I think. Therefore, I am. It's the philosophical
equivalent of just do it. Everyone knows it's
on T -shirts. It's on coffee mugs. It's probably
tattooed on a few undergrads right now. Cogito
ergo sum. It is the catchphrase of Western civilization,
essentially the bedrock. Right. But here's the
thing. When I hear that phrase, I picture a very
serious old guy in a wig, you know, sitting at
a mahogany desk with a quill, having this profound
moment of clarity. I do not picture a mercenary
soldier shivering in the middle of a German winter,
locking himself inside a heating furnace to hallucinate.
It is a bit of a disconnect, isn't it? The foundation
of rational thought coming from a man who was,
well, arguably having a nervous breakdown in
a very small, very hot room. And it gets weirder.
I mean, we're talking about a guy who believed
that if you kicked a dog, it didn't feel pain
because it was just a broken machine making a
squeaking noise. And guy whose skull, his actual
physical head bone, was stolen, sold, swapped
and passed around Europe like a grim trading
card for centuries. It is a story that has everything.
War, visions, stolen body parts and a fundamental
rewiring of how humans understand reality itself.
Exactly. So today we are doing a deep dive into
Rene Descartes. But we're not just going to recite
his Wikipedia page. We want to understand how
he broke the world and how he put it back together.
Because whether we realize it or not, we are
all living in the house that Descartes built.
We absolutely are. He's also called the father
of modern philosophy, which sounds like a nice
title to put on a resume, but it implies something
massive. Before him, knowledge was about authority,
the church, Aristotle. After him, knowledge was
about you, the individual. So we have a stack
of sources here, his biographies, his letters,
and the big ones, discourse on the method and
meditations on first philosophy. Our mission,
to track this guy from the stove to the skull
and figure out if he was a genius, a madman,
or both. I would argue he was a bit of both,
definitely. But to understand the madness, you
have to understand where he started. Let's rewind
to the beginning then, 1596. La Haye -en -Touraine,
France. A town so proud of him, they literally
renamed it Descartes. Which, by the way, is a
total power move. It is. Imagine having a town
named Smith or Jones. It's a significant honor.
But his start in life was incredibly fragile.
His mother, Jeanne, died just a few days after
childbirth, about a year after René was born.
So he's an infant, motherless, and incredibly
sickly. The doctors didn't think he would survive
childhood. He was raised by his grandmother,
right? His father was always away. Yes, his father
was a busy man, a counselor in the Parliament
of Brittany, so he was away on business constantly.
Rene was left in this quiet, rural environment,
constantly being told he was too weak to play,
too weak to run. And that fragility, that sense
of being delicate, it really shaped his entire
lifestyle. This brings us to the one detail about
his school life that I am infinitely jealous
of. He goes to this fancy Jesuit college, La
Flèche. It's basically the Harvard of 17th century
France. Strict discipline, rigorous schedule.
But René, he gets a pass. The Jesuits were smart.
They were very pragmatic. They saw he was brilliant,
but physically delicate. So while the other students
were up at 5 a .m. for prayers and chores, Descartes
was allowed to stay in bed until noon. Until
noon, in a boarding school. That is the dream.
I mean, can you imagine? But he wasn't just sleeping.
He was lying there, awake, staring at the ceiling,
thinking. He did map in his head. He contemplated
philosophy. He developed this lifelong habit
of doing his heavy intellectual lifting while
horizontal. He needed that quiet, warm solitude
to function. It's funny because we think of working
hard as sweating, running around, being dizzy.
Descartes' version of working hard was lying
under a duvet for seven hours staring at a fly
on the ceiling. And that habit of solitude is
crucial. Because even though he was getting the
best education money could buy, learning Latin,
Greek, Aristotelian physics, he started to get
this nagging feeling. A feeling that would eventually,
you know, tear down Western philosophy. The feeling
that it was all nonsense. Not necessarily nonsense,
but shaky. Unreliable. He looked at what he was
being taught, the physics of Aristotle, which
said rocks fall because they want to go home
to the center of the earth. Right. Purpose driven
physics. Exactly. Or the scholastic philosophy
that relied entirely on, well, the church says
this or Aristotle wrote that. He realized that
none of it was proven. It was all just people
repeating what other people had said for centuries.
