about your trying that one right a minute but we are going to do that one before the end of today okay but this is another reason we set it out logic book style because you can look straight at those arguments and you can pretty well see what the form is can't you you can the other ones you can see whether they're good arguments you can tell straight off but this is now those of you who found arguments from magazines or newspapers of this week where your arguments more like that one or more yes okay and this is why they're so difficult because actually when we're in the pub arguing with each other about whether euthanasia is acceptable or not at whether we should go for assisted suicide or not we add all sorts of things to our arguments we say things like well if that's true I'm a Dutchman what does that mean if that's true I'm a Dutchman what does that mean in English it's not true so when I say if that's true I'm a Dutchman all I'm actually saying is that's not true okay let's see if I can think of another one no I can't cuz I'm doing it off the top of my head but in in English when we're talking we use all sorts of colloquialisms we add all sorts of things we have all sorts of UNH's and arse and ears and and it makes it very difficult to identify the argument itself and that's what you're doing when you set out an argument logic book style is you're getting rid of all the irrelevant C's okay here's a set of steps for analyzing arguments I'm not using this microphone by the way can people at the back hear me yeah okay here's a set of steps for analysing arguments we're going to follow these steps today and I meant to actually write them out on the board and I forgot so you'll have to keep referring back as I asked you what do we do next you'll have to keep referring back to slide 11 okay firstly let's look at identifying premises and conclusions we've we've already done quite a lot of this so this is fairly easy we look through the argument indicators and I've given quite a few here and then we identify well okay in identifying the conclusion what are we looking for what tell me again what a conclusion is another bit of revision now careful what is the conclusion it's not the reason for the truth of the other premises the other premises is what you said that she isn't it what yeah that's right it's what it is you're arguing for isn't it it's it's the final you were just getting mixed up there and it's very easy to get mixed up and when you get mixed up of course you invert it which gets everything wrong but that's easy to do but the conclusion you can only tell which is the conclusion by looking at the function of that sentence in the arguments and what a conclusion is is the thing you are arguing for it's in effect the statement you're making and then the premises are the supporting evidence or the supporting reasons not to be a bit careful with evidence because they're not always their arguments rather than evidence yep exactly - yeah okay good let's here's an easy one and identify the argument indicators in these arguments what about the first one which is the argument indicator in this one there are two actually since good is there another one for well done you're getting good at this okay what about this one put up your hands this time I'm going to okay what's the argument indicator in this one stick your hand up if your went once you've found it because some people and I have to admit I'm one of them think quite slowly and if people yell out it's they don't get a chance to think okay now you can all yell out together because that's right yep good okay what about this one put your hand up again quite easy this one isn't it okay again yep no me up and there it is you've got them all right close actually the red isn't very good is it can you see that I've marked them all in red if you can't see you'll see it on your handout that's a shame I didn't realize that the red doesn't show okay now we're going to practice looking at conclusions with a weekend we've done this before so this isn't difficult at all what's the conclusion here what is it have another don't yell out okay have another look at the argument remind yourself what a conclusion is and tell me Socrates is mortal yes why did you get that confused I mean there's a very good reason for getting it confused what is it what or what it's not at the end you are you're you're being expecting to see the conclusion at the end haven't you but but as you see from this one it doesn't need to be at the end in this one it's in the middle isn't it so it's remember what I say that the complete you can only tell which is the conclusion by looking at the function of played by a particular sentence the conclusion is the sentence you are arguing for okay so here's the and it's this in red just as you said Socrates is mortal is the conclusion okay find the conclusion of this argument now put up your hand again rather than yelling out and don't worry if it takes you a bit of time some people just do think more slowly and that's fine okay what is it ah you're brilliant no you are exactly right socialism was doomed to failure okay as picked out in red and what about this one hands up okay would you like to have a go yes okay they will continue to need help from industrial nations now here's a little hint for something that's coming do you remember I said that setting something out logic book style enables you to remove cross references irrelevant sees and whatever the other one was okay look at this one can you have an idea of what I meant there because this put up your hand if you can see if you think you see what I can mean okay no that's that's actually not what I mean there I was thinking I think you thought I meant in the whole argument but actually I just meant in they will continue to need help from industrial nations just look at the conclusion