Chapter 7 Rene Descartes and the Transition from Medieval to Modern Thinking.

Chapter 7Chapter 7

Rene Descartes and the Rene Descartes and the Transition from Medieval Transition from Medieval

to Modern Thinkingto Modern Thinking

What is the geocentric model of the universe? What is the geocentric model of the universe? What developments led to the formulation of the What developments led to the formulation of the heliocentric model of the universe? Why was the heliocentric model of the universe? Why was the

Medieval Catholic Church resistant to this Medieval Catholic Church resistant to this model? What is the Cartesian Method? What is model? What is the Cartesian Method? What is Cartesian Doubt? What is the Cogito? What is Cartesian Doubt? What is the Cogito? What is the relationship between mind and body of the the relationship between mind and body of the Cartesian system? How does Descartes offer a Cartesian system? How does Descartes offer a

way to resolve the conflicts between science way to resolve the conflicts between science and religion?and religion?

Descartes—Dreamer, Genius, or Madman?Descartes—Dreamer, Genius, or Madman?

Have we advanced towards Have we advanced towards the Truth?the Truth?

Do you believe that we know more than Do you believe that we know more than Plato, Aristotle, Augustine, or Aquinas?Plato, Aristotle, Augustine, or Aquinas?

Why do you believe this? Why do you believe this?

Could you be wrong? Could you be wrong?

Who has the Truth?Who has the Truth?

The ChurchThe Church

Truths given by religious Truths given by religious doctrinedoctrine

ScienceScience

Truths given through reason Truths given through reason and observationand observation

The Geocentric Model of the UniverseThe Geocentric Model of the UniverseReason tells us that the Earth lies at the center of the Reason tells us that the Earth lies at the center of the

Universe. After all it is a heavy mass, and the appropriate Universe. After all it is a heavy mass, and the appropriate place for a heavy mass is the center. place for a heavy mass is the center.

Crystal SpheresCrystal SpheresObservation tells us that the Earth is at the center of the Observation tells us that the Earth is at the center of the

Universe. After all, it does not move either from its spot or Universe. After all, it does not move either from its spot or around its own axis. around its own axis.

The Geocentric ModelThe Geocentric Model

If reason and experience both support the If reason and experience both support the geocentric model of the Universe, why geocentric model of the Universe, why shouldn’t we accept it as scientifically shouldn’t we accept it as scientifically

true?true?

Retrograde Motion of Mars Retrograde Motion of Mars How does this happen? Sometimes a sphere within a sphere How does this happen? Sometimes a sphere within a sphere rotates backwards in the geocentric universe. This accounts rotates backwards in the geocentric universe. This accounts

perfectly for our observations.perfectly for our observations.

The EpicycleThe EpicycleThis approach accounts for the observed This approach accounts for the observed

movement of the planets.movement of the planets.

Reason and ObservationReason and Observation

Do reason and observation support only one Do reason and observation support only one world view?world view?

If not… How are they different from religion?If not… How are they different from religion?

Why think the view you’ve adopted is Why think the view you’ve adopted is correct?correct?

Is science over?Is science over?

The development of the geocentric and The development of the geocentric and geostatic view of the universe progressed geostatic view of the universe progressed

as science progresses now.as science progresses now.

So why think that we currently have So why think that we currently have everything right? everything right?

The Heliocentric ModelThe Heliocentric Model

Copernicus—astronomical Copernicus—astronomical revolutionary!revolutionary!

The SunThe Sun

Where is it, in Where is it, in relation to the relation to the

Earth?Earth?

Why do you believe Why do you believe as you do?as you do?

Evidence?Evidence?

Evidence—or Authority?Evidence—or Authority?

Do you yourself have evidence for your Do you yourself have evidence for your living in a heliocentric universe—or do you living in a heliocentric universe—or do you just take it on trust from authority figures?just take it on trust from authority figures?

If the latter…. If the latter…. How are you any different How are you any different from people who accepted the authority from people who accepted the authority

of the Churchof the Church? ?

Galileo—Escaper from the Cave!Galileo—Escaper from the Cave!

Would you want to be like Galileo, or like his Would you want to be like Galileo, or like his colleagues who refused to look through the colleagues who refused to look through the

telescope?telescope?

Which do you resemble in your own life?Which do you resemble in your own life?

Have you ever spoken up for what you believe Have you ever spoken up for what you believe to be true, even if everyone around you to be true, even if everyone around you

would have opposed you?would have opposed you?