It's like playing a game of telephone that's
been going on for 2000 years. At some point you
realize, wait. How do I know the guy at the front
of the line actually saw anything? That is the
perfect analogy. He left school feeling that
the only thing he had really learned was how
ignorant he was. He had a law degree, he had
a classical education, and he felt he knew absolutely
nothing for certain. So naturally, the fragile
guy who loves sleeping in and doubts everything
decides to become a mercenary soldier. Makes
that make sense. It does seem like a hard left
turn, doesn't it? I am frail and I love philosophy.
Please hand me a pike and send me to the 30 years
war. It's completely counterintuitive. But you
have to understand the era. If you wanted to
see the world, really see it, you joined an army.
And more importantly, Descartes was interested
in the science of war. Ah, okay. So he wasn't
there to stab people. He was there for the engineering.
The math. Ballistics. Fortifications. Logistics.
War was becoming a mathematical exercise in the
17th century. He joined the army of Maurice of
Nassau in the Netherlands first. Maurice was
a military innovator who used math to organize
his troops. For Descartes, this was like a field
trip for applied geometry. So he's treating it
like a mobile laboratory. In a way, yes. But
he's not just doing math. He's traveling. He
goes to Germany. And this is where we hit the
inciting incident of the movie. November 1619,
Neuerurg under Donau. It is the middle of the
Little Ice Age. Germany is freezing, just brutally
cold. Descartes is traveling with the army and
he gets stuck in this town because of the weather.
To escape the cold, he shuts himself in a room
with a stove. Okay, let's clarify the stove thing
because I've seen cartoons where he's literally
inside an oven like the witch in Hansel and Gretel
is about to cook him. That's not right, is it?
No, no, it is a translation issue. The French
word is pool. In this context, it refers to a
masonry heater or a cockle stove. It's a massive
ceramic structure that you feed wood into from
the outside, and it radiates heat into a small
enclosed room. So he wasn't in the fire, but
he was in a very small, very hot, probably very
stuffy room, sitting right next to the heater.
So he superheated. He's alone. He's socially
isolated. And his brain starts to do somersault.
He spends an entire day and night there. And
on the night of November 10th, he has three dreams.
And these aren't just, I showed up to school
in my underwear dreams. These were vivid, hallucinatory,
spiritual experiences that he believed were sent
from God. Okay, break them down for us. What
did he see? Well, the first two were terrifying.
In one, he's caught in a whirlwind, trying to
reach a church, but he's being blown around.
He can't stand up straight. He sees ghosts. It's
a nightmare of weakness and confusion. In the
second dream. In the second, he hears a massive
clap of thunder, an explosion inside his room.
Whoa, an explosion. Just the sound. Sounds so
loud, he wakes up terrified, thinking the room
is on fire. He sees sparks flying in front of
his eyes. It's a full sensory hallucination.
You mentioned in the pre -show notes that there's
a medical theory for this. Yes. There is a condition
called exploding head syndrome. It sounds made
up, but it's real. It's a parasomnia where just
as you're falling asleep or waking up, you hear
a deafening noise like a bomb going off or a
gunshot that originates inside your own brain.
It's harmless, but it is absolutely terrifying
if you don't know what it is. So he thinks he's
being attacked by spirits or that God is sending
him this violent snack. He's in a state of religious
terror. But then comes the third dream. And it's
completely different. It's calm. He sees a book
of poetry on a table. He opens it and reads a
line. That's pretty on the nose. Gets more so.