there can you see what I might have meant by saying we need to remove cross references and inconsistent terms and so on well done because this they is an anaphoric reference isn't it it takes us back to something that's already been said and we need to identify that because when we separate it out as the conclusion we're left with a statement that actually has no meaning does it in the they will continue to need that while who's they so we need to remove that cross-reference and we'll be seeing how to do that later indeed there is and we'll be looking at that later I think good well done okay there's the conclusion though picked out in red I'll pick it out in green next week yes okay that's good idea I'll do that yes because it's already in bold but I could easily do teams or I could do it in capital letters couldn't I okay identify all the premises of this argument and don't forget that they might be a suppressed premise now this is going to take you a little longer don't call out you might have to write it down and put up your hands when you've identified the premises of that argument and a hint there are two of them put up your hand when you've finished you'll have to paraphrase a little bit and if you're finding that don't don't worry about it if you're thinking I can't be right because I'm not using exactly the same words don't worry about that paraphrase is fine what what you mustn't do is change the meaning of anything but paraphrasing it to get the grammar right or whatever is fine okay right would you like to tell us yep okay that's premise 1a right okay yes that that would do okay any variation on those themes so here it is premise 1 incentives are needed for a prosperous economy premise to socialism did not provide incentives conclusion socialism was doomed to failure okay do you see where both those premises come from okay they're needed which one is the suppressed premise yes that's right the first one was suppressed in the original arguments but but it's made explicit as we set out the argument logic book style and if you had any variation on this theme that's fine so long as it has the same meaning does anyone want to check some and well I think what you're thinking well is this what you're thinking of doomed to failure I mean you want something like you will only succeed if you have a prosperous economy don't you okay that's really in you've got that in premise one haven't you or you can have something like you have succeeded only a few if you have a prosperous economy you could add that okay um you don't need to me I mean quite honestly if you make explicit everything you might find yourself is that my mobile no it's yours good well bad but better than it's being mine I completely accept your point I I think you could easily add another premise in there and you could say prosperous companies are needed for success incentives are needed for prosperous economies socialism did not provide incentives there for socialism was not a success or something do you see I we could easily have added that one in as well and made explicit to suppress premises yeah fair enough okay anyone else have anything not quite this no okay good let's do it again with this one so since many newly emerging nations do not have the capital resources needed forces necessary for sustained growth they will continue to need help from industrial nations you'll find actually as you practice at this it gets much much easier and another trick is if you're not quite seen it is to identity identify the sentences that make up the premise if if you can I mean here you've only got one sentence and then see what else you need to make May in argument okay let's let's try some okay so many newly emerging nations will continue to need help yeah anyone have anything different yes that's certainly implicit in that argument so you can make it in explicit if you like yep okay well no now now now you've got to be careful because when you're identifying the premise don't put in anything that you happen to believe what you're doing is you're identifying the argument that whoever it is that wrote this is making now we haven't we're not yet evaluating the argument we may decide that that they're wrong in all sorts of ways but what we don't do is add things on all we're doing here is is sticking to the meaning of the original we can paraphrase but we mustn't change the meaning to change the meaning is really bad really really bad okay is there anything else that anyone wants to try this is oh yes one more yup okay and when when you're adding suppressed premises try and be careful not to add more than you need for the argument that I mean let's have a look there let's see what I put down and then let's see whether we still need that so I've put down many newly emerging nations do not have capital resources capital resources are necessary for sustained growth if a newly emerging nation is to sustain its growth and it does not have capital resources it will need help from industrial nations conclusion many newly emerging nations will need help from industrial nations well is it now remember in the very first week we looked at the difference between implication and entailments does anyone remember what the difference between implication and entailment is and don't worry if you don't because it's a very sophisticated distinction but it's important to realize ah if we've got an if-then statement are we asserting either the antecedent the if clause or the consequent the then clause or are we just saying if P then Q we're not actually claiming that P or Q are we if we say if P thank you are you with me so so is there a conclusion in if P then Q is does a something of that structure have the premise and conclusion structure that would make it an argument no it doesn't does it what it has is two sentences combined with the logical phrase