• TheMadFool
    13.8k
    The problem of induction:

    [By the principle of induction it is true that the future will resemble the past.
    The principle of induction is true because the future has resembled the past.]

    The circularity is explicit above. The common notion is that induction is deductively deficient, being an instance of circular reasoning.

    However, I find all instances of deductive logic to suffer from the same problem(?). Everyone knows the Munchausen trilemma. Since no proposition can be stated without evidence we're left with three options: 1)Infinite regress OR 2) A starting point arbitrarily chosen OR 3) Circular reasoning. If we don't choose one of the above, deductive logic is impossible. In this particular instance (that of induction) we've chosen option 3 (circular reasoning).

    So, everything seems prim and proper and there's nothing totally unexpected going on.

    Why all the hullaballoo?
  • unenlightened
    8.8k
    no proposition can be stated without evidenceTheMadFool

    Well there's a self-defeating proposition for you. Evidently it has been stated without evidence, and that is evidence that it is false, even if you hadn't been paying attention to current affairs.

    The proposition that all men are mortal can be easily defended with a suitable weapon; each doubter slaughtered strengthens the evidence, which does not consist merely of propositions, but of corpses.

    I'll say it again, in case anyone missed it: evidence does not consist merely of propositions.

    This other, non-propositional stuff is sometimes called the world, or the ground of reason. It's what everyone except philosophers and politicians talks about.
  • TheMadFool
    13.8k
    Well there's a self-defeating proposition for you.unenlightened

    I'm referring to a general principle of logic. I'm sure you've come across many cases in which the principle was violated and the result was bashing the truth. That's my evidence for my statement.

    This other, non-propositional stuff is sometimes called the world, or the ground of reason. It's what everyone except philosophers and politicians talks about.unenlightened

    We apprehend the meaning, if there's one, of the universe through propostions. How else could we do it?
  • unenlightened
    8.8k
    We apprehend the meaning, if there's one, of the universe through propostions. How else could we do it?TheMadFool

    Rubbish. We apprehend the meaning or meaninglessness of propositions through the universe. First the world, then we can talk about it. And we talk sense to the extent that we conform our talk to the sensible world. Logic merely tells us how we structure our talk.
  • TheMadFool
    13.8k
    First the world, then we can talk about it.unenlightened

    I agree.

    And we talk sense to the extent that we conform our talk to the sensible world.unenlightened

    I agree. And how do we talk? Through propositions.
  • unenlightened
    8.8k
    And how do we talk? Through propositions.TheMadFool

    Propositions about the world, evidenced by the world. Not propositions evidenced by propositions. The way out of the circularity of talk is not to start with talk.
  • tom
    1.5k
    However, I find all instances of deductive logic to suffer from the same problem(?). Everyone knows the Munchausen trilemma. Since no proposition can be stated without evidence we're left with three options: 1)Infinite regress OR 2) A starting point arbitrarily chosen OR 3) Circular reasoning. If we don't choose one of the above, deductive logic is impossible. In this particular instance (that of induction) we've chosen option 3 (circular reasoning).TheMadFool

    Another problem with the principle of induction - the future shall resemble the past - is that it's false in general. The Sun may rise every day, but one day it really won't, it will engulf and incinerate the earth.

    Also, if you rely in induction you will never discover the reason the sun shines, no matter how many times you look at it!

    However, if you make a guess as to why the sun rises, you may, if it is a good guess, be able to deduce some testable consequences of that guess e.g. seasons, Milankovitch cycles etc. This is known as the hypothetico-deductive method, or more succinctly, the scientific method. And it works!
  • tom
    1.5k
    I agree. And how do we talk? Through propositions.TheMadFool

    Criticism of propositions. Most scientific theories die that way. e.g. no observations have ever been made which contradicts either the Standard Model, or General relativity, despite the LHC and LIGO. Yet, we know there is a problem!
  • TheMadFool
    13.8k
    The way out of the circularity of talk is not to start with talk.unenlightened

    Agreed! The problem is with deductive logic with the Munchausen trilemma looming over it like a malicious spirit.
  • tom
    1.5k
    Since no proposition can be stated without evidenceTheMadFool

    That is simply false.
  • TheMadFool
    13.8k
    That is simply false.tom

    What do you mean?
  • Numi Who
    19


    ON SUFFICIENT DEFINITIONS/PERSPECTIVES
    You are beginning with an insufficient perspective, and thus definition, of inductive and deductive reasoning. Consider the following definitions:

    Deductive Reasoning: takes data from the many cases and applies it to one case.

    Inductive reasoning: takes data from one case and applies it to many cases.

    Note that they BOTH assume the future will follow the rules of the past. The value in inductive reasoning is that it identifies new possibilities (which is a critical phase in science). The value in deductive reasoning is that it is used to verify possibilities (another critical phase in science).

    Example: A rubber ball bounces on a cement sidewalk. Using inductive reasoning, you will propose that since one ball bounces on a cement sidewalk, then ALL rubber balls will bounce on ALL cement sidewalks, From here, you then apply deductive reasoning to verify this, and perhaps broadening your verifications (and thus your conclusion) to include variations - such as in weather or gravity.

    CONCLUSION
    You can now see that both modes of reasoning are mere tools, and it is in how adeptly they are applied that determines their results, and thus their value (toward the survival of higher consciousness in a harsh and deadly universe, just to give you an objective value from which to apply value judgements).
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