Transcript for:
Understanding Arguments in Critical Thinking

all right so welcome back this is the second lecture of the introductory module where we're laying down some basic foundational concepts that will guide us through the initial portion of the class the initial portion of the class is dedicated to basic concepts of critical thinking and the basic task that we have is to master three interrelated skills remember what i said in the previous uh lecture that is that critical thinking is a skill or a set of skills that we need to master sequentially and we're going to start with the simplest skill in this particular lecture which is argument identification how can we identify the parts of an argument what are the parts of an argument why does it matter well hopefully throughout this presentation these questions will become clear and by the end of this presentation you'll have a basic outline a strategy how to find the conclusion of an argument and then what you will find are some practice exercises to confirm whether or not you've mastered that particular skill those will follow as a separate posting in the module after this lecture so the idea is read the section called what is an argument work through this powerpoint take some good notes make sure you've got the basic concepts down then do the exercises don't check the answer key that i will be posting right away learn to trust yourself get confident that you're on the right track after you've done all the exercises check your results and that will tell you if you've mastered the concept or not this is always a good idea it's the difference between learning and studying you can check learning you could see whether your learning has accomplished anything by seeing how well you're doing on things like tests or exercises whereas studying really has no way to be measured and so therefore it's relatively an ineffective modality or way to think about the the process of acquiring knowledge so work through this material learn the material test your learning and if it turns out when you do the exercises you're not getting as many correct as maybe you had hoped that's a sign that you need to go back and perhaps re-listen to the lecture or re-read the section because it's a sign of a lack of understanding okay this is pretty basic material if you don't get this foundational material everything we build upon it will become murky and the class will become more and more indecipherable as we go on so set a good precedent lay a good foundation for your future learning and everything will go well so let's turn to our initial question what is an argument you might recall from our discussion of critical thinking that the word critical often has a negative connotation and i talked about this last time in class where when someone is critical of us this is usually something that we don't appreciate this is something that we try to avoid and we generally don't want to be critical of other people because of this negative connotation however in the context of critical thinking the term critical actually has a positive connotation because it involves being able to critically discriminate good from bad arguments in this particular case and in class i talked about the analogy of a of a film critic for example someone who can determine which films have qualities that make them good films from which films have qualities that make them bad films well in critical thinking that's what we're trying to do with arguments trying to determine which arguments are good arguments and which arguments are bad arguments so that's actually a positive thing to be able to do now the term argument is also one of those terms that can have a negative connotation as well in ordinary everyday speech when you get in an argument with someone clearly that's not a positive thing that's a verbal altercation or a verbal fight and most people don't like to do that most people strive to avoid that but in critical thinking the term argument has a very different meaning one that is not negative and in fact is extremely important for all effective positive communication so let's see what that is in logic and critical thinking the term argument does not have a negative connotation an argument is simply making a case for something and we make a case by presenting evidence or reasons why a certain statement or belief should be accepted so basically an argument is just a set of statements now some of these statements are presented as support or evidence for another statement and the the totality of all these statements together is what we call an argument and one of the most important things we try to learn in this class is how to effectively support our claims how to effectively make strong arguments for our opinions our beliefs and things we take to be true and also to be able to evaluate the arguments that are presented to us as well now that definition may seem a little bit abstract so it might be useful to have just a couple of quick examples of some arguments to get a sense of what i'm talking about here are a couple of examples the first one says the following you should floss your teeth regularly because it helps to prevent gum disease this is an argument what we have is a claim that you should floss your teeth regularly and we also have another claim or statement that is intended to support that belief why should i floss my teeth regularly because it helps to prevent gum disease so we have a reason given for the conclusion when the reason does support the conclusion then we have a good argument and i think this one here is a pretty good argument the next one says if you want to be successful you need to complete your education and you want to be successful therefore you or so you need to complete your education again here the conclusion is that you need to complete your education the reasons for that conclusion or the reasons for that claim are that you want to be successful and if you want to be successful you need to complete your education so because of those two prior statements it follows that you need to complete your education so what we have here are a couple of cases where reasons or evidence are given for a claim and do seem to be reasonably related to that claim and give us reasons to accept that claim so we have examples here of two basic arguments so as should probably be clear the statements that comprise an argument are not all doing the same thing some are providing support and one is being supported depending on which role these statements are serving we give them different names the statements that are providing the support or evidence we call the premises of an argument premise if there's one premise sees if there's more than one the statement that is being supported is the conclusion it's what we are aiming towards it's what the premises claim to lead us to so the most basic structure and argument can have would be to consist of two statements one statement the premise giving a reason and another statement the conclusion being what we think is supported by that reason and so the simplest argument you could have would be a premise and a conclusion like our previous example should you desire to have healthy gums then you should floss your teeth so there you have a reason um given for a conclusion that is a simple argument that's as simple as an argument