Dr Greg Bahnsen - Critical Thinking: Argument (Part 3)

Lets begin this morning with a word of prayer. Lord, we do thank you again that we can come into your holy presence knowing that our Savior Jesus Christ intercedes for us. We would not dare to stand before you apart from his merit and intercession. We thank you for the grace and mercy you have shown us in him, and ask that you would be with us this day. Empower us by your spirit to glorify your name. Be faithful to your word. We ask for clear minds as we study this new material. Ask that you would help us to understand it and make good application of it, that we would live lives that are more pleasing to you, that we might be more persuasive in our dealing with others, and that we might better glorify our Savior who is the truth. For it's in his precious name that we pray. Amen. We're going to begin today where we left off yesterday. Yesterday's lecture was a discussion of argumentation. What goes into an argument, different kinds of arguments, inductive, deductive, the relationship of truth and validity, what the nature of logic was. And then I gave you a very brief theological overview of logic and why there's a good biblical warrant for doing it, even though we have to have some kind of restraint on our adulation of logic as well. Anyway, that was yesterday's lecture and now I've had you read the first chapter in Kopi's book that covers some of the same ground and the first chapter in Morris Engel's book that covers some of the same ground on the nature of logic and argument. And what I'm going to do is go through the books and just review the chapter. And as we come to various exercises, then we'll stop and do some exercises and make sure that we've caught on to this thing. So if you will turn with me in your car. Copi textbook introduction to logic, the 8th edition. And I'll just go over the things that I have underlined are worthy of repeating. Copi begins by asking, what is logic? Since this is a textbook in logic, that won't surprise you. And he tells us at the very beginning, logic is the study of the methods and principles used to distinguish good from. From bad reasoning. Or you could put it correct, from incorrect reasoning. And I hope you can see in that a reflection of what I taught you yesterday. Logic is a second order discipline. It looks at those who are engaged in first order argumentation, arguing about politics or about biology, whatever it may be. The logician looks at arguments and tries to discern the principles that will help distinguish correct from incorrect reasoning. He adds right away that this is not to imply that only the student of logic can reason well or correctly any more than only the student of baseball can hit a home run. That isn't true. Copie tells us in the next paragraph that logic is an art as well as a science. It is something that you can be trained in, but you have to have some initial ability in as well. And then as we turn the page to page four, he tells us that we study logic. We'll gain acquaintance with the pitfalls that have to be avoided in reasoning. We'll also gain methods for testing the correctness of any different kinds of reasoning. He says something interesting in the next paragraph. He tells us that appeals to reason are more effective than appeals to emotion. I don't think at first we'd be inclined to agree with that. We're often discouraged, aren't we, at how appeals to emotion seem to sway people and they don't listen to good reason. What he says, though, is that the appeal to reason is more effective in the long run and can be tested and appraised by criteria. Well, maybe he's not a Christian, as far as I can see. Maybe he's a post millennial unbeliever, though, and that he thinks in the long run reason wins out. I'm not so sure that is true to human nature. He didn't come to take a class on theological anthropology. But in the long run, it seems to me, appeals to emotion have long lasting effects. I mean, what happens in a culture, politically, socially, what have you. Anyway, this much is true. Appeals to reason can be tested. That's the sort of thing that's more open to objective evaluation and discussion and dialogue than our appeals to emotion. I told you this yesterday, and it's repeated here, that logic is not the science of the laws of thought, nor is it the science of thinking, because in the first place, psychologists also study thought and thinking. Moreover, not all thinking is reasoning, he tells us. And then if somebody would say, okay, well, then logic's the science of reasoning. He goes, well, same problem. Psychologists still include reasoning as one of the kinds of thinking that they would study. And so on the top page five, we give this important observation. The logician, however, is concerned primarily with the current correctness of the completed process of reasoning. Psychologists are not concerned with whether the reasoning is correct or incorrect, and they're more concerned with the process, the actual what goes on in the head of somebody, than they are with the completed product. You know, logicians kind of look at the reasoning process at the complete from the completed end backward, trying to decide whether it's correct or incorrect reasoning. And then he reminds us that the distinction between correct and incorrect reasoning is the central problem with which logic deals. So that's right back to where we began. Logic is the study of the methods and principles used to distinguish correct from incorrect reasoning. All seems so simple. You put it that way. And then we're going to the more we go into this, we're going to see what a huge field can be. I trust you'll really profit from. You'll learn not only in your own thinking, but as you watch the TV or talk to people, these things will come back to you. And you say, oh yeah, I see how language is being used here and how this is being defined and what's wrong with that argument and so forth. It will improve your own mental apparatus, I'm sure. Okay, Section two distinguishes between premises and conclusions. This is not all that difficult. Copie tells us. Inference is a process by which one proposition is arrived at and affirmed on the basis of one or more other propositions. So inference is that process itself. And then he tells us that propositions can be asserted or denied can be true or false. And that's not true of other kinds of linguistic functions. Exclamations aren't true or false, commands are not true or false, but propositions are. And then he distinguishes between sentences and the propositions that sentences utter. Two sentences, say, in two different languages, or having two different grammatical forms, may assert the same proposition. Then on page six, he tells us that in different contexts, exactly the same sentence can be uttered to make very different statements. He uses the example the present President of the United States is a former congressman. At some times that would be true, and at other times it would not be true. So the sentence is open ended a bit, but the proposition that is asserted and is intended by that sentence is not okay. In the middle of the page, he says, corresponding to every possible inference is an argument. And it is with arguments that logic is chiefly concerned. An argument is any group of propositions of which one is claimed to follow from the others, which are regarded as providing support or grounds for the truth of that one. You remember this from yesterday. An argument, then, is a group of propositions where one is said to follow from the others, or the others are supposed to provide evidence for the 1. There's a structure to an argument. Then the conclusion