Descartes and BuddiesDescartes and Buddies

““To be or not to be, that is the To be or not to be, that is the question”question”

As the world shiftsAs the world shifts

ContradictionsContradictions

Carpe diemCarpe diem (seize the day)(seize the day) Momento moriMomento mori (remember you (remember you

must die)must die) Based on the Based on the

concept that life is concept that life is briefbrief

Life is a Theater, therefore, Life is a Theater, therefore, ShakespeareShakespeare

All the world’s a All the world’s a stage/And all the men stage/And all the men and women merely and women merely players:/They have players:/They have their exits and their their exits and their entrances;/And one entrances;/And one man in his time plays man in his time plays many parts. many parts. As You As You Like ItLike It

Life’s but a walking Life’s but a walking shadow, a poor shadow, a poor player/That struts and player/That struts and frets his hour upon the frets his hour upon the stage,/And then is stage,/And then is heard no more; it is a heard no more; it is a tale/Told by an idiot, tale/Told by an idiot, full of sound and full of sound and fury,/Signifying fury,/Signifying nothing.” nothing.” MacbethMacbeth

If it isn’t a stage, what is it?If it isn’t a stage, what is it?

Idealism and materialismIdealism and materialism

IDEALISMIDEALISM Some philosophers Some philosophers

believed that all that believed that all that exists is, at bottom, exists is, at bottom, spiritual in naturespiritual in nature

MATERIALISMMATERIALISM Others believed that Others believed that

all real things come all real things come from concrete from concrete material substances—material substances—particles of matter particles of matter (even the soul starts (even the soul starts with movement of tiny with movement of tiny particles in the brain)particles in the brain)

Motion WinsMotion Wins

Newton applied motion to all Newton applied motion to all changes on earth and in space: changes on earth and in space: principles of universal gravitation principles of universal gravitation and the motion of bodiesand the motion of bodies

Everything was thus governed by the Everything was thus governed by the same unbreakable laws same unbreakable laws (mechanisms).(mechanisms).

Possible to calculate every natural Possible to calculate every natural change with mathematical precision.change with mathematical precision.

The world as a machineThe world as a machine

If so, then everything that happens is If so, then everything that happens is predetermined (“It’s written in the predetermined (“It’s written in the stars”)stars”)

Bye-bye free willBye-bye free will Everything is a product of Everything is a product of

mechanical processes, even our mechanical processes, even our thoughts and dreamsthoughts and dreams

He was convinced that knowledge is He was convinced that knowledge is attainable only through reasonattainable only through reason

Can’t trust old informationCan’t trust old information Can’t trust sensesCan’t trust senses Can this be Plato again?Can this be Plato again? Long live the rationalists.Long live the rationalists.

If nothing is “true,” what do you do?If nothing is “true,” what do you do?

Come up with the new philosophical Come up with the new philosophical system that will direct the world from system that will direct the world from this moment forward.this moment forward.

How about two questions:How about two questions: What can we know? (certain What can we know? (certain

knowledge)knowledge) What is the relationship between What is the relationship between

body and mind?body and mind?

SkepticismSkepticism

Is it true that we know nothing? Is it true that we know nothing? Skeptics thought so.Skeptics thought so.

But Descartes thought: If natural But Descartes thought: If natural sciences develop a method to sciences develop a method to provide exact descriptions of natural provide exact descriptions of natural sciences, why can’t philosophy? sciences, why can’t philosophy?

The big question: In a mechanistic The big question: In a mechanistic view, what’s the relationship view, what’s the relationship between the body and the soul?between the body and the soul?

The SoulThe Soul

Before the 17Before the 17thth century: century:• Soul was “breath of life”Soul was “breath of life”• Pervaded all living creaturesPervaded all living creatures• Soul and spirit meant “breath” or Soul and spirit meant “breath” or

“breathing”“breathing”• Aristotle saw soul everywhere as the Aristotle saw soul everywhere as the

“life principle”—could not be separate “life principle”—could not be separate from the bodyfrom the body

Big Question:Big Question:

If the body is a machine, surely the If the body is a machine, surely the soul could not be part of this body soul could not be part of this body machinery.machinery.

WHAT IS THE SOUL, THEN?WHAT IS THE SOUL, THEN?

Mind / BodyMind / Body

I decide to lift my I decide to lift my armarm

I decide to run for I decide to run for the busthe bus

I think of I think of something sadsomething sad

The arm lifts itselfThe arm lifts itself

My legs start My legs start movingmoving

I start cryingI start crying

Discourse on MethodDiscourse on Method

We cannot accept anything as being true We cannot accept anything as being true unless we can clearly perceive itunless we can clearly perceive it

Break down compound problem into as Break down compound problem into as many single factors as possiblemany single factors as possible

Point of departure comes in simplest idea Point of departure comes in simplest idea of allof all

Philosophy should go from the simple to Philosophy should go from the simple to the complexthe complex

Ensure new insight with constant vigilance Ensure new insight with constant vigilance (mathematical in model)(mathematical in model)

Doubt everythingDoubt everything

When we dream, we feel that we are When we dream, we feel that we are experiencing realityexperiencing reality

““When I consider this carefully, I find When I consider this carefully, I find not a single property which with not a single property which with certainty separates the waking state certainty separates the waking state from the dream…how can you be from the dream…how can you be certain that your whole life is not a certain that your whole life is not a dream?” Descartesdream?” Descartes

What else is true?What else is true?

Descartes concluded that in his mind Descartes concluded that in his mind was a clear idea of a perfect entity. was a clear idea of a perfect entity. He’d always had this idea, so it He’d always had this idea, so it clearly did not come from himself, clearly did not come from himself, since he was imperfect. Therefore, since he was imperfect. Therefore, the idea of a perfect entity must the idea of a perfect entity must have originated from that perfect have originated from that perfect entity itself: God. God’s existence, entity itself: God. God’s existence, then, was as self evident as his own then, was as self evident as his own thinking.thinking.