if-then but actually you're you're not claiming anything and you're not backing up anything by offering reasons so it's not an argument it's an implication do you understand that B is another suppressed premise in now which is that industrial nations are the only source and that would be a case of putting in a suppressed premise too far from my perspective and I think that's because we haven't specified what help they need here we're just saying okay you've got if that then that and that's saying the if is true if you like so then that we don't actually need to spell out what the that is I can see why I want that but I would say it's not necessary for the argument you could just say what would need help from the World Bank well yes the the fact is what we're doing is we're identifying the argument we're not evaluating it yet do you see do you see the difference we're just identifying it then we evaluate it so we do have to let the content go but he is quite right that if there is another if suppressed premise there that's needed for the argument we need to bring it out but I don't think that was one of them well it's this argument saying what sort of help they need from I mean I agree it's an implication there but I don't think it's um okay so it could be that instead of it will need help we should change that help to capital resources do you see what I mean so so it would then read many newly emerging nations do not have capital resources capital resources are necessary for sustained growth if a newly emerging nation is to sustain its growth and it does not have capital resources it will need capital resources from industrial nations do you see what I mean and then the in the same way we'd say many newly emerging nations will need capital resources from sustain so that we would be getting the premise that you want in by removing inconsistent terms rather than by adding another premise but but I'm saying it is well I'll tell you what let's come back to this when we've looked at inconsistent terms because I hope then I'll be able to convince you that it is actually in there it's just in there in an inconsistent way okay but but do remind me to come back well no because the conclusion is that they will need help I mean don't forget the premises may be false I mean nobody's saying that the premises are true we're just wanting to identify the premise that well that we worry about later when we're not evaluating the argument at the moment we're just analyzing it we're putting down exactly what was said in the argument or what was said and what was implied in the argument well I think if we change that to capital resources it does say that I mean aren't we implying in this argument that the help that the industrialized nations are giving to the newly emerging nations is capital resources yes absolutely yeah but that's why when when we get rounds to removing inconsistent terms which we haven't got round to yet that's one of the things we would want to make explicit so they're different ways of making things explicit one is by adding suppressed premises and another is by removing inconsistent terms and and we'll I've already promised we'll come back to this argument when we've done that and make sure that we're clear on that I wouldn't not at the moment I wouldn't and okay now you've done so well we're going to try the really complicated argument okay we'll do that for the rest of this session here's the argument okay this is the one by the end of this session you will have analyzed this argument and seen how it works okay firstly identify the conclusion of this argument okay right who wants to who hasn't had to go would you like to have a go what stickers oh sorry I was asking that lady there you deserve to get scratched there's a bit more to it than that the that is part of the conclusion well it's not if you tickler tummy is it it's if you if okay somebody is somebody else um just she didn't want you to tickle her tummy okay nope wrong but absolutely is the whole sentence it's actually a conditional conclusion if the poor thing did want you to tickle her tummy you deserve to get scratched so it's not that you deserve to get scratched on its own because it's you only deserve to get scratch if she did want you to tickle her tummy do you see what I mean that that's the whole thing is a conditional conclusion and you said something like if you tickled her tummy and I wasn't sure whether you were leaving out there if she wanted you to tickle her tummy because actually that's that's very important because there's a big difference between you tickled her tummy and she wanted you to tickle her tummy isn't there and and for the purposes of this argument that's actually quite an important difference so the the conclusion and and I said there was a nice large argument indicator right in front of it and here it is so if the poor thing did want you to tickle her tummy you deserve to get scratched that's the conclusion okay everyone happy with that can you see that the fact that it's a conditional sentence a complex sentence doesn't stop it from being a conclusion because a conclusion is what again it's it's the the claim for which you're arguing that's right it's a statement you're making and that you're backing up with reasons okay what's the next thing we do having identified the conclusion we identified the premises okay identify the premises of that argument yes yep there's sometimes within an argument you get sort of sub arguments but don't worry about that treat it as a premise not a conclusion okay I think we're getting there I'm going to reveal what I've got and then you can tell me if you've got something else okay this is premise one well perhaps she didn't want you to tickle her tummy or she didn't realize that's what you were going to do now I've just realised that I've misled you in something