 OK, and let's start with the Greek word skeptis, which means investigation, inquiry, examination. Essentially, what a skeptic is is somebody who is investigating something. They haven't made up their minds about it yet because they're still looking into it. They're still making an inquiry into it. They're still examining the claims about how the thing is one way or the other. But to the skeptic, the situation hasn't been resolved yet. So they continue to inquire into it. Now, in antiquity, we talk about two different kinds of skepticism. So actually, let me digress just a moment to point out skepticism is not an unknown word to you. This isn't some alien Greek philosophical notion. You're familiar with the idea of skepticism. And this is something that's really neat about Hellenistic philosophy, is that these philosophies were so influential on the subsequent development of philosophy and culture in general, that we still use terms that relate to the Hellenistic period. So outside of a few of my colleagues in the philosophy department, we don't really talk about people being Platonists or Aristotelians anymore, much less Anax-Agarians or debauchertians. But we do talk about people being stoic, or being Epicurean, or being skeptical. And all of those three philosophies were all developed in this period. Now, in the ancient period, especially in the Hellenistic period, we get a development of two different schools of skepticism. One, we call academic skepticism. And academic skeptics hold the view that we cannot know anything, knowledge as such as impossible. There is no such thing as knowing. Peronian skeptics, in a way, are even more radical than that, because they are so committed to the idea that we can't know anything that we can't even know whether we can know anything or not. Or rather, we don't know whether we know anything or not. We don't know whether knowledge is possible or not. And so we're still inquiring into the matter and examining it. And Peronian skeptics charge academic skeptics with not being real skeptics, because they appear to take a dogmatic position on at least one thing. That is, that knowledge itself is not possible. Now, I'm going to say very little about academic skepticism today, but we are going to be reading a work of a committed academic skeptic in Cicero's On Moral Ends is a work by somebody who is a card-carrying academic skeptic. And so we will have a lot of opportunities to examine that philosophy as we read through his approach to each of the other schools. That is, his approach to Epicureanism, his approach to Soicism, and then the view on moral ends that he thinks is correct. But we can go back as far as Socrates, and so arguably the beginning of philosophy in this tradition as such. And one of his most famous sayings is, all I know is that I don't know anything. So Socrates did seem to make a knowledge claim, but his knowledge claim was, I don't know anything. But he was surrounded by people who thought they knew everything. So he was surrounded by people, for example, who thought they knew what holiness was, what it meant to be a pious person. And so he examines a professor of religion who says, oh, I'll tell you what holiness is, this guy named Euthyphro. And he shows that Euthyphro doesn't have any idea what it is, because he can't produce a coherent definition of it. Every attempt he makes to give a definition of it results in a contradiction and an untenable position. And so Socrates, so that dialogue of Plato, in which Socrates is the main character, ends in what we call aporea, which is a Greek word that means perplexity, confusion, essentially inability to go forward, because we don't understand something. And many Platonic dialogues portray Socrates engaged in a discussion with somebody who has a pretense to knowledge and exposing the fact that they don't actually know what they're talking about. So another example is in the minnow, where the question is, what is virtue? And they start examining this question. All of the definitions presented are problematic. They get sidetracked into a discussion of whether virtue can be taught or not, and the dialogue ends in perplexity. We don't actually know what virtue is. A third example in the dialogue Theatetus, the question there is, what is knowledge itself? Several possible definitions of knowledge are considered. Knowledge is just perception. Knowledge is true belief. Knowledge is true belief plus being able to give an account of the thing. Turns out none of these will actually work or function as a definition of knowledge. The result is, we don't know what knowledge is, and that's how the dialogue ends in operia or complexity. Arguably, we remain in exactly the same position with respect to each one of those. So you might argue, we don't have any idea what holiness actually is, and neither does anybody else. And we don't know what virtue is, and neither does anybody else. And we don't even know what knowledge is, and neither does anybody else. And if you find yourself agreeing with those positions, then you're agreeing with the skeptical position. But we haven't actually got this figured out yet. Now, developments within Plato's academy actually initially tended towards a more dogmatic position. So people interpreted various things in Plato's dialogues, especially his later dialogues, where Socrates isn't essential of a character, and where Plato starts developing theories about how knowledge might be possible, and that sort of thing, appealing to the theory of forms and other theories like division and definition and so forth, in order to seemingly make some more clear claims about what knowledge would be like. Now, since those are always made in the context of a dialogue and not in a treatise, we