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Je pense, donc je suis - is this right ?

  1. May 21, 2007 #1
    "Je pense, donc je suis" - is this right ?

    "Je pense, donc je suis" - "Im thinking therefor I am"

    <Rene Descartes>

    Is this correct ? Why should I have to think to know that I am ?

    Is there any good reason to believe that this expression is correct or is just a result of some historical fashion ?

    It is possible today, to say something like this: "I'm tired of all this thinking but still I believe I am" ?

    Is this logikal "fundament of all fundaments" for Rene Descates still valid today, or are there other alternative fundaments to relay on ?
  2. jcsd
  3. May 21, 2007 #2


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    DesCartes' problem was deciding if there was anything we could be absolutely sure of- without having to assume that what we see is true, etc. That is, is there anything at all we cannot "doubt"? His conclusion was that the one thing he could not doubt, was that he was doubting! From that he concluded that there must be something doing the doubting- perhaps more accurately, "I doubt, therefore I am".
  4. May 21, 2007 #3
    :rofl: Find a counterexample. Prove that you can think and not be at the same time.

    Is Descartes ruling out other possibilities for you to know that you exist without good reason? I think not.

    I don't think you should take the meditations as being exhaustive of all possibilities either. Doesn't seem like that was Descartes intention with the work.
    Last edited: May 21, 2007
  5. May 22, 2007 #4
    All I experience is a stream of thoughts, I only assume that "I" am "thinking" the thoughts. In other words, perhaps there is no thinker but only a stream of thoughts.
  6. May 22, 2007 #5
    Did he really say that ? What is the argument to claim that he said that ?
    (It would be very interesting as this would mean that he said something wery diffrent from what I thought or belived he did say, until now. But I did not say that I'm right about it".

    If you look at the sentence:

    I think it says something like: Because I am thinking I can now that I am. (= I have existence.)

    If he said something like: "I am thinking. This is something I am quite sure about." - This would be something else.

    One other problem I'm not really sure about is what Descartes would mean with the term "thinking".

    If Mr. Descartes were sitting down looking at the sunset and enjoing life, would he be considering that he was "thinking", or would it be only at that time that he was doing mathematics and that kind of stuff that he was "thinking".

    Is thinking according do Descartes much the same as "reasoning" or "argumenting" or will it also include some other intellectual activities.

    Would Descartes concider a hunter hounting for wild animals in Afrika to be "thinking" in the same way or at the same level as an english scientist at that time ?

    Did Descartes connect the ability to rational thinking to the term existence ?

    Did Descartes with the term "Thinking" mean "rational thinking" or would he also include in the term "thinking" also other intelectual activities.

    Would "enjoying the sunset" or "love to hunt" or "love to drink" be thinking for Descartes ?

    In general: Were emotions concidered to be "thinking" for Descartes ?

    Machines are doing a great job for rational reasoning today.

    An inexpensive PC with the right program can easy outperform me while playing Chess. The machine will be more clever than me while doing the rational reasoning related to Chess.

    Did Descartes really express something like this: All those that thinks and make reasoning like a machine, they exist, while all those that has not the capability to "rational machinery alike thinking", they do not "exist" on the same level like me.

    What about a 1 year old child that still have not learned to speak, and that does not have the capability to think the thought "I think so therefor I am", does it not exist ?

    What about cats, monkeys, elephants and dogs, do they exist ? Do they "think". Do they have some emotions ? (As Descartes would have seen it)

    What about my one year Hewlet Packhard Laptop, that such a great rational thinker, at least when it comes to chess and calculus, does it exist ?

    Is existence connected to emotions ot is it connected to rational "machinery alike thinking" ? (As Descartes would have seen it.)

    To be honest I have not read Descartes for years, and I have not read him to much either, so it could be that I am wrong about what he really said ?

    Anybody who knows bether ?
    Last edited: May 22, 2007
  7. May 22, 2007 #6
    Is "thinking" equal to "rational thinking" or is relating emotionaly to someone or something also "thinking".

    Will a lazy man, a dog or a child, and someone just enjoying life also be existing ?

    What about a machine or a man that performs cold and precise calculations without any relations to emotions, will it be "thinking" ? Will it be existing ?

    What is the differece between a "calculating man" and "calculating machine" ?

    Who got the "existence" ?

