So now we've discussed two levels of language, the linguistic level and the speech act level. In this lecture, we want to look at the third level of language, normally the level of conversational acts. And the basic idea is really simple. We use language to bring about a change in the world. For example, I might turn to a friend and say, could you loan me your car? Well, what am I doing? I'm performing a speech act of requesting, or asking a favour, something like that. But am I doing it just for its own sake? Did I ask a favor just in order to be asking a favor, like it was fun to ask a favor? No. I was asking a favor to bring about a certain effect. I wanted him to hand over the keys to his car so I could use it. And I wanted him to give me permission to use his car, so I could do it legally. So I'm trying to bring about a change, not only in the physical location of the keys, but also in the legal rights that I have with regard to his car. So I'm trying to bring about a change in the world, simply by uttering those words, could you please loan me your car? It happens all the time. Here's another example, suppose my friend is wondering whether the moon is full, and I say, the moon is full. Well, am I uttering those words just to expel hot air? No. Am I uttering those words just to express my own belief? No. I'm trying to inform my friend. I'm trying to bring about a change in my friend's beliefs. And that's to bring about an effect in the world. So that's a conversational act, to bring about the effect in the world of informing my friend. Informing is a conversational act. And almost all speech acts have, particular effects that are associated with them. When you ask a question, you're trying to bring about someone answering the question. When you apologize, you're trying to bring about forgiveness. When you promise somebody, you try to bring about the person relying on your promise in order to believe that you're going to do it. So speech acts are often associated with particular effects that the speaker intends to bring about. And the bringing about of that effect is the conversational act. So, if we want an official definition of a conversational act, we can say that the conversational act is the bringing about of the intended effect, which is the standard effect for the kind of speech act that the speaker is performing. That's what a conversational act is. Now, since the conversational act is the bringing about of the standard effect. The conversational act does not occur when that effect does not occur. And that might seem weird that what kind of act you perform depends on whether the effect occurs. Maybe several seconds, maybe even longer, in the future. But it's not that weird when you think about it. Because if you pull the trigger of a gun that's pointed at someone, then whether your act of pulling the trigger is an act of killing depends on whether the person dies. And yet the person's death is something independent of it. It's an effect that occurs maybe quite a while in the future. But your act wasn't an act of killing unless the person died. And that's the story of conversational acts. Your act is not this conversational act unless the effect occurs. It has to be the intended effect, that's the standard effect, for the kind of speech act that you're performing. So. The really tricky question is, How are we going to bring about these effects? because it's not so easy. Think about how other people bring about effects. Think about a baker baking the cake. Well, the baker needs to. Get together the right ingredients, and bring them to the right place, and get the right amount of ingredients. You know, if a baker fills the entire kitchen with flour he's not going to have any room left over to bake the cake. And has to bring the right ingredients, that means if instead of bringing flour he brings gravel, he can't bake a cake. And he has to put together those ingredients, in the right way, in the right order, for example. You can't mix them in the wrong order, the cake won't work out. It has to bake it for the right amount of time, and so on, and so on. So there are a lot of tricky rules about how to bring about the effect of a good cake. Well, the same thing applies to conversational acts. There are going to be rules that have to be followed in order to bring about the conversational act that you're trying to bring about. That is, in order to have that intended effect of the speech act in the circumstances. And the same kind of rules apply to any rational person trying to pursue any goal. Whenever you want to bring about an effect, you have to follow certain general rules. And so. It applies to people who are trying to bring about effects. By language. That is, to people who are trying to perform conversational acts. If you want to inform someone, that is, to have an effect on their beliefs, then you need to speak in a certain way. And if you want to promise someone, that is, to get them to rely on you, that's the conversational act associated, associated with the speech act of promising. But you're not going to get them to rely on you unless you follow certain rules. And so what we need to try to understand are the rules of language that allow us to bring about these effects that are the conversational acts. Now on this question, Paul Grice helps us out a lot. He's one of the great philosophers of the 20th century. And he layed out a series of rules governing conversational acts. He called them, the conversational maxims. And we're going to look at them one by one. Grice focuses in on context where people are stating things and where their cooperating with each other and trying to inform each other. He's not trying to provide a general theory, so it's for statements and a cooperative context. So the first maxim is the rule