Proof?

[Morallyangelic]

Just want to throw a few questions out there to get some opinions.

So my first question is this : Can lack of proof act as proof for the opposing argument?

And secondly: Does ' proof ' mean different things to different people or is there a standard on what acceptable proof is? Does proof have to be 100% tangible in all cases where proof is needed? If not can you give me an example or an analogy?

Thanks everyone.

 

[KhaTzek]

The definition of proof depends on the context:

* Mathematical proof is a logical set of deductions based on a number of base axioms. As it is not emprical, we can achieve certainty

* In science there is no such thing as "absolute certainty," all ideas about how the universe works are subject to potential revision as new evidence comes to light. As Gould says:
"In science, 'fact' can only mean 'confirmed to such a degree that it would be perverse to withhold provisional assent.' I suppose that apples might start to rise tomorrow, but the possibility does not merit equal time in physics classrooms."
The more evidence that is amassed for a particular theory, the less likely it becomes that fundamental changes to it will have to be made in the future. It is not about finding truth, but rather gradually approaching it.
Science uses methodological naturalism, it does not assume that nature is all that exists, but recognises that it is all we can reliably test. It could very well be that we all have invisible/intangible goblins sitting on our shoulders right now, but if we cannot test it, then it is not a part of science.
There are an infinite number of ways that the universe could work, but only one way that does work, and so the probability of determining this through faith alone becomes infinitely small.

I'll let someone else tackle defining what proof is in terms of society and culture


As for your first question: as the saying goes, absence of evidence is not evidence of absence. However that is not to say that there is no such thing as evidence of absence. For example, if you have a box, and a theory that there is a ball inside, then open the box and find no ball, this can be construed as evidence that there is no ball inside it
Also on a related note, keep in mind that when someone thinks are only two opposing theories, there are often actually many, and so evidence against one is not evidence for another.

 

[TheGMan]

Mathematical proof is a logical set of deductions based on a number of base axioms. As it is not emprical, we can achieve certainty

And in mathematics absence of proof is definitely not evidence for the opposite theory. The fact that nobody has found an odd perfect number does not prove that there are no odd perfect numbers.

As for your first question: as the saying goes, absence of evidence is not evidence of absence. However that is not to say that there is no such thing as evidence of absence. For example, if you have a box, and a theory that there is a ball inside, then open the box and find no ball, this can be construed as evidence that there is no ball inside it

Yes. Absence of evidence can be evidence of absence when we expect to see that evidence if the claim was true. If I tell you I have an elephant in my garage and, after searching the garage, you find no evidence of an elephant you are probably justified in concluding it was never there in the first place.

 

[Morallyangelic]

If I tell you I have an elephant in my garage and, after searching the garage, you find no evidence of an elephant you are probably justified in concluding it was never there in the first place.

But does that prove there never WAS an elephant in the garage? There are probably a million different variables that could have taken place and that is why the elephant is no longer there.

But that doesn't mean that it never was there to begin with.

 

[TheGMan]

But does that prove there never WAS an elephant in the garage? There are probably a million different variables that could have taken place and that is why the elephant is no longer there.

But that doesn't mean that it never was there to begin with.

Well, I think if you had an elephant in your garage for any length of time, there'd be some evidence - the smell if nothing else. You could work out a scenario where there had been an elephant at one point but someone had tried to cover that up. But generally the elaborate your excuses get the less likely the original proposition is.

If you turned to me and said, "Well I don't see an elephant."

And I said, "Maybe it went out for a walk. He'll be back in 10 minutes."

...you're probably going to be less convinced that I have an elephant than more convinced. If the elephant doesn't come back in 10 minutes and I invent another excuse you're going to be less convinced still. Although the point at which you feel you've actually proved to yourself that I don't have an elephant is probably quite hard to pin down.

 

[xAtheistx]

The absence of evidence is not evidence of absence.

That said, the burden of proof lies in the affirmative (that there was indeed an elephant in your garage once... you wouldn't ask him to prove that there was never an elephant there, for it's illogical to prove something didn't happen, or doesn't exist)

 

[TheGMan]

The absence of evidence is not evidence of absence.

I'd rephrase slightly. The absence of evidence is not necessarily evidence of absence. It doesn't of itself prove an absence. However, the absence of big piles of elephant manure in the garage is hard to reconcile with the idea that there has been an elephant living in there. At this point it does become evidence of absence because the evidence was expected.

That said, the burden of proof lies in the affirmative (that there was indeed an elephant in your garage once... you wouldn't ask him to prove that there was never an elephant there, for it's illogical to prove something didn't happen, or doesn't exist)

I'm not convinced by this. The burden of proof lies with whoever is trying to prove something. If I'm trying to convince you of the elephant's existence then the burden is with me. If you're trying to convince me that I never had an elephant and that perhaps I'm in need of some psychiatric help then the burden is on you.