is what is asserted. The premises are that upon which it is asserted. And he tells us on page seven that the order in which the premises are given is not significant. On page eight, he begins by saying some arguments offer several premises in support of their conclusions. In the middle of the page he tells us premise and conclusion are relative terms because the same proposition can in one context be a premise and in another context be a conclusion. On page nine, you can't tell the difference between a conclusion and the premise just in terms of the position. You find them in the formulation of the argument. Sometimes premises are stated first and conclusion last. Sometimes conclusion first, preface premises last. Sometimes they're mixed up. And so he gives a list of conclusion indicators and a list of premise indicators, and it would be good for you to look at those. They are not the be all and end all. There are other ways in which we have to find premises and conclusions when they aren't found, for instance, and sometimes language like them is used and it's misleading. It's not really an indication of the premise or conclusion. But in most cases this is pretty helpful to know. You find the conclusion after words like therefore or hence, or thus, or so accordingly, in consequence or consequently, something proves that or as a result of this, for this reason or reasons, it follows that we may infer that. I conclude that. Now that's a giveaway, isn't it? I. I can do that which shows that, which means that which entails that which implies, which allows which points. Okay. Different ways in which you might catch on to this is what the person's trying to demonstrate. This then is their conclusion. The premise indicators include things like since such and such or because such and such for or for this reason as it is the case that it follows from. And then you give premises as shown by these premises, inasmuch as these premises, or as indicated by the reason is that or for the reason that it may be inferred from, may be derived from, deduced from, or in view of the fact that all of these are common ways in English that we indicate premises in an argument on page 11, Copious tells us something that is a sad fact for students of logic who have to do so many homework assignments. Not everything said in the course of an argument is either a premise or a conclusion. Sometimes there's stuff there that's just irrelevant. You know, the interesting thing is that's not just a headache for students who have to do homework problems and say, is this important or not? Is this relevant or not? There are people you're going to find when you start using this in real life, not not just in this academic setting of the classroom. There are people who have all kinds of things put into their arguments and their speeches, sometimes their term papers, which are irrelevant, you know, and they. And they don't seem to be aware of that fact. They just. They think, well, you know, this has something to do with the subject, but it's not really relevant to proving a point or moving the subject along. Don't anybody get hurt feelings by that last remark. I actually meant that to be applied mainly. You'll see that when you follow a debater or somebody on TV trying to make a point, often they're filling a lot of space and you're saying, yeah, okay, but that's not relevant to proving your point. So Kofi reminds us that happens on page 12. He says sometimes propositions are located, are found, but not because they're in a declarative sentence. Sometimes they'll be in the form of rhetorical question. In the middle of the page, he says, sometimes we have a noun phrase that, for purposes of logic, would be translated into a declarative sentence. And then on page 13, the part that made all of you so happy, he said, sometimes the formulations of arguments don't contain explicit statements of their conclusions. It's kind of like it's supposed to be so obvious, you know, that I don't even have to state it. And then this is an important observation, the last line on that page 13. He says, Some logical ability is presupposed in the study of any subject, including logic itself. Now, there's two points here. The reason why logic is such a valuable tool is because you can't study anything without using logic. Every field of endeavor uses argumentation. So logic is, in a sense, presupposed by everybody. But here's the second, and I think, even more interesting point. Even the study of logic presupposes the use of logic. As Copie lays out his approach to logic, he's trying to be logical. He's offering arguments of his own. And then he gives a nice summary paragraph that I don't think I'm going to bother to read this morning. On page 14. Puts everything together here as to what logic is. Propositions and so forth. Let's do some of the exercises. And let me turn to my assigned. Okay, in this first set, you were to do numbers one through 15. Is that right? Okay. No, I'm not having you turn them in. There may be a point at which I'll ask you whether you've done all of your homework, you know, just as a way of checking so you don't have the temptation to say, well, he might not call on me, so I won't, you know, do this work. But, you know, you're in college now. You should be responsible. You're good Christian students. You're going to do your homework. I know that. Right. Household looks. Number one, we're supposed to identify the premises and conclusions in the following passages. And he tells you it's a giveaway. Here there's only one argument, so it's a little bit easier. Number one. But the price of fossil and nuclear fuel is only a small fraction of their total cost. Society pays the other costs for damaged health and property, oil spills in the oceans, polluted or poisoned, poisoned rivers, lakes and beaches, acid rain, killed or poisoned fish and oyster beds and human misery. It appears to me that the second sentence is the premise and the first sentence is the conclusion. Is that what you all got? Now, this is a starred exercise. Did you check it in the back? Am I right? Okay, now this is going, I was telling Pete on the way over a little bit, something that may not sit well with you, but it's just a fact of life. That is, I'm going to sit here and we may disagree over some of these, and there may not be an absolutely clear or right or wrong way of looking at some. Now, some are going to be so obvious that I have to hold you accountable for that, I guess. But in many cases where there's numerous arguments in a passage, especially different ways of schematizing them. Now you're all saying, last night, I wish I would have known this. I wouldn't have thought there's only, you know, like in algebra, only one right answer. And so I'm trying to get to it. Some of it has to do with interpretation. And so that's why, even though I'm supposed to know this material fairly well, I look at this and I have to ask you, is that what the author said, too? Did I get it right? Do we agree? Maybe that's a better way to put it. It's not who has it right, who has it wrong, but we all agreed on this, and I guess on the first. So, number two. Now, it is hard to argue that Western astrology must be true because it has such a long tradition behind it, because Chinese and Indian astrology have equally long traditions. If one is right, the others are wrong. It is hard to argue that Western astrology must be true because it has such a long tradition behind it. I'm not even sure the grammar of this one. Yeah, because Chinese and Indian astrology have equally long traditions. Okay. The conclusion seems to be something of the along the nature that it's hard to argue that Western