But see, there's a problem with that example... if this someone thinks that the magician's powers are real, then they must either think that those powers are a part of nature that they don't understand, or they must define nature to be a subset of that which is real.

There's also a notable similarity between defining supernatural as that which originates from an intelligent deity and defining supernatural as that which originates from an intelligent entity.  For example, natural foods are commonly considered to be those produced without the use of chemical agents or mechanically produced components... because other foods arguably involve direct manipulation from an intelligent entity (a human).  That may not be the best example, but my point is that if you define supernatural in terms of what is and is not natural, then you need a good definition of natural.  A theist might decide their god exists, and therefore is a part of nature, but others would disagree.

If natural is defined in terms of supernatural, and supernatural is defined as natural, then neither of term has really been defined at all.  Moreover, simply not knowing what the natural explanation is for a phenomenon doesn't mean that no such explanation exists, so if supernatural is defined to mean that for which the natural explanation is not yet known, then I don't think you can make a rational case that that which is determined to be supernatural does not exist.

 todangst did a good treatment of supernatural:

Supernatural and immaterial are broken concepts

I'm not saying that belief IN these occurrences is stupid, I'm saying that thinking that they're supernatural is silly because by default - if it happened it's natural. How can there be a believable supernatural occurrence when the entire reason for it being supernatural is the person's inability to explain it.

Going back to our magic trick example - I believe that the magic trick occurred, I do not believe that it was supernatural.

Those are just the different meanings of natural, some people take natural to describe a lot of things, I think that we're using the scientific definition which means that natural is something that acts through natural phenomenons, laws, w/e.

You can't explain one unexplained thing with another.

So what are we discussing here?, the common use of the word "supernatural"?, yes it is associated with super powers, ghosts, aliens, UFO's and lots of other things - but I'm sure that you already understand what I mean by it when I say natural.

Sure, I believe the vase moved, I just don't believe the person who says it's a ghost because AS FAR AS I KNOW  ghosts do not exist.

There doesn't have to be an immediate explanation, the fact something happened means that it's natural, sure it might be something we don't yet understand, but once we will understand it we WILL be able to explain it - explanation is not the important part here, the fact something HAPPENED is the important bit.

Then how could humanity's first explanation have come about?

My question is not what the common uses of the word supernatural are, nor is it what you mean by the word natural.  What I'm asking is what these 2 irrational precepts are claiming to be irrational.

I wouldn't expect you to believe that a ghost was responsible... at least not without spending a decent amount of time observing the phenomenon for yourself... but the relevant issue, as I see it, is whether or not it's rational for the person in the hypothetical scenario to believe that a ghost was responsible, having seen consistent evidence that highly correlates to him thinking about ghosts.

Sorry... I'm sure you're not the only one.  But, I wouldn't be raising the issue if I didn't think it was important.  And, if the definition we're going by is anything that's commonly referred to as supernatural then I would have to contend that such beliefs are rational provided that the believers in question have seen sufficient evidence to warrant belief (whether or not they're in a position to show such evidence to others) and have seriously considered and investigated any possibility that someone may be trying to deceive them.

That's what worries me... the thought of legitimate phenomena which actually happen getting categorized as supernatural and then not being duly investigated.  If such phenomena don't get seriously investigated, how would they become understood and explained?

That example doesn't meet your criteria.  Neither gravity nor wind have been explained in that scenario, yet you're using them to explain a falling vase.  In your example you're trying to do exactly what you said couldn't be done.

We've already established that those are the definitions of natural and supernatural that you prefer, and I've made the case that those definitions are not useful for addressing specific claims.  I'm not the first one to make that case on these forums either, so let's try to move past that....

Maybe, maybe not.  We can certainly see that scientific discoveries have been made in the midst of superstitious and irrational thinking, so there is some support your argument.  I don't like the way you phrase it though... "had enough evidence to have actually occurred" makes it sound like whether or not an event occurred is dependent on how much evidence it leaves behind.  I hope I don't have to point out the fallacy in that line of reasoning.

Consider something like this:

http://www.youtube.com/watch?v=sBQLq2VmZcA

What if cameras hadn't been invented?  What evidence would be left behind besides eye witness testimony (which would likely be labeled as anecdotal or an outright fabrication)?

Furthermore, even if such phenomena would all eventually be investigated and explained, I would much prefer if such investigations and explanations were not unnecessarily delayed a few centuries or millennia due to close-minded thinking.  Here's what I'm trying to discourage:

That same video I linked to, I've also showed to friends.  I was both amused and disappointed at the responses I got.  A typical discourse would go something like this:

Friend: I know how he did that.  He's walking on clear poles in the swimming pool.

Me: Well, it's true that a transparent material with the same index of refraction as a liquid it's in appears invisible to the naked eye.  But, if you look at the video closely, at one point a girl swims directly underneath Chris Angel.  If he were walking on poles, she would have collided with them when she attempted to do that.

Friend: Okay, I know how he did that.  There are clear beams extending the length of the pool that he's walking on, just below the surface of the water.  That's why his jeans get wet.

Me: Okay, ignoring for the moment the question of whether or not we have the technology to build something like that which could extend across the length of a swimming pool and support the weight of a healthy adult male without breaking, at one point in the video a girl passes right in between his legs from the left side of him to the right side of him while breaking the surface of the water the whole time.  If he were walking on the kind of beams you describe, she would have collided with them.  Also, if you look closely, his jeans are longer than his legs and hang below his heels.

Friend: Okay, okay, I've got it!  He walks on beams up to the point in the video where he takes off his shoes.  Then, he walks on poles the rest of the way.  That way, the first girl can swim under the beams and the second girl can swim around the poles.  Everyone in the pool has been paid and trained in advance to avoid the beams and poles.  That's why when he takes off his shoes, he kind of takes a step and then withdraws it, and why he takes a bigger step afterwards.  He realizes that he's reached the end of the beams, so backs up and then takes the bigger step to ensure he reaches the poles.

