Logic vs evidence

Discussion in 'General Philosophy' started by Magical Realist, Mar 30, 2016.

  1. river Valued Senior Member

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    Define logic pad
     
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  3. paddoboy Valued Senior Member

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    The pursuit of knowledge by using reason and logic has led to mankind's meteoric rise in capability. Critical thinking skills, where information is vetted through rational thought processes, have proven foundational.

    Yet surprisingly, many people in modern society willingly forego these tenets of intellect for dubious claims of everything from paranormal and superstition to bad medicine based on long-proved false science.

    All we ask is that people look at their faith and ask "does it add up?" Does prayer work as advertised? Do verifiable miracles happen? What really is the evidence for evolution and an old earth? Why does a loving God sentence the vast majority of humanity to eternal hell while being so coy about his very existence? And many other questions. If it doesn't add up, you should be asking yourself why.
    http://www.celebrationofreason.com/

    The above of course being the scientific method.....

    There is no equal in mankind's quest for knowledge than the tool of science. The Scientific Method has powered our engine of learning since it was unleashed several centuries ago. At that point we finally cast off the shackles of superstition and began using the Method to learn, then start controlling our environment.

    The scientific method is merely a way of understanding our surroundings. It involves observation, testing, building hypotheses, testing, and modifying the hypotheses until they accurately represent knowledge. The Method's power is exercised when these hypotheses are able to make predictions that allow action.
     
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  5. paddoboy Valued Senior Member

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    No.
     
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  7. river Valued Senior Member

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    Why ?
     
  8. paddoboy Valued Senior Member

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    Missed this post earlier.
    While agreeing I would sum up by saying that common sense intuitiveness and logic, are driven by the limitations of our current observations: The further we see, and the more evidence we gather, can change what we assign as logical.
    And like the scientific method, while scientific theories remain valid, as we observe further, and conduct more precise and technically advanced experiments, the more likely becomes their certainty in application.
    As you said, things that are labelled paradoxes, are not really paradoxes.
     
  9. river Valued Senior Member

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    Define logic pad .
     
  10. Daecon Kiwi fruit Valued Senior Member

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    Define evidence riv.
     
  11. paddoboy Valued Senior Member

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    Riv is doing what he does best...trolling.

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    A shame that's where his talents end.
     
  12. river Valued Senior Member

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    Define logic pad
     
  13. wellwisher Banned Banned

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    Logic will draw conclusions. Conclusions provide a type of predictive data, which may be true or untrue. If I throw a ball at 45 degrees and 100 mph, it will go so far. The conclusion from the math theory may well be a valid data point. However, in science, these conclusions will need to be confirmed with experiment. Once confirmed the conclusion is now a piece of evident.

    Say the required experiments need resources, or very special and expensive resources, like particle accelerators. The lack of these resources, to confirm a conclusion, and turn it into evidence, could cause forward progress to stall. It is not uncommon, when resources are not available, to make tangible evidence from conclusions, one will make use of reasonable conclusions, as evidence. This allows one to extrapolate, rather than just sit on your hands, becoming a salesman instead of a scientist. Many people with new theories, in these forums, who lack resources to test each step, will often take this approach.

    One wild card that has been added, that messes things up is statistical data. The type of data/evidence allows even some bad theory and conclusions to stand using the experimental criteria for evidence. If we have a group of theories, each of which predicts a different result, they can all be considered valid if the fuzzy dice data lies within the range of all conclusions.

    For example, computer weather models use internal logic and premises to predict a range of conclusions, yet all are considered acceptable. Logic breaks down when you use fuzzy evidence.
     
    Last edited: Apr 4, 2016
  14. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

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    Um... so you've never heard of Fuzzy Logic?


    (And no, he's not an American golfer!

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  15. Michael 歌舞伎 Valued Senior Member

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    I think it's useful to first identify if time is a component of the question being asked. Logical operations work wonders on mathematical questions that do not involve time. Once time is recognized as being integral to the question, then you're probably going to move from asking deductively sound questions with valid conclusions into inductively cogent questions with strong conclusions.

    The time variable can be critical towards delineating the two types of arguments.
     
  16. Yazata Valued Senior Member

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    We also should probably distinguish between two closely related uses of the word 'logic'.