can't really say that those were Plato's views, because they're presented in the mouths of other people who are in the context of disagreements and so forth. But after Plato died, early members of his school started trying to develop a kind of dogmatic philosophy of Platonism, oriented around mathematical knowledge. Later in the development of the academy, a couple hundred years later, there was an innovation to return basically to what was called the old academy. So let's go back to the old way of doing things like Socrates, where we're not dogmatizing about mathematical subjects and pretending like we know the nature of the universe. Let's get back to this idea of inquiring into things and taking people who have a pretense to knowledge but don't really know what they're talking about and exposing the fact that they don't know what they're talking about. And so this inaugurated a skeptical phase of the academy. And there were generations and generations of academic skeptics who continued to do battle with the other schools of philosophy, especially the Stoics, who maintain a strong dogmatic line that knowledge is possible. And in fact, they know everything relevant about physics, logic, and ethics. And the academic skeptics challenged them point by point, arguing against their logical claims, arguing against their claims in physics, and certainly arguing against their claims in ethics. But they became so intertwined in debating with these Stoics that one of their members, a guy named Anissa Demis, thought that they were essentially becoming like Stoics. And so he broke off from this old academy view and decided to found his own school of skepticism. And he named it after this much earlier figure named Piro of Ellis. And so that's how we came up with the idea of Peronian skepticism. Now, why did he name it after Piro of Ellis? Or what do we know about Piro of Ellis? Well, very little. Like Socrates, Piro of Ellis wrote nothing. And he founded no school. He did have followers and students. But he didn't, as you might expect for a skeptic who doesn't believe in he knowledge as possible, he didn't set up a university. And he didn't write down a bunch of texts and so forth that could be studied in order to figure the truth out. And so since he didn't leave any writings, we're totally dependent on what later people said about him. Many of these people are hostile to skepticism and so are sources for what Piro said are very problematic. But it seems that if we sort of triangulate our different sources, both the critics and the later people who were trying to develop a new school of skepticism of which he was the sort of mascot, then we can find some commonalities in their views and perhaps say a couple of things. At any rate, he's associated with the ideas of ungraspability. That is, we don't happen to grasp anything clearly and the idea of suspension of judgment, that we should suspend our judgment and not make definite assertions about anything. And so for example, we should not make definite assertions that anything is either honorable or shameful, just or unjust, good or bad. Nothing exists in truth. Everything that we do is on the basis of custom and convention. And nothing is any more this than it is that in general. And so we're told that Piro himself was so committed to this view and lived this view that he would not even take precautions like avoiding oncoming cars or avoiding walking off precipices, because after all, he don't know if it's good or bad to walk off of other precipices. Is it shameful or not shameful to be hit by a car? He's totally indifferent to these matters, so he didn't care. Fortunately, he had students that would sort of get him out of the way. And if he was walking too close to the edge, they would pull him over and say, no, no, Piro, go, go this way. Other people claim that those stories are a false description of him made up on the basis of his philosophy in order and cooked up those stories by his enemies in order to make him look bad. But he may have lived this kind of life that seemed outrageous to people, refusing to agree that things that seemed to them obviously good or bad, shameful or honorable, just or unjust, that his refusal to agree with their views on this enraged a lot of people, but also entertained other people. And so he was kind of a popular figure. And so when it came around to let's start, let's branch off and have a real school of skepticism where we're really not committed to any views at all, then we're going to take this earlier guy who really lived that kind of thing as our representative. Now, he was also said to be totally unaffected by things around him. So if he's talking to people, if he's talking to somebody and that person walks away while he's talking, he just keeps talking as if nothing happened. He still has to say what he wants to say. It doesn't matter if anybody's listening or not. He'd also just get up, start wandering around the city and just conversing with anybody that he ran into and just start interrogating them about what are you doing. And in this way, he takes on a kind of Socratic-like character. It's also said that one of his students, Anax Orcus, was injured and fell into a ditch one day. And Piro saw that he was laying there suffering in the ditch, but just walked right by him because who knows if pain is good or bad or being crippled is good or bad? And a lot of people blamed Piro for this and said, this shows really how bad your philosophy is and what kind of bad character you're creating. But Anax Orcus, the student said, no, this is great. And praised his indifference that he wouldn't give in just because it was somebody that he knew. So that was a kind of controversial figure of the school. And there are a lot of