because I I can I praised you for leaving out the argument indicators whereas actually the only argument in two cases I want you to leave out of the synthesis and fours and so on and this or here is making this these two sentences into a complex sentence so it's you should leave that in okay so the premise there you can see the structure that can't you P or Q so the or is part of it yeah and no you mustn't the only one you can actually separate like that his and because if you have P and Q then just two separate premises will do but if you have P or Q do you see that that the or is rather different isn't it logically you can't just have one Center if I say look here's a way of doing it and we're taking if I've got a pen yes right we're moving ahead a little bit here and what I'm going to tell you so if you start getting confused just stop your ears up when we eventually get round to evaluating arguments what we try and do is to set out the conditions under which each premise is true so we can then set out the conditions under which they're all true together okay don't worry about how we do that at the moment it's just that's what we try and do now if I look at P and Q I can say well this is true this whole sentence is true isn't it if there's one world in which P is true and Q is true is that right do you see intuitively that so what is it for P and Q to be true well it's for P to be true and Q to be true in the same world or in the same situation if you prefer so I can represent it just with one line and putting P and Q on the same line whereas if I say P or Q I can't do that can i P or Q is true just in case what yeah either P is true or Q is true or sometimes both so I'll have to draw two lines and put P on one line and Q on the other wouldn't I in order to say P or Q so that they have their different words different logical words and you see how if I separate the P and Q in one premise it doesn't really matter whereas if I separate the P or Q it does matter because then I've only got one on each line so I must keep them together in fact what I should do is keep them all together and just because at this moment you don't know what the difference between and and or and so on is so any any complex sentence just keep them together okay did anyone have something different from that other than just separating the two sentences and actually you're separating the two sentences was because I misled you in the beginning so don't knock yourself for that well what thick of it what we're doing here do you remember I said we've got to keep the meaning the meaning has got to be the same whatever else we do now this sentence is saying either this is true or this is true is that right okay so if we separate them so we've lost the or and we've just got this is true and this is true Juicin and it doesn't matter whether she realizes what you're doing or not she still doesn't want you to tickle her so they still stand into they're two independent centers I completely agree you I mean it might be true that she did one didn't want you to tickle her and it might be true that she didn't realize that you were going to tickle her but what this sentence says is that either this or this and that's what we have to get I mean okay so the premise of the argument is we start off with either this or this do you remember the first when we were doing the argument well look at P or Q P a sorry not P therefore Q okay do you remember that argument P or Q not P therefore Q okay what okay one okay now I'm not understanding why not there's a statement which is she doesn't want you to tickle her tummy now if that is the case it doesn't matter whether she realized you wanted to tickle her tummy or not her reaction was independent oh but why is that a problem because remember here the two sentences are completely independent of each other we talked about its if it's it's either sunny or rainy now that shouldn't give you the because we could say it's either sunny or windy but we haven't said that if then is completely different from or if then is a different logical claim right no no I'm sure you're not the only person who's confused by this and all this says here is either this is true or this is true and this says this isn't true therefore this must be so listen to the logic again either this or this sorry I'll to either this or that not this therefore that and it doesn't matter what this all that is do you see what I mean so so here well yeah but yeah but hang on this is only but nothing follows from this is there's only one premise we've got to get the whole argument before anything follows no I was just using that to illustrate that the or can stand between two two independent sentences doesn't matter what the sentences are their content is irrelevant okay if you still don't understand that see me after it um is there anyone else still bothered by they - put your hands up if you want me to go over that again no okay see me afterwards if you're still hung cuz it okay does anyone have anything else for premise 1 than this other than having divided the two up no okay good premise - if she didn't realize then you obviously went about it in the wrong way does anyone have something different for that no premise 3 in that case you deserve to get scratched unless you really thought she was such a perceptive cat that she'd understand wolf wolf meant rollover sorry said askin well because remember that you're not evaluating the argument at this point or what you're doing is you're trying to capture the meaning of each premise if you left out in that case you deserve to get scratched unless you so you just have an unless you just have unless you really thought she was such an the perceptive cat nor that actually not even a sentence is it in order to be a premise it has to be a sentence it might be a complex sentence but it has to be a