The Philosophy of Sextus Empiricus: Master of Ancient Scepticism

Okay, so here's a question that's probably crossed your mind at some point. What if everything

you're absolutely certain about is wrong? Not just a little wrong, not, oops, I misread the

data, wrong. But fundamentally, completely, can't even know if you're wrong, wrong. Now,

most philosophers throughout history have heard that question and responded with something

like, Well, that's terrifying, so let me spend the next 500 pages proving why I'm definitely

right about everything. But there was this guy, a physician actually, living in the Roman Empire

around 200 CE, who heard that question and thought, you know what? That sounds peaceful. His name

was Sextus Empiricus. And today we're diving into one of the most counterintuitive philosophical

positions ever developed. The idea that doubt itself might be the path to inner tranquility.

Welcome to the ancient art of not being sure about anything, and why that might be exactly

what you need. So let's start with the man himself, because Sextus is one of those historical figures

where we know just enough to be frustrated by how little we actually know. Here's what we've

got. Sextus Empiricus, and yes, that's a Latin name, which tells us he was probably a Roman

citizen, lived and worked sometime around 160 to 210 CE. We're not entirely sure where he

was born, but he likely taught in one of the major intellectual centers of the ancient world.

Alexandria, Rome, or Athens. And here's where it gets interesting. He wasn't primarily a

philosopher. He was a physician. Specifically, he belonged to what was called the Empiric

School of Medicine. Now, the Empirics had this radical idea. Instead of developing grand theories

about how the body works based on abstract principles, you know, the Four Humors, and all that, they

said, let's just observe what actually happens. Let's see what treatments work. And let's not

pretend we know why they work. Experience over theory, observation over speculation. Sound

familiar? Because that same instinct, that same skepticism about grand theoretical claims,

is exactly what Sextus brought to philosophy. But here's the thing that makes Sextus absolutely

crucial. He wrote the most comprehensive account of Peronian skepticism that survived from the

ancient world. His major work, the Outlines of Pyrenism, is basically our only detailed

window into this entire philosophical tradition. Without Sextus, We might have lost this way

of thinking entirely. And there's this beautiful irony here that I want you to catch. Sextus

was a doctor, someone whose job was to heal people, to relieve suffering. But instead of

prescribing herbs, or bloodletting, or whatever the medical fashion of the day was, he prescribed

doubt. He looked at human mental suffering, anxiety, dogmatism, the endless conflicts that

arise when people are absolutely convinced they're right. And he thought, What if the cure isn't

finding the right answers? What if the cure is learning to live without needing them? Which

brings us to the key question we're going to explore today. What if the cure for mental

suffering isn't finding the right answers, but learning to live without them? Now, before

you think this is just ancient navel gazing, let me tell you, this question is shockingly

relevant today. We live in an age of absolute certainty. Everyone's convinced they're right.

Political tribalism, online arguments, conspiracy theories, Ideological echo chambers? What if

a second-century Roman physician had already figured out the antidote? Let's find out. How

do we respond to the search for truth? Sextus identified three distinct philosophical approaches.

One, the dogmatists, Aristotle, the Stoics claim, we have discovered the truth, possess

certain knowledge of reality, build entire systems on foundational certainties. 2. The academic

skeptics, Plato's later followers, claim, truth is unknowable. 3. Deny the possibility of certain

knowledge. 4. Assert that we cannot know. The Peronian septics, Sextus' approach, claim,

we're still investigating. 5. Suspend judgment on all dogmatic claims. Avoid both assertion

and denial. The Crucial Difference Peronians don't claim to know that nothing can be known.

They simply Keep looking. Époqué, Épochie. The suspension of judgment. How it works. Step

1. Examine opposing arguments on any question. Step 2. Find them equally strong, weak. Step

3. Recognize equal probability on both sides. Step 4. Naturally stop affirming or denying.

Result. Ataraxia, Ataraxia. Inner peace and tranquility. The Paradox. Freedom comes not

from finding truth, but from releasing the need to grasp it. Alright, so Sextus looked around

at the philosophical landscape of his time, and honestly, it wasn't that different from

today. And he noticed something fascinating. When it comes to the fundamental question of

truth and knowledge, people basically fall into three camps. Let's break these down, because

understanding these distinctions is absolutely crucial. First, you've got the dogmatists.