other entertaining stories about him. But the later developments of what we call Peronian skepticism, almost none of them, nothing of it can be attributed to him. He's kind of an inspiration for their developments and not a real figure and not a real philosopher in the sense of putting down arguments that we can still analyze and debate whether they're valid and sound and so forth. So let's now talk about Peronian skepticism, which was developed by these later writers, such as Anisa Demis, and especially by a much later and rather obscure writer named sexist empiricus about the third century AD. And he wrote a number of works. One of them is called The Outlines of Peronian Skepticism, which is what most of the excerpts that you read for today come from that work. But he also wrote a work called, which has one of the best titles of a work of philosophy ever, I think it's called Against the Professors. And it actually is 10 books of arguments where you go down every single discipline and argue systematically against all of them. So Against Book One, Against the Grammarians, Book Two, Against the Rhetoricians, Book Three, Against the Geometers, Book Four, Against the Arithmeticians, Book Five, Against the Astrologers, and Book Six, Against the Musicians. So those are mostly fields of rhetoric, mathematics, and a basic education. And he went through and attacked them and said none of this actually constitutes any knowledge and you can oppose these by equally plausible counter-arguments and suspend judgment about all of them. Now, those are mainly used today be insofar as he's arguing against these various kinds of arts. And so he actually preserves views about ancient grammatical theory, ancient musical theory, ancient geometrical theory, and so forth that provides us valuable information about what people were actually claiming in those areas. And we tend to ignore the skeptical counter-attacks on them and build up theories about the endless progression of science since Greek antiquity. But there's something interesting about the fact that if we think that the ancients were deficient in knowledge that they didn't really have as advanced sciences as us. It's often taught there's this kind of potted history that says science started in the 17th century or something like that. Before that it was just confusion and there was no knowledge. I think that's a ridiculous view of scientific history but suppose that view was true, if it was true, then the views of the Pranian skeptics would have turned out to be right, that there was no such thing as knowledge and that all claims being made about scientific knowledge were actually false. Now three other books, I just wanna mention of that work against the professors that are especially important for our purposes and they're sometimes grouped together and called by the generic title against the dogmatic philosophers or against the dogmatists. And this divides into three parts and I think you could predict what those parts are. Part one against the logicians, part two against the physicians and part three against the ethicists. That is we take each of the systematic parts of philosophy and we go through every conceivable view advanced in each of those fields and we skeptically inquire into them and we show that there is no actual knowledge contained in any of it. And so that's a much later ancient work and again it can be mined for fragments of information about these philosophers whose ethical, logical and physical views were still interested in even though their original works have disappeared. But beyond using them as sources of fragments to reconstruct dogmatic philosophies we can also appreciate this skeptical approach that says, that inquires into whether this is really knowledge or not. Now did some of you raise their hand that I missed? Yeah. I don't understand how they justify saying that that inquiry didn't begin. Like we used the words that they came up with describing these things in that time. How do they say that science didn't begin and if that's the words we use or the words that they gave us? Well, so what you're saying is because we use ancient Greek terms in our science and our science is science then how could somebody back then have denied that it was really science? I'm saying like the people now that you mentioned that say that it didn't, that science really began in the 17th century. Yes, why do people say that? You'd have to read some of those people or really that's way of characterizing the history of science has pretty much died out as it's been demonstrated there was scientific knowledge. And in fact, the scientific knowledge of the Greeks may be the only scientific knowledge we've had until about the 20th century or so. But so it's hard to argue that Euclid's elements is a geometrical work of science that is scientifically valid. Of course, then we have later developments about non-Euclidean geometry and so forth that show that you might not wanna actually accept any of the principles of Euclidean geometry. But it's just that's the way the history's been written and presented is that there was a scientific revolution in the 17th century and science is such taken off from there. I don't share that view and I think that what was happening was a revival of ancient scientific views and a renaissance of them actually to use a very old fashioned term. And so I can't really, I'm not interested in explaining to you why people hold that set of false views, but they do. And if that view was true, then those people would have to agree with the substance of the views of Peronian skeptics who argued that nobody actually has got scientific knowledge here at all. I think that's false. And I also think that skepticism is false because I think we do