# Reality **URL:** \ **Category:** Great Debates\ **Created:** [August 31, 2000, 5:55pm UTC](https://boards.straightdope.com/t/reality/31520 "2000-08-31T17:55:33Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Liberal](https://avatars.discourse-cdn.com/v4/letter/l/848f3c/32.png) [@Liberal](https://boards.straightdope.com/u/Liberal)\ **Post date:** [August 31, 2000, 5:55pm UTC](https://boards.straightdope.com/t/reality/31520/1 "2000-08-31T17:55:33Z")
**QuickSilver** > [@](#): > > Though we are diametrically opposed regarding our beliefs in God, I thought that in our prior discussion we had come to some sort of conclusion about at least sharing the same physical relm. So unless this is all a mass illusion a la Matrix, isn’t there just a slight chance that at least some things can be objectively proven to exist? No, I’m afraid not. The chance is zero. > [@](#): > > At least to the extent that we humans can manage objectivity. As humans, our consciousness is a **closed reference frame**. We can “manage” subjectivity only. > [@](#): > > Or was Descartes completely wacked out on crack? Descartes attempted to use a reason epistemology to prove his own existence, and then later (in Meditations III) a very complicated attempt to prove the existence of God. Unfortunately, to prove anything at all, including your own existence, you must first exist, since a being who does not exist cannot leave such evidences. That makes your existence axiomatic. Because your axiom (that you exist) will match your conclusion (that you exist), your argument begs the question, and is a circle. > [@](#): > > If I am wrong then I would like to challenge myself further on this topic but in another thread - you start it though, I wouldn’t know where to begin. Begin here. ---
**Author:** ![Scylla](https://avatars.discourse-cdn.com/v4/letter/s/a5b964/32.png) [@Scylla](https://boards.straightdope.com/u/Scylla)\ **Post date:** [August 31, 2000, 6:06pm UTC](https://boards.straightdope.com/t/reality/31520/2 "2000-08-31T18:06:11Z")
“Unfortunately, to prove anything at all, including your own existence, you must first exist, since a being who does not exist cannot leave such evidences. That makes your existence axiomatic.” But that doesn’t prove that a being that does, can’t. Therefore it’s not necessarily axiomatic. ---
**Author:** ![Liberal](https://avatars.discourse-cdn.com/v4/letter/l/848f3c/32.png) [@Liberal](https://boards.straightdope.com/u/Liberal)\ **Post date:** [August 31, 2000, 6:12pm UTC](https://boards.straightdope.com/t/reality/31520/3 "2000-08-31T18:12:46Z")
A being that does can’t because of rules of tautology (as explained). The only way you could prove that you exist is if you didn’t. But then you couldn’t. ---
**Author:** ![Scylla](https://avatars.discourse-cdn.com/v4/letter/s/a5b964/32.png) [@Scylla](https://boards.straightdope.com/u/Scylla)\ **Post date:** [August 31, 2000, 6:22pm UTC](https://boards.straightdope.com/t/reality/31520/4 "2000-08-31T18:22:43Z")
Isn’t your closed reference frame unproven, and hence axiomatic? ---
**Author:** ![Liberal](https://avatars.discourse-cdn.com/v4/letter/l/848f3c/32.png) [@Liberal](https://boards.straightdope.com/u/Liberal)\ **Post date:** [August 31, 2000, 6:24pm UTC](https://boards.straightdope.com/t/reality/31520/5 "2000-08-31T18:24:22Z")
Yes, of course. _Every_ truth is axiomatic. ---
**Author:** ![Scylla](https://avatars.discourse-cdn.com/v4/letter/s/a5b964/32.png) [@Scylla](https://boards.straightdope.com/u/Scylla)\ **Post date:** [August 31, 2000, 6:29pm UTC](https://boards.straightdope.com/t/reality/31520/6 "2000-08-31T18:29:14Z")
Is “I think therefore I am” axiomatic? How about “2 + 2 = 4?” or “a=b=c, then a=c?” ---
**Author:** ![Robot\_Arm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robot_arm/32/18280_2.png) [@Robot\_Arm](https://boards.straightdope.com/u/Robot_Arm)\ **Post date:** [August 31, 2000, 6:37pm UTC](https://boards.straightdope.com/t/reality/31520/7 "2000-08-31T18:37:51Z")
> [@](#): > > \*Originally posted by Libertarian \* > A being that does can’t because of rules of tautology (as explained). The only way you could prove that you exist is if you didn’t. But then you couldn’t. This sounds like a job for _Reductio-ad-absurdum_ Man! I assume that I don’t exist. But then how can I be assuming anything? Contradiction, therefore my assumption is wrong. ---
**Author:** ![QuickSilver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quicksilver/32/7832_2.png) [@QuickSilver](https://boards.straightdope.com/u/QuickSilver)\ **Post date:** [August 31, 2000, 6:38pm UTC](https://boards.straightdope.com/t/reality/31520/8 "2000-08-31T18:38:25Z")
…Oh boy, this is going to hurt me more than it hurts you, Lib. If I understand you correctly, you believe that you exist while I must prove to you that not only do I exist but so do you and all the other wonderful people on this planet. Is that the challenge then? ---