    1. First, there are the principles of reasoning that people use in real life (and in science too). This can be called informal logic or 'natural logic'. This has an obvious psychological component and is closely related to the study of pragmatics and language syntax in natural languages. Examining the modes of thinking used in various human activities is a big part of what philosophy does.

    http://plato.stanford.edu/entries/logic-informal/

    There's both a descriptive and a prescriptive component to that, since not only are investigators trying to describe how people do in fact think in various situations, educators are concerned with how they believe their students should think. Hence the proliferation of 'critical thinking' classes at some universities. (That seems to be one of the biggest topics of conversation here on Sciforums as well, since countless threads involve people angrily or dismissively telling other people how they believe they should think. The religion, para-normal and fringe threads seem to consist of little else.)

    2. And second, there are formal systems intended to model some of these processes of natural reasoning in (since the early 20th century at least) in something like mathematical form. Doing this has generated a new set of often very technical issues unique to this kind of endeavor, such as consistency, completeness and compactness therems, and model theory.

    http://plato.stanford.edu/entries/logic-classical/

    One of the things driving the ongoing development of formal logic has been the desire to better model what's happening in natural informal reasoning. One result has been all kinds of extensions and modifications to more traditional logical systems. Classical Aristotelian logic has been restated as a predicate calculus, it's been quantified with 'some' and 'all' operators, and new operators have been introduced to represent things like necessity and time. There have been attempts to expand the bivalent distinction between true and false into many valued and 'fuzzy' logics intended to better capture reasoning about probabilities and degrees of certainty. There are epistemic logics that include belief operators, relevance logics and ethical logics with 'should' and 'shouldn't' operators.There have even been changes in logic that reinterpret the 'if-then' implication relation in various ways and paraconsistent logics that permit what seem to be logical contradictions in certain situations. Other modifications have more technical motivations, such as desires to address some of the 'weirdness' of quantum mechanics or issues in the foundations of mathematics.

    http://plato.stanford.edu/entries/logic-temporal/

    This has led to the proliferation of different formal logical systems during the 20th century.

    http://plato.stanford.edu/entries/logical-pluralism/

    https://en.wikipedia.org/wiki/Non-classical_logic

    http://plato.stanford.edu/entries/logic-paraconsistent/

    http://plato.stanford.edu/entries/logic-epistemic/

    http://plato.stanford.edu/entries/logic-deontic/

    http://plato.stanford.edu/entries/qt-quantlog/

    http://plato.stanford.edu/entries/logic-fuzzy/

    http://plato.stanford.edu/entries/logic-intuitionistic/
     
    Last edited: Apr 5, 2016
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  17. Yazata Valued Senior Member

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    Posted by mistake - deleted
     
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  18. Michael 歌舞伎 Valued Senior Member

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    Some of those operators are very counter intuitive. Material implication for example.

    Most people would agree with the statement: If it rains today, then the ground will be wet. I think most would assign this a truth value of T.

    Some people would agree with the statement: If 3 + 3 is 7, then pigs can fly. I think some people would assign this a truth value of T.

    Almost no one would agree with the statement: If 3 + 3 is 6, then pigs can fly. I don't like this statement. But it's logically assigned a truth value of T.

    I suppose it's where formal logical operations and English clash?
     
  19. river Valued Senior Member

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    The defintion of logic ;

    knowledge ; followed by the reasoning based on this knowledge ; followed by the logic based ; on both of the former.

    Logic is based the consequence of knowledge and then reason .

    Therefore logic is the last line of thought upon this and/or that ; line of thinking.
     
  20. Michael 歌舞伎 Valued Senior Member

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    I can't agree with this definition. One of the great things about logic, is it can be applied without any regard as to the content (knowledge).
    For example:
    S = P
    P = Q
    therefor: S = Q

    It doesn't matter what S and Q are for this statement to be valid. That validity is what logic studies (even if the premises are unsound).

    Or, so I thought, but then again, I'm not a logician.
     
  21. river Valued Senior Member

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    I see your point ; symbolic logic however is just that. Symbolic .

    Don't see how this has anything to with this thread .
     
  22. Michael 歌舞伎 Valued Senior Member

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    Maybe I am incorrect, however I thought the defining feature of Logic is that is is the study of argument validity, not soundness. IOWs, it doesn't study the content (which I presumed is what you meant by knowledge) it studies the form. The content can be studied in other disciplines. For example, the premise, all Swans are White can be studied empirically. A triangle (which only exists as an abstract concept) can be studied mathematically.

    I suppose what I'm getting at is, Logic has a specific pursuit, as does any other discipline. I don't see the benefit in suggesting it is more than it is. Logic is a rather limited and specific topic within argument analysis.

    I would agree it falls under the umbrella of types of Reasoning.
     
  23. river Valued Senior Member

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    That is my point logic is limited .


    Not only the umbrella of reasoning but the essence of reasoning ; knowledge .

    Logic is limited .
     

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