    Why might it be that the one got "existence" while the other propably does not ?
    Last edited: May 22, 2007
  8. May 22, 2007 #7
    Do you neccesarily have to think to be? Some creatures are born without any higher brain function, but they still are.
  9. May 22, 2007 #8


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    He wasn't concluding that only thinking things exist, but that because he is thinking thing, he can conclude that he exists. He can doubt the existence of all other things, but in order to doubt his own existence, there has to exist something that is doing the doubting, thus proving its existence through the very act of doubting it.
  10. May 22, 2007 #9
    I think Descartes was a bit silly actually. You can't doubt the existence of a lot of things before you doubt your understanding of what "existence" means. If you find yourself unable to accept the existence of a lot of things, that can only be because you have some mental disorder.

    (we did not invent the language so we can't say that a sentence like "X exists" is not necessarily true; some might be)
  11. May 22, 2007 #10
    Notice the subjective nature of Descartes' statement. I am, I exist. Not "That guy thinks, so he must exist." Descartes' wasn't aiming for that. When I asked for a counterexample, I also phrased in using the second person. "Prove that you can think and not exist at the same time."

    How are you going to do that?

    I think it's cool to question the nature of thought, what constitutes a thought, and how other beings may think, but that's not really the same as questioning the truth of Descartes' claim, is it? It's more like using Descartes as a springboard into other topics.

    That is a valid criticism, and decently undermines Descartes' claim. Until I can figure out what this "I" is, I might have to hold off asserting that I exist.
    Last edited: May 22, 2007
  12. May 22, 2007 #11


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    It was noted by Descartes critics even in his time that his conclusion was too strong. All he could really prove was that thinking existed.
  13. May 22, 2007 #12
    Good point to know, loseyourname. I have believed for a while that particular criticism came from Nietzche, but it's probably from someone earlier.

    From the second meditation, p19, edited by Cottingham:

    "But what am I then? A thing that thinks. What is that? A thing that doubts, understands, affirms, denies, is willing, is unwilling, and also imagines and has sensory perceptions."

    Those all qualify as thoughts according to Descartes. Again, I doubt that this list is meant to be exhaustive, but it does provide some decent examples.
  14. May 23, 2007 #13


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    That is not implied. (P implies Q) does not imply (~P implies ~Q). Google http://www.google.com/search?q=denying+antecedent". (Also note that (~P implies ~Q) is equivalent to (Q implies P), whichever form you meant.)

    By the bye, http://www.gutenberg.org/etext/59" is freely available in several languages from several places online, so you don't have to speculate about the rest of his argument based solely on this one sentence. You can read it for yourself and ask questions here as necessary.
    Last edited by a moderator: Apr 22, 2017
  15. May 23, 2007 #14
    "I am" of Descartes is a tautology. Kant has a good discussion of it in the Critique of Pure reason- and shows how it is a tautology. It does not tell you anything about the "I". It is an empty concept. Descartes has to smuggle in the idea of God to show that there are two distinct substances- the mind or the "I" which is a thinking substance and matter-apart from the "I" everything can be reduced to matter and motion-and, hence, can be reduced to physics. In short, Descartes was founding a metaphysical ground for physics-in the Aristotelean scheme physics was the trunk which ended in metaphysics as the branches-with Descartes it is the reverse-the tree is reversed and physics is the branch, hence, a need for a metaphysics to ground it.
    This has resulted in the mind body problem which has plagued philosophy ever since-stuff that no longer interests me at all-but on which I wasted a few years on as a philosophy major for my first degree. Nice to get a sense of the history of ideas though.
    Last edited by a moderator: May 23, 2007
  16. May 23, 2007 #15
    Exactly. Now the western science world is plagued by this and does not even realize that (which is worst than if it was just plagued). Since the god of descartes was done away with, there is a gap which we dont know how to close. The obvious apprach is to reduce everthing to matter, which resuled in bunch of philosophies of science, still did not bring long term solution.....
  17. May 23, 2007 #16
    I like 'I am, therefore I think'.
  18. May 23, 2007 #17
    I rather like: I think, therefore I think I am. I think. Sorry!
  19. May 23, 2007 #18
    "Of cource I am. I'm just bussy doing some thinking."
    Last edited: May 23, 2007
  20. May 23, 2007 #19
    Realy interresting. Did Mr Descartes really say this, with the same weight on all the mentioned variants of "thinking" !?

    Possibly an imaginary interview with Descartes would have given this comment: "Me - a rationalist - oh not at all, the history just made me to be one." :-)
  21. May 23, 2007 #20
    Could it be that the "mind body problem" is not the problem at all, but it is "the instrument" itself, the way in which western philosophy tradition have thought that thinking should be performed, for some houndred years, that might be the problem ?

    Could it be that methods derived from physics is not wery well suited for metha-physics ?
    Last edited: May 23, 2007
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