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How Does One Prove One Exists?

  1. Sep 17, 2007 #1
    So ya....my philosophy teacher assigned me to write an essay proving that I exist. Being fairly new to philosophy I've got no idea how to go on about proving that I exist, which sounds pretty weird. I've been around the philosophy section of this site a few time and I gotta say some of you guys have given me more to think about then any other human being I've ever known in my life. I think there are some great minds here. To get to the point, I need help on how to prove I exist, I haven't thought this much about my existence since the last time I saw The Matrix while high.:rofl: So can anyone help me out? Thanks in advance.

    -The One Celled Brain
  2. jcsd
  3. Sep 18, 2007 #2
    The short answer is that you can not.

    The long answer is that there is strong evidence for your existence that such a conclusion is reasonable given the available information and when it comes to 'Why not Matrix', the burden of proof is on the one making the positive assertion (see Russell's Teapot).

    Furthermore, one could argue that the concept of 'I' is so vague and ill-defined that any description at all is impossible given the available information and will only yield tautologies such as 'I think, therefore I am'.
  4. Sep 18, 2007 #3


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    Yeah I guess Moridin is right "you cannot" but then again how should we go about proofing this statement!

    to set up a proof, you shall first need some axioms (ways of doing things or define what is "logical" and what is not....) basically your inability to find a set of universally accepted, and perhaps consistent axioms (you may ask why we need axioms, well... do you think you can do anything at all otherwise?) makes "proofing" something impossible. Or at least I won't call that a "proof" because you can't just right down a bunch of stuffs and call that a proof. axioms allow you to do things in some kind consistent manner. But then why must the World be consistent? So, if it is not consistent in the first place, then there is no need for a proof.. because inconsistency means that nothing is predictable, absolutely nothing (including this statement itself)

    ok, back to your initial problem.... your first task is to define what it is meant by existence... not suggesting that you can do it to everyone's satisfaction .... but that's what philosophy is all about, getting one to think about this sort of things. :smile:
  5. Sep 18, 2007 #4


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    Remember DesCartes' "I think, therefore I am"?

    Rene DesCartes was one of the first to really explore the idea of "what can we be certain of?" He knew perfectly well that people could be fooled by experience or produce invalid mathematical proofs. Is there anything we CAN'T doubt? His answer was- I cannot doubt that there is something doing the doubting! "I think, therefore I am" would perhaps be better, "I doubt, therefore I am".
  6. Sep 18, 2007 #5
    That seems like a tautology. Surely, to accept 'I doubt' one would have to accept the conclusion before the premise of the argumnet?
  7. Sep 18, 2007 #6
    As I see it, the part that must be accepted is that doubting requires existence. If you believe that thinking does not require existence then, sure, the reasoning fails. But then you have to wonder what existence means if something can happen even if nothing exists... So the conclusion is not a tautology but a consequence of the fact that thinking requires existence, and the strength of the proof is that you cannot rationaly think that you are not thinking.

    Now, it is much easier to prove to yourself that you exist than to prove it to others. There is always this approach:

    Q: Prove that you exist.
    A: Who are you asking?
  8. Sep 18, 2007 #7
    If it were me, I'd hand him a blank sheet of paper then punch him in the jaw. That could shift the topic from "prove you exist" to "if no one exists, how do non-existent beings (oxymoron) interact with each other? i.e. contact, bleeding, etc..."
  9. Sep 19, 2007 #8
    There are two different types of objective facts: things and events. You are a 'thing' so to prove your existence everyone would have to see that you are visible to them or photographic evidence will do.
  10. Sep 20, 2007 #9
    A -> B
    Not Necessarily A

    You can provide evidence for your existence, but you cannot prove it.
  11. Sep 20, 2007 #10
    Surely, I cannot prove it. I am confined within myself and cannot go outside of myself to show that I truly exist. But if I'm visible to 6 billion other humans and I have significant photographic evidence of myself then I could say with good confidence that I do in fact exist.
  12. Sep 20, 2007 #11
    I think it would be funny if you wrote your name on a piece of paper, and just handed that in. "I have a name, I exist" type of thing.