can get most arguments do however have more than one premise and the reason is that most of the time when you have a complex conclusion you're going to need more than one simple statement to support it now an argument will typically have more than one premise an argument however can only have one conclusion by its very nature so you're often going to have a situation where you have multiple reasons all adding up to or supporting a single conclusion if you find that you're dealing with a passage of text that seems to have two conclusions then what you really have are two separate arguments so to recap every argument must have at least one premise but will usually have more and every argument can only have one conclusion and it cannot have more than one conclusion so just for clarification i want to talk about what a statement is as we've seen arguments are comprised of statements so what is a statement well it's not necessarily a sentence because a sentence can contain multiple statements or multiple claims within it a statement is basically a claim that has a truth value that is it's a claim that's either true or it's false so an example of a claim would be that today is tuesday if today actually is tuesday then that claim is true if in fact it is saturday and i say today is tuesday then i've made a statement or a claim that is false so a statement is just a claim that's either true or false and statements differ from other uses of language like exclamations for example if i stub my toe against the desk and i yell ow well that that expression ow does not have a truth value it's neither true nor false it's just an expression or an exclamation of pain similarly questions don't have truth values because questions are soliciting information they don't have any value in terms of being either true or false so only statements have truth values and statements are the com the parts that make up an argument so now that we have a pretty good sense of what an argument consists of we have to take the steps to master the first of our skills that will lead us to be able to evaluate arguments and that is learning to identify the parts of an argument we know that arguments consist of conclusions that are supported by premises or reasons so in order to begin the process of understanding an argument we have to be able to find what the conclusion is we have to be able to identify what the premises are and then we have to see the relationship between them to see if it is a good or a bad argument basically so in order to analyze an argument into its constituent parts our first skill we're going to learn a four-step procedure that can accurately identify conclusions and premises and therefore get us on our way towards evaluating complete arguments now the first thing we're going to do when we're dealing with an argument is we're going to try to find the conclusion the simplest way to do this is to first of all look for conclusion indicator words or phrases as the name implies these are words or short phrases that indicate that a conclusion is being given and here is a partial list of some conclusion indicator words therefore wherefore thus consequently accordingly hence we may conclude as a result it follows that for this reason implies that it must be that so these are words that are used to indicate a conclusion is being given since you want to live a long healthy life therefore you shouldn't smoke now the word therefore is supporting the conclusion that you shouldn't smoke and what came before are the reasons now most of these expressions we do not use in ordinary language when we're just speaking to each other these are often used in more formal writing you will often encounter these in textbooks or in literary sources for example now in ordinary language the most common conclusion indicator that we use is the word so so is often a good indicator of a conclusion for example it's sunny outside i don't have to work today so let's go to the beach and in that case the word so is telling you that that's the conclusion i want you to reach that we should go to the beach and the reasons are because it's sunny and because i do not have to work so so functions like these other words to indicate that a conclusion is being given so the first thing you're going to do when you're dealing with an argument is you're going to look for a conclusion indicator word if you find it then your job is basically done because you found the conclusion everything else is going to be support or evidence for the conclusion however sometimes you don't find a conclusion indicator and then if that is the case then we have to go to step two when you're evaluating an argument and you do not find any conclusion indicator the next step that you're going to take is that you're going to start looking for premise indicator words or phrases this is not as efficient because there's only one conclusion so if you find it with an indicator you know you've you finished that part of the evaluation however by searching for premise indicator words if you can find all of the premises in the argument then you'll be you'll have something left over that is being supported by those premises so the premise indicators will indicate the reasons and what's left over will be the conclusion so a partial list of premise indicator words is contained here the most important is probably because as the word implies when you say you should think something because the because part is giving a reason so it's functioning as a premise or reason giving indicator some other indicators are since as for and then a whole bunch of synonymous expressions like given that granted that provided that assuming that seeing that etc that is if you grant that or if you accept this evidence then you should accept the following conclusion so these kind of phrases function as premise indicators so step one you look for conclusion indicators if you do not find a conclusion indicator then you look for premise indicators so far so good but what do you do when there's no indicator words at all and that's the step we need to look at next when there is no indicator word in an argument the next step you're going to do is you're going to test the first statement because very often when there's no indicator word the conclusion of the argument will be the first statement in the passage and the rest of the passage will be providing reasons for that initial assertion so the reason for this is often that we're we're taught to put our thesis or our main claim first and we often do that that's synonymous with our conclusion so we're taught to put our conclusion first and then put our reasons afterwards now this is not foolproof there will be some arguments where the conclusion is not the first statement even though there's no indicator however in the vast majority of cases when there's no indicator word the conclusion will usually be the first statement now you can't use that rule to go on autopilot you still have to think through the argument and ask yourself is the rest of the passage providing support for this initial statement and if the answer is yes then that initial statement is the conclusion and the rest of the passage is the or are the premises or the support for that conclusion here's an example of the kind of thing i'm talking about the chargers are definitely going to make the