Descartes' Meditations 80-100: Introduction to Philosophy June 4, 2009 Instructor: Karin Howe...

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Descartes' Meditations 80-100: Introduction to Philosophy June 4, 2009 Instructor: Karin Howe Carnegie Mellon University

Transcript of Descartes' Meditations 80-100: Introduction to Philosophy June 4, 2009 Instructor: Karin Howe...

Page 1: Descartes' Meditations 80-100: Introduction to Philosophy June 4, 2009 Instructor: Karin Howe Carnegie Mellon University.

Descartes' Meditations

80-100: Introduction to Philosophy

June 4, 2009

Instructor: Karin Howe

Carnegie Mellon University

Page 2: Descartes' Meditations 80-100: Introduction to Philosophy June 4, 2009 Instructor: Karin Howe Carnegie Mellon University.

Descartes' Project: Meditation I

• What's the problem that Descartes' is trying to solve?– Familiar problem: wants to eliminate false

beliefs

• How does he propose to proceed?– Tear down everything and begin again from the

foundations

Page 3: Descartes' Meditations 80-100: Introduction to Philosophy June 4, 2009 Instructor: Karin Howe Carnegie Mellon University.

How can he tear down everything and start over?

• Can he just show each of his beliefs to be false (or true?)?– Too hard!

• Plan:– Reject (set aside) any belief which can be doubted

• Does he need to look at all of his beliefs?– No. Start with the foundational beliefs, and the rest will

follow

Page 4: Descartes' Meditations 80-100: Introduction to Philosophy June 4, 2009 Instructor: Karin Howe Carnegie Mellon University.

Okay, let's get started…

• What sorts of things are indubitable?– Evidence from our senses (our eyes, ears, etc)?

– That we are here, sitting in this room?

– That we have hands, and eyes?

– That things like hands or eyes exist?

Page 5: Descartes' Meditations 80-100: Introduction to Philosophy June 4, 2009 Instructor: Karin Howe Carnegie Mellon University.

How about other things?

• Physics, astronomy, medicine?

• Arithmetic or geometry?

• God?

• What else?…– Basically, EVERYTHING!!– "I'm forced to admit that nothing that I used to

believe is beyond legitimate doubt"

Page 6: Descartes' Meditations 80-100: Introduction to Philosophy June 4, 2009 Instructor: Karin Howe Carnegie Mellon University.

Okay, now what??

• "[I]t's not enough to have noticed this: I must also take care to bear it in mind."

• Why? What does he mean by this?

Page 7: Descartes' Meditations 80-100: Introduction to Philosophy June 4, 2009 Instructor: Karin Howe Carnegie Mellon University.

"I will suppose, then, not that there is a supremely good God who is the source of all truth, but that there is an evil demon, supremely powerful and cunning, who works as hard as he can to deceive me."

Why does he do this? What does this get him?

Page 8: Descartes' Meditations 80-100: Introduction to Philosophy June 4, 2009 Instructor: Karin Howe Carnegie Mellon University.

Descartes' Solution: Meditation II

• Recall Descartes' plan: "I will reject whatever is open to the slightest doubt just as though I have found it to be entirely false, and I will continue until I find something certain–or at least until I know for certain that nothing is certain."

• Build up from new foundations - all we need is "one fixed point" and we can get the rest..

Page 9: Descartes' Meditations 80-100: Introduction to Philosophy June 4, 2009 Instructor: Karin Howe Carnegie Mellon University.

Eureka!!

• What does Descartes find that he can be certain of???

• Cogito ergo sum– "I think therefore I am"

– "I am, I exist"

Page 11: Descartes' Meditations 80-100: Introduction to Philosophy June 4, 2009 Instructor: Karin Howe Carnegie Mellon University.

Discussion: Small Groups

• Do you think it is really possible to build all true beliefs out of "I am, I exist?"

• Descartes' conclusion that he can doubt his body, but not his mind lead him to dualism, the theory that physical things (body, brains, etc.) and mental things (the mind) are different "stuff." Do you think he is correct in this belief, or not? Why?

• What are the basic lessons that you take away from Descartes' Meditations?