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Descartes' Second Rule vs. Uncertainty

  1. Apr 27, 2003 #1
    Descartes' Second Rule of the Direction of the Mind is:

    He then continues...

    There is more to it, which I will post if I see it necessary, but that is basically what he is trying to say.

    The point of this thread is to determine the level of certainty that is "healthy".

    There are those that would have you embrace a complete Uncertainty, in which absolutely nothing is certain (a concept which I believe to be paradoxical, much in the same way as Limitlessness is paradoxical (and this too may be discussed in this thread)). However, there are others who would have you accept some things as certain, and use those things as foundations for progressing in knowledge.

    Perhaps there are even some who agree with Descartes' (as quoted above), that we should not trouble ourselves with things that are merely probable, but should stick to that which can be readily demonstrated as factual.
  2. jcsd
  3. Apr 27, 2003 #2
    BTW, Descartes' talks about Arithmetic and Geometry, calling them the only two fields which we can be certain of, because they make themselves evident to us all of the time. There is a lot more to it, than I am posting, but that's because it (the whole second Rule) fills 1 1/2 book pages.

    He concludes by saying this:

  4. Apr 27, 2003 #3
    what a style this Descartes guy has.really highly inteligent tougths.
    i'm like an vilage boy in compare to him.this is how i overtrown uncertainty principle:
    E = FX = energy = force times distance
    impulse of force = p = Ft = force times time
    Et = FXt = pX
    Edt+tdE+dEdt=Xdp+pdX+dpdX <=>
    (E+dE)dt+tdE=(X+dX)dp+pdX <=>
    dp,dX,dE and dt are all proportional
    unlike the uncertainty claims:
    dEdt>const and dXdp>const reciprocional
  5. Apr 27, 2003 #4
    I like most of what he says. I think that he could have mentioned the reliability of scientific-law...
    As I see it, science is the reasoned-analysis of the sensations. And since the sensations are mere representations of whatever 'reality' may be, then this means that knowledge is questionable. However, I do not think that this extends to science; for scientific-knowledge is concerned with universal-behaviour, rather than with universal-identity. And I see no rational-argument which can be formulated to state that our perceptions of universal-behaviour are doubtfully-unsure... since the Laws of Physics are absolute.
    Where our science is sure and absolute, then that knowledge is considered 'absolute' too. Of course, not all scientific-theories are "sure and absolute"; but for reason to have any impact on anything, we must assume that Einstein - as one example - was absolutely correct. And I can see no reason to argue that he isn't.
    Physics is the purest of the sciences, I think. Not perfectly pure, but striving to be so.
    Not to cause any more argument; but I think that materialism is the 'knowledge' not to be trusted. But science is largely trustable.
  6. Apr 27, 2003 #5
    So, you agree with Descartes', about relying on what we know to be absolutely true?

    What I appreciate about his Second Rule is how he denounces those who would doubt everything that they learn. He says that they might just as well not have learned anything. This coincides with his First Rule (quoted at the end of all of my threads), which shows that the end of study should be the ability to make good judgements in all manners that come before you. If you doubt everything you know, then you will not be able to make sound judgements on any matter that comes before you.
  7. Apr 27, 2003 #6
    Oh, do you intend to do this with certainty?

    Descartes was a fundamentalist after Aristotle's own heart. I'd put him up against a southern Baptist preacher any day of the week. Preferably in a nude mudd wrestling contest. :0)

    If you are talking about me, I object. This is not what I believe. When I say acceptance of uncertainty I don't mean throw yourself off the cliff or worship QM!!! All I'm saying is stop rejecting it as evil, axiomatically false, etc. That you haven't been able to hear me saying that over and over again after all this time reminds me of just how futile it is to argue with a Southern Baptist preacher as well!

    The paradox of existence is factual. It constitutes demonstrable emperical evidence. Likewise, the chaos of QM constitutes demonstrable emperical evidence. Neither one proves anything beyond a shadow of a doubt, but I leave such absolute faith in the way things are to Southern Baptists and others.
  8. Apr 27, 2003 #7
    There are two questions to be asked about existence:-
    1. What is it? This is a question of identity.
    2. What is it doing? This is a question of behaviour.