sentence yeah yeah anyone have anything different there no good you're doing very well premise for if you thought that you're an idiot but you're not an idiot you're just twisted anyone have anything different for that if you thought that you would sorry what did you have okay okay at this point I actually sympathize with your having left that out and you'll see why in a minute but you shouldn't have left it out at this point because it is actually in there so you should put it in what were you going to say okay at the moment we're not removing irrelevant C's but perhaps when we do we'll take this out but at the moment we'll leave it in okay but but your intuition that it's irrelevant is a good one as you'll see in a minute okay so there's the argument set out logic books style as it actually stands at the moment but of course we haven't finished at the moment because we need to remove all sorts of bits and pieces so on your list of the steps to set out an argument logic what style what's the third step we've identified the premises and the conclusions what do we do next sorry right actually I'll tell you now there aren't any suppressed premises so so we don't have to worry with that here what's the next step remove irrelevant C's okay let me see how we've done that okay what we need to do is take each premise separately now the nice thing about how they identified the premises and the conclusion separately is we can treat each one separately now we don't have to do them all all at the same time and that that helps us so let's look at premise one and let's remove the irrelevant C's from premise one just get rid of any words that are not contributing to what that sentence means that are just bits of fluff if you like well yes that that can go can't it I mean that that doesn't do anything what else anything else perhaps I think perhaps can go as well yep okay there's one more word I'd get rid of actually not all know tummy who said tummy yep you can get rid of tummy can't you so what you've got is she didn't want you to tickle her or she didn't realise that was what you were going to do so here we are there green is that green easier than red okay so if we get rid of well perhaps and tummy we've got she didn't want you to tickle her or she didn't realize that's what you were going to do okay let's try premise two what have you got then and obviously if she didn't realize then I leave the then in yeah but they obviously can go can't it the obviously is just a bit of you know whether it was obvious or not is completely irrelevant it might not have been obvious it wouldn't really matter would it okay so we take out the obviously next premise three you take out only really unless you really thought you can certainly take out really yep not in that case why not in that case can anyone exactly the it refers it says if this if that is true then something so in that case is really very important okay I'd show you what I'd take out I'd take out the lot yeah in that case you deserve to get scratched because actually if you look at the fourth premise which I'd also take out completely if you thought that you're an idiot but you're not an idiot you're just twisted this is this is just a little insult that somebody's putting into the argument in order to Ram it home isn't it oh come on you idiot you can't not believe this which means what well it means just this doesn't it if I say P and you're an idiot if you don't believe it what what am I saying just on the whole well yes I'm also saying you're an idiot if I put it that way don't but so premises for premise for can go completely and premise three to see that let's go back to the whole argument okay and let me read it out to you because it's sometimes much easier if you ever find you're having trouble with an argument try reading it out loud because that'll the tonu put on it will give you much better idea of where you're going with the logic so let's read it out well perhaps she didn't want you to tickle her tummy or she didn't realize that's what you were going to do if she didn't realize then you obviously went about it in the wrong way in that case you deserve to get scratched unless you'd really thought she was such a perceptive cat that she'd understand more for meant roll over but if you thought that you're an idiot but you're not an idiot you're just twisted so if the poor thing did want you to tickle her tummy you deserve to get scratch you see this is this actually cancels itself out from here because you're saying let's let's look at the structure of it P unless Q okay Q is you really thought she was such a perceptive cat that you done should understand what fourth meant rollover okay if if you thought so if Q then you're an idiot if Q then are but not off and you're just twisted is just an insult added on P and less q If Q then R but not R can you see how that all cancels each other out P and less q If Q then R but not R so it all just becomes but but again don't worry about the figure the letters I've put in here just do it in your own try reading it out and see what really counts okay let's so here's the argument with the irrelevant C's oh okay one more thing the conclusion I've just taken out the tummy again because we took out the tummy from the first premise so do it in the conclusion so here's the argument with the irrelevance ease removed and I hope you agree it starts to look much more simple much easier to evaluate she didn't want you to tickle her or she didn't realize that's what you were going to do if she didn't realize then you went about it in the wrong way in that case you deserve to get scratched so if the poor thing did want you to tickle hurt you deserve to get scratched but let's continue what's the next step sort of question first it could be a conclusion but don't forget anything could be a conclusion a conclusion is