of quantity and it basically says. Don't say more than is required for the purpose you're trying to achieve. If you say too many words, the point gets lost in the words, so you shouldn't say more than you need for the purpose at hand. Second part of the rule of quantity is you shouldn't say too little. Right? Because if you say too little then that's going to be misleading and it's not going to fulfill your purpose because the person that you're talking to won't have all the information that they need. Second rule is the rule of quality. The rule of quality says don't say what you don't believe to be true. Don't lie, don't mislead, don't deceive. Right? But also, this is second part of the quality. Don't say something that you lack adequate justification for. Because you shouldn't just be talking off the top of your head with no reason to believe what you're saying. These are all pretty common sense rules, but they weren't apparent to people until Bryce formulated them. The third rule is a rule of relevance, and it's the toughest of all. Rule of relevance says, be relevant. Look, it's short. I'll grant you that. It's going to be easy to remember, I'll grant you that. But it really is kind of tricky to apply the rule because you have to remember what's relevant. And we'll see some problems with that, but for now just remember that it should be obvious. When you're talking about a subject and you want to achieve a certain purpose and the person you're talking to is cooperating with you and Greiss is assuming. Then you ought to be talking about things that are relevant. And if you change the subject that's going to be very misleading. And the fourth conversational maxim is the rule of manner. It says be brief, be orderly, avoid obscurity, and avoid ambiguity. Pretty simple, it's all about style because if you're not brief enough people won't pay attention to you. If it's not orderly people will get confused by that. And if you're ambiguous or obscure then people won't understand what you're saying. So these four rules are followed by speakers when they're cooperating with each other. When people aren't cooperating, they're trying to trick or deceive each other, they might violate these rules and mislead people by abusing these rules. But when they are cooperating, these are the rules they follow, and that makes them able to deceive people by violating them. And also notice that these rules might not be completely clear. You might not have ever thought of them before. But now that we mention them, they probably seem pretty obvious. It's kind of like the finger and singer rule that we saw before regarding pronunciation. That's a rule that you hadn't thought of before. But once it's pointed out, it seems kind of obvious. Well that's what Grice has done. That he's shown us the rules governing conversational acts will enable us to bring about certain effects by language. Now we can use these rules to understand what's going on in a lot of conversations. Imagine you're in a restaurant, and the waiter walks up to your table and says, well, for dessert, you can have cake or ice cream. Well, what has that waiter suggested? He suggested that that's all you could have. Cake, ice cream. Well he didn't mention pie, So you can't have pie. Footnotes, if he's a good waiter, and he knows that they have pie back there, and you could order it, then he ought to be telling you about the pie. He would be violating the rule of quantity, that is not providing you all the relevant information if he said, you can have cake or ice cream. And you could also have pie, but he didn't mention pie. So because you assume that he's cooperating with you, and trying to get you what you want to eat, since he is your waiter, after all, there must not be pie available, so you say, I'll take ice cream even though you would have preferred pie. What's happening here is called conversational implication. When the waiter said you can have cake or ice cream, he was conversationally implying that you can't have pie. And the reason that a conversation implied that is because if he were cooperating, and following the conversational rules or maxims, then he would have mentioned pie. So you assume that since he said only cake or ice, cake or ice cream, that you can't have pie. He, in effect, conversationally implied that you cannot have pie. And the way you figure that out was you took what he said, a little background knowledge about him being a waiter and having certain goals, and what happens in restaurants, performed a little mini calculation using the maxim of quantity, and inferred that he must believe that you can't have pie. And of course, since he's a waiter, he ought to know whether you can have something else or not. And therefore, you can't have pie. But what if he had a favorite customer at another table? And he knew there was only one slice of pie back there, and he didn't want you to order it? And he said, you can have cake or ice cream. I didn't mention the pie so you wouldn't order it and his favorite customer would get it instead of you. Well, he still conversationally implied that you can't have pie. But he misled you. He misled you because he was trying to get the pie for somebody else. He was not coperating with you. So the tricky thing about these conversational maxims is that they work perfectly fine when you're cooperating with the person. And try to give them all of the information that they need for your common purpose with that other person. But if you're not cooperating, then you can use them to mislead the other person. And that's the double edged sword of conversational implication. But one of the features of conversational implication is really important to arguments. And that's that you can cancel conversational implications. The waiter can say. You can