    I believe that science is largely the study of question-2. It doesn't really address question-1. And question-1 is the thing which most of us cannot agree upon. That's why people who give you answers to question-1 are largely regarded as 'chancers', at the very-best. The answers to this question are extremely diverse. But scientific-law is true. There is a universal-acknowledgement of universal-behaviour.
    Some knowledge is fact. Since some knowledge is universal. Exactly like the mathematics and geometry he mentioned. And this includes much scientific-stuff.
    That's why I feel justified/comfortable in using scientific-axioms as the basis of my philosophy.
  9. Apr 27, 2003 #8
    Please, let me clarify, I'm not talking about the Uncertainty Principle of QM. I was talking about the principle of Uncertainty, where one is supposed to be uncertain of all things (see posts in the thread, "I think therefore I am", fourth page).
  10. Apr 27, 2003 #9
    That's just as bizarre and paradoxical as saying it is certain nothing is random.... I like it! But that doesn't mean I believe it.
  11. Apr 27, 2003 #10
    I apologize for the confusion. It is entirely my fault.

    Again, I'm talking about Uncertainty (with a capital "U") as meaning the state of being Uncertain of all things. I was not wishing to discuss QM's uncertainty. Please forgive my blunder, in not making myself more clear.
  12. Apr 27, 2003 #11
    No sweat, semantics in philosophy are just too touchy an issue to get upset by the occational mistake.
  13. Apr 27, 2003 #12
    One can't go about doubting everything, it's a complete waste of time believe me I've tried, but then the mind needs and craves a concrete framework on which to build knowledge. To me the base is simply God exists and is everything, and everything after that is merely variations of so true as to virtually never require doubt, to high probability truth, to low probability truth, to entirely crackpot products of my own imagination or my crazy friends on physicsforums.com.
  14. Apr 27, 2003 #13
    And when did you get that 'universal acknowledgement'?
    Have you made an agreement not only with all the earthlings, but also all the otherlings around the universe?
  15. Apr 27, 2003 #14
    Since your argument (taking the existence of God as a fact) contains the assumption that there is no material world in the first place, you have not stopped doubting, but have transformed that doubt in an Absolute Doubt (about the material world).
  16. Apr 28, 2003 #15
    I trust that the laws of physics are singular.
  17. Apr 28, 2003 #16
    I agree that it is paradoxical. In the thread, "I think therefore I am", I related it to the Paradox of Limitlessness (do you see the connection?).
  18. Apr 28, 2003 #17


    User Avatar
    Science Advisor

    Greetings !
    Well, first of all - there are more mathematical
    fields availible today. :wink:
    Second, if only the same levels of certainty
    as mathematics are required then I'm afraid
    I can't press the keyboard anymore because
    I'm highly uncertain of its existence...
    Something Wu Li said about mud-bath wrestling
    comes to mind when I read that stuff.

    Live long and prosper.
  19. Apr 28, 2003 #18
    Exactly, it seems all paradoxes either succumb to rational explanations or are eventually reduced to variations of the Liar's Paradox or the Sorites Heap Paradox. Either they explicitely defy explanation according to our current understanding or they contain vague terms like infinity or indeterminacy. The paradox of existence, can be described using either paradox.
  20. Apr 28, 2003 #19
    According to Descartes' reasoning, it seems that your doubt of your own existence makes you just as one who doesn't exist (or something like that). IOW, your existence loses meaning when you start to doubt it.
  21. Apr 28, 2003 #20
    Good point.

    What paradox of existence? :wink:

    Actually, this is an important point. You say that all paradoxes can be either explained, or reduced to the same kind of paradox as the Liar's paradox. However, I see no paradox of existence that even resembles the Liar's paradox. Yes, I understand that you use "paradox" to mean "inexplicable" usually, and I may or may not agree with that, but I don't see any kind of self-contradiction in existence, and the Liar's paradox is that kind of paradox (the self-contradictory kind).
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