A stranger appears in the dream and hands him
another poem that starts with yes and no. Yes
and no. That feels significant for a guy obsessed
with truth and falsehood. He interpreted it all
as a divine mission. The violent dreams were
the errors of his past life. And the calm dream
was the future. He believed the spirit of truth
was telling him to unify all human knowledge,
to take the certainty of mathematics and apply
it to philosophy, to nature, to everything. He
walked out of that heated room believing he had
the key to unlock the universe. Talk about a
burning bush moment. But instead of a bush, it's
a masonry heater. And instead of Ten Commandments,
he gets analytic geometry. and a method for finding
absolute truth. So this is where the real work
begins. He leaves the army, he wanders around
Europe for a while, he's a bit of a nomad, and
eventually settles in the Netherlands to write.
He wants to build this new system of knowledge.
But before he can build, he has to destroy. This
is the core of his discourse on the method. He
uses this brilliant architectural metaphor. He
says, look, if you live in a house that's falling
apart, The foundation is cracked. The walls are
rotting. You don't just paint over the cracks.
You don't just replace one brick and hope for
the best. You bring in the bulldozer. The wrecking
ball. You tear it down to the ground. Completely.
You dig out all the loose topsoil until you hit
bedrock. Solid stone. Only then do you start
building. For Descartes, the rotting house was
everything he thought he knew. All the facts
he learned in school. All the common sense beliefs.
He decided to treat anything that could be doubted.
as if it were definitely false this is what you
call hyperbolic doubt it's doubt on steroids
it's weaponized skepticism it is doubt as a tool
a methodology he didn't literally believe his
hands didn't exist but he decided to test the
belief if there was even a one percent chance
it was fake he threw it in the trash so walk
us through the levels of this uh this demolition
process what goes first first the census the
most obvious source of information he says my
eyes have deceived me before We've all seen a
stick in water. It looks bent, but when you pull
it out, it's straight. We've seen a tower in
the distance that looks round. When you get up
close, it's square. Okay, sure. Optical illusions
exist. But I'm sitting here. I can feel the table.
I can smell my coffee. Surely that's real. That's
not an illusion. And that's level two, the dream
argument. He says, Renee, you've had dreams where
you were sitting at a table smelling coffee.
And in the dream, it felt 100 % real. You didn't
know you were sleeping until you woke up. That
is the one that always gets me because I have
had those dreams where I wake up and I'm genuinely
confused about what day it is or where I am for
a few seconds. The feeling is that real. Exactly.
He asks the killer question. Is there any definitive
mark or sign that distinguishes waking life from
a dream? He concludes, no. At any given moment,
you could be asleep. So you can't trust the existence
of the physical world. But wait, what about logic?
Even in a dream, logic still works, right? A
square still has four sides in a dream. Two plus
three equals five in a dream. Those are truths
of reason, not of the senses. That brings us
to the final boss, the deepest, most corrosive
level of doubt, the evil demon. This sounds like
a horror movie villain, the genium malignant.
It is the ultimate paranoid scenario. Descartes
imagines. What if there is no God? What if the
universe is run by an evil genius, an entity
who is infinitely powerful and infinitely deceptive?
So, like the Matrix, the machines are feeding
you a total simulation. Perfectly analogous.
The demon is feeding you a simulation. He makes
you see the sky, feel the table, hear my voice,
but none of it is there. He even messes with
your mind so that when you count the sides of
a square, you count four. But maybe there are
really five. Maybe two plus three actually equals
six, but the demon wires your brain to think
five every single time you do the math. That
is genuinely terrifying. It's total mental gaslighting.
It means you can't trust your senses, you can't
trust your memories, and you can't even trust
your own logical reasoning. You are floating
in a void of lies. And that is where Descartes
wants us. That's the bedrock he's digging for.
He has stripped everything away. The house is
gone. The ground is gone. He is floating in nothingness.
He writes that he feels like he has fallen. into
deep water and can neither touch the bottom nor
swim to the top. It's a crisis. But then he hits
the bedrock. He finds the one thing that can't
be washed away. He realizes something. Even if
the demon is tricking him about the sky, even
if the demon is tricking him about his body,
even if the demon is tricking him about math,
there is one thing the demon cannot trick him
about. The fact that he's being tricked. Exactly.