Now this includes some heavy hitters, Aristotle, the Stoics, basically anyone who walks around

saying, I've figured it out, I know how reality works. These are the philosophers who build

massive systematic theories. They'll tell you about the nature of the soul, the structure

of the cosmos, the foundation of ethics, the ultimate purpose of human life, and they'll

do it with certainty. The good life consists in virtue. The universe operates according

to rational principles. Knowledge comes from sense perception properly understood. And look,

I'm not saying these people were stupid. Far from it. Some of the most brilliant minds in

human history were dogmatists. But Sextus noticed something. They all disagreed with each other.

Profoundly, fundamentally, if everyone's so certain and everyone's certain about different

things, what does that tell you? Then you've got the academic skeptics. These were followers

of Plato's Academy who took a different route. They looked at all this disagreement and said,

You know what? Truth is unknowable. We can't have certain knowledge. Period. Now, this sounds

similar to what Sextus is doing, But here's where it gets weird, and this is crucial. The

academic skeptics are making a dogmatic claim about knowledge. They're saying they know that

you can't know. You see the problem? They've just smuggled certainty back in through the

back door. They're absolutely certain that absolute certainty is impossible. It's like saying,

I'm positive that you can't be positive about anything. The statement defeats itself. Which

brings us to Sextus and the Peronians. And this is where it gets really interesting. The Peronian

doesn't say, I know the truth. But they also don't say, truth is unknowable. They say, I'm

still looking. I'm still investigating. And right now, I'm not making any definitive claims

either way. It's not nihilism. It's not giving up. It's something much more subtle and honestly

much more difficult to maintain. We're still investigating. Think about what that means.

Every time someone demands you take a position, do you believe in free will or determinism?

Is there objective morality or isn't there? Does God exist or not? The Peronian response

is, show me the arguments on both sides. and I'll tell you if either one is convincing enough

to warrant certainty. Spoiler alert, they never are. So, how does this actually work in practice?

This is where we get to one of the most important concepts in Sextus' philosophy, epoche. Epoche.

It's Greek for suspension or holding back. And it's not some mystical meditation technique.

It's actually a pretty straightforward intellectual process. Let me walk you through it. Step 1.

You examine opposing arguments on any question. Let's say, is the soul immortal? You find that

the arguments on both sides are equally strong, or equally weak, depending on how you look

at it. The point is, they balance out. You recognize that there's equal probability, or equal improbability,

on both sides. You genuinely can't tell which position has better support. And here's the

key. You naturally stop affirming or denying, not because you're forcing yourself, but because...

well, what else can you do? If the arguments are genuinely balanced, making a definitive

claim would be arbitrary. And then... this is what Sextus discovered. Something unexpected

happens. Ataraxia. Inner peace. Tranquility. Now this is the part that blew my mind when

I first really understood it. Sextus isn't saying, suspend judgment because it's intellectually

honest. or because it's the logically correct position. He's saying, try it and see what

happens to your mental state. Think about the last time you were in a heated argument, political,

religious, whatever. Think about how it felt, the anxiety, the need to be right, the mental

energy spent defending your position, attacking the other side, lying awake at night thinking

of better arguments you should have made. All that suffering comes from attachment to belief.

from clinging to certainty about things that might not be certain at all. And here's the

paradox that Sextus discovered, the beautiful counter-intuitive paradox at the heart of Peronian

skepticism. Freedom comes not from finding truth, but from releasing the need to grasp it. When

you stop needing to be right, when you genuinely suspend judgment on questions where the evidence

is balanced, you stop suffering about them, not because you've given up, not because you

don't care, but because you've recognized that clinging to unverifiable beliefs causes more

pain than it relieves. Now I know what some of you are thinking, but Professor Leshley,

doesn't this lead to paralysis? If I suspend judgment on everything, how do I make decisions?

How do I live? Excellent question. And Sextus has an answer. But before we get there, we

need to understand his method, the actual tools he used to achieve this suspension of judgment.

