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.