have knowledge in certain of these areas. As an Epicurean, I think it's true that pleasure is a good thing, for example. And I think I can argue that as long as a skeptical inquirer wants to debate about it. But that's another point and we'll have to wait until we get to a consideration of those views in order to talk about it. But what I wanna do now is show how it is what methods the skeptics developed in order to counter every dogmatic claim that's made. What kinds of tools did they use in order to do that? Because it's a tall order. It's not just a lazy thing where you say, well, I just don't really believe what these people are saying or something. No, it's actually a very sophisticated thing where you develop modes of argumentation that get deployed against any conceivable claim of knowledge. And these tools that they developed and these modes are so strong that we haven't really been able to answer all of them satisfactorily to this day. And so epistemologists who are people that investigate the theory of knowledge, what knowledge and what science is, how we know when we have it, how it relates to truth, how it relates to perception, experience, that sort of thing. Epistemologists are still grappling with certain skeptical arguments that are extremely difficult to answer. And so I'm gonna introduce those arguments. But first, Sextus' account of how Heronian skepticism got going. He tells a sort of fable about how it got started. He says that certain talented men started looking into the nature of things and they became confused by all the different conflicting appearances. And this is most clear in the case of what's good or bad. So, and you can think about all the conflicting appearances and claims you have about this. So some people are telling you that in order to be successful, you need to be rich and you need to earn lots of money. Other people are telling you that focusing on money in a materialistic lifestyle is a bad thing. Some people are telling you you need to worship God and that God really exists. And other people are telling you God doesn't exist at all and you're wasting your time if you do that. Other people are telling you you're gonna survive after your death and go somewhere else like heaven. Other people are saying, no, that doesn't happen. It's just obliteration or something. And so when thoughtful people start to reflect on, well, there's all these different conflicting claims. Which ones of them are true and which ones of them are false? I should probably look into that, especially the ones that relate to my own happiness, success, whether I'm doing good or bad things. Presumably I wanna do good things and I don't wanna do bad things, but then I need to know what's good and what's bad. And different people are telling me that certain things are good, that other people happen to think are bad and things that other people think are bad, these other people think are good. So what do we do? Well, those inconsistencies they found in every subject of inquiry led them to become doubtful about what propositions they should assent to and which ones they should refuse to assent to. And so they started to make a more general inquiry into the truth of things in order to make progress and attain freedom from the disturbance you feel when you don't really know whether you should assent to something or not. I don't really know if what I should make my life about is trying to make money or not, whether I need to become a professional or that's not that important, whether I should have children or not have children. These are disturbing things to not know which way you should assent on it. Should I get married or not? And so this disturbance makes us investigate into the matter in order to come to some kind of definite resolution. But these so-called talented people found that for every argument on one side of a dogmatic equation, like pleasure is good or wealth is good, they could find equal counterarguments on the other side, pleasure is bad or pursuit of wealth is bad. And these considerations seem to balance each other out. And so then the position that they would take relative to these things is called suspension of judgment. Okay, I just won't make a judgment. I can't tell whether pursuit of wealth is good or bad. And so I will suspend judgment and not believe either that pursuit of wealth is good or the pursuit of wealth is bad. And so they suspended judgment systematically on everything that they could not resolve one way or the other. And a surprising thing happened when they suspended judgment on all of this. Tranquility followed. They stopped being bothered by it all. They were no longer distressed and disturbed about, oh, maybe this thing's really good and I don't have it so I need to get it or maybe this thing's really bad and I risk having that or engaging in that. And they just stopped worrying about those things. Who knows whether it's good or bad. And then a nice pleasing tranquil state followed. And the goal of this form of skepticism is to get that kind of tranquility that follows when you suspend judgment about things. And so although I presented Aristotle's theory about happiness and success, Eudaimania last time as being a general framework that everybody agrees to, this is one example of a school that doesn't accept that framework. Of course they don't accept it because they're skeptics and they don't accept anything but specifically they don't accept the notion that our lives should be devoted to a pursuit of happiness or success. In fact, they say this whole notion of success and excellence and everything that people are constantly inflicting on you and have been since grade school and telling you that this is what you need to focus on, that's all a bunch of