just the role that something plays in an argument and in this arguments this is not playing the role of a conclusion it is perhaps playing the role of a sub conclusion but but this is the conclusion do two again remember that the conclusion is that for which you are arguing and that's the only thing that makes it a conclusion but you're absolutely right that could play the role of a conclusion okay what's the next step No remove inconsistent terms okay and cross-references okay inconsistent terms what do we mean by inconsistent terms well if we go back to that argument that we were looking at earlier okay this one and do you see how people wanted to have another premise in there something about industrial nations need to give emerging nations capital capital resources or whatever it was and if we look round to this one if a newly emerging nation is to sustain its growth and it does not have capital resources it will need help from industrial nations what does this it need help mean it will need what's what's the help that is implied here capital resources so we're using two different terms for capital resources aren't we here we're using capital resources and here we're using just help but actually they mean the same thing don't they so actually the way this argument we can reveal the argument much more carefully by saying many newly emerging nations do not have capital resources capital resources are necessary for sustained growth if a newly emerging nation is to sustain its growth and it does not have capital resources it will need capital resources from industrial nations many newly emerging nations will need help need capital resources from emerging nations can you use what sorry Pro hey well you couldn't use then there will it make many newly emerging nations will need oh then you mean capital resources I see I'm sorry I know what well what you're aiming to do is to reveal the structure of the argument and you do that by getting rid of as many things that are distracting you from the structure of the argument as you can and one of the things that's distracting you here is the fact that two different words or phrases are used for the same thing so what you do is you change them so that they using same word throughout the arguments now you could just use many newly emerging nations do not have help help is necessary for sustained growth I mean this suggests we shouldn't use help doesn't it okay so let's use capital resources instead then is actually a pronoun that you're on the whole you're trying to get rid of rather than put in so I wouldn't use that but I see why you wanted to yeah okay do you see what I mean about removing inconsistent terms and have I convinced you you were right about what so you need to book so that should be capital resources yes yes you were right about that but I hope I was right that that wasn't a suppressed premise it's a matter of an inconsistent term needing to be removed or needing to be made consistent so let's try it with this the argument we're looking at now I've now forgotten which slide we were on now I was just explaining what inconsistent terms are okay that's what an inconsistent term is what about a cross-reference if we've got Maryanne always wears jeans on Friday she is wearing jeans not money on what have we got there that we could um it's like an inconsistent term this is the not the jeans but she because she is referring to Mary Ann so either make both she that would be fine but but it might fall down elsewhere in the argument or make both Mary Ann so remove the she and and make it explicit that you mean Mary Ann so let's try that in this premise now I'm just gonna get a hint here we're going to leave the she in here because throughout the argument it's she isn't it we're never introduced to the cat's name we don't know what her name is and nor is she referred to as the cat at any point or anything like that so in fact this isn't an inconsistent term it's consistent throughout even though it's exactly the sort of thing that you would usually be removing okay so she didn't want you to tickler or she didn't realize that's what you were going to do any one can see anything that once you want to what put up your hand if you see something that you'd like to remove she didn't want you to tickle her or she didn't realize you were going to tickle her that was what you were going to do stands in for you were going to tickle her doesn't it we're not changing the meaning by by making those two terms consistent we're just making explicit something that in the original premise is left implicit and here it is she didn't want you to ticular or she didn't realize that you were going to tickle her I've left her that out but that doesn't matter see okay anyone have any problems with that nope okay let's move on what about premise two if she didn't realize then you went about it in the wrong way very nearly right the first bit was certainly right if she didn't realize you were going to tickle her Julie do you see you need to add this in because otherwise if you didn't if she didn't realize isn't actually a sentence is it until you add you were going to tickle her so you complete that sentence by adding nothing what what about the second half anyone have any ideas here then you were going to tickle her in the wrong way yes something like that keep it as similar as possible because all you're doing is trying to get rid of the complications you're trying to make it as simple as possible so as to reveal the structure of the arguments and you do that by getting rid of all the things that that are just confusing you so if she didn't realize you were going to tickle her then you were going to tickle her in the wrong way okay anyone any questions about that no good premise three good well done in that case refers back to the previous premise doesn't it and it says if