In order to be deceived, there must be a me.
to deceive. In order to doubt, there must be
a doubter. The very act of thinking, even if
that thought is wrong, even if it's a hallucination
planted by the demon, proves that a consciousness
exists to experience it. He calls himself a res
cogitans, a thinking thing. That's all he knows.
He doesn't know if he has a body yet. He doesn't
know if he has a brain, but he knows he has a
mind. He has found the one single point of certainty
that not even an all -powerful demon can destroy.
It's such a cool moment in intellectual history.
It's like he's in a free fall and suddenly grabs
a ledge. Okay, I exist, but it's not much, is
it? I exist is great, but it's a lonely existence.
If he stops there, he's the only thing in the
universe. That's the trap of solipsism. The idea
that only I exist. Descartes knows he can't stay
there. He wants to do science. He wants to study
medicine. He can't do that if he thinks the physical
world is just a demon's illusion. He needs a
bridge to get from me to the world. And the bridge
is God. Right. And this is where modern readers
often get frustrated or where they feel Descartes
is pulling a fast one, you know, a bit of a cheat.
But we have to follow his logic because to him
it was ironclad. And he has to do it using only
his own mind. He can't look at a sunset and say,
look at God's handiwork, because the sunset might
be the demon. Precisely. He has to look inward.
He rummages through the ideas in his mind and
finds one very specific, very powerful idea,
the idea of perfection or infinity. Okay. So
he's thinking about a being that is flawless,
all -powerful, all -knowing. A perfect being.
And he asks, where did this idea come from? This
leads to the trademark argument. Can you break
that down? Because I can imagine a lot of things
I've never seen. I can imagine a flying spaghetti
monster. That doesn't mean it's real. But you
construct a flying spaghetti monster out of parts
you have seen. Pasta, wings, eyeballs. You are
assembling finite things. Descartes is using
a principle he calls causal adequacy. Think of
like a lot of physics. You can't get more reality
or perfection out of an effect than was in its
cause. Okay, sort of like thermodynamics. You
can't get more energy out of a system than you
put in. Exactly. If you have a pot of water boiling
at 100 degrees Celsius, the fire under it must
be at least 100 degrees. You can't boil a pot
of water with an ice cube. The cause must have
as much reality or perfection as the effect.
Okay, I'm with you. Nothing comes from nothing.
Ex nihilo nihil fit. So Descartes looks at himself.
He says, I am finite. I am full of doubt. I am
imperfect. I am like a room temperature glass
of water. But in my head, I have the concept
of infinite heat. I have the concept of absolute
perfection. And a room temperature glass of water
can't turn itself into boiling magma. It cannot.
He argues that a finite human consciousness simply
cannot manufacture the concept of the infinite
from scratch. It's too big. It's too heavy. The
cause is not adequate to the effect. Therefore,
the idea must have been placed in his mind by
something that is actually infinite and perfect.
Like a trademark stamped on a product. Made by
God. That's the argument. The idea of God is
the signature of the artisan on his creation.
And he has a second argument, too, the ontological
one. Right. That one's even more abstract. It
is. It basically says that the very definition
of a supremely perfect being must include existence.
Because if this being didn't exist, it would
be lacking something in existence, and therefore
wouldn't be perfect. So it has to exist. It's
a bit of a brain twister. It feels like defining
something into existence. A lot of philosophers
have thought so. Right. But for Descartes, it
was a logical necessity. So now he has two proofs.
God exists. How does that kill the evil demon?
Because of the definition of God. If God is perfect,
he cannot be a deceiver. Deception comes from
weakness or fear or malice. A perfect being has
no reason to lie. Therefore, the evil demon scenario
is impossible. God wouldn't allow it. So the
universe isn't a trap. Right. If God gave us
senses and gave us a strong natural inclination
to believe the world is real and God is not a
liar. then the world must be real, at least in
its basic measurable properties. He used reason
to save God and then used God to save science.
