In the previous lecture, we looked at the skeptical regress problem and I kind of introduced three different ways of solving that problem in practical life. Namely assuring, guarding, and discounting. Those are three ways to solve the skeptical regress problem in practical life, and in the next three lectures what we're going to do is look at each of these, in much more detail, and more carefully, so as to understand how they work. Let's begin with assuring. Here's an example. I assure you that smoking is bad for your health. If I say, I assure you, then I'm trying to get you to accept that claim on my authority. Now I might have some reason for saying that smoking is bad for your health, namely, I've read the US Surgeon General's report, which cites the scientific evidence to show, that smoking is bad for your health. But notice that I don't actually say it, when I say, well it's obvious that smoking is bad for your health. Or everybody knows that smoking is bad for your health. Or I assure you, certainly, clearly, smoking is bad for your health. Then what I'm doing is I am trying to get you to accept that premise without actually citing the Surgeon General or anybody. I haven't cited the evidence. I simply have indicated to you I do have evidence. I do have a reason to believe that smoking is bad for your health, but I haven't given you what the reason is. So what good is that? It's a lot of good, because what it means is that if I don't give the reason, you can't question the reason. If I simply say everybody believes it, it's certainly true, then you can't ask whether those people who believe it have any reason to believe it. Or rather I have any reason to be so certain about it. If I don't give the reason, I've cut off your attack of the reason that I would give. So assuring is kind of tricky. I say I assure you, and if you can trust me, that's fine. But if you can't trust me, then you should be asking, well, what kind of reason does he really have? There are many ways to assure people. There are three kinds that we're going to look at: authoritative, reflexive, and abusive. Let's start with authoritative. Authoritative is just what it says, it cites an authority. So, I might say I assure you that smoking is bad for your health. The Surgeon General has shown that smoking is bad for your health. And I cite an authority, the Surgeon General. Okay. Fine. But, have you seen the studies? Have I cited the numbers? Have I told you when the studies were done, how many subjects, under what circumstances? Which statistical tests were used? How do you know it's causation instead or correlation and so on and so on. No, I just say the Surgeon General has shown this. And you're supposed to take my word for it that those are good studies, unless of course your share my assumption that the Surgeon General is trustworthy. So, that's the way an authoritative assurance works. It cites an authority that the audience shares as an authority with the other person. They share the assumption that that the authority is trustworthy. Now, sometimes it's the Surgeon General and the Surgeon General is pretty reliable. But you also get this kind of thing from reporters they say, an unimpeachable source close to the President has assured me that the President's plans are such and such. And they cite an unimpeachable source, but they won't tell you want the source is and they won't tell you how the source knew it was true. So they're citing an authority but they're not telling you what the authority is, or what reason the authority has for what the authority claims. Now if you trust that authority, then that's fine. And if authority's reliable, then you might be safe, but if you don't know who the authority is or where they got their information, there can be problems. And here's my favorite. Here's my favorite. I sometimes hear students say, but Professor [UNKNOWN] Armstrong, my teacher in the other course said that blah, blah, blah, blah, blah. Well, why do you trust your professors? I mean why do you trust me? You shouldn't be trusting me or your other professors any more than you're trusting an unimpeachable source close to the president. So, you have to trust somebody sometime, and you have to decide who you're going to trust. And then, it's going to be okay to cite an authority, in this kind of assurance, but you have to watch out for tricks when people start citing authorities that aren't really authorities, because even the best authorities sometimes do studies that aren't very careful, and might even be wrong. A second kind of assurance, is what I call reflexive, reflexive because it's talking about yourself. I believe that, I know that, I am certain that, I feel sure that. And you're signing something about your own mental state. You feel sure. Great, you feel sure, but why do you feel sure? Notice however, that this assurance works, because people don't want to question what other people feel sure about. If I say, well, I feel sure that this is going to happen, in many societies, it's going to be impolite to go, well, I don't feel sure. Matter of fact, I think you're wrong. Or, why do you feel sure? because then you're questioning the person. And if that's impolite, then using this type of phrase, I am certain that, will get people to shut up and not say anything. So here's an example from Monty Python. >> Now let's get one thing quite clear, I most definitely told you. But my favorite is when people say you know, I've held this opinion for years or I've thought about it year after year. It's really bothered me and you know, after careful consideration I've come to the conclusion that blah, blah, blah, whatever, and you're supposed to say, well, since you've thought about it so much, I'll save myself a lot of trouble of thinking about it, and trust you and go along with what you say. Well if you let other people do your thinking for you, then that's up to you. But you're going to be misled in some cases cause they thought about it for years and years and gotten themself into a tizzy and ended up at the wrong conclusion. So the fact that somebody's thought about it for years doesn't necessarily mean it's right. But somehow in conversation, when