**Author:** ![jb\_farley](https://avatars.discourse-cdn.com/v4/letter/j/9d8465/32.png) [@jb\_farley](https://boards.straightdope.com/u/jb_farley)\ **Post date:** [August 31, 2000, 6:45pm UTC](https://boards.straightdope.com/t/reality/31520/9 "2000-08-31T18:45:41Z")
no QuickSilver. You **can’t** prove to Lib that you exist. Ever. Your job appears to be to demonstrate how you know that Libertarian is a real being and not some hallucination of yours or an artifact of a peculiar universe, and to prove that demonstration. good luck. ---
**Author:** ![QuickSilver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quicksilver/32/7832_2.png) [@QuickSilver](https://boards.straightdope.com/u/QuickSilver)\ **Post date:** [August 31, 2000, 7:12pm UTC](https://boards.straightdope.com/t/reality/31520/10 "2000-08-31T19:12:07Z")
…and in order to do that I must first step out of that particular universe, demonstrate it’s existance and then demonstrate Lib’s existance therein. I think I feel a brain aneurism coming on… Okay, look, this is preposterous! If I must prove that Lib or anyone else exists prior to entering into any kind of dialogue with them, let alone some kind of contractual agreement (in a libertarian sense as I understand it) then I have to acknowledge their existance as truth. Else, what would compell me to honour that contractual agreement? I could simply wish them out of existance without carrying out my side of the bargain. They cannot wish me out of existance because this is my construct in which I am god. So if all this is subjective reality, what is it that compells us as humans to function in a co-operative, even symbiotic manner? Is it our lack of intellectual ability to percieve any other kind of reality but this one? If so, how are we able to contemplate the possibility of other realities? ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [August 31, 2000, 7:17pm UTC](https://boards.straightdope.com/t/reality/31520/11 "2000-08-31T19:17:26Z")
I know it’s a painful concept Quicksilver but I’m afraid Lib has gotcha. As jb\_farley said you cannot ‘prove’ anything to anyone else as each person is their own reference frame. As far as I know my hallucination that is this universe just had you do whatever it was you did. You’re still just a figment of my imagination however. I will say, however, via the concept of “I think therefore I am” and Robot Arm’s example that I exist. I may not exist in the form I think I do (ala The Matrix) but there is _something somewhere_ that is me or at least that I am a part of. I may not be able to prove it to you but then again you can’t prove to me I don’t exist either (although I think that might be asking you to prove a negative which is a no-no). No-no or not it does give me some peace of mind to know that you can’t prove I do not exist. I’m not sure what I’d do if you did… ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [August 31, 2000, 7:23pm UTC](https://boards.straightdope.com/t/reality/31520/12 "2000-08-31T19:23:45Z")
I meant to add one other thing to my post then forgot till just reading Quick’s post just above. This may all be a painful concept but it’s best left as a mental exercise. I don’t think telling a robber pointing a gun at you that he must prove his existence to you a very useful or prudent course of action. In the end it’s best if we all assume everyone else we see around us not to mention the entire universe as really existing. A minor exception to this may be some religions. I believe Christian Scientists hold as a tenet that your body, this world, indeed this universe, is an illusion and strive to rise above it (sort of an enlightenment). Some of these people go to extremes and forgo medical care as one aspect of their faith. Beyond that, however, most people act as though this world is real. ---
**Author:** ![jb\_farley](https://avatars.discourse-cdn.com/v4/letter/j/9d8465/32.png) [@jb\_farley](https://boards.straightdope.com/u/jb_farley)\ **Post date:** [August 31, 2000, 7:28pm UTC](https://boards.straightdope.com/t/reality/31520/13 "2000-08-31T19:28:20Z")
also, keep in mind that ‘reality’ is a construct in your head based on memory and sensory data (note that just because it is a construct does not mean that it is false or fictional). reality is nothing but the present moment. and keeping in mind that the average person spends one third of their existence asleep (and that dreams or dream-like sensations are believed to occur throughout sleep), then you can easily deduce that a full third of what you normally comprehend as an outer objective reality has no basis in reality. i didn’t mean that you must prove he exists before you can theoretically debate him. more along the lines that, since the debate focuses on subjective reference frames, your job is to deal with your head, and not with Lib’s. salud. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [August 31, 2000, 7:46pm UTC](https://boards.straightdope.com/t/reality/31520/14 "2000-08-31T19:46:24Z")
Part of the problem of proving you exist to someone else is the fact that we are all locked inside of our own skulls. If, however, telepathy (or better yet a Vulcan Mind Meld) existed would that change the equation for anyone? ---