He did. And it's fascinating because he really
thought this would make the church love him.
He thought, look, I proved God without using
the Bible. I used pure logic. This will defeat
the atheists. Spoiler alert, the church did not
love him. Not at all. Not even a little bit.
We have to remember the context. This is the
era of Galileo. Galileo was condemned by the
Inquisition in 1633. Descartes was actually writing
a book called The World that agreed with Galileo
that the earth moves around the sun. When he
heard about Galileo's trial, he literally hid
the manuscript in his desk and said, nope, not
publishing that. Smart man. He liked his head
attached to his body. He did. But even with his
caution, his proofs for God were seen as incredibly
dangerous. By relying on human reason to prove
God, he was making human reason the ultimate
judge. The philosopher Blaise Pascal, another
genius of the time, famously said he couldn't
forgive Descartes. He said Descartes only used
God to give a little flick to start the world
moving and then had no more use for him. That's
the deist view. God is the watchmaker who winds
up the universe and just walks away. Exactly.
And eventually the Pope put his books on the
index of prohibited books. Which, let's be honest,
is usually a sign that you've written something
important. But okay, so now he has his mind,
he has God, and he has the world. But he has
created a brand new problem. A problem that philosophers
are still fighting about. The mind -body problem.
Dualism. The ghost in the machine. He has cleaved
the universe into two totally different incompatible
substances. On one side, you have Rez Codginton's
mind, consciousness, soul. It had no size, no
shape, no weight is pure thought. On the other
side, res extensive matter, the physical world.
It has size, shape. It follows mechanical laws.
It is unthinking. So my body is a machine. It's
a meat robot, basically. And my mind is this
floaty, ethereal spirit who's supposed to be
the driver. Correct. Yourself is the thinking
thing, the mind. The body is just a vehicle it
occupies. But here's the issue. And I think everyone
feels this intuitively. How do they touch? If
my mind is a ghost, how does it pull the levers
of the meat robot? How does a non -physical thought
cause a physical arm to move? You hit on the
interaction problem. It plagued Descartes his
entire life. Princess Elizabeth of Bohemia, one
of the few people who really, truly challenged
him, wrote him these brilliant letters asking
exactly this. She basically said, Renee, explain
to me how a non -physical soul pushes a physical
substance. It breaks the laws of physics. It's
like trying to punch a wall in a ghost movie.
Your hand should go right through. Descartes
struggled with this. He knew it was a problem.
So he went on a hunt through anatomy books. He
needed a joystick, a physical interface where
the non -physical could interact with the physical.
And he thought he found it in the pineal gland.
That tiny little pea -sized gland in the center
of the brain. Why there? He chose it because
it was the only part of the brain that he could
find that wasn't doubled. We have two hemispheres,
two eyes, two ears. The pineal gland looked singular
right in the middle. He decided this was the
seat of the soul. So he thought the soul sat
in the pineal gland and... Legaled it? Essentially,
he had this very elaborate theory. He believed
the soul vibrated the gland and the gland then
directed animal spirits, which were these fine
pressurized fluids he thought flowed through
the hollow tubes of the nerves to inflate the
muscles and make them move. It's hydraulic robotics.
He's describing the body as a hydraulic machine.
It is entirely hydraulic. He viewed the body
exactly like the moving statues in the royal
gardens of his day. You'd step on a hidden plate
that would trigger a valve, water would rush
through pipes, and a statue of Neptune would
raise his trident. That is how he thought we
worked. And he also developed a theory of reflexes
based on this, right? Things that don't even
need the soul. Yes, his reflex theory was groundbreaking.
He described how if you put your hand near a
fire, the heat would pull on a thread in your
nerves, which would open a valve in the brain,
and the animal spirits would rush out to pull
the hand back automatically. No thinking required.
