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Can one prove a negative?

  1. Apr 20, 2009 #1
    It's often claimed that you cannot prove a negative. On the surface, it seems to be true: if Person A says “I think Unicorns exist” and Person B says “I don’t think unicorns exist”, it’s pretty clear that Person B is going to have a hard time proving that there isn’t a God. However, if you look a little closer, it actually depends on the nature of the negative statement being made. Here are some negative statements that can be proven very easily:

    Five is not equal to four

    The ancient Egyptians did not watch Seinfeld

    The tsetse fly is not native to North America

    Clearly, it’s possible to prove a negative statement. The real problem here is clearly the nature of the positive statement being refuted. When a person asserts that X exists, and he does not specify the nature of X – that is, is X small, large, blue, red? And where is he? Of course it is not possible to prove that X does not exist, if X is a thing that has no definition, no characteristics, and no location. In fact, you can prove just about any kind of negative you can think of – except for (surprise!) the non-existence of mystical beings. When you get right down to it, the statement “you cannot prove a negative” is really just a different way of saying “You can’t prove me wrong because I don’t even know what I’m talking about.”

    Logical statements have to abide by certain rules and restrictions. In order for a statement to be logical, it must be falsifiable, which means that it has to be presented in such a way that it could be proven incorrect. A statement is not logical if it cannot be tested to make sure it is true. The statement "X" exists is therefore absurd and nonsensical. No one even knows what X is supposed to be.
     
    Last edited: Apr 20, 2009
  2. jcsd
  3. Apr 20, 2009 #2
    Wow. Is this a scientific way of proving that God does not exist?
    Or did you made up this thought in a conversation about God? :P
    Regardless, good thinking.
    Seems to be a nice way to prove wrong statements that I wouldn't normally mess with.
     
  4. Apr 20, 2009 #3
    No, it's not proof that God does not exist. First we'll have to define God scientifically. My real point here is that what scientists use to claim - that you cannot prove a negative - is not necessarily true.
     
  5. Apr 20, 2009 #4
    Ok, sorry. I was just joking.:P
    By the way, I don't think anyone could "define God scientifically." It wouldn't be God if he could...
    I didn't also knew that scientists claim that you cannot prove a negative so sorry again.
    And I agree with you, you can prove a negative with simple examples (like the given ones).
     
  6. Apr 20, 2009 #5

    Ivan Seeking

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    You can't prove a general negative [I forget the proper terminology here].

    One can prove that there is no fly in the jar [for example], but one cannot prove that there are no flies. And it doesn't apply only to mystical ideas. For example, prove that there is no intelligent life in the universe beyond that here on earth.
     
  7. Apr 20, 2009 #6
    That's why scientists should not waste their time trying to disprove the existence of God. One can argue philosophically against the existence of such a being, but there's no way of testing it scientifically, even if we had all the technology and instruments we could dream of.
     
  8. Apr 20, 2009 #7
    Isn't that just because of technological limitations? God on the other hand, is not disprovable, because you have no way of knowing what it would look/hear/smell/feel like if you observed it.
     
  9. Apr 20, 2009 #8

    Ivan Seeking

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    That is, unless God showed up for a test.
     
  10. Apr 20, 2009 #9
    How would you know it was God?
     
  11. Apr 20, 2009 #10

    Ivan Seeking

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    You could show evidence that a being meets the definition of God.
     
  12. Apr 20, 2009 #11
    But what is that definition?
     
  13. Apr 20, 2009 #12

    Ivan Seeking

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    It depends on who you ask. Generally, omniscient and omnipotent are considered to be part of the definition, so you could show evidence for this.
     
  14. Apr 20, 2009 #13

    f95toli

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    Statement 1 can possibly be proven IF the person you are trying to persuade accepts the fundamental axioms of math.

    Statement 2 is impossible to prove. We can't know with 100% certainty that the ancient Egyptians did not have access to time-traveling technology that allowed them to receive broadcasts from the future. It is obviously not very likely:wink:, but the point is that you can't prove it.

    And I have no idea how one would prove statement 3. Granted, discovering that the tsetse fly IS native to NA would be a sensation; but as far as I know it wouldn't violate any known laws or nature, or even change the way we think of biology and/or the migration of species in any fundamental way. I am not even sure it would be more surprising than e.g. the discovery that Coelacanth is still around (to take just one example).
     
  15. Apr 20, 2009 #14
    The ancient Egyptians did not watch Seinfeld because he is Jewish. For comedy they liked Malcom In The Middle of all things.
     
  16. Apr 20, 2009 #15

    Gokul43201

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    How would a test-God demonstrate that it is omniscient or omnipotent? (Besides, is there even a definition of these terms that is logically consistent within some axiomatic framework?)
     
  17. Apr 20, 2009 #16
    It's not possible to find evidence for these.
     
  18. Apr 20, 2009 #17

    Ivan Seeking

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    Well, how about if he made the heavens cease to exist?

    Any number of tests could be done to test for knowledge that couldn't possibly be had. For starters, it could be as simple as "what's in my hand?" From there, predict the time and location of the next nova or solar flare.

    I don't understand your objection.
     
  19. Apr 20, 2009 #18
    Omnipotence is impossible. Can God create a stone that is so heavy that he can't lift it himself?
     
  20. Apr 20, 2009 #19

    Ivan Seeking

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    True or not, that has nothing to do with the discussion. All that you are doing here is arguing that God doesn't exist, which is a violation of the posting guidelines. You asked about proof of a negative.

    For a moment he could make himself not a God. :tongue:

    Religious discussions [debates] are not allowed.
     
    Last edited: Apr 20, 2009
  21. Apr 20, 2009 #20
    That argument does not disprove omnipotence...the usual reply is:

     
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