    And, I don't think that you can "prove" that you exist.

    The thing that I hate about these classes is that even though there are no real answers to these questions, your teacher is expecting you to write something more substantial than "I can't". Even though ,IMO, any answer is equally valid.

  13. Sep 20, 2007 #12
    Thinking is a self-reflective process, which is unavoidable, if one is thinking. So one can say that 'thinking exists'. If that is the case then 'something that thinks exists' is a valid statement. Whether you can extract an 'I' from that is another story. However since thinking appears localized, its a good inference.
  14. Sep 20, 2007 #13
  15. Sep 20, 2007 #14
    In mathematics its an assumption, or starting point, and in philosophy, its something that is 'self-evident', however there is much argument about what is self-evident amongst philosophers, not only in terms of existence but also ethics. Descartes believed that the only self-evident thing was 'thinking', since in order to ask the question; what exists? One must exist as a thing that can ask the question.
  16. Sep 20, 2007 #15
    Ohhh so you mean to answer the question Do I exist? I have to exist.

    Also whats a good definition for the word existence, some of the dictionaries if looked up use the word exist in the definition....
  17. Sep 20, 2007 #16


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    mmm... finally some ppl have picked my points about axioms and definitions
    I think if you think hard (too hard) at it, nothing is going work and you just be at a stand still because you just can't do anything with nothing.... unless there is something (like a god) which supposedly give you something with nothing or nothing with something or anything that is remotely (un)imaginable. it is a difficult task, but perhaps your teacher is looking for clear thinking rather than being pedantic??
  18. Sep 20, 2007 #17
    LOL The funny thing is that I was able to follow all that in one read. And ya I think he is looking for something simple but the truth is I hate being simple when I want to be creative and abstract.
    Oh and do you know of a good definition of the word existence?
    Last edited: Sep 20, 2007
  19. Sep 20, 2007 #18


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    what do you mean by "good"? :smile:
  20. Sep 20, 2007 #19
    I donno something not like this
    1. the state or fact of existing; being.
    2. continuance in being or life; life: a struggle for existence.
    3. mode of existing: They were working for a better existence.
    4. all that exists: Existence shows a universal order.
    5. something that exists; entity; being.
    It doesnt make sense for the word or the rootword to be used in the definition, it isnt really a definition is it then?
    How would you define the word existence in your own words?
  21. Sep 20, 2007 #20


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    that's the whole point, your definition of "existence" is no better or worse than mine or anyone else really....but this is certainly the first thing to think about in your attempt to "prove" your own existence...
  22. Sep 20, 2007 #21
    Ohhhh that just turned on the light bulb :smile:
    Last edited: Sep 20, 2007
  23. Sep 20, 2007 #22
    I agree with arildno here, why are you getting such stupid assignments?

    The question is also pretty vague, prove in what way? To yourself? To him and everyone else? Prove that consciousness exists, the brain, the body or the soul?
  24. Sep 20, 2007 #23
    I think you're missing the point of the assignment.

    Dealing with the questions you are asking, is exactly what the professor wants you to do. In other words, examine all the different ways something can exist, and how you would prove them, and if they are provable, and what assumptions one is making when one uses those definitions.

    Mathematics professors don't just give you the answers and send you home, they make you work through proofs so you understand how to get to the answers.... and find new ones.
  25. Sep 20, 2007 #24
    Regarding a definition for existence, you can figure one out by looking at differences between what exists and what does not exist. Things that exist can have a color, a mass, a size, a position, energy, any property at all. Things that don't exist are devoid of any of that. It seems to me that existence simply means having some kind of property and non existence is the absence of any.
  26. Sep 20, 2007 #25
    JoeDawg, ah yes, I suspected that was the reason but wasn't sure.
    I guess my point was it's a pretty broad assignment, which leads to very little depth in one area I find, and as you can see this fellow had very little idea of where to even begin.

    Entire books can be written on the subject of existence and proof, leading into all sorts of alleys like infinity, determinism, primordial cause, qualia, the i, the you, and in the end the entire universe.

    I guess it's a good test to find out which of his students have the inspiration to become a true philosopher :P
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