 

[xAtheistx]

I'd rephrase slightly. The absence of evidence is not necessarily evidence of absence. It doesn't of itself prove an absence. However, the absence of big piles of elephant manure in the garage is hard to reconcile with the idea that there has been an elephant living in there. At this point it does become evidence of absence because the evidence was expected.

You're assuming that it no dung means there has been no elephant. Unless that's one of your "givens," which would have to be true in every case (e.g. an elephant takes a **** every three inches it walks) ... it's assumed, and therefore not a proof.

If you're trying to convince me that I never had an elephant and that perhaps I'm in need of some psychiatric help then the burden is on you.

Ridiculous. Prove to me that there is not a troll standing on my head.

 

[Morallyangelic]

Well, I think if you had an elephant in your garage for any length of time, there'd be some evidence - the smell if nothing else. You could work out a scenario where there had been an elephant at one point but someone had tried to cover that up. But generally the elaborate your excuses get the less likely the original proposition is.

If you turned to me and said, "Well I don't see an elephant."

And I said, "Maybe it went out for a walk. He'll be back in 10 minutes."

...you're probably going to be less convinced that I have an elephant than more convinced. If the elephant doesn't come back in 10 minutes and I invent another excuse you're going to be less convinced still. Although the point at which you feel you've actually proved to yourself that I don't have an elephant is probably quite hard to pin down.

Just because I have proved to myself there never was an elephant doesn't mean I could prove that there never was one to other people does it?

I mean you have Bob saying the elephant was there, he saw it, he fed it once and he even talked to it for awhile ... he can even describe it! but then when he went to show me the elephant there was not one there ... I didn't see the elephant, I didn't feed it, smell it and so on. Now if Bob and I were to tell ANOTHER person each of our accounts is there any actual proof one way or the other?

By the way: Assume Bob isn't known to be deceitful or insane and neither are you.

 

[TheGMan]

You're assuming that it no dung means there has been no elephant. Unless that's one of your "givens," which would have to be true in every case (e.g. an elephant takes a **** every three inches it walks) ... it's assumed, and therefore not a proof.

Well yes. But the fact is there are certain things we would expect to see if there had been an elephant in the garage for any length of time. If we don't see them then that is evidence against the idea that there was an elephant in the garage. Does it prove that there was never an elephant in the garage beyond all doubt? No. Does it count as evidence against it? I think it does.

Ridiculous. Prove to me that there is not a troll standing on my head.

Why? Do you think that you have a troll standing on your head? And even if you did think that, why would I want to prove you wrong? If it makes you happy to believe that you have a troll standing on your head then bully for you.

It does make me think you're a bit weird though!

 

[TheGMan]

I mean you have Bob saying the elephant was there, he saw it, he fed it once and he even talked to it for awhile ... he can even describe it! but then when he went to show me the elephant there was not one there ... I didn't see the elephant, I didn't feed it, smell it and so on. Now if Bob and I were to tell ANOTHER person each of our accounts is there any actual proof one way or the other?

Well what do you mean by proof? You can't prove conclusively that there was never an elephant in the garage.

However, if the garage is clean, there is a shiny red car in the middle of it and bicycle that quite obviously hasn't been trampled by an elephant propped up against the wall, these things are all evidence that there wasn't an elephant in the garage. Why? Because it's not what we'd expect to see if there had been an elephant in the garage. So if the third person goes into the garage and sees that who is he more likely to believe, you or Bob?

Of course, Bob could probably come up with an explanation as to why the garage looks like it does despite the fact there was an elephant in there. But the point is that once you start coming with excuses like that, it often indicates that the original story is less than plausible. Not always but more often than not. So it doesn't necessarily prove that Bob was lying or mistaken but it makes it more likely that he was.

But there's no clear point at which you can draw the line and say "It is now proven." But I think it's clear that an absence of evidence is evidence of absence in this case - but not conclusive proof.

 

[KhaTzek]

It is simply not necessary. The burden of proof never moves from Bob. Unless he can provide evidence of the elephant, then we stay empirically agnostic of his claim. We certainly don't base any beliefs on it.

 

[Morallyangelic]

But what could Bob use as proof for an elephant being in the garage without an actual elephant?

 

[TheGMan]

But what could Bob use as proof for an elephant being in the garage without an actual elephant?

Well if the car in the garage looks like its been sat on by a large animal, the bicycle has been trampled on and there's a big pile of elephant manure in the corner these might be considered indicative of the fact that there had been an elephant in the garage, even if it had wandered off recently.