Because it's not enough to just say, I'm going to suspend judgment. You need a systematic

way of examining arguments of finding that balance point where certainty becomes impossible. And

that's exactly what we're going to explore next. Sextus Famous 10 Modes, the toolkit for cultivating

doubt. Okay, so now we get to the really fun part, the how of Peronian skepticism. Because

it's one thing to say, suspend judgment. It's another thing entirely to actually do it when

you're confronted with arguments that seem convincing, or when your own perceptions seem obviously

true, or when everyone around you is absolutely certain about something. Enter the Ten Modes,

and these are brilliant. Absolutely brilliant. Now, Sextus didn't invent these, he inherited

them from an earlier pyronean named Inesidymus, who lived a couple centuries before him. But

Sextus refined them, systematized them, and turned them into a genuine philosophical toolkit.

Think of these as ten different strategies for showing that any claim to certain knowledge

can be challenged. Ten ways of demonstrating that for every argument, there's a counter-argument

of equal strength. Let's go through them, and I want you to notice something as we do. How

practical these are. How they apply to everyday life, not just abstract philosophical debates.

First mode. Different animals perceive the world differently. Okay, simple example. A dog experiences

the world primarily through smell. Their olfactory reality is so rich, so detailed, that we can

barely imagine it. Meanwhile, we're visual creatures, we navigate by sight in ways that would be

completely alien to a bat using eco-location. So here's the question. When you look at a

rose and see red petals, and a bee looks at the same rose and sees ultraviolet patterns

we can't even perceive. Which one of you is seeing the rose as it really is? The dogmatic

philosopher says, well, obviously we are. Human perception is the standard. But why? What makes

human perception privileged? What makes your sensory apparatus the one that reveals objective

reality? You see the problem. Once you start asking that question, certainty starts to slip

away. Mode 2 Variability among humans. Second mode. Even among humans, we perceive and judge

things differently. Think about taste. Some people love cilantro, others think it tastes

like soap. And that's actually genetic, by the way. Some people are colorblind, some have

perfect pitch. Some are supertasters with more taste buds than average. But it goes deeper

than just physiology. Cultural background, personal history, psychological state... All of this

shapes how we experience and interpret the world. So when two people have a fundamental disagreement

about morality, about politics, about what's beautiful or disgusting or sacred, how do you

determine who's right? What's your standard? Your own perception? Why is yours more valid

than theirs? Mode 3. Different sense organs. Third mode. Our different senses give us conflicting

information about the same object. Classic example from Sextus. Honey tastes sweet, but it looks

yellow. Which property is more real? Its sweetness or its yellowness? Well, both, you might say.

But here's the thing. You're already making a judgment about how to reconcile conflicting

sensory data. You're interpreting. You're not just passively receiving objective truth. And

if you're interpreting, you could be interpreting wrong. Mode 4. Circumstances and Abconditions.

Fourth mode. The same object appears different under different circumstances. Wine tastes

different when you're sick versus when you're healthy. Colors look different in daylight

versus candlelight. Sounds are different when you're moving versus standing still. Your judgment

of temperature depends on whether you just came in from the cold or the heat. So which perception

is the true one? The one when you're healthy? Why? Because that's normal. But who decides

what counts as the normal standard condition for perceiving reality? You're starting to

see the pattern, right? Mode 5. Positions, distances, Fifth mode. Perspective matters. Where you're

standing changes what you see. A tower looks round from a distance, square up close. The

same painting looks different from different angles. The oar in water looks bent, out of

water, straight. And here's what Sextus is getting at. There's no privileged vantage point. No

cosmic perspective from which you can say, this is how things really are, independent of any

observer's position. You're always observing from somewhere, and that somewhere shapes what

you observe. Alright, five down, five to go, and these next ones get even more interesting

because they start to move beyond just perception into judgment, culture, and meaning. Mode 6,

add mixtures. Sixth mode. We never perceive anything in isolation. Everything comes to

us mixed with something else. You don't see pure color. You see color on a surface, in

a context, surrounded by other colors. You don't taste pure flavor. You taste food mixed with

saliva, affected by temperature, influenced by smell. So when you claim to know what something

is, you're really only knowing how it appears when mixed with all these other factors. You've

never encountered the thing in itself. Kant's going to make a whole philosophy out of this

idea 100 or years later, but Sextus already saw it. Mode 7. Quantities and compositions.

Seventh mode. The amount and arrangement of something changes its properties. A single

grain of sand? Harmless. A beach full of sand? You can drown in it. One glass of wine? Pleasant.