you say I've thought about it for a long time and checked all the sources I could, then people will take the fact that you've reached a certain conclusion to be okay for them to reach the same conclusion. And that's how this reflexive type of assurance works. The most fun of all is the abusive assurance. Here's another example from Monty Python. >> No, no, nonsense! >> Maybe he's right. Maybe it is nonsense. That the point is that he gets you to accept what he believes by abusing you and calling it nonsense. And the same thing happens when somebody says, nobody but a fool would think that. Everybody knows this. If you say, everybody knows it, then you're saying, well, if you don't know it, then you're a dummy. And so they're abusing you in order to get you to agree with them by making a conditional abuse that applies to you only if you don't agree with them. And you don't want to be a dummy. You don't want to speak nonsense. You don't want to say something that's stupid. So if somebody says, you'd have to be stupid to disagree with me about this, then that's going to incline you to agree with them. Some of these abusive assurances are a little bit more subtle, so it's worth mentioning one that's used all the time, and this is what might be called appeal to common sense. Someone says, it's just common sense that such and such. It doesn't matter what the such and such is, the point here is simply that if you deny that, then you're telling that person you lack common sense. And nobody wants to lack common sense. So by saying, it's just common sense that, it's just plain common sense. People say it all the time, but what they're doing is they're abusing their opponents by saying that their opponents lack common sense. So it's a little bit more subtle, but it shows that abuse of assurances occur either subtly or openly all the time. So we've see three different types of assurances. Okay. The first is authoritative, the second is reflexive and the third is abusive. And they're all used in common speech to stop the skeptical regress problem. So why do we need any of these assurances in the first place? And the answer is, we've got limited time. You know, you can't go out and check every study, you can't go out and look into every issue. You've just got to accept authorities and listen to other people and learn from them, or you'll never be able to figure out the issues that matter to you in life. So assuring can be a perfectly good thing. If you trust the Surgeon General of the United States instead of going out and starting your own laboratory and doing your own statistical studies, there's absolutely nothing wrong with that. But when you start trusting authorities that are not worthwhile, or not trustworthy, then, you can get yourself into trouble. And we'll talk later in the course, about, ways to tell which authorities are reliable or trustworthy and which ones are not. That tells you why, assurances are needed in general, but what about particular cases? Well when you're talking to a certain audience, if they share your trust of a certain authority, or if they trust you when you give a reflexive assurance, or if what you're saying really is something that everybody with common sense believes in, then again, it can be perfectly fine to use an assurance. It saves you the time of having to go check out every issue and it helps you avoid the skeptical regress problem in a very practical way. So assuring can be a really useful tool in argument. But, you have to be careful because assurances are also subject to a lot of tricks that you have to learn to watch out for. We've already seen that you can cite authorities that aren't trustworthy and that's kind of obvious. But something that's maybe a little less obvious is that people use assurances at points in their argument in order to distract you. When something really is questionable, they often say, well, that's obvious. In order to get you to not pay attention to it. So when someone says that's obvious, it's certain, I'm sure, it's worth looking carefully at what they're so sure about and asking yourself whether you agree with them because people try to paper over the cracks in their arguments with these assurances, at least in some cases, and you have to learn to watch out for that. Another trick is when assurances get dropped. People will start off saying, you know, he believes this, I believe that, and then they drop it and start talking as if it's true. You know, my favorite example of this was a case a few years ago when there was a person caught in Germany for cannibalism. And it started off with the reporters saying, well he, the person accused of cannibalism says that there are lots of other cannibals in Germany. And then, it becomes, it is reported that there are lots of cannibals in Germany. And then it became, sources have said that, as if the sources are reliable. And pretty soon they were saying, there are lots of cannibals in Germany. And it moved from, he believes it to there are lots of them. And that's the trick of dropping the assurance in a way that can be illegitimate. So, assurances can be useful and they can also be misleading. And, that's going to be true of all the different ways of stopping the skeptical regress. There can be uses and abuses of all of these tricks. For assurances, we want to have an assurance when, first of all, somebody might question it. Second, the audience accepts the authority that is being referred to. And third, it would be too much trouble to actually cite the study and all the numbers, and the evidence, and the particular people. The assurances are not appropriate when nobody would question the claim anyway. Then why are you wasting your time assuring people? When the authority that you're basing your assurance on is not really trustworthy. Because then, why should they believe your assurances? And third when you've got plenty of time and it would be really easy to give the reasons straight-forwardly instead of simply assuring them. So, you've got good and bad uses of assurances. And I hope we understand what they are and how to distinguish them, but let's do a few exercises just to make sure that we've got the general idea.