have cake or ice cream. Oh yeah, and you can also have pie. And when he said, and also you can have pie, he did not take back, you can have cake or ice cream because you can still have cake or ice cream. It's just that you can also have pie. So he can cancel the conversational implication that you cannot have pie by saying, oh yeah, and you can also have pie. So, with a conversational implication, if a certain sentence P conversationally implies another sentence Q, then you can deny Q, and P still might be true. And that's an important fact because it distinguishes conversational implications from logical entailments or logical implications. If I say, Alice is my sister, then that implies Alice is female. And I can't go, Alice is my sister, oh yeah, and she's not female. That doesn't make any sense because see she's not female, she can't be my sister because that's a logical implication or entailment. But with a conversational implication instead, you can deny what is conversationally implied, and the original sentence is still true. So if the waiter says, you can have cake or ice cream, and then, I find out that he's been saving the last piece of pie for this other table, then I can come up to him and say, wait a minute, you lied to me. He didn't really lie to me, because what he said was still true. I could have cake or ice cream. It's still true, I can have cake or ice cream. He didn't say anything false to me. He simply didn't mention the pie that I could also have. So that's very different in the case of conversational implication than in the case of logical entailment. And that'll be important to us especially when we get to formal logic in a later part of this course. So let me give you another example that's more important. Imagine a politician says, I've got a policy that's going to reduce crime by getting criminals off the streets. And the policy is lock them all up. When people are suspected of crimes, you lock them all up. That's going to get criminals off the street. Well, that might convince people, if they don't notice that he's left out another fact. He's not just going to get people off the street who are criminals, he's going to get lots of other people off the street too. He didn't give you all the relevant information, like the waiter who mislead you with the pie. He suggested that his policy will solve the problem of crime by putting people in prison who would commit crimes. And, just left out the other relevant fact that it's going to put lots of other people in prison too. So he has conversationally implied that there's no other relevant facts to consider, by only mentioning that it's going to reduce the crime rate. And you have to be good at looking through that implication and asking, yes, but is there something he's leaving out? And that's often what you need to do in order to avoid being misled by sleazy politicians and other people who leave out the relevant information for the issue that you're talking about. Now of course the politician might not care that he misled you. That might be the goal. He wants to persuade you and he doesn't care whether he misleads you, because it's persuasion not justification that he's interested in, as we talked about in the first lecture. In addition, he's got his defense ready. He can say, but I didn't say anything false, what I said was true. If we put all those potential criminals in jail, we're going to reduce the crime rate. Maybe it's true that we're also put some innocent people in jail, but we will reduce the crime rate, and that's what I said. And what Grice's maxim of quantity does is it tells us exactly why we have a criticism of him now. We can say he's not cooperating because he's not following the conversational maxim of quantity, he's not giving us all the information that we need in order to achieve our purpose if we have a common purpose. And this politician is pretending to have a common purpose with us, the good of the country, when actually he doesn't have a common purpose with us. He just wants to get elected. And so Grice gives us an insight into what's going on when we get misled in those contexts, and also, what we need to do to respond to those types of bad arguments. Now this distinction between conversational implication and logical entailment is crucial to arguments, because it tells us something about how to refute arguments. When you don't like the premise of an argument because it's misleading, because it conversationally implies something false, that's not a way to show that the premise is false. In order to show it's false, you have to show that it actually logically entails something that's false, then you can infer that the premise itself is false. This will become important later when we look at the role of conversational implication and logical entailment in arguments. But for now, the important thing is to understand the distinction between conversational implication and logical entailment. The speakers usually follow these conversational maxims that Grice enunciated when they speak and when they're cooperating, but they don't always follow these maxims. Sometimes they violate them. And of course, as always, there's a lot more to be said about conversational acts. If you want to learn more about conversational acts, you should look at the chapter in Understanding Arguments in the text that accompanies this course. But I think we've learned enough about conversational acts to move on, because so far we've looked at language in general. At the linguistic level, at the speech act level, at the conversational act level. Now we want to take these lessons and apply them more specifically to the language of argument. That is, the particular kind of language that gets used in arguments. And that's what will be the topic for the next few lectures.