bullshit and it's just wrong. And these people are acting like they know things about human nature and so forth but they have no idea what they're talking about and if you skeptically examine what they're claiming you'll see it's all ridiculous. And once you come to see that then you're gonna get a nice, pleasing, relaxed feeling that okay I'm not living up to these standards that these other people have but it just doesn't bother me because I see through the claim that it's either good or bad. Question. So isn't, I mean that sounds kind of like happiness to me and so then it would seem that they might not, I'm just trying to understand. So it sounds like they're not against the idea of attaining happiness or pursuing that state but they're against what others have stated is that goal. Yes, well, good, good, good point. If we take happiness in this ultra-generic platitudinous way that even Aristotle recognized to say that we all pursue happiness as a platitude, in that sense, yes, that's what everybody's doing. And then the debate is about what constitutes happiness and maybe we could say that this tranquility of the skeptics is just their version of happiness but they want to distinguish the goal they have from these other things because happiness looks like a happiness or success or prosperity or whatever looks like it's got more content to it and some sort of positive thing other than just not having beliefs about anything and so not being disturbed by them. And so their term is not, I translated it as tranquility but the term they use is actually a negative one. It's adoraxia which means not being stressed out or not having anxiety. It's like lack of anxiety is their goal. It's as if somebody was to say to you, I'm not so concerned to get happiness or to be a successful person, I just don't wanna be anxious anymore. I was really disturbed by being an anxious person about whether I'm on the road to success or not, whether I'm really excellent and outstanding and an achiever and all this. I was really worried about that before but now that I've come to see that there's actually no basis for any of those claims then I get this feeling where I'm no longer anxious about it and so it really seems that as opposed to these dogmatic views that say, look if you wanna be a happy successful person you need to attain these kinds of goals and that sort of thing. They wanna group all of those together in a way as that all being a kind of dogmatic philosophy that has a goal that itself has a bunch of different contradictory interpretations. That's crucial to the skeptic position. Well some of them are saying it's about pleasure. Some of them are saying it's about nobility. Some say it's about wealth. Some say it's about honor. It's all incoherent and none of that is conclusive. So we suspend judgment about it and the feeling that comes from that is not exactly happiness in any way that any of those people define it. It's just not being disturbed by things and not being too anxious about them. Would you say that this kind of basic projection of all the ruling concepts of happiness, whatever is also essential as a prerequisite for the Epicureans is like, I'm just here to get you happy. They're all their judgments about what success is they can sort of go fuck themselves and we're going through it. Well the Epicureans as we'll see want to take a strong line on this and say, no there is really a thing called happiness but these other schools are confused about what it is. It actually is this other thing. Now the Epicureans, Adorexia is actually really important for the Epicureans as well. So in a way their end starts to look kind of like kind of like the skeptics but neither skeptics nor Epicureans would admit that they have the same. In order to really punish the idea of a pleasure and the experience that you have to go through this first like, where's that? You know, it's not something successful. Yes, and the Epicureans want to get mileage out of assuring their followers that they will have pleasure and so forth. Now it turns out that pleasure is defined as something like not being disturbed and not being in pain and so forth. But a big part of the marketing of the school is no, we can really give you happiness. We can really give you pleasure and so forth. Whereas this one wants to say, all of this stuff you're hearing, all of this chatter and talk about happiness and success and prosperity and that sort of thing is actually all a sham. And it's not actually all worked out. So I wanna define three different spaces of possibility here. One is with respect to any matter that you could investigate but specifically the ones that we're talking about in this class. So I mean, if we're investigating logic, if we're investigating physics, if we're investigating ethics, we could, the result could either be that we discover the truth of the matter, okay? Or we deny that the truth has been discovered or will ever be discovered or we continue the investigation. So in philosophy, some people have claimed that we have found the truth and that we know what's really true. And these are the people we call dogmatists. For example, Aristotelians, Epicureans and Stelics say they know the truth about these matters. Others have denied that it's possible to find the truth. Those are the academics who have taken a dogmatic line on the impossibility of truth. And others claim that they simply continue to investigate the matter. And those are the Peronian skeptics. So there's actually a claim here that Peronian skeptics, in theory, if you could prove something to me to be true, then I would accept it as true. But it just hasn't happened yet. And I can counterbalance your claims with any other sort of claim. So when they are confronted