A whole barrel consumed at once? Fatal. Shavings of a goat's horn look white. The whole horn

looks black. So what color is the horn, really? The point is, properties aren't just in the

object. They emerge from quantity, from arrangement, from context. Mode 8, Relativity. Eighth Mode.

Everything we know is known in relation to something else. This is huge. This is maybe the most

important mode. We say something is large, but large compared to what? We say it's good. Good

for whom? In what circumstances? We say it's moving. Moving relative to what reference frame?

Sextus point is that we never grasp things in themselves. Absolutely. Independent of any

relation. All our knowledge is relational. All our judgments are comparative. And if that's

true, if we can only ever know things in relation to other things, which we also only know in

relation to other things, then we're caught in this infinite web of relations with no absolute

foundation. No bedrock. No certainty. Mode 9, frequency of occurrence. Ninth mode, familiarity

and rarity change our judgments. The sun rises every day, we barely notice it. But a solar

eclipse? Everyone stops and stares. Same celestial mechanics, different reaction. Or think about

this. If you'd never seen a human being before, and someone showed you one, you'd think it

was the weirdest, most improbable creature imaginable. Bilateral symmetry, opposable thumbs, the ability

to make complex sounds. But because you see humans all the time, you think they're normal.

So our sense of what's normal, what's remarkable, what's worthy of explanation, All of that depends

on how often we encounter it, not on any objective property of the thing itself. Mode 10. Customs,

laws, beliefs. Tenth mode. Different cultures have radically different beliefs about what's

true, what's moral, what's sacred. The Persians thought it was pious to marry your sister.

The Greeks thought that was abhorrent. Some cultures bury their dead, others burn them,

others leave them for birds. Who's right? And this isn't just ancient history. Today, we

have fundamental disagreements across cultures about gender roles, about individual rights

versus collective responsibility, about what counts as justice, about the relationship between

humans and nature. So when someone claims their moral beliefs are objectively true, Sextus

asks, How do you know? How do you prove that your culture's values are the correct ones

and everyone else is wrong? You can't. Not without already assuming what you're trying to prove.

Okay, so let's zoom out for a second and see what Sextus has done here. These ten modes

aren't just random observations. They're a system, a method, and the pattern is always the same.

Every claim about reality can be countered with an equally plausible opposing view. Not a better

view, not a worse view, an equally plausible view. That's the key. Sextus isn't trying to

prove that your beliefs are wrong. He's showing that for any belief you hold with certainty,

there's a counter belief that's just as well supported by the evidence. And when you genuinely

see that, when you really grasp that the arguments balance out, you can't help but suspend judgment.

The result? Justified suspension of judgment. Epoké. Not because you're intellectually lazy,

not because you don't care about truth, but because you're being honest about the limits

of what you can actually know with certainty. And that honesty... that intellectual humility

is the first step toward the tranquility Sextus promises. But here's where it gets really interesting,

because now we have to ask, if Sextus is right, if we really should suspend judgment on all

these fundamental questions, doesn't that create some serious problems? I mean, how do you reason

at all? How do you make arguments? How do you justify anything, including skepticism itself?

Sextus saw these objections coming, and his responses are, Well, they're either brilliant

or deeply frustrating, depending on your perspective. Let's find out which. Alright, so we've seen

Sextus' toolkit, the 10 modes that systematically undermine our confidence in dogmatic claims.

But now, we need to go deeper. Because Sextus wasn't just interested in showing that our

perceptions are unreliable. He wanted to show that the very foundations of knowledge, the

bedrock that philosophers thought they could build on, are fundamentally unstable. and he

identified three devastating problems that any attempt to establish certain knowledge has

to face. These are... these are genuinely difficult. Even today, 1,800 years later, philosophers

are still wrestling with these issues. Problem 1. The Infinite Regress. Okay, imagine you

make a claim. I know X is true. I ask you, how do you know? You say because of criterion A.

But now I ask, how do know Criterion A is valid? How do you know it's a good way of determining

truth? So you appeal to Criterion B to validate Criterion A. But then I ask about Criterion

B, and you need Criterion C, and then Criterion D. Where does it stop? At some point, you have

to just assert that one of your criteria is valid without being able to prove it. You have

to make an arbitrary stopping point. You have to say, This is just self-evidently true, and

I'm not going to justify it further. But that's dogmatism. That's assuming what you're trying

to prove. And here's what's devastating about this. It applies to everything. Logic? You

need a criterion to validate logical principles. Sense perception? You need a criterion to validate

that senses are reliable. Reason itself? You need a criterion to validate that reason works.