playoffs this year they've made big improvements on defense and special teams also the offense looks like it will be healthy and they have added several outstanding wide receivers they also have an easier schedule this season and they don't have to play as many teams with winning records as they've had to play in the past or last year now looking over this argument we're going to use our method the first thing we do is we look for conclusion indicator words words like therefore or thus consequently and we don't find any there is no conclusion indicator in this passage so then we go to step two and we look for premise indicator words words like because or since and as we go through the passage we see no there are none of those either so there's no conclusion indicator and there are no premise indicators so then our assumption is going to be that the first statement is the conclusion that the charges are definitely going to make the playoffs this year now if this is indeed the conclusion the rest of the passage should be providing reasons why we should accept that conclusion why should i think the chargers are going to make the playoffs well let's look at the following claims they've made big improvements on defense and special teams is that a reason yes it is the offense looks like it's healthy and they've added several outstanding wide receivers is that a reason yes it's another reason and so on throughout the rest of the passage so we see that these subsequent statements are providing reasons for the initial statement so the first statement is the conclusion and the rest of the statements are the evidence for the conclusion now keep in mind at this point we're just looking at the parts of an argument and i'm not making any claims as to whether this is a good argument or a bad argument but it is an argument it has the requisite features an argument has to have it has a conclusion and it offers reasons for that conclusion if you follow this method you'll find that it works almost every time and you'll almost never get to step four but sometimes you will have no conclusion indicator no premise indicators and you look at the first statement and that's not the conclusion it doesn't seem as though the rest of the passage is supporting it well at that point then you have to proceed systematically and ask yourself okay well is the second statement the conclusion well if it is the conclusion then the rest of the passage should be supporting it including the first statement and so if that is the case then the second statement would be the conclusion and the rest would be the premises if not then you have to go to the third statement and so on eventually if you have an argument you will be able to find the conclusion by going systematically through the argument however like i said this last step you will rarely encounter and if you're consciously looking for indicator words and if there's no indicator word you're looking at that first statement most of the time you won't get to this point but sometimes you will and it's nice to know that there's this last ditch effort that you can make that will help you to find the conclusion here's an example of the kind of thing i'm talking about this is an argument airplane travel has become a major hassle these days you have to wait in line forever and the tsa agents are always rude they really ought to hire more tsa agents and train them better in public service if there were more well-trained agents then everything would go more smoothly and travel would become more pleasant instead of the ordeal that it has turned into so again we use our step-by-step method and i will do this more briefly than i did in the previous example there are no conclusion indicator words there's no premise indicator words so then we test the first statement airplane travel has become a major hassle these days now is the rest of the passage providing support for that claim or is that claim providing support for another claim it doesn't seem as though this is an argument for airplane travel being a hassle rather it seems as though the fact that airplane travel has become a hassle is a reason for another claim and as we go systematically through the passage we come to the third statement that they really ought to hire more tsa agents and train them better in public service now if this is the conclusion the rest of the passages in the surrounding paragraph should support that and the first statement that airline travel has become a hassle and you have to wait in line forever and the agents are rude these are reasons for the conclusion for the claim that they ought to hire and train tsa agents better and in the last passage if there were more well-trained agents then everything would go more smoothly and so forth that also provides support so here we have an example of a relatively typical argument where the conclusion is right in the middle of the statement some reasons are given kind of as an introduction that support the conclusion which is in the middle and then the passage concludes with additional reasons to shore up the conclusion this is not an unusual structure and it is very common in ordinary communication where we're less concerned with formal well-developed arguments and we just kind of speak naturally and develop our ideas naturally however even though that is the case using our four-step method we can eventually find the conclusion of this argument now we know what it's about and now we're in a good position to begin to classify and evaluate this argument to determine if it's a good argument or a bad one well now we've got enough to get started we now know the basic features of an argument an argument is making a case for a claim that claim is called the conclusion and an argument only has one conclusion and the reasons that we should accept that claim or that conclusion are called the premises so an argument consists of at least one premise usually more in support of a conclusion and there's only one now that of course indicates our strategy in terms of how we analyze an argument since there's only one it would be most efficient if there's only one conclusion to seek the conclusion first rather than try to sort out all the premises and that's basically what our strategy advocates is to first try to find the conclusion and only when that fails then do we use a process of elimination and find all the premises and then isolate the conclusion that way so now it's time to practice this and what you'll find posted after this lecture within the module are some exercises that are from the textbook that i wrote but i've posted them as separate exercises where your task is simply to find the conclusion of the various arguments using the method that i indicated after this you will find a review of the exercises an answer key so you can check your answers and of course along the way if there are any of the exercises that are puzzling to you or you get a result that doesn't accord with what i have posted uh please post that i'm not infallible sometimes i may even make a mistake in an answer key or perhaps i didn't make a mistake and i can clarify where your understanding may need some assistance all right so uh on to the exercises and then that'll pretty much bring this initial introductory module to a completion and we will have mastered the first of our basic skills