with dogmatic arguments, skeptics oppose them by various methods. Generically what they do is they oppose appearances with theoretical ideas. They oppose theoretical ideas with appearances. But sometimes they oppose appearances with other appearances and sometimes they oppose theoretical ideas with other ideas. That is, they make use of all available means of argumentation in order to undermine dogmatic claims. An example of an appearance versus appearance claim. Suppose you said that tower over there is square. And then I said, well, yes, but if you look at it from 150 feet away, it appears to be round. And so we cannot make a determination about whether it is square or round. Or opposing idea to idea. Suppose you have the idea that God has ordered or designed everything providentially. Then they will oppose that by saying, well, there's a lot of disorder and chaos, bad people flourish, well, good people suffer. So that suggests that there isn't actually a God providentially ordering everything for the better. Or opposing an idea to an appearance. It appears to us that snow is white and everybody in here would seem to think it's obvious that snow is white. Well, there's an argument that shows that snow is black. Snow is just frozen water. Water is transparent. Transparency is lack of color. Lack of color is blackness. Therefore, snow is black. That sort of argumentation. Now, then they make a general argument, which today we're still grappling with again, called the pessimistic meta-induction. And it goes like this. Take the entire history of science, whether you want to start it in the 17th century or you want to start it earlier. And what you find is that every scientific claim ends up getting overturned and shown to be false and replaced by another one later. And so all the things that appear to us scientifically true now, we can expect if we make an inductive generalization that they too will be overturned and shown to be false. Now, if you don't want to accept the method of induction, then you will immediately undermine scientific claims. Empirical science is based on induction. But if you do accept induction, then you have to accept an inductive argument that covers all claims to scientific knowledge whatsoever. And if all scientific claims or everyone that we've seen when we studied them in history have turned out to be false, then we can expect that later ones will turn out to be false. And they deploy various modes of argumentation. They group these into sets of arguments, the five modes, the 10 modes, the three modes, the two modes, et cetera. I'll start by describing to you the five modes of a grip because I think that is the most powerful one. So what this says is that you make a claim. Some dogmatist makes a claim. For example, that pleasure is good or pleasure is bad. Let's just use the example, pleasure is good. Well, first thing I do is point out your argument's unsupported. There's no reason I'm just going to believe that pleasure is good. And so that's the first thing I do is point out that all you've done is advance to a hypothesis with no support. Pleasure is good. No reason for me to accept it. And in fact, I notice that there's lots of disagreement with this argument. This is the second mode. I can easily construct an opposite of your argument. Now, what is an opposite to the argument pleasure is good? There's actually a lot of different possible opposites, like some pleasures are not good or no pleasures are good. At any rate, I formulate a disagreeing statement. So now you're obliged to provide an argument in support of your hypothesis. So here's your hypothesis. And you've put it here. And I've made something that rejects your hypothesis over here. And we're trying to figure out which of these arguments is better. So this tilde means no. It means I've rejected this thing. So you're going to support your hypothesis now with further arguments. So you're going to have argument 1. And then what I'm going to do is say, well, why should I believe argument 1? It's merely a hypothesis. And you say, well, OK, because of argument 2. And then I say, well, but I don't believe argument 2. And furthermore, I can formulate a counter argument. I can always formulate a counter argument to it. So then you say argument 3. And you can see where this is going to infinity. And so this is the third mode, is we force an infinite regression of arguments. Now, you can never complete an infinite regression of arguments. And therefore, you can never ultimately support your hypothesis unless perhaps you circled back and found support for one of your hypotheses by earlier claims that you were making. So perhaps you support one of your later arguments and say, well, it does have a foundation in an earlier argument that I made. Then I deploy the circular mode that you cannot support the argument you're trying to prove by assuming that it's true, which is what you would have to do in order to make a circular argument. So any defense of a hypothesis, first of all, can be disagreed with. And we can formulate something opposite to it. If it can be supported by arguments, every one of those can be questioned onto infinity. If a circular argument is made, then we point out that that doesn't constitute knowledge. And finally, even if you did purport to establish that you had arrived at the nature of something, that the true nature of pleasure is good, for example, then I would deploy the relative mode and point out that that is only true in a relativistic sense and is false in several other senses. And that mostly relates to the 10 modes, which I will describe in a moment. But I think there was a question. Yeah? I'm wondering, are you writing the arguments that were assumptions? So do the counter-argument