help with Intro to Logic | INFJ Forum

help with Intro to Logic

Discussion in 'Science and Technology' started by Blind Bandit, Feb 19, 2009.

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  1. Blind Bandit

    Blind Bandit Blind Man Being Lead to Nowhere
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    Some I'm taking PHIL 106 or intro to logic.

    I feel like I'm not getting it to be blunt. I'm so frustrated I know this will help me make better argument and provide a good base for further courses. But I can't seem to get a lot of the concepts. Even thought I know the benefit of applying logic its difficult to get this stage.

    I've never been good at math. it seems this is a related issue.

    We just finished Categorical Syllogisms and we are working on propositional logic.

    We are using intro to logic by Hurely.

    Any imput would helpful.
     
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  2. just me

    just me GONE

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    http://www.iep.utm.edu/p/prop-log.htm

    After watching your inquiry go answerless for awhile, it piqued my interest to try and give an answer of sorts. Obviously, I would have to further study the subject. From what I can see, math is going to be a major part of this. Just studying the history of it and running into Abelard was interesting, as I have run into him before. Hopefully someone can step in with some help for you. Trying to find the time to properly answer your question may be difficult, but not impossible; I can therefore say helping answer your question would not be easy, though possible. Good luck. I'll check back here every now and then.
    (T&D)
    A= ______ It seems they want to place statements and/or questions into
    mathematical equations. I have never studied the subjects
    (D&P) mentioned. I do know from experience that some difficult
    mathematical questions are solved much faster with logic,
    though it would be difficult for me to explain the logic in a
    mathematical formula. Good luck and let us know how things
    are going.
     
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  3. Stu

    Stu .
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    euclid

    There is a reason that Euclid's "The Elements" is the most influential book ever written bar none.
     
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  4. Duty

    Duty Permanent Fixture

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    What specifically are you having trouble with? Truth tables? Propositional calculus?

    Feel free to ask me any questions you need to, I know enough I could teach an intro to logic class. :)
     
    #4 Duty, Feb 15, 2010
    Last edited: Feb 15, 2010
  5. Faye

    Faye ^_^
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    Guess what class I took last term and what book we used? Yep....

    I had Hurley 10th edition and am fairly familiar with it, so I can probably help you- just PM me. I am selling the book soon though.

    My advice:

    1. Study like hell. It's a bitch. I did prop. logic equations literally at least 20 hours before the final, and I still wasn't ready for it. I did all the difficult problems in the book even though I wasn't assigned them- I still couldn't finish the final (I also had an old-school/difficult prof.).

    2. After you learn the 18 basic rules of replacement and implication, learn conditional and implicit proofs (CP and IP, all on back cover) regardless of whether they teach it to you or not. I made the mistake of not learning these. On the final, which was worth 50% of my grade, I was unable to finish, probably because I didn't know these rules. It dropped me a letter grade in the class.

    The fact of the matter is that this class, and this book, relies on the kind of complex algebraic (left-brain-ish) reasoning and intuition that you either have or you don't. If you are like me and don't see the solutions to the problems just by looking at them and can't just suddenly understand why things go together, you have to learn things mechanistically (learn all the rules and exactly how they apply). Once you get good at seeing how things fit together with the rules, you'll be able to start sorting through the problems.


    If you're stuck on a quiz/exam, just do steps even if you don't know where they are going.
     
  6. tiwilkie

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    can anyone help solve?
    1 s>(k*r)
    2 (~r>f)>u
    /s>u
     
  7. GracieRuth

    GracieRuth Permanent Fixture

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    This is one of the most important classes you will ever take. I am not sure why you haven't gotten responses.

    Basically an argument has different components.
    1. The facts upon which you base your argument need to be true. Oh sure you can have bad facts and just be sheer luck accidently stumble on the right answer, but obviously don't count upon it. If two people disagree, often what needs to be done is VERIFY THE FACTS. You see this happening when one person asks the other to supply the source of their statistics or cite a scientific study.
    2. The argument itself must be sound. If it is not sound, then we say that the reasoning is fallacious. Your class will teach you any number of known fallacies. Here is an example of a fallacious arguement: Daisies are yellow. Lemons are yellow. Therefore daisies are lemons. Here is another: You are a moron, therefore I don't have to reply to your argument. And yet another: Most people believe X, therefore X must be true. There is a great website with a tutorial on fallacies at http://www.nizkor.org/features/fallacies/appeal-to-popularity.html

    Beyond that, I'd need to know more specifically what is giving you trouble.
     
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  8. Faye

    Faye ^_^
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    What rules are you allowed to use? Are you solving them sub-proof style with fitch bars, or are you allowed to use the more complicated rules like DeMorgans and not using sub-proofs?

    In either case, the only real difficulty is getting from k*r to ~r>f. You could eliminate the k because it is irrelevant, and then I'm not sure how to get your ~r>f. My guess, if you are using subproofs, is that you would want to get a contradiction by introducing a subproof with ~r after you have r alone, and then you can get anything you want (namely the f) from the contradiction. From there you should be able to finish it off as you use > elimination to get you out of the subproofs.
     
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