**Author:** ![jmullaney](https://avatars.discourse-cdn.com/v4/letter/j/85e7bf/32.png) [@jmullaney](https://boards.straightdope.com/u/jmullaney)\ **Post date:** [August 31, 2000, 8:31pm UTC](https://boards.straightdope.com/t/reality/31520/15 "2000-08-31T20:31:10Z")
Oy. I hope **Ren** is reading this – this answers your doubt that logic and wisdom are separate realms. If you don’t use widsom to choose your axioms, you get into all kinds of trouble. ---
**Author:** ![oldscratch](https://avatars.discourse-cdn.com/v4/letter/o/ed655f/32.png) [@oldscratch](https://boards.straightdope.com/u/oldscratch)\ **Post date:** [August 31, 2000, 8:40pm UTC](https://boards.straightdope.com/t/reality/31520/16 "2000-08-31T20:40:31Z")
Taken from “The thing in itself” "the appearance of ÒphenomenaÓ when our sense-organs experience an impact from external objects, the disappearance of ÒphenomenaÓ when some obstacle prevents the action upon our sense-organs of an object which we know to exist. The sole and unavoidable deduction to be made from this Ñ a deduction which all of us make in everyday practice and which materialism deliberately places at the foundation of its epistemology Ñ is that outside us, and independently of us, there exist objects, things, bodies and that our perceptions are images of the external world.! " If I do not exist, I can have no perceptions of things that do exist. As these things do exist, I can sense them when they are present, I can not sense them when they are not, I must conclude I do exist. If I did not exist, nothing would prevent me from smelling things in the future or past. ---
**Author:** ![Ptahlis](https://avatars.discourse-cdn.com/v4/letter/p/a8b319/32.png) [@Ptahlis](https://boards.straightdope.com/u/Ptahlis)\ **Post date:** [August 31, 2000, 8:46pm UTC](https://boards.straightdope.com/t/reality/31520/17 "2000-08-31T20:46:49Z")
> [@](#): > > \*Originally posted by Jeff\_42 \* > \*\*Part of the problem of proving you exist to someone else is the fact that we are all locked inside of our own skulls. > > If, however, telepathy (or better yet a Vulcan Mind Meld) existed would that change the equation for anyone? \*\* Nope. I could still be a brain in a jar, hallucinating that “other” presence in my head. ---
**Author:** ![Liberal](https://avatars.discourse-cdn.com/v4/letter/l/848f3c/32.png) [@Liberal](https://boards.straightdope.com/u/Liberal)\ **Post date:** [August 31, 2000, 8:52pm UTC](https://boards.straightdope.com/t/reality/31520/18 "2000-08-31T20:52:24Z")
Dammit. Okay, back soon. ---
**Author:** ![Liberal](https://avatars.discourse-cdn.com/v4/letter/l/848f3c/32.png) [@Liberal](https://boards.straightdope.com/u/Liberal)\ **Post date:** [August 31, 2000, 10:27pm UTC](https://boards.straightdope.com/t/reality/31520/19 "2000-08-31T22:27:33Z")
**Scylla** > [@](#): > > Is “I think therefore I am” axiomatic? No. That is an implication. Implications are of the form “A implies B” or “If A then B” or “A therefore B”. > [@](#): > > How about “2 + 2 = 4?” No. “2 + 2 = 4” is a conclusion that can be derived from the Peano axioms. > [@](#): > > or [if] “a=b=c, then a=c?” Well, no. That is an implication. But it is often presented axiomatically as an associative or implicative law. **QuickSilver** > [@](#): > > If I understand you correctly, you believe that you exist while I must prove to you that not only do I exist but so do you and all the other wonderful people on this planet. Is that the challenge then? Huh? No. The challenge (and an impossible one, I’m afraid) is to prove that you — just you — exist without using a tautology. (Remember, that’s what drew your initial reaction, when I said that you can’t **objectively** prove that anything exists because all epistemologies are tautological). The request that I, as a man of faith, prove God exists is quite common. And I am willing to provide that proof to anyone who will first prove to me that he, the person desiring my proof, exists. **J B Farley** > [@](#): > > no QuickSilver. You can’t prove to Lib that you exist. Ever. You are exactly right. Not without begging the question, anyway. **QuickSilver** > [@](#): > > Okay, look, this is preposterous! Dude! I opened the thread at _your_ request! (See Opening Post.) ---
**Author:** ![Liberal](https://avatars.discourse-cdn.com/v4/letter/l/848f3c/32.png) [@Liberal](https://boards.straightdope.com/u/Liberal)\ **Post date:** [August 31, 2000, 10:46pm UTC](https://boards.straightdope.com/t/reality/31520/20 "2000-08-31T22:46:57Z")
Sorry. Missed this one from **Robot Arm** > [@](#): > > This sounds like a job for Reductio-ad-absurdum Man! I assume that I don’t exist. But then how can I be assuming anything? Contradiction, therefore my assumption is wrong. Reverse cause. Thank you for playing anyway. 🙂 You may _assert_ that you don’t exist, but you may not _assume_ that you don’t exist (because you can’t assume until you _do_ exist). And that makes your existence axiomatic. You can’t say that A=B if you have not first established that A=A. [Next page](https://boards.straightdope.com/t/reality/31520.md?page=2)