It's a purely mechanical loop. It's brilliant
engineering, but terrible biology. And this mechanical
view leads us to the darkest, most controversial
part of the story, the beast machine. This is
the part of Cartesian philosophy that is very
hard to stomach today. Because Descartes defined
consciousness or mind as rational thought and
language, he concluded that animals didn't have
it. They have bodies, the res extensa, but they
don't have minds, the res cogitans. Right. To
him, a dog was just a very complex clock, an
automaton. But dogs yelp when you step on their
tails. They look sad when you leave. They look
happy when you come home. Descartes argued that
was just the machinery creaking. He said, if
you step on a dog, the noise it makes is no different
than the noise a bagpipe makes when you squeeze
it. It's just air escaping through a valve. There
is no ghost inside to feel the pain. No subjective
experience of suffering. That is just horrifying.
And the consequences of that idea were real,
right? This wasn't just an abstract thought experiment.
They were gruesome. This philosophy was used
to justify vivisection for centuries. Scientists,
Cartesian scientists, would nail living dogs
to boards and cut them open to observe the circulation
of the blood while the dog was screaming. And
they would scold anyone who felt pity, saying,
don't worry, it's just a machine breaking. It's
a stark reminder that pure, cold logic doesn't
equal empathy or wisdom. You can logic your way
into some pretty dark and cruel places. Indeed.
But we also have to give credit where it's due.
The same mechanical view of the world is what
gave us modern science. By stripping the magic
and spirits and desires out of nature, he made
it something we could study objectively with
mathematics. And specifically, to map it, we
need to talk about the mathematician. Because
if he had never said a single word about God
or souls or evil demons, we would still know
his name because of high school geometry. We
absolutely would. We need to picture the world
of math before Descartes. It was segregated.
You had geometry, which was all about shapes,
drawing with a compass and straight edge. It
was visual. Then you had algebra, which was symbols,
equations, finding X. It was abstract. They were
two different languages. It didn't really talk
to each other. Not in a systematic way. Descartes
was the translator. He built the bridge between
them. There is a famous story, it's likely a
legend, but it's a useful one, that relates back
to his habit of lying in bed. The Fly Story.
The Fly Story. He's lying in bed at La Fleche,
or maybe in his army tent. Staring at the ceiling,
he sees a fly buzzing around. And he wonders,
how could I describe the exact location of that
fly at any given second so someone else could
find it without me pointing? You can't just say
it's over there. That's not precise enough. Right.
He realized that if he looked at the corner of
the ceiling where the two walls meet, he could
use that as a fixed reference point, an origin.
He could then measure how far the fly was from
one wall and how far it was from the other wall.
Two numbers. Two numbers. Coordinates. Give me
those two numbers, x, y. And I can pinpoint that
fly anywhere on the flat surface of the ceiling.
Boom, the Cartesian plane. The x -axis and the
y -axis. The foundation of analytic geometry.
It seems so simple and obvious to us now, but
it was revolutionary. It meant you could turn
any shape, a circle, a parabola, an ellipse,
into an equation. And you could take any equation
and turn it into a shape, a graph. He unified
all of mathematics. And without that, I mean,
the implications are massive. Without that, we
don't have calculus. Newton built his work directly
on Descartes' foundation. We don't have computer
graphics. Every single pixel on your screen is
defined by Cartesian coordinates. We don't have
GPS or engineering blueprints or modern physics.