astrology must be true because it has such a long tradition behind it. And the premises would be Chinese and Indian astrology have equally long traditions. If one is right, the others are wrong. Therefore, it's hard to argue that Western astrology is right because it has a long tradition. Is that the way you got it? Okay. How do you do it, Pete? So you want to take the last sentence as the conclusion. You think the author here is trying to convince us that if one is right, the others are wrong? Okay, let's. Again, I can't be absolutely sure, but it seems to me that that's not the sort of thing you need to argue for. That would be kind of obvious. If one is right, the others are wrong. And so that might have been an early tip off, but that's not the conclusion. The author, in the first sentence seems to be pointing to a defect in the way some people try to support astrology. And he says, I can show you that's a defective way of thinking. You know, that if one is right, the others are wrong. And there are others that have equally long traditions. And so I appreciate you working at that. It doesn't seem to me though, that last sentence is really the conclusion. Anyone else thinking it's a conclusion? Okay, well, the conclusion could be that in astrology, only one can be right. That is, if one is right, the other is wrong. That could be a conclusion. It's not so much that. It's a premise and a conclusion together. It's a hypothetical statement, remember? And there's a difference between that and the conclusion argument. Let's try number three. Fair tests charged that another examination, the sat, which most colleges use as one measure of which high school students they admit was biased against girls, again pointing out that they, as a group, scored lower on that test even though they earned better grades than boys. This one's easy, Pat. Take it right. The fact that the girls scored lower on the test and then the fact that they are in better grades than the boys shows that as a conclusion, the SAT is biased against girls. Okay. Number four. Lying is as much a part of normal growth and development as telling the truth. The ability to lie is a human achievement, one of those abilities that tends to set them apart from all other things species. Okay, Jay? Yeah. Anybody have any problem with that? Human achievement. Ambiguous, probably. The fact that it's a bad argument or that has ambiguities in it doesn't change what the structure of the argument is, though, that's all you need to worry about in this exercise. Yeah, I suppose you can say the ability to lie is a human achievement. Perhaps. Premise one, Ability to lie is an ability that tends to set humans apart from other species. Premise two, and then conclusion. Lying is as much part of normal growth and development as telling the truth as your conclusion. But now I think Pete's suggesting that the ability to lie is a human achievement might be the conclusion. And looking at it that way, that's interesting. Then you'd have as a premise, lying is as much part of normal growth as telling the truth. Another premise lying is one of those abilities that tends to set humans apart from other species, and therefore the ability to lie is a human achievement. Actually, I think that may be superior to what Lisfir suggested. Please don't be too frustrated. What happens is you have here only two sentences, three clauses, and if you don't know the context, you don't know what the guy does with this. We just kind of jump into this thing from outside. You can't be absolutely sure, but I think I would favor that second interpretation. Well, we know number five will be easy because the author gave us the answer. I say that tongue in cheek. Because you know what, we can disagree with the author too, can't we? Although he may know a lot more about it than I do, or you all do. That's a possibility. Okay, number five. The light we see from distant galaxies left them millions of years ago. And in the case of the most distant object that we have seen, the light left some 8,000 million years ago. Thus, when we look at the universe, we are seeing it as it was in the past. Alyssa David, I'm not hearing you because you're talking down. What was the first clue that that was the conclusion? Yeah, the conclusion indicator. Thus, very good. Number six, the advanced technologies applied in supercomputers tend to quickly permeate the entire computer industry. So the nation that leads in supercomputer development tends to have a jump on other countries in producing more powerful and more lucrative lower level computers. And how did you know that? Very good inclusion indicator. So gives that one away. Number seven, Forbear to judge, for we are sinners. All. Right, the premise would be we are sinners all inclusion. If we want to take it out of its imperative form, we'd say one should forbear to judge. But anyway, you've got the right order of the conclusion. And premise number eight, males born into poverty are more likely to commit crimes with teenagers and adults than are more privileged males. So a boom in births among poor mothers can be expected to exert upward pressure on the crime rate 15 to 20 years later. James? Alright, how did you know that? The word so shows you the conclusion. Number nine. He that loveth not knoweth not God, for God is love. Melissa. And how did you know that? Premise indicator. Very good. Number 10. Thomas Moore, the director of domestic studies at the Hoover Institution at Stanford University, argues that poverty statistics overstate the number of poor people because researchers don't add in such non cash benefits as food stamps or Medicaid when calculating family incomes. Okay, now let me indicate here the part that says Thomas More argues that is not the conclusion. See, this person is not trying to prove that Thomas More said something. This is just a. This is just a report on what Thomas More argued. And Thomas Moore's argument is conclusion. Poverty statistics overstate. And his premise is researchers don't add in non cash benefits. Is that all clear to everybody? It's not a big, big deal, but I just want to make sure that you are aware that Thomas More is not part of the conclusion because nothing in the premise proves that Thomas More did something. This is just a report of Thomas More's argument. Okay, number 11. Since there are no mental diseases, there can be no treatments for them. I like that. Go ahead. No, that's not the premise. I'm just catching you on a slight thing because we're going to start getting picky here. You said the premise is since there are no mental diseases, what's really the premise? Pat, There you go. Right. And how do you know that the premise is there are no mental diseases. What kind of indicator? Premise indicator. Okay, number 12. All the game is Scottish and its ancestry. Golf has become an undeniably American pastime. An estimated 21.7 million Americans are golf and according to the national golf foundation, 8 million more will be playing by the year 2000. Jay, what about this part that says although the game is Scottish in its ancestry, that's extra information, okay? Not irrelevant. And it sets up why this is being said, but it's not part of the premise or the conclusion. 