you were going to tickle her in the wrong way you deserve to get scratched there's two quite separate sentences aren't there you were going to tickle her in the wrong way and she didn't realize you were going to tickle her now those are different sentences you mustn't complate them because actually they matter to the arguments as very much so okay any other questions about premise 3 no let's move on what about the conclusion it's an easy one isn't it ok if she did want you to tickle her you deserve to get scratched ok so we take out the poor thing put in she okay question yes does the conclusion not have to stand as a sentence that makes sense in its own light this is one of me from the very beginning well you didn't want you to take all how you deserve to get scratched doesn't make any sense mister does what mister what does that telling you she wanted you to take all her you deserve it doesn't well if the poor cat wanted you to tickle her oh I see you think okay if she wanted you to tickle her okay I see where you're going and it is a sentence but you're wanting okay shall I tell you what you're doing and and I completely sympathize with what you're doing and what's more you are not the only person in this room who's doing it you're probably the only person who's got the courage to question me on it what you're doing is you're trying to put the logic in here okay you're trying to to make this you're trying to make it all follow so that it makes sense as an argument and what you should be doing is just trying to identify what is said here what you want to put in is this I think so if she did want you to tickle her but you went about it in the wrong way or something like that then you deserve to get scratches that is that right there's a missing link to the premises somehow for me in but the but the conclude yeah you're wrong okay that that's all I'm saying right now you're wrong and what what you should do is I have a look at the argument over the week and if you're still thinking that if you still don't see what I'm saying come and see me next week and I'll like I'll explain it again this will convince you I'm going to reveal the structure of this argument by formalizing it and if that doesn't convince you nothing will okay we're going to put it into P's and Q's and it'll be a revelation to you how putting it into P's and Q's will make it make much more sense okay what we've got to do is identify each of the Constituent sentences of the argument and assign it a sentence letter now have I gone no okay I haven't done this okay let's look at premise one we've got to identify the Constituent sentences of that premise and assign it a letter so just looking at premise one what are the Constituent sentences what's the first one she didn't want you to tickle her okay and the other one she didn't realize you were only going to tickle her okay well here are two sentences let's provide them with sentence letters and I'd ask you which ones you wanted but I want you to choose certain ones so you can choose either P or Q and I'd rather and at P for this one good okay what what about the next one q well done good choices I have to say okay so whenever we use the sentence letter P with that that means that sentence it's just standing in for that sentence okay and whenever you use the sentence letter Q that just stands in for that sentence okay it's dead simple nothing magical about these things at all and the reason we use capital letters from this side this part of the alphabet that's just conventional we if we use capital letters like FG etc we tend to use them for other parts of the language and if we use lowercase letters like ABC that's for another part of language so there is a conventions about which part of language use for which sentence letters so that's why I want you to use letters from here okay so premise one has two constituent sentences she didn't want you to tickle her and she didn't realize you were only going to tickle her and we've labeled them P and Q okay premise two what are the constituents sentences in this letter this one what's the first one she didn't realize you're only going to tickle her well we've got that already haven't we so we don't need to put that down what about the other one you were going to tickle her in the wrong way okay you were going to tickle her in the wrong way okay it needs a sentence letter what should we have oh good yes well done you've got the idea here see you can formalize things dead easily okay that's premise two isn't it good premise three okay you were going to tickle her in the wrong way that's that that's our again you deserve to get scratched okay you deserve to get scratched what should we call that s good okay and conclusion so if she did want you to take all her now that's interesting because up here we've got she didn't want you to tickle her now do which I'm going to put her outside the room no don't it is say it's very good that you question things cuz that's important and we won't need another sentence that because what can we use instead not P can't we you don't you certainly don't need P and not P because you've got that just in having P and the word and the logical word not okay so if she did want you to tickle her you deserve to get scratched do we need anything else that's s already exactly so we here we've got all the sentences that make up the argument Emily all the sentences that that constitute the argument now I need somebody to hold this please suddenly come up and hold this for me okay there we there we have an interpretation that's what that's called an interpretation now premise one what's the form of that there's a logical word in that that's holding together two sentences what are the sentences and what are the logical words P or Q good that's premise one isn't it what's premise two so if is it Q she didn't realize okay