It's criteria all the way down. And at the bottom? Nothing solid. Just an arbitrary decision to

stop asking questions. Problem 2, circular reasoning. Or, or, you try to avoid the infinite regress

by going in a circle. Classic example. How do I know the Bible is true? Because the Bible

says it's the Word of God. How do I know the Bible is the Word of God? Because the Bible

is true. You see the problem. You're using the thing you're trying to validate as the validator.

But this isn't just a problem for religious fundamentalists. It's a problem for any foundational

claim. do I know reason is reliable? Because reason tells me it is. How do I know my senses

give me accurate information? Because my senses tell me they do. It's like asking a pathological

liar, are you lying right now? And accepting their answer as definitive proof. Sextus's

point. You can't use a criterion to validate itself. That's not justification. That's just

assertion with extra steps. Problem 3. the problem of induction. And then, then, we get to what

might be Sextus's most profound insight. And it's wild that he saw this in the second century

because it wouldn't become a major philosophical problem until David Hume raised it again in

the 18th century, the problem of induction. Here's how it works. We observe particular

cases, the sun rose yesterday, the sun rose today, the sun rose the day before that. And

we generalize to a universal law. The sun always rises. But how do we know that's true? How

do we know the future will resemble the past? Well, because it always has, you say. Every

time we've checked, the future did resemble the past, so we can be confident it will continue

to do so. But wait. You just used induction to justify induction. You observe that induction

has worked in the past, and you're using that observation to conclude that induction will

work in the future. You're assuming the very thing you're trying to prove. It's circular

reasoning all over again. And this isn't some abstract philosophical game. This is about

everything we claim to know scientifically. Every natural law. Every prediction. Every

generalization from observed cases to unobserved ones. We can't prove that the future will resemble

the past. We can't prove that the laws of nature will continue to operate tomorrow the way they

operated yesterday. We just... assume it. Because what else can we do? Ensextus saw this. Won't

thou fieve hundred years before Hume? The foundations of knowledge are far more uncertain than dogmatists

admit. So let's take stock of where we are. We can't escape infinite regress without arbitrary

assumptions. We can't use circular reasoning without begging the question. We can't justify

induction without using induction. Every attempt to establish certain knowledge runs into one

of these problems. And this is why Sextus says, Stop trying. Stop clinging to the illusion

that you can achieve absolute certainty. Recognize the limits of human knowledge and suspend judgment

on claims that go beyond what you can actually justify. But now, and this is crucial, we have

to address the obvious objection. Because I know what you're thinking. I know what the

objection is. Okay, Professor Leshley, this is all very clever. But if I suspend judgment

on everything, if I stop believing things with certainty, how do I live? How do I make decisions?

How do I get out of bed in the morning? Doesn't this lead to paralysis? To nihilism? To just

sitting in a corner, unable to act because you can't be certain about anything? And this is

where we need to understand something absolutely fundamental about Sextus's philosophy. Not

nihilism, a therapeutic practice? Sextus is not saying you can't live a normal life. He's

not saying you can't make decisions or have preferences or act in the world. He's saying

you can do all of that without dogmatic certainty. Remember, Sextus was a physician, and he uses

medical practice as a model for how the skeptic lives. A good doctor doesn't have a rigid theory

about how the body works, and then force every patient to fit that theory. A good doctor observes,

sees what works, adjusts treatment based on experience. If this remedy helps this patient,

use it. If it doesn't, try something else. You don't need to know why it works. You don't

need a grand theoretical explanation. You just need to pay attention to what actually happens.

Same with the Peronian skeptic. You don't need to know the ultimate truth about reality to

navigate life successfully. You just need to respond intelligently to appearances, to experience,

to what works. So what does this actually look like in practice? First, you follow appearances

without asserting they're true. Honey appears sweet to you. Fine. Eat the honey. Enjoy it.

You don't need to make a metaphysical claim about the objective mind-independent sweetness

of honey. You just need to respond to how it appears. Fire appears hot. Don't stick your

hand in it. You don't need certain knowledge about the ultimate nature of heat. You just

need to respond to the appearance. Second, you accept customs and conventions pragmatically.