and the argument have the same assumption at all? Do what? Because you say that skepticism wanted to start an infinite regression of arguments. So that means that there are no assumptions to start with? No, there's an assumption which is your claim. The skeptic doesn't make claims. The skeptic waits for dogmatists to make claims. And when the dogmatist makes a claim, the skeptic says, what is your support for that claim? Because I can formulate a claim that's exactly opposite of it. And so why should I believe yours? And then you say, well, because of this argument. And I say, well, I can formulate something opposite of that argument. And then so you say, because of this other argument. Now, you cannot complete an infinite chain of arguments in order to support that. So you're going to have to either circle back on yourself or take it that one of these claims is somehow self-evident or axiomatic or something like that. And at which point, I'm going to point out that it's not self-evident, that there is lots of ways in which it's only relativistically true. Go ahead. So I feel like the fundamental disagreement between skepticism and other things that those skeptical people, they don't accept any assumptions to start with. Right. Why should they? Why should anyone just accept an unsupported assumption? In fact, you might think it's a general rule. No one should ever believe any unsupported assumption. Does the math have axioms? Well, now we're talking about axioms. And so what are axioms? Axioms are claims that certain things are self-evident. We don't accept that they are self-evident. We'll argue that they're not and show that they aren't. And that's why we've written books like Against the Arithmeticians and Against the Geometricians to show that the supposed hypotheses of these sciences are not as they claim self-evident and so forth. So we would have to get into the details of those scientific claims specifically. And perhaps you think that in the case of mathematics, it's true. And so maybe the skeptics will lose their arguments about geometry and so forth. Maybe. I think probably not. But maybe they will. But the arguments in ethics are a lot more solid because the claim that things are self-evident in ethics is a very difficult claim to defend. And very easy to counter with other examples. Yeah? Isn't the claim that a spreadsheet from death nothing leads to nothing really? Isn't that the claim? So they say that they don't assert it dogmatically. They just notice that it follows. And they notice they get that feeling when they do that thing. And so that's why they do it. But they don't dogmatically claim it. And they're open to the view that you could show that it creates, that it doesn't relieve anxiety. So I want to tell you a story. I had an undergraduate here who is now doing a working on a PhD in psychology and philosophy at Yale. He wrote an honors thesis on this topic. Let's actually empirically investigate the question whether suspension of judgment does relieve anxiety. So he developed a way of giving a questionnaire to people about how dogmatically they held claims or how skeptical they were. And then he gave them a separate questionnaire about the level of anxiety that they feel in general. And we have lots of good tests for anxiety to test about whether you're a dog with hystereoskeptosis. That's actually a lot more difficult to do. But to the extent that those questionnaires were right, Mario Atti, and he wrote the sample essay that I put up as a good example of a research essay, he found that there was actually a significant reverse correlation. Dogmatic people are actually way less anxious than skeptical people. And what he was thinking is happening is that when people have anxiety, what they do is latch on to dogmatic ideas, like about thought and about religion and so forth. And this actually relieves their anxiety by believing them. But people that don't know whether anything's true or not, that that can be a really stressful thing. And so that's actually a weak point of this. Because as you're pointing out, they cannot argumentatively defend it and make it a dogmatic claim. So they have to assert that it just happens to be correlated or just happens to follow. But then we can actually skeptically investigate whether it does actually happen to follow. And Mario Atti's research appears to show that it doesn't. If we're really concerned about anxiety, we might want to become dogmatic nuts about stuff. Because those people seem to be really mellow compared to people that are actually skeptically looking into this. We learned in my epistemology class about introspection as a sort of knowledge. Basically, you can know what your interstates are. When skeptics agree that that's a kind of knowledge, because they talk about communicating their inner state of skepticism. They would not agree that it's a kind of knowledge. But they claim, if you ask, how does the skeptic get by in life? They say, we get by just on the basis of feelings. So we'll assert things like, I feel cold. I won't say, I know that I am cold. And I know what cold is. And I know that it's bad to be cold. But they will say things like, I feel cold. And I'm in the habit of putting on a coat. And I feel cold. And so I put on a coat. And I'm in the habit of walking out of doors instead of into walls. And so that appears to me a door. And so I'll walk through it instead of walking into this thing that appears to me to be a wall. And they get by on the basis of these kind of necessary feelings. I feel hungry. So when I eat food, I don't know how it is, but it tends to relieve that hunger. Customs, habits, and these kind of feelings. But they would certainly deny that those constitute a basis for anything as significant.