Descartes and Certainty

#1 09-01-2005, 02:20 AM

For those of you who have studied Descartes then you may know that he is the author of this famous quote: "Cogito, ergo sum" (I think, therefore I am). Descartes determined that whatever he could bring himself to doubt, he would, until he saw reason to no longer doubt. He came to realize that they only thing he could be sure of was his own existence. Doubting his own existence was proof that he did, in fact, exist.

Descartes was sure of his own existence, but could not be sure of others. As far as he could prove (or not prove), nothing outside of his mind existed. With this in mind (pun intended), how does that make you feel? It's a fundamental philosophical problem which really can't be proved. I can't prove that the world outside of my mind really exists. For the sakes of simplicity I accept that it does, perhaps for the sake of my sanity too. To think that the world outside of my body is simply created by my brain is quite disturbing.

David Sklansky · #2 09-01-2005, 02:41 AM

So you created me in your mind? Ok but now you come up to me and ask me a tough probability question that you only know haw to do the long way. I give you an answer in ten seconds that you write down. Five minutes later you verify it. That doesn't fully disprove solipsism because it is conceivable that your subconscious brain is as good at math as me. But aside from this technical objection, my scenario should ease your mind.

(A seond example would be to drop something from 13 feet, see how long it takes to drop and then go to the library to look up the appropriate physics formulas and see if they jive. Again not an ironclad proof but good enough.)

#3 09-01-2005, 03:10 AM

Right, not iron-clad proof at all, but I suppose that's the nature of philosophy. Pondering the questions that we can't answer. For the record I do believe that there are objects and other minds outside of my own. I suppose the proper word is that I have faith that there are other objects and minds outside my own. Faith since I can't prove that they do really exist.

jester710 · #4 09-01-2005, 03:16 AM

I don't think the proofs work at all. Using physical proofs is useless, as he can't be sure the physical world (or anything else) even exists. I don't really see how one can "disprove" solipsism, so offering proofs against it seems like a waste of time.

Of course, Descartes's logic is circular, but I get the feeling you both knew that already.

m1illion · #5 09-01-2005, 03:56 AM

[ QUOTE ]
For those of you who have studied Descartes then you may know that he is the author of this famous quote: "Cogito, ergo sum" (I think, therefore I am). Descartes determined that whatever he could bring himself to doubt, he would, until he saw reason to no longer doubt. He came to realize that they only thing he could be sure of was his own existence. Doubting his own existence was proof that he did, in fact, exist.

Descartes was sure of his own existence, but could not be sure of others. As far as he could prove (or not prove), nothing outside of his mind existed. With this in mind (pun intended), how does that make you feel? It's a fundamental philosophical problem which really can't be proved. I can't prove that the world outside of my mind really exists. For the sakes of simplicity I accept that it does, perhaps for the sake of my sanity too. To think that the world outside of my body is simply created by my brain is quite disturbing.

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Not sure what I'm, missing here. Hold a loaded .45 caliber pistol, with the safety off, to your knee. Pull the trigger and discuss with me the possibility that the bullet is a figment of your imagination.

xniNja · #6 09-01-2005, 04:58 AM

[ QUOTE ]
Not sure what I'm, missing here. Hold a loaded .45 caliber pistol, with the safety off, to your knee. Pull the trigger and discuss with me the possibility that the bullet is a figment of your imagination.

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This is sort of a good, pragmatic argument... but Descartes would probably argue that the bullet, your knee, and the pain you feel from the bullet hitting your knee is your "imagination."

To put it more clearly, it wouldn't make much sense to argue Descartes ideas on existentialism/and/or certainty of reality by addressing physical pain, as physical pain is a manifestation of the mind at best and at worst perceived by the mind.

DougShrapnel · #7 09-01-2005, 05:21 AM

When I took philosophy in college, I had a bit of trouble with the proof that anything exists. The story that the world is nothing but shadows on the wall and not real, was difficult for me to grasp as legitimate, however I could not disprove it as impossible. I eventually realized that pioneers of fields aren't normally correct but they are important because of what they started. Not their actual contribution. For instance, the ID, Ego, and Super Ego are certainly incorrect at least partially, but Freud was able to start a new science which was a much more important contribution.

Proofs that I exist and that the world exists aren’t necessary. Just assume it. And get to the meat of philosophy. Where actually important things are discussed.

m1illion · #8 09-01-2005, 05:27 AM

[ QUOTE ]
[ QUOTE ]
Not sure what I'm, missing here. Hold a loaded .45 caliber pistol, with the safety off, to your knee. Pull the trigger and discuss with me the possibility that the bullet is a figment of your imagination.

[/ QUOTE ]

This is sort of a good, pragmatic argument... but Descartes would probably argue that the bullet, your knee, and the pain you feel from the bullet hitting your knee is your "imagination."

To put it more clearly, it wouldn't make much sense to argue Descartes ideas on existentialism/and/or certainty of reality by addressing physical pain, as physical pain is a manifestation of the mind at best and at worst perceived by the mind.

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Then, if I may, I will change the argument slightly. I will put one bullet in a (for arguments sake)six bullet capacity pistol. I will place the bullet in the third chamber to fire. You will not have that info nor any way to aquire that info. Place the pistol against your knee and pull the trigger six times. Thereafter, begin your discussion on the relative merits of the bullet's reality.

jester710 · #9 09-01-2005, 05:49 AM

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Proofs that I exist and that the world exists aren’t necessary. Just assume it. And get to the meat of philosophy. Where actually important things are discussed.

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While I'm pretty sure you're aware of this, Descartes wasn't actually considering the possibility that he didn't exist. One of the basic problems of philosophy is that pretty much anything has to be based on an assumption somewhere. Usually, this is the assumption that the world and what we see is real. If pressed, no philosopher can give up indisputable "proof" of this. This is what Descartes was trying to do, and if he had succeeded, he would have revolutionized philosophy, possibly to the point that most of the great questions could be answered (in this case the existence of God). I think that counts as pretty meaty philosophy, just as molecular biology is pretty meaty science.

DougShrapnel · #10 09-01-2005, 06:14 AM

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This is what Descartes was trying to do, and if he had succeeded, he would have revolutionized philosophy, possibly to the point that most of the great questions could be answered (in this case the existence of God). I think that counts as pretty meaty philosophy, just as molecular biology is pretty meaty science.

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You make it sound interesting enough so that I had the opurtunity to rethink my position. I didn't change my mind. I don't think failure is meaty other than to realize not to go down that road. Just assume that the world exists as given.