So every time I use Google Maps, I'm using the
intellectual fruit of Descartes' fly -watching
epiphany. You are. And he also standardized the
notation we still use. You know how in algebra
we always use 6 to x, y, z for unknown variables
and b, c for known numbers? That was him. He
just decided it one day and it stuck. And the
little superscript number for exponents like
6 by 2 tellers? That was him too. He cleaned
up the language of math. The guy literally wrote
the grammar for modern mathematics. He did. He
also tried to rewrite all of physics, but he
was a bit less successful there. For instance,
he didn't believe in a vacuum. He thought space
couldn't be empty. He thought it was a logical
impossibility for nothing to exist. So he believed
space was filled with an invisible plenum, or
subtle matter. He thought planets were swept
around the sun in giant vortices, cosmic whirlpools
of this invisible matter. Like a rubber duck
in a bathtub drain. Exactly. It was an elegant,
purely mechanical model. Newton came along later
with the theory of gravity acting at a distance
and proved it wrong. But for a while, the vortex
theory was the leading contender. He also had
some wild theories about meteorology. He thought
thunder was clouds crashing into each other like
avalanches in the sky and that lightning was
flammable exhalations getting squeezed out and
igniting. He was swinging for the fences on...
Everything. Mechanics, biology, optics, math,
God, weather. He wanted a theory of everything
before that was even a term. He absolutely did.
A unified mathematical science of the universe.
So let's look at the man himself in his later
years. He's famous. He's controversial. He's
living in the Netherlands, moving house every
few months to stay hidden and avoid distractions.
Did he have a personal life? Or was he just a
brain in a jar, a pure res cogitans? He was very
private, but he wasn't a robot. He had a relationship
with a servant girl named Helena Jans van der
Strom, and they had a daughter, Francine. And
this is the part that really breaks the unfeeling
machine narrative for me. It does. Francine was
born in 1635. And by all accounts, Descartes
adored her. He planned to bring her to France
to have her educated. He called her his niece
in public to hide the illegitimacy, which was
common then, but he clearly loved her deeply.
But in 1640, when she was only five years old,
she contracted scarlet fever. And died. She died.
And Descartes, the man of reason, the man who
said we should master our passions. broke down
he wept he wrote to a friend that he wasn't one
of those stoic philosophers who thought tears
were a weakness he said it was the greatest sorrow
of his life it's interesting some historians
and biographers think this tragedy changed the
course of his work right it seems to have shifted
him profoundly Before Francine died, he was obsessed
with medicine and mechanics. He honestly thought
he could crack the code of aging and live to
be 500 years old. He told people he was going
to conquer death through science. After Francine
died, he realized medicine had its limits. He
pivoted back to the metaphysical, to the soul,
to the question of the afterlife. He realized
the body is a machine that breaks. And sometimes
you can't fix it, no matter how much you understand
the mechanics. Exactly. It was a brutal personal
lesson in the limits of his own philosophy. So
enter the final act. The Queen of Sweden. Queen
Christina, the Minerva of the North. She was
young in her early 20s, brilliant, masculine
in her habits, incredibly energetic, and she
became obsessed with Descartes. She wanted the
most famous philosopher in Europe to be her personal
tutor. It sounds like a great gig on paper. Royal
patron, good pay, prestige. It was a death sentence.
Descartes resisted at first. He was in his 50s,
he was frail, and he hated the cold. Remember,
this is a guy who needs to sleep until noon and
stay warm to function. Sweden was the opposite
of his ideal environment. But you don't say no
to a queen forever, I guess. He eventually agreed.
He arrived in Stockholm in October 1649. And
it was a complete disaster from the start. Christina
was a ferocious early riser. She demanded her
philosophy lessons at 5 .08 a .m. Oh, no. That
is his kryptonite. In a giant, unheated castle
library. In the middle of the Swedish winter,
Descartes had to get up at 4 a .m., travel in
a carriage through the freezing dark, and stand
in a drafty library to talk about stoicism with
the queen. It was everything his body couldn't
handle. Literally. Within four months, he had
pneumonia, or as they called it then, inflammation
of the lungs. He fell ill in early February 1650.
And true to his skeptical form, he didn't trust
the doctors. He refused their main treatment,
which was bloodletting. The doctors wanted to
drain his blood to balance his humors, and he
basically told them to get lost, saying, spare
me, monsieur, spare me. He probably knew the
math didn't add up on that treatment, but eventually
he was too weak to resist. He died on February
11, 1650. His last words were supposedly, my
soul, it is time to depart. But the story doesn't
end there, because now we have to talk about
the skull. This is my favorite part of the weirdness.