You live in a society with laws, with social norms, with expectations. The Peronian doesn't

need to believe these are objectively true or absolutely right. You just follow them because...

Well, because that's how you function in society. You stop at red lights not because you have

certain knowledge that the traffic laws are metaphysically justified, but because stopping

at red lights prevents accidents and that seems like a good idea. Third, you act on probabilities

without claiming absolute knowledge. This is huge. Sextus isn't saying you can't make judgments

about what's likely or unlikely. He's saying you can't claim certainty. Is it going to rain

tomorrow? I don't know with certainty. But the sky is dark, the air feels humid, The weather

forecast says 90 % chance of rain. So I'll bring an umbrella. That's not dogmatism. That's just

reasonable response to available evidence. you respond to natural inclinations. Hunger, thirst,

pain, pleasure. You're hungry. Eat. You're tired. Sleep. You're in pain. Seek relief. You don't

need a philosophical theory about the nature of hunger to respond to it. You don't need

certain knowledge about the metaphysics of pain to want it to stop. And here's what Sextus

discovered, and this is the beautiful, counter-intuitive heart of Peronian skepticism. When you live

this way, when you respond to appearances without clinging to dogmatic beliefs about ultimate

reality, you experience freedom. Freedom from mental conflict and anxiety. Peace that comes

from non-attachment to beliefs. Tranquility through suspension of judgment. Think about

the mental suffering that comes from dogmatic certainty. You're absolutely convinced your

political ideology is right and everyone else is wrong, so you're constantly angry at the

other side, constantly anxious about them gaining power, constantly in conflict. You're absolutely

certain about the afterlife, so you're terrified of death, or you're judging others for not

believing what you believe, or you're sacrificing present happiness for a future you can't actually

verify. You're dogmatically committed to a particular view of how your life should go. So when reality

doesn't match your expectations, you suffer. All of that suffering comes from attachment.

From clinging to beliefs you can't actually justify with certainty. And Sextus says, let

go. Not of life, not of action, not of preferences or values or meaning. Just let go of the certainty.

Let go of the need to be absolutely right. And when you do, peace. Now, this is crucial,

and I want to make sure you understand it. Sextus doesn't deny everyday reality. He denies our

ability to know the ultimate truth behind appearances. He's not saying tables and chairs don't exist.

He's not saying your experiences aren't real. He's not saying nothing matters. He's saying

you experience a table. Fine. Call it a table. Use it as a table. Just don't make dogmatic

claims about its ultimate metaphysical nature, about what it really is. Independent of all

perception and context, you experience moral intuitions. You feel that kindness is good,

that cruelty is bad, fine. Act on those intuitions. Just don't claim you have certain knowledge

that these are objective features of reality that everyone must acknowledge. Live in the

world of appearances. Respond intelligently to experience. Just don't pretend you've grasped

the ultimate truth behind it all. Because you haven't. None of us have. And admitting that,

really admitting it. is the beginning of wisdom. So that's Sextus Vision, a way of life that's

fully engaged with the world, that makes decisions and takes action and has preferences. But that's

free from the anxiety and conflict that comes from dogmatic attachment to unverifiable beliefs.

Now, the question is, did it work? Did this philosophy actually influence anyone? Did it

matter? Oh, did it ever? The story of Sextus' influence is one of the most fascinating in

the history of philosophy, and it starts with his books being completely forgotten for over

a thousand years. Alright, so we've explored Sextus' philosophy, the methods, the arguments,

the way of life, but now I want to tell you a story. Because what happened to Sextus' ideas

after he died is absolutely fascinating, and it starts with those ideas disappearing completely

for over a thousand years. Picture this. It's around 200 CE. Sextus Empiricus has just finished

writing his major works, the outlines of Pyreneanism against the professors, these comprehensive

accounts of Pyrenean skepticism, and then... nothing. The Roman Empire is in decline. Christianity

is rising. The intellectual climate is shifting toward religious certainty, toward revealed

truth, toward dogmatic theology. Not exactly the ideal environment for a philosophy that

says, Maybe we should suspend judgment on all dogmatic claims. So Sextus works get copied

a few times, preserved in a few libraries, but they're not widely read. They're not influential.

For over 1,200 years, Peronian skepticism is basically a footnote in the history of philosophy.

