Descartes' Meditations : 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

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

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?

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"

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?

"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?

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..

Eureka!! What does Descartes find that he can be certain of??? Cogito ergo sum –"I think therefore I am" –"I am, I exist"

How can he be so sure?! being a founder of modern philosophy is nothing but ess tea arr ee ess essbeing a founder of modern philosophy is nothing but ess tea arr ee ess ess

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?