Should Galileo have been Should Galileo have been tortured?tortured?

Should Galileo have submitted to torture Should Galileo have submitted to torture rather than publicly recant his views?rather than publicly recant his views?

Why not, if standing up for what you believe Why not, if standing up for what you believe is so important? is so important?

Kepler’s ModelKepler’s Model

A painful transition!A painful transition!

If the universe is infinitely If the universe is infinitely large…large…

……where is Heaven and Hell?where is Heaven and Hell?

And if the Earth is just one of many planets, And if the Earth is just one of many planets, why are humans special in any way? why are humans special in any way?

Plato and the ChurchPlato and the Church

Why might Plato agree with the Church’s Why might Plato agree with the Church’s persecution of heretics such as Giordano persecution of heretics such as Giordano

Bruno?Bruno?

Don’t Don’t youyou think that people who have a lot think that people who have a lot of influence over others should be of influence over others should be

accountable for their actions—including accountable for their actions—including their possible adverse effects?their possible adverse effects?

Rene DescartesRene DescartesCan scientific discovery coexist with Can scientific discovery coexist with

Catholic doctrine? Catholic doctrine?

Cartesian DoubtCartesian Doubt

How can doubting help you How can doubting help you find Truth?find Truth?

Have your senses ever fooled you?Have your senses ever fooled you?

So how do you know that they’re not fooling So how do you know that they’re not fooling you now?you now?

Indeed—how do you know that your sense Indeed—how do you know that your sense have fooled you? Did you test them with have fooled you? Did you test them with

your other senses? your other senses?

Why believe that those senses were not Why believe that those senses were not fooling you?fooling you?

DREAMSDREAMS

Could you be Could you be dreaming now?dreaming now?

How do you How do you know?know?

REALLY? REALLY?

If you can’t trust your senses…If you can’t trust your senses…

……to give you accurate information about to give you accurate information about physical objects, physical objects, then how can you trust then how can you trust the physical sciences to lead you to the the physical sciences to lead you to the

TruthTruth??

Are you deceived?Are you deceived?

Could you, right now, be being deceived Could you, right now, be being deceived about everything—including mathematical about everything—including mathematical

truths—by an “evil genius”?truths—by an “evil genius”?

Are you in the Are you in the Matrix?Matrix?

How do you know?How do you know?

Are you in the Are you in the Matrix?Matrix?

How do you know?How do you know?

Can you doubt that you are Can you doubt that you are thinking?thinking?

Do you believe that there are other people in Do you believe that there are other people in this room?this room?

WHY?WHY?

Moving beyond solipcismMoving beyond solipcism

What ideas do you have?What ideas do you have?

Where do they come from?Where do they come from?

Could any of them have come from nothing?Could any of them have come from nothing?

Do any of them have any content that couldn’t Do any of them have any content that couldn’t have come from a finite being such as yourself?have come from a finite being such as yourself?

Chaos!Chaos!

Do you think that complexity can be Do you think that complexity can be generated from simplicity?generated from simplicity?

How? How?

Look at the desk in front of you. Look at the desk in front of you. What do you experience? What do you experience?

The desk—or the The desk—or the sensationsensation of of the desk? the desk?

If you only experience the sensation of the If you only experience the sensation of the desk…..desk…..

……..why believe that the way that the desk why believe that the way that the desk appears to you is the way that it really appears to you is the way that it really

is? is?

Do you agree with Descartes that we should Do you agree with Descartes that we should refrain from making judgments about refrain from making judgments about

things until all the facts are in?things until all the facts are in?

Do you Do you alwaysalways abide by this principle? abide by this principle?

Why might you be tempted to violate it?Why might you be tempted to violate it?

The External The External World!World!

Do you Do you nownow have reason to have reason to believe that the believe that the external world external world

exists?exists?

What are you?What are you?

What do you think you are What do you think you are made of?made of?

Are you embodied?Are you embodied?

Are you a thinking being? Are you a thinking being?

Cartesian Cartesian DualismDualism

How do your How do your mind and body mind and body interact, if they interact, if they

are utterly are utterly distinct distinct

substances?substances?

Descartes and Wondrous Descartes and Wondrous DistressDistress

Are you persuaded by Descartes?Are you persuaded by Descartes?

If not…..If not…..

……..how can you save how can you save science from skepticism?science from skepticism?