Until the Renaissance, 1562. A Latin translation of Sextus's outlines of Pyrennism is published

and starts circulating among European intellectuals, and it explodes. Because here's what you have

to understand about the intellectual climate of 16th century Europe. This is the age of

religious warfare. Catholics versus Protestants. Each side absolutely certain they have the

truth. Each side willing to kill and die for their certainty. And into this environment

comes Sextus Empiricus saying, How do you know you're right? What's your criterion? Can you

prove it without circular reasoning or infinite regress? It's like throwing a philosophical

grenade into the middle of a theological war. Suddenly, intellectuals across Europe are reading

Sextus and thinking, wait, the ancient Greeks, these brilliant philosophers we've been revering,

they couldn't achieve certainty about fundamental questions. They had all these arguments showing

that knowledge is impossible or at least deeply problematic. So what makes us think we can

do better? The most famous example is Michel de Montaigne, French nobleman, essayist, one

of the most influential thinkers of the Renaissance. Montaigne reads Sextus and has this profound

intellectual conversion. He adopts as his personal motto, qu'est-ce que j'ai? What do I know?

And he writes these brilliant essays that are basically Peronian skepticism applied to everything.

Morality, religion, politics, human nature, cultural practices. He asks, how do we know

our customs are better than those of the indigenous peoples being discovered in the New World?

How do we know our religion is the true one when people in other cultures believe just

as fervently in theirs? How do we know animals don't have rational souls when we can't even

define what a rational soul is? And what's radical about Montaigne is that he's not using skepticism

to tear everything down. He's using it to cultivate tolerance, humility, openness. He's saying,

if we admitted how little we actually know with certainty, maybe we'd stop killing each other

over theological disagreements. Skepticism as a path to peace, just like Sextus promised.

But Sextus' influence doesn't stop with Montaigne. In fact, you could argue that the entire project

of modern philosophy from Descartes onward is a response to the skeptical crisis that

Sextus helped create. Descartes reads the skeptics and freaks out. He realizes that all his beliefs

could be wrong. So he develops his method of radical doubt. Doubt everything until you find

something absolutely certain. And what does he find? Now Sextus would have problems with

this. He'd ask how Descartes knows that thinking requires a thinker. How he knows the I persists

from one moment to the next. But the point is, Descartes is responding to Sextus. He's trying

to rebuild certainty in the face of skeptical arguments. Then you get David Hume in the 18th

century, and he basically revives Sextus' problem of induction. Hume says, we can't justify our

belief that the future will resemble the past. We can't prove that natural laws will continue

to operate. All our scientific knowledge rests on a foundation we can't rationally justify.

This is pure Sextus, and it creates another crisis in philosophy, which leads to Kant,

who spends his entire critical philosophy trying to answer Hume. trying to show how we can have

genuine knowledge while acknowledging the limits of human reason. The whole architecture of

modern epistemology, the study of knowledge, is built on questions that Sextus raised 1,800

years ago. But here's what I want you to understand. This isn't just history. Sextus is relevant

today, maybe more relevant than ever. We live in an age of absolute certainty. Everyone has

an opinion about everything, and everyone's sure they're right. Political polarization,

each side convinced the other is not just wrong, but evil. Conspiracy theories, people absolutely

certain they've seen through the lies. Online arguments where nobody ever changes their mind

because everyone's too invested in being right. And what does Sextus offer? Epistemology, fallibilism,

intellectual humility, critical thinking and scientific method, cognitive biases and the

limits of human reasoning. Epistemology, the study of how we know what we know. Sextus forces

us to examine our assumptions about knowledge itself. Fallibilism. The recognition that we

could be wrong. That our beliefs are provisional, subject to revision. Intellectual humility.

The willingness to say, don't know or I'm not sure, instead of pretending to certainty we

don't actually have. Critical thinking. The ability to examine arguments on both sides.