Of course, you could then try to explain the evidence away by saying that Bob had faked an elephant sitting on the car and trampling the bike with sledgehammer and had acquired the manure from the zoo. But then it's you trying to explain away the state of the garage and not Bob. It's your story that the evidence makes less plausible and that requires additional explanation.

 

[Morallyangelic]

If those things could serve as proof FOR an elephant, how can it not be proof that there wasn't an elephant if those things were not in the garage?

I guess another good question would be is are we using proof in the same sense that we would use the word ' fact ' or ' know ' ?

 

[TheGMan]

If those things could serve as proof FOR an elephant, how can it not be proof that there wasn't an elephant if those things were not in the garage?

I guess another good question would be is are we using proof in the same sense that we would use the word ' fact ' or ' know ' ?

Well, they're not proof that there was an elephant in the garage, they're evidence that there was an elephant in the garage. In the same way, the absence of crushed bicycles and elephant poo is evidence that there wasn't an elephant in the garage.

Exactly what amount of evidence you need to prove something depends on just how sure you want to be about it. In criminal trials, for instance, you want to be pretty sure that you've got the right man before you put him prison so you stipulate that you want enough evidence to prove his guilt beyond reasonable doubt. But that is not the same thing as beyond all doubt. It's possible that aliens could have faked all the evidence against him.

 

[Morallyangelic]

Well, they're not proof that there was an elephant in the garage, they're evidence that there was an elephant in the garage. In the same way, the absence of crushed bicycles and elephant poo is evidence that there wasn't an elephant in the garage.

Exactly what amount of evidence you need to prove something depends on just how sure you want to be about it. In criminal trials, for instance, you want to be pretty sure that you've got the right man before you put him prison so you stipulate that you want enough evidence to prove his guilt beyond reasonable doubt. But that is not the same thing as beyond all doubt. It's possible that aliens could have faked all the evidence against him.

So there is no 100% answer on what proof is then? It just depends on who you ask?

Say Bob has a scratch on his car which he says was caused by the elephant. Jane might accept that as proof whereas I may not accept that to be enough proof?

Or can you have proof at all without any tangible evidence?

 

[TheGMan]

So there is no 100% answer on what proof is then? It just depends on who you ask?

Say Bob has a scratch on his car which he says was caused by the elephant. Jane might accept that as proof whereas I may not accept that to be enough proof?

Or can you have proof at all without any tangible evidence?

Well it is more likely to depend on the context than who you ask. But outside of mathematics there's no such thing as 100% proof.

But yes essentially that's it. You might think that the scratch on Bob's car was caused by the Jane's kids therefore you have got a more plausible explanation than the elephant. Jane, on the other hand, refuses to believe her kids would be so badly behaved and so the elephant is the only plausible explanation. So it depends, to a very great extent, on where you start from.

In science and law, there tends to be a general agreement about what is initially plausible or not and what the standards for proof are. So lawyers and scientists tend to find it easier to agree when something has been proved. But when you got on to history or theology or philosophy you don't have that agreement and so it becomes a lot harder to work out when something has been "proved".

 

[Zakath]

So there is no 100% answer on what proof is then? It just depends on who you ask?

Essentially, yes. The two words, "evidence" and "proof" are used synonymously by many of us. There is essentially no difference between the two words, as most people use them. In the field of mathematics, the term "proof" has a particular meaning that is not used by the general public.

Say Bob has a scratch on his car which he says was caused by the elephant. Jane might accept that as proof whereas I may not accept that to be enough proof?

Yes, again. "Proof" is considered by some people to be a bit more rigorous or convincing than "evidence", but not by all of us.

One can say, "I have proof that there was an elephant in Bob's garage." or "I have evidence that there was an elephant in Bob's garage." To many people those sentences mean essentially the same thing.

You are pointing out that "proof" or "evidence" is not universally conclusive. Based on my own experience, I'd agree. What serves to validate a point for one person may not do so for the next one.

A common example is when a fervent religionist points to a beautiful sunset and proclaims that this is proof, to them, of the existence of a deity. To me, an atheist, it's not proof of any such thing; though it's still a beautiful sunset.

Or can you have proof at all without any tangible evidence?

Certainly. Much religious belief is based on alleged "proofs" with no tangible evidence. Christian religionists have fought (sometimes literally) for centuries over dogmas and doctrines (the Trinity, for example) that have no tangible evidence, merely a few textual references in the translation of an edited copy of a book that most of them could not even read in its original language. Yet they consider their side of the argument to have more than ample "proof" to justify their position.

 

[Morallyangelic]

Okay thank you for your replies - Been very helpful.