if Q then not therefore you're confusing implication and entailment whoever that was and if Q then s was it R ok then the third premise if you were going to tickler in the wrong way you deserve to get scratched if R then s and the conclusion is if not she didn't want you if not P then let where's the not where's the not then it's not wrong you'll be outside to in a minute I there was no not know I'm putting them hang on I'm putting the not in front of the P because we've got P was she didn't want you to tickle her and the not here is if she did want you to tickle her okay but this says you deserve to get scratched doesn't it and this says you deserve to get scratched there's no not snuck in here I'm saying not P but I'm not saying not a Sam I know you don't know because well what you put actually if you use if you you know this is if not P then s whoops no that's okay so only the P that's been negated not the S not the S okay now you're getting me confused now hold on we've got four minutes to go let's finish okay that's fine because actually no we might need that in minutes stay there okay so this pqrs and and here's premise one oh I was going to make you do it like this but it's alright you've done it so here so there's the whole argument which is exactly what you've had there what you've got there and oops I should have put a knot there shouldn't I and I haven't but that's my mistake okay there's only a knot there she didn't want you to tickle her or she didn't realize you were going to tickle her okay that's a straightforward either-or isn't it either this is the case or that's the case then this says if she didn't realize that you were going to tickle her then you were going to tickle her in the wrong way now obviously if you like something's happened she's scratched you hasn't she and and somebody said if she didn't realize you were going to tickle her then obviously you went about it in the wrong way so going about it gently push pause pause you shoved your hand into her tummy and scratched so if she didn't realize you were going to tickle her then she and the implication there is that if she had realized you wouldn't have got scratched is that right that's the implication there if she had realized you wouldn't have got scratched okay no no we're not talking about wanting here at all known that but the premises are separate the premises are completely separate we're looking at the meaning of each one separately okay so this one the implication is if she had realized then then you wouldn't have got scratched if you're going to ticular in the wrong way you deserve to get scratched okay so as a good question dessert coming in here and so the conclusion if she did want you to tickle her and you went about it in the wrong way then you deserve to get scratched so the poor thing was longing for you to tickle her and and what she did when you did tickler was scratch you why did that happen because she went about it in the wrong way have we got it right I'm going to shut you up now okay let's I don't I don't want to leave on a note of confusion the important thing is that what we've done today is we've taken an argument that you lucked out right and when you look to date you won didn't you okay well I said we're going to set it out logic book style all we're going to do is identify the argument we're going to analyze the argument reveal its structure so what we've done is we've taken the argument we identified the conclusion of the argument we all did that fairly easily we identified each premise we all did that fairly easily yes okay we looked for suppressed premises but I told you there weren't any so so we didn't bother with that one then we went through each premise and we removed inconsistent terms cross-references and irrelevant seized and revealed the argument which might be a very bad argument for all we know but but we revealed the argument that was there what we didn't do is try and impose the argument we would have made because it would have been a better one on the argument that we were trying to analyze are you with me so all we've done is revealed to the arguments here we've revealed a structure we've even got it down to P's cues ours and s's now what you should do for next week is take one of the arguments that you found this week and try and do that and an awful lot of that's going to be removing irrelevant C's cross references and things like that and adding suppressed premises and but it'll give you practice in doing it and don't forget this is the important thing you can apply this methodology either somebody else's arguments which is what we've been doing here and what you will do if you look at arguments from the newspaper or you can apply it to your own arguments and you think of something for which you often argue climate change or something like that or or I don't know what's that okay that's a good one that'll do okay anyway find something for which you like to argue in the pub writes down your conclusion and write down your premises and try and make the arguments the argument you actually give so that then when we start evaluating arguments we can look at it but you will have identified your own arguments and set it out logic book style because people often don't do that with their own arguments and therefore don't see that they're missing out a huge premise or that this is happening all that's happening or or whatever okay so your homework for this week either take the arguments you found last week and set them out logic book style or choose a client claim you'd like to make and see if you can set it out as an argument logic book style okay cool I'm exhausted

Channel: University of Oxford

Views: 23,910

Rating: 4.8600001 out of 5

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

Id: kwxTte0U9Rc

Length: 80min 31sec (4831 seconds)

Published: Fri Oct 22 2010