13. Since an individual's lifetime earnings typically follow an up and down pattern, low while a young adult highest just before retirement, and then a leveling or reduction, there always will be a natural level of income inequality at any one time, if only because of the age distribution. Okay, if only because of age distribution strikes me as a premise. So what you have is an individual's lifetime earnings follow an up and down pattern. There's always an age. Well, there's an age distribution, therefore there'll always be a natural level of inequality. Yeah, you might have to reword it to make it. Although you can just put, oh, I see. Because of the. Well, that's one of those noun phrases, the age distribution. You want to say there is an age distribution in society or something like that. Number 14 missiles are easier to defend than cities for two reasons. First, missile sites are small and tough. Our cities are large and vulnerable. Second, a defense of missile sites is considered effective if it can save half the missiles, whereas the defense of cities has to try to save them all. Okay, you've done well. Only one problem. I mean, you got the structure right, and this is not a big deal. But you broke this down into four premises. What is it that the author says here that would tell you that there's only two premises? He says for two reasons. Now, sometimes authors say, just like pastors will sometimes say in the pulpit, I'm going to give you three reasons this morning for this. And then they give you four or two instead of, you know, so sometimes it's hard to count. So you're not absolutely wrong in doing that. But I might have just said, well, there's two premises, two long ones with the whereases in them. Okay, let's move ahead. I think we've caught on to premises and conclusions pretty well. And just remember, what I've added that Kofi hasn't told you is that this is not an absolute science. A lot has to do with the ability to catch on to what the author or the speaker is trying to say and to. In some sense, I don't want to make it mystical. Please don't misread me. But there is something about having a feel for it that goes beyond any rules or any objective public way that we can necessarily. Everybody agree this is what this isolated passage must be arguing and how it is arguing. Okay. In section 1.3, Copie begins to explain diagrams for single arguments. And he tells us very simply that a diagram is a spatial representation. The value of the diagram, by the way, they didn't do diagramming in the old days when I was in college. This is something that's new here, and it isn't crucial, but it is valuable. It's valuable because it's good to see how arguments relate, how premises or statements in a passage relate to each other, so that we realize there are a lot of different ways to organize arguments. If nothing else, the diagramming will accomplish that. Then he gives the convention that he uses for diagramming. You go through the various propositions and number them, use a circled number to stand for it, and then an arrow points to the conclusion. And then if you have two or more premises working together, you bracket them somehow and then you have an arrow going to the conclusion. Now just look through the book pages. What, 19? Well, you can have 18 too, but 19, 20, 21, 22. And if you just look at those diagrams, that in itself teaches you what he wants you to learn. Here you see how different arguments can be part. The real easy One on page 20 is first premise, second premise in the order of appearance in the paragraph, and then the conclusion stated. Third. But then look at the second diagram on page 21. There you'll notice that the conclusion is the second assertion in the paragraph rather than the third. And then if you go above that, even the first assertion in a paragraph can prove to be the premise. The interesting thing about the diagram, the first diagram on page 21, is that you actually have two arguments for the same conclusion. One is a single premise argument and the other is a double premise argument. So sometimes you have different ways of arguing for the same thing. Where's the page? Yeah, if you turn over to page 34, you see that sometimes you have the same premise proving two different conclusions. So it's just incredible, all the variety that you can have as to how many arguments, what the order of mention of premises will be, how they're grouped together and so forth. That's the value of the diagramming. He uses the convention of a broken circle. If a conclusion is not explicitly stated, but is supposed to be obvious enough. And I ask you to do some exercises one to five, All right. On page 22 in these exercises that are given. Given. Let me try to do number five. This is that stark. Let me find out if I know what I'm doing. I have opposed the death penalty all my life. I don't see any evidence that it's a deterrent. And I think there are better and more effective ways to deal with violent crime. We have the first proposition. I've opposed the death penalty all my life. That could be a personal proposition that is something about the individual, or could just be the expression that the death penalty ought to be opposed. Something like that. So that would be number one. Number two would be, I don't see any evidence that it's a deterrent. Again, either autobiographical about his beliefs or the assertion that there is no evidence that it's a deterrence. And then number three is Going to be. I think there are better and more effective ways to deal with violent crime. And as I read it, you have two and three bracketed. And I guess there should be an arrow here then, to number one, which is the conclusion. First of all, before we check Kofi, who is. No, he's not here to defend himself. Did any of you do it differently than this? Oh, no. Oh, so I did do it wrong. Well, good. Before I find out what I did wrong, let's see if we can. If I can learn from this. Okay. Okay. I proposed the death penalty all my life. I don't see any way for that not to be the conclusion here. And so I don't see any evidence that it's a deterrent. And I think there are better and more effective ways to deal with violent crime. It would seem that my mistake is that I bracketed those two together as though you have to team them up to draw that conclusion. But you don't need to team them up to draw the conclusion. Each by themselves would be ground for that conclusion. So instead of diagramming it in the way that I have here on the board, we should actually have two leading to one with an arrow, and then up here, three leading to one with an arrow as well. Now, did I get it right? Is that what the back of the book says? Okay, very good. Well, let's give some of the rest of you an opportunity here to do this as well. All right, Pete, find number two, the tough one. Okay, Pete, first of all, what do you think the conclusion in number two is? Okay, why isn't the conclusion that it has the advantage of being easier to inject? Well, it seems to me that it being more soluble means that it takes less to inject. It takes less mass. And you have this information about the wasted person having little muscle mass to begin with. So the point is, it takes so much more morphine to accomplish the same thing that heroin will do. That is more mass. Therefore, it's easier to inject the heroin than the morphine. Ask the class. What all did you do with this, Kat? You took the 50 times more soluble and the little muscle mass of the wasted person as premises to prove what? So that's a single line of proof for the same conclusion. I mean, an additional line of proof for the same collusion so that you have the 50 times more soluble and the little muscle mass proving the advantage that it's easier to inject. And then you have the 5cc's of morphine. I'm sorry, what's the next part of the argument. So you have those two sentences as premises also showing the advantage that it's easier to inject. Okay, what other lines do we have here before we. So you would agree with Pete's approach in that you think there's an implied conclusion, and that conclusion has to do with the advantage. It's