To recognize when evidence is insufficient. To suspend judgment when appropriate. Scientific

method. Which is fundamentally skeptical. Science doesn't prove things true. It provisionally

accepts hypotheses that haven't been falsified yet. Cognitive biases. Modern psychology has

shown us all the ways our reasoning goes wrong. Confirmation bias, motivated reasoning, the

Dunning-Kruger effect. Sextus would recognize all of this. We need Sextus today. We need

his reminder that certainty is often unjustified. That intellectual humility is a virtue. That

you can live a meaningful and engaged life without claiming to have all the answers. So let me

bring this home. After everything we've explored, the methods, the arguments, the way of life,

the historical influence, what's the enduring wisdom of Sextus Empiricus? What can we take

from this ancient physician-philosopher that actually matters for how we live today? I think

it comes down to three core lessons. First, question certainty, especially your own. Look,

I'm not saying you can't have beliefs. I'm not saying you can't have strong convictions. But

I am saying, be honest about the difference between I believe this, and I know this with

absolute certainty. When you find yourself thinking, I'm obviously right about this, pause. Ask

yourself, what would it take to change my mind? Have I genuinely considered the strongest arguments

on the other side? Or am I just surrounding myself with people who already agree with me?

Genuine inquiry, real intellectual honesty, requires openness to being wrong. It requires

the willingness to say, I could be mistaken about this. And here's what Sextus understood.

That's not weakness. That's wisdom. I could be mistaken is a mark of wisdom, not weakness.

The people who are most certain are often the most wrong. The people who admit uncertainty

are often closer to truth. find inner peace through non-attachment to beliefs. This is

the therapeutic heart of Sextus' philosophy, and it's profoundly relevant today. Think about

how much mental suffering comes from clinging to beliefs, from needing to be right, from

the anxiety of defending positions you're not actually certain about, from the conflict that

arises when your beliefs clash with someone else's. What if you could let that go? Not

the beliefs themselves necessarily, not your values or your preferences or your sense of

meaning, just the attachment, just the desperate need for certainty. You can act decisively

without absolute certainty. This is huge. You don't need to know the ultimate truth about

morality to act morally. You don't need metaphysical certainty about the nature of justice to fight

for justice. You don't need absolute proof that your life has meaning to live meaningfully.

You just need to respond honestly to your experience, to your values, to what appears good and right

and true, while remaining open to the possibility that you might be wrong. And when you do that,

when you hold your beliefs lightly instead of clinging to them desperately, You experience

what Sextus promised, ataraxia, peace, tranquility, not because you've given up, but because you've

stopped suffering over things you can't actually control, like whether your beliefs correspond

to ultimate reality. embrace intellectual humility. This is maybe the most important lesson, and

it's the hardest one. We live in a culture that rewards confidence, that celebrates people

who speak with authority, who never admit doubt. who always have an answer. But Sextus reminds

us that true wisdom lies in recognizing the limits of human knowledge. True wisdom lies

in knowing what you don't know. This goes back to Socrates, right? I know that I know nothing.

But Sextus takes it further. He gives us a method, a practice, a way of life built on that recognition.

And here's what I want you to understand. Intellectual humility doesn't mean you can't have expertise.

It doesn't mean all opinions are equally valid. It doesn't mean you can't make judgments or

take stands. It means you recognize that your knowledge is limited, that your perspective

is partial, that you could be wrong, that there might be considerations you haven't thought

of, evidence you haven't encountered, arguments you haven't heard. It means you approach disagreement

with curiosity instead of defensiveness. You ask questions instead of just asserting. You

listen instead of just waiting for your turn to talk. And most importantly, Most importantly,

it means you examine your own certainties. The examined life includes examining your own certainties.

The beliefs you're most confident about? Those are the ones that most need examination. Because

those are the ones you've probably stopped questioning. So let me end with Sextus himself, with his

own words about what the skeptical art actually is. The skeptic's art is the ability to oppose

phenomena and noumena in any way whatsoever. with the result that, owing to the equal force

of the objects and reasons opposed, we are brought to suspend judgment and then to peace of mind.

Phenomena and numena, appearances and reality, the world as we experience it and the world

as it supposedly is in itself. Sextus is saying we can always oppose these. We can always show

that our claims about ultimate reality are balanced by equally strong counterclaims. And when we

genuinely see that balance, when we really grasp that the arguments on both sides have equal

force, We naturally suspend judgment, not because we're forced to, not because we're being intellectually

dishonest, but because what else can we do? How can we claim certainty when the evidence

doesn't support it? And then, then, we experience peace. Not the peace of having all the answers,

not the peace of being absolutely certain, but the peace of letting go, the peace of non-attachment.

The Peace of Intellectual Humility. Thank you.