It is a truly macabre epilogue. So Descartes
was buried in Sweden, in a graveyard for unbaptized
babies and orphans, because he was a Catholic
in a staunchly Protestant country. Not a very
fitting final resting place for the genius of
the age. France agreed. Sixteen years later,
they send a mission to dig him up and bring his
remains back to Paris for a grand reburial. They
exhumed the body. put the bones in a copper coffin,
and shipped it back. But when they arrived in
Paris and opened the coffin for the ceremony,
something was wrong. The head was gone. The skull
was missing. It turns out, during the original
exhumation in Sweden, the Swedish captain of
the guard had seemingly pocketed it. He just
swiped the skull. Why would you do that? Relics.
In that era, owning the skull of a genius was
like owning a signed Babe Ruth baseball today.
It was a status symbol, collector's item. The
skull spent roughly 150 years bouncing around
private collections in Sweden. People would have
dinner parties and show it off. No way. And they
wrote on it. They literally wrote graffiti on
it. There is a skull in the Musée de l 'Homme
in Paris today that is believed to be Descartes.
And it has a poem written on the forehead in
Latin. It has signatures scribbled on it from
its various owners. That is wildly disrespectful
and also completely hilarious. And it gets even
better. Another piece of the skull, a fragment,
somehow broke off and ended up at the University
of Lund. So the man who famously argued that
the mind and body are two completely separate
things ended up with his body separated into
pieces all over the continent. His res extenso
was fragmented and scattered, but his res cogitans,
his ideas, stayed intact. That is the perfect
way to put it. So let's land the plane. We've
covered the stove, the demon, the math, tragic
death. Why does this matter today? If I'm not
a philosopher, if I'm just living my life, why
should I care about Descartes? Because of what
we could call the anthropocentric revolution,
a revolution centered on the human. Before Descartes,
the foundation of truth came from the outside
in. The king told you what was true. The pope
told you what was true. Aristotle told you what
was true. Authority was external. And Descartes
flipped it? He turned it inside out? He made
the individual mind the starting point of all
knowledge, I think. My consciousness is the bedrock
of reality. This single shift allows for everything
that follows. It allows for the enlightenment.
It allows for the concept of individual rights,
for democracy. Because if every individual have
the natural light of reason, then every individual
should have a say in their own governance. It's
the birth of the modern self, the idea of the
autonomous individual. It is. We are all Cartesians
because we all experience the world from the
inside out. We value our own subjectivity, our
own inner experience as the most real thing we
know. But I want to go back to that beast machine
idea for our final thought because I think it's
coming back to haunt us in a very real way. I
guess so. Descartes looked at a dog and said,
it acts like it's alive, it makes all the right
noises, but there's nobody home. It's just complex
machinery. It's just code. Right. It's a simulation
of life without the inner experience. Today,
I open my laptop and I talk to an AI. It answers
my questions. It tells me jokes. It writes poetry.
It can argue with me and seem to understand my
feelings. It passes every external test for thinking.
But is there anyone home? That is the ultimate
Cartesian question for the 21st century. We are
building machines that perfectly mimic res cogitans.
They mimic thought. But are they thinking things?
Or are they just incredibly sophisticated beast
machines? And the scary part is, thanks to Descartes'
own method, We know we can't prove it either
way. I know I exist because of the Kojido, but
I can't get inside your head to know for sure
that you're not a philosophical zombie. And I
definitely can't get inside the AI. We might
be creating a new kind of evil demon. A simulation
that can fool us perfectly. Without a soul, without
consciousness, behind the curtain. The ultimate
test of his philosophy. On that uplifting note
of existential dread, thank you for joining us
on this deep dive. Always a pleasure to doubt
reality with you. Don't trust your senses, folks.
At least not completely. See you next time.