advantageous to use heroin instead of morphine. One of the arguments is it's easier to inject. Right. Okay, but then what is the rest of this that explains it being easier to inject? Here's. Here's the problem. And from my perspective, the artificiality of some of this, which contains a single argument, we know that means there can only be one conclusion that we're going to be working on here. And the approach that you are taking would mean that we'd have to drop all of those premises that prove that it's easier to inject heroin than morphine. And that doesn't seem very likely that he would put all that in there. And so I think what you've done and what Pete has done would be possible ways to take this. I'm not going to be real strict about this, as I've already indicated to you. However, given the rules that the author has laid down, the textbook author, very likely we are not to dismiss all those premises as completely irrelevant. They seem to all be ways of proving that it's easier to inject morphine. And then the question is, how many different lines of proof does he have for that conclusion? There's little drug, it's more soluble. Well, however you do it, I do think that's going to be the conclusion. It's easier to inject. And one of the lines approved proof that it's easier to inject is that it's extremely painful to have an equivalent amount of morphine injected because of the little muscle mass of the wasted person and so forth. And the equivalent dose of heroin can be given to anyone. Something like that. This one is a tough one. You were right. Yeah, yeah. I'm not sure that we were supposed to get anything from that necessarily. You were saying, Pat, the explanation for the soluble being mentioned, actually, it's not half. It's 150th. Right. But the point is, it would take more vehicle in which to dissolve the heroin than it would. I mean, morphine. It would take more vehicle to dissolve the morphine than it would to dissolve the heroin. And that's why it doesn't take as much mass. And injecting that much mass is painful. We spent enough time on this one thank you very much. I think you did good work trying to do it that way. Jay, why don't you do number three for us? Only in a reasonably tolerant society can civil disobedience flourish. That means we should expect more of it in a more just society, especially as a more just society is more likely to tolerate extreme views. What is the conclusion? And there's only one by the rules we're playing by here. Okay, does everyone agree with Jay that that's the argument? It seems to me that's the argument. Okay, Melissa, did you see it the same way? Civil disobedience and the two premises would be, Only in a reasonably tolerant society can civil disobedience flourish. And a more just society is more likely to tolerate extreme views. Therefore, we should expect more of it in a more just society. And Jay has diagrammed this as two separate arguments for that conclusion. Does the class agree with him in that? Are those two separate arguments or are they supposed to be teamed together? Say it again, Pete. Okay, if we team them together, then we're saying, only in a reasonably tolerant society can civil disobedience flourish. And the more just the society is, the more likely it is to tolerate. And therefore. Yeah, it doesn't seem to me that they separately support it. I think they do need to be teamed together because the one tells you what will make for a just society. I mean, for a tolerant society, and then the premise that a tolerant society will allow civil disobedience to flourish. And then you can draw the conclusion from justice to tolerance to the flourishing of civil disobedience. So very good. So we should bracket one and three, leading to two. Any disagreements now? Are we all having fun? This is the best part of the course. No, I'm kidding. We'll get through this. Actually, what we should do, because time is getting away from us, is turn to the hard direction exercises. And so let's go to page 30. In the book. But before we get there, there's some text about recognizing arguments that I want to review for you. Beginning on page 25, on recognizing argument, turn to page 26, right in the middle. The author says about the example just given. No claim is made, either explicitly or implicitly, that any of them provides grounds or evidence for any other. So no argument is present. There is no argument. This is what we began with yesterday. We have to get this, you know, really firmly entrenched in our thinking. You don't have an argument unless somebody is setting forth some premise or premises in support of another one. And the author's just reminding us of that if there's no implicit claim that certain premises provide grounds for the other premise that is taken as a conclusion, then there's no argument present. And then on page 27, he says neither alternative nor hypothetical propositions involve the assertion of their component proposals. If I say A or B, I'm not asserting A, and I'm not asserting B, I'm asserting A or B. That's a third thing, if you will. Count one as asserting A, count two as asserting B. A third kind of assertion is A or B without asserting one or the other. And then hypothetical propositions are the same way. If I say if P, then Q, I'm not telling you that P is true. And I'm not telling you that Q is true. I'm just telling you that if P is Q, then if P is true, then Q is true as well. So the author tells us in the middle of the page, what is asserted is only that the former implies the latter, but both could be false. For all the statement in question says no premises asserted, no inferences made, no concept conclusion is claimed to be true. There is no argument. And then, of course, the kicker is at the bottom of the page. Context, however, is extremely important. Well, yes, no kidding. When we try to do your exercises, Dr. Koeppi, we find out we don't have enough context to be absolutely sure you know context. And he mentions common knowledge, things that sometimes are just taken for granted that you have to fill. And then I think it's important to notice on page 29 that he says argument indicators sometimes have other functions as well as indicating arguments. That's part of the trick here, is that when you see those words that often give away premises or conclusions, they can be used in other ways as well. I'm not sure. I can't remember if he uses this example or your other author does. The word sense. Sense can have a temporal meaning. It can also have the logical force of this is the conclusion to be drawn, or these are the premises from which the conclusion is drawn. At the bottom of page 29, Copie says that the word because can be an indication of an explanation rather than an argument. How do you know the difference between an explanation and an argument? He gives a hint on page 30, if we're interested in establishing the truth of Q and P is offered as evidence for it, then Q because P formulates an argument that's trying to show the truthfulness of Q. However, if we regard the truth of Q, Q as being unproblematic, as being at Least as well established as the truth of P, but are interested in explaining why Q is the case, then Q, because P is not an argument but an explanation. I think that helps, doesn't it? When I use the word because and I'm arguing for the truth of something else, then that's an argument. When I use the word because to explain to you how or why it happened, then I'm giving obviously an explanation. If the purpose is to establish the truth, or if the purpose is to explain or account for something, then you can see the difference between the logical and causal uses of the word because. Okay, now we come to the exercises on page 30. And you were supposed to do the first 10. No, hypothetical propositions are not arguments. Arguments. Right. And I remember now, as I was reviewing this, I was a little confused at that point too. The important thing to remember is that a hypothetical proposition does not assert the P or the Q. If P, then Q. And for that reason it's not an argument by itself. Although. It's not an argument. If you changed it to since P, then Q, then you'd have an argument. Then Q is asserted on the basis of P. The other is just saying that if P is true, that Q has to be true as well. It's an assertion about a relationship between P and Q, but it's not an assertion about P or Q themselves. And page 30, then you have the first 10. And he says only some of the following passages contain arguments. Find those with arguments and diagram the arguments they contain in the case of explanations indicate what is being explained and what the explanation is. So let me follow the same teaching technique that we used a moment ago. See if I can be the goat here. I'll try to do number five, and then we'll check the back of the book to see if I did it right. As I look at number five, it seems to me that there's no argument here that you don't have the truth of some proposition being asserted on the basis of other propositions. But rather you have a situation that's being explained. And the situation that's being explained is that scientists are perplexed. And why are they perplexed? Because they've detected a gamma ray source whose characteristics do not conform to conventional theories of physics. And then you have a further explanation of that by saying the radiation is a new twist on a common occurrence or a new occurrence altogether. So I'm ready to be slam dunked. Did I do it right or wrong? He scores. All right. So the author and the teacher agree that Always makes it easier on the students. Now let's see how you guys do. Who didn't get to diagram something here? Melissa didn't. Okay, let's let you do number two then. Because their best physicists were not zealous for weapons, because they made uncorrected mistakes, because Hitler was Hitler and and because men like Speer always had more urgent production priorities, the Germans never really tried to make an atomic bomb. Well, let's work through this. Why at first did it appear not to be an argument? Well now, if the premises didn't necessarily back it up, you might be telling us that it's a bad argument. It doesn't prove its point. But the question is, is this intended as an argument or is this intended as an explanation? Well, tell me. But now you think it's an argument. Okay, now what's an argument? An argument is some premise being asserted on the basis of other ones. So what premise is being asserted here? Now, what's the conclusion? Okay, so you're saying that here you have a proposition that is taken as a conclusion. The Germans never really tried to make an atomic bomb. And the truth of their not really trying to make an atomic bomb is urged on the basis of propositions that. Are you saying all the other ones Because. Because. Because are then the premises for that conclusion. Let's get the rest of the class involved. Pete, what do you think? It's an attempt to explain it. Maybe it's a bad explanation. But it seems to me that you don't have an argument here. It's not the truth of the Germans never really tried to make an atomic bomb. It's more. Here's why it came about that they never really tried. What do you think, Pat? Okay, well, we're all agreed that means it must be right. Truth is the majority opinion and I'm just being lighthearted. Don't take me seriously here. Well, then we need to. Let me diagram something. Will number four be a good one to diagram? Melissa? Okay, let's read it and then you tell me what you think the conclusion is. The steep climbing angle jet transports from require for noise alleviation would cause passengers in rearward facing seats to hang from their seat belts instead of having the comfort that a backrest provides forward facing seats in steep climbs. Because of this discomfort and the possible preference of passengers to look forward coupled with the safety questions, the views of passengers should be established before rearward facing seats are adopted. Well, before you come up, let's make sure that we have a conclusion here. What's the Conclusion. The conclusion is the views of passengers should be established before. Okay, so you think that that recommendation is being urged on the basis of certain premises. Okay, then how would you diagram it? Sure, yeah. No, wait a minute. One and two you have bracketed together. And number one is. Rearward facing seats would cause passengers to hang without the comfort of a backrest and steep climbs. Number two, this is uncomfortable. And for those two reasons together you draw the conclusion abuse of passengers should be established. That doesn't seem to follow though, does it? Okay. One reason why passengers should be consulted first are their views established is the discomfort of rearward facing seats in a steep climb. And then two and three would be what? Preference of passengers to look forward coupled with the safety questions. Now, how is it the preference of passengers to look forward is actually in the argument coupled with safety questions bracketed, as you've done it doesn't seem to me two and three have to be put together for the drawing of that conclusion. Let me suggest, just so we can save some time, and you correct me, it appears to me that 1, 2 and 3 are all individual lines of support for number four. Well, okay. Do you accept that number four is the conclusion? What, you counted them, you mean? Okay, well, before we go on then, her four is your number five. Do you agree that those are separate lines of argument? How about you? You said it was an explanation. Yeah, well, but it's not explaining anything, is it? There's no event taken for granted. There's this controversial idea that the views of passengers should be established before adopting something. And so you see, it's not like we all know that to be true. Now, how does it come about that? That is. That's not being explained. That's being urged. The author is urging you consult the views of passengers before you adopt this change. So I'm fairly convinced this is not an explanation, this is an argument. And I do think Melissa's got the conclusion right. I just don't think that two are bracketed. Now let's go back to Jay. Which two do you think should be bracketed? Yeah, I see. Well, he's counted them differently. One way of doing it is combine all of that into the premise that it would be a discomfort to be in a rearward facing seat in a steep climb. And he's put two things together to show that. Okay, as we come to the end of this chapter, looking at the exercises that begin on page 40, this is a case of diagramming passages that have more than one argument. Remember, on page 34, this is a Key. The author says the number of arguments in a passage is determined by the number of conclusions it contains. So whenever you're involved in doing analysis of an argument, or if you want to diagram it, the first thing you have to establish is how many different conclusions are found here, and then how are those conclusions supported and how do they relate to each other? And for the sake of time, I'm going to do one on my own and then have the check of the author. Should I do number one or five? Was number one difficult? Did you feel? Okay, let's try number one. General Mercier, leaving for Rennes to appear as a witness, issued his order of the day. Quote, dreyfus will be condemned once more. For in this affair, someone is certainly guilty, and the guilty one is either him or me. And it is certainly not me, as it is certainly not me. It is Dreyfus. Let me take a moment to reflect on this, and then I'll put it up on the board. All right. We'll take as our first proposition, Dreyfus will be condemned once more. The second proposition. In this affair, someone is certainly guilty. The third proposition, the guilty one is either him or me. And the fourth proposition would be, it is certainly not me. It is Dreyfus. Now, one implicit. I mean, one argument that should be pretty obvious here is you have the guilty one is either him or me, and it's certainly not me. So we have three and four bracketed together. And if the guilty one is either him or me, and it's certainly not me, then the conclusion is, it is Dreyfus. Oh, there's five propositions. It is Dreyfus counts as a separate one. So three and four bracketed together prove five. Then Dreyfus will be condemned once more, because in this affair, someone is certainly guilty. There must be someone guilty. Dreyfus is guilty. Okay, this may be too easy. But it seems then that if Dreyfus is guilty, if number five is proven from three and four, that five then proves one. That proves as well that he will be condemned once more. For in this affair, someone is certainly guilty. I guess 5 and 2 can be bracketed, And that would prove one. Close. No banana. What is the textbook author say about it? Well, okay, one at a time, Pete. Two, three and four go together. Okay, so he has two, three and four as proving, and then five, one. Yeah, well, I'm not going to bother to argue with you on that. In terms of the flow, it can be either way, because here what you have is these two coming into one. Add this in Here, then you get the other, and here you just put them all together into okay, well, we've had enough fun diagramming arguments and so forth. The frustration that you feel in doing these exercises I could have helped you with if I hadn't been good enough to tell you ahead of time that there's some. There's room for disagreement and movement in this because we don't have the full context and so forth. And there may be in some cases equally legitimate ways of doing it. So please don't be discouraged by the difficulty of the opening exercises. Let's turn to Engel now and review what he has told us about logic and go over some of those exercises as well. Chapter one in Engels book With Good Reason. Before we actually get to chapter one, he has an introduction to part one in which he likens logic to medicine. In the case of medicine, he says, it requires a knowledge of correct functioning before we can fully appreciate what often goes wrong. Logic is like that and you have to understand. You have to have some good examples of reasoning in your mind before, or you can move out from that to find out what's wrong with other cases of reasoning. He reminds us that reason is only one of the tools used in argument. The other is language. That's why today's lesson is going to be equally important. You have to understand reason as well as language. The obvious point is much of what we hear, read, say and think every day is less than correct from a logical point of view. Maybe I should stop just here and have a little devotional thought for you. As Christians, it can be something we can laugh at each other about. I've taught classes where we jost each other about this. You're going to find out as you go along. In this class you learn more. You're going to be able to really slice and dice people because most people don't think about reasoning correctly. You'll be amazed the more you pick up sensitivity. You can find it everywhere. In the grocery store, on the tv, talking to people, maybe even in sermons. I mean, you're just going to find, well, that's not really a good argument. So forth. And if you bother to correct everybody, guess what? You're going to be a Persona non gracia real fast. Philosophers in general, logicians in particular, can become real pest. And so it's important that you develop not only your logical skills, but also your skills in sanctification and social relations so you realize God hasn't made you everyone's teacher or corrector and so forth, and try not to get discouraged when you find how little reasoning goes into what many people say and what we run into every day. Okay, enough of a little devotional thought there. Engel tells us that the. The Greeks began to make catalogs of various errors, logical errors. That's what this book amounts to is he's in his own way tried to continue this cataloging of how mistakes are made. Now why do we do that? Well, in the same way that doctors try to catalog different diseases and medicines from dealing with them, it's easier then to identify and to treat situations when you know what some of the possibilities are and you've organized them systematically. And then he ends by telling us errors and logic can cause serious problems. We may laugh about many of the things in here, there's cartoons and all that, but the mistakes that people make in their reasoning can often cause tremendous pain and suffering and confusion in social circumstances or for an individual. Many times in counseling with people, I have found what I have to do is correct their thinking process. They've gotten to depressed or angry or whatever it may be because they have not been thinking clearly. So we can use the cartoon examples, but let's never forget that this is something that's very important at times in people's lives, in the lives of societies. And he tells us we're going to sharpen our ability to recognize bad arguments by going through this book. And I hope that's true. Page five, the opening, you're going to find a familiar definition. I've given it to you. Copie's given it to you. Engel says one purpose of a study of logic is to gain tools with which to distinguish good arguments from bad ones. The only difference is, he says, that's one purpose. He doesn't go on to tell us what the other ones are, but generally this is considered the central purpose of logic. Is logic a science or an art? Remember Copa gave what about one sentence to that? And Engel goes into it more in depth. There's a sense in which it's a science. And he brings up this interesting conundrum. Either we already know how to reason or we do not. If we already possess the faculty, we need no instruction in it. If we do not possess it, instruction won't help us. And that looks clever, right? What's wrong with it? Well, the premise that says we either know or we don't, but it's not one of those sorts of things. We might know in part, but not completely. And so if we know in part, then the study of logic can help develop that partial grasp that we have. He points out that other people, people consider logic's value to be practical. It trains the mind, and I don't think we have to choose between the two. He indicates that the stress in his book is going to be the world of everyday affairs. That's one of the reasons why this is a popular book and Kofi's kind of intimidating to people. It'll be much easier to read this. The explanations are easy. It's not nearly as precise or technical. In that sense, he's not as good an instructor in logic. In other sense, he's a more effective instructor because he can keep your attention and you don't run away from it. But he likes to use common examples, and that's real value. Okay. In section two, he tells us an argument doesn't mean quarreling. You've already been taught that an argument, page 7 is reasoning in which one or more statements are offered as support for some other statement. He gives his own short list of premise indicators and conclusion indicators. What do you do when they aren't present? He says, where such indicator words are absent? Try to find the conclusion by determining the main thrust of the argument. Ask, what is the point here? What does that tell you? There's a little bit of intuition, a little bit of experience in human language and relations. You just have to kind of go on background ability to identify what the point is when the indicators are not given explicitly. He tells us in page eight that sometimes the tone, well, that's really getting subjective and away from objective indicators. But he's right every once in a while, that's why we argue. I said, well, from his tone, I thought he came down harder on this point than that. So that's his conclusion. Section 3 Arguments and non Arguments he says, if a piece of writing makes no claim support by such reasons, it is not an argument. Thus, questions are not arguments, nor are announcements, complaints, compliments or apologies. We have to be strict here. When we see some paragraph or hear somebody speak, if they are not saying this because of that, they're trying to support the truth of something on the basis of something else. They're not giving an argument. And then Engel gets into this ambiguity on because, you know, is because giving a justification or is it giving a clarification? He tells us sometimes what we have is not argument for the truth of something, a justification, but just a further elaboration or clarification of what's going on. And then of course, he discourages you. I on page 12, when he says cases won't always be as clear cut as the illustrations he's given. Sometimes explanation and justification simply blend into each other. When we look at examples, he says, ask for the primary intention. Is it primarily to justify or to explain? And if it is primarily to explain, then it's not an argument. In section four, the author tells us, sometimes when you analyze a passage, you have to eliminate verbiage that's in there. Arguments as ordinarily expressed are encumbered with a great deal of repetition, verbosity and irrelevance. And it's good that we're reading Engel, because that point needs to be made. Sometimes you just have to really cut out a lot of stuff so you get to the heart of the matter or to the real structure of the argument. It says it's best to rewrite arguments as concisely as possible, with the premises arranged in their logical order. If you rewrite the argument, it's easier to see what is really the heart of what the author is saying. Also to evaluate it. Now, in doing it, there'll be some loss. He says we're going to have to discard some of the poetry or literary elegance. In section five, he talks about highlighting cesspool elements. An element is suspect if it's made to carry more weight than it's really capable of doing. When asked whether sufficient evidence is being given, whether it's relevant evidence, whether it's even meaningful, what the person is saying, he recommends on page 21 you not be intimidated. He says you shouldn't hesitate to demand proof when a presentation seems overblown or questionable. Ask questions about who is saying something, under what auspices, things of that nature. This section, as he tells you, is really just an anticipation of what the book's all about. The book's going to help you find suspect elements. Then, in analyzing arguments, sometimes there are missing components. Section six tells us an argument structure may be obscured because it is too sparse and has missing components. That is, there may be important assumptions made on which the argument rests that aren't stated. The example that he offers is where you have this kind of argument, an argument in this form, a generalization, a specific case, and then an applied conclusion. Now, where you have the generalization as the backing, the specific case is the observation drawn from it. It's pretty easy to see in arguments which element of that is missing and what you have to fit in. At the bottom of page 24, an important point is made. Not all such omissions are innocent or done for the sake of literary elegance or brevity. Often what is omitted is highly questionable and omitted for that very reason. When you look at advertisements and so forth, often what is not stated which is necessary to make the argument work is. Is the very thing which you've stated to draw your attention to it. And you'd say, well, you know, maybe that's not true. He says to state it explicitly is to call attention to it and risk having it questioned. So be aware of that. However, there are good reasons to omit things mentioned on page 26. It's simply too obvious or for dramatic reasons sometimes because you want to be more guarded and cautious in what you are asserting. Alright, section 7 deals with deductive and inductive arguments. I like the way he lays out on page 28, a premise can support a conclusion either fully, partially, or not at all. A premise can support a conclusion fully. There you have a deductive argument, partially, an inductive argument, not at all. You have a seductive argument, a fallacy. Notice he lists seduction along with deduction and induction. That's kind of clever. Okay, when an argument states that the conclusion follows with necessity from the premises, it's deductive. If it follows with probability, even high probability, it's inductive. And then he explains a little bit further that in the case of a deductive argument, the premises contained all the information needed to reach the conclusion that follows. Whereas with an inductive argument you're always going a bit beyond the information provided to you in the premises. Okay, so if I say that such and such a drug has cured Pete, a certain disease, Sension Center Dog has cured. Cured Melissa of a certain disease, and Jay and Pat as well, and Dr. Bonson. And then we say such and such a drug will cure anybody of this disease. We've gone beyond the information we really have at our disposal. Now, it may be a safe step to take, but it's going beyond what the premises actually told us. Deductive arguments are evaluated as valid or. Or invalid. How are inductive arguments evaluated? As strong or weak? Strong or weak? And the author tells you on page 31, most of the arguments you encounter in daily affairs are of the inductive variety rather than deductive variety. Okay, now section 8. He talks about evaluating arguments. Truth, validity and soundness have to be considered. Validity, he says, refers to the correctness with which a conclusion has been inferred from its premises. Truth, on the other hand, refers to whether those premises and conclusion accord with the facts. Soundness results when the premises of an argument are true and its conclusion validly derived from them. And then he doesn't give as much detail as copy does but he shows there are various possibilities. He says our premises could be true and our inference valid and then the conclusion would have to be true as well. Of course that's number one's the nice one that's what we always wish were the case number two our premises might be true and we reason invalidly. Now you can't tell then whether the argument going to have a conclusion that is true or not Sometimes it will happen to be true sometimes it won't be but even when it happens to be true it won't be true because of the reasons given because of the invalid reasoning structure if you will a third possibility is that one or more of the premises is false and we reason validly from the false premises. He gives an example all movie stars live in Hollywood that's false Robert Redford is a movie star that's true Therefore Robert Redford lives in Hollywood that's a.