Me: I still have a few problems with your explanation.  If you look closely, that "step" he takes when he removes his shoes doesn't actually come in contact with the water... so it's not indicative of him finding the end of the beams you're suggesting.  Actually, I don't see any point in the video where he changes his mind about where to put his foot once it comes in contact with the water, excepting the obvious last step where he instead just steps out of the pool.  Furthermore, that raises the question of how he would know where such a transition in mechanism would occur... and in fact, how he would be able to tell where the poles you suggest are since they're not visible.  Also, the post-event interviews appear to be genuine, though I admit I'm not a trained expert in reading body language and detecting lies.  Furthermore, I would expect it to be difficult, though admittedly not impossible, for the swimmers in the pool to perfectly avoid invisible obstacles.  So, strictly speaking I don't see anything in the video that explicitly refutes your explanation if I ignore the part where you talk about why and how he removes his shoes.  However, it seems like a very contrived explanation to me.  That said, I acknowledge that Chris Angel is a talented and experienced professional magician... a profession which involves doing something in such a way that they appear to be doing something else.  However, it seems to me to be a simpler and more straightforward explanation to say that he has some unrevealed ability to generate a force which is opposite in direction to gravity and sufficient in magnitude to counteract enough of the the force of gravity so that the buoyant force from the water would cause him to float like a boat.  Such an explanation would also neatly explain quite a few of his other demonstrations, actually.

Friend: Meh.  The only way I would consider that as a possibility is if he didn't know in advance where he would be walking in the pool.  In the video, he walks from one corner to another, so he has a well-established path that he could have rigged in advance somehow.  For me to consider what you suggest, I would have to insist that a ball be thrown into the pool by a volunteer and allowed to drift a bit to produce an effectively random location.  Then he would have to walk to that location, pick up the ball, and walk out of the pool via another route.

Me: If he can rig part of the pool, why couldn't he rig the entire pool?  Alternately, if he can bribe and train a lot of swimmers in a public pool to avoid invisible obstacles, why can't he bribe one person to throw the ball to a specific part of the pool... and have the ball and/or the pool rigged so that the ball "randomly" drifts to a specific location that he's decided in advance?

Friend: ...

Now, before I get straw manned, let me just explicitly state that I'm not saying that my friend should have believed the explanation that I gave.  I'm also not claiming that watching this video is sufficient evidence to warrant belief in such an explanation.  Here are the problems as I see them:

1) My friends tended to express far more confidence in their explanations than was warranted for the amount of scrutiny applied to the available evidence.  This is evident by the fact that it usually took me only 1-2 additional views of the video to find something that clearly contradicted their explanations.

2) None of my friends even considered the possibility that there could be a force acting upwards on Chris Angel that neither they nor the swimmers in the pool had knowledge of until I explicitly introduced that explanation into the conversations.

Essentially, I'm claiming that they displayed an irrational bias towards explanations that fit most comfortably within their existing world views.  I see this as being the exact same problem that leads to so many people believing in fraudulent displays of allegedly psychic or paranormal abilities, and it appears to me to be extremely widespread.  If that's the challenge being issued by the irrational precepts I'm asking about, then I couldn't be more enthusiastically in support of them.  If, however, these irrational precepts are claiming that there's something inherently irrational about believing claims that the average person would label as supernatural, then I couldn't be more strongly opposed to them.  Because if they are, then it seems to me that they're claiming that the people in that swimming pool (assuming that they are, as they appear to be, legitimate observers and not trained participants in the demonstration) or more importantly, that Chris Angel himself, would be irrational to believe that he can do what he appears to do in that video.

So, in other words, it's a partially explained concept.  How is that different from the partially explained concept of a ghost?  Oh, sure, most people have experienced wind, and it would appear that the majority of people never see evidence of ghosts... but we can't know that no one sees evidence of ghosts.

Certainly not... unless, of course, that person were willing and able to demonstrate the phenomenon by cutting off his hand and allowing neutral observers to watch it regrow or could provide some other convincing evidence... and even that wouldn't be enough to attribute the phenomenon to Jesus.

Of course it doesn't... and I would never suggest that it would.  I tried to make that clear.  But, I have to point out that the popularity of an explanation in no way contributes to the accuracy of that explanation.  If you've heard from several different people that the correct explanation is one that seems to be refuted by the available evidence, that would seem to only strengthen my point.

I never suggested that he could do anything that hasn't been done before, or that he did anything that anyone couldn't do if they knew how.  All I suggested is that he could have done something that isn't commonly known.  Also, Chris Angel states quite a few times in other videos that his goal is to get people thinking about what's possible, but never states an intention to prove any specific phenomenon to be true.  And, he certainly doesn't need the million dollar prize from the JREF.

If you can't come up with a sound explanation that's supported by the available evidence, the rational choice is to admit that you just don't know.

I agree with you, and I think you're not quite getting the points I'm trying to make.  I saw a Carl Sagan quote the other day that summed up one of my complaints beautifully, but I just can't seem to find it.  The gist of it though, is this: People require extreme evidence to support claims that fall outside of their existing world views, but accept claims that fall within established dogma unquestioningly.

The other major complaint I have is this: while I agree with you that people shouldn't easily believe the claims of people encountering phenomena that are not generally known to be true, it's irrational to simply assume that those claims are false or that the people making the claims don't have legitimate reason to believe that they're true.  That's why I'm such a big fan of James Randi... he doesn't claim that no unknown phenomena exist, he just challenges people that make such claims and discredits them through experimentation.  That's the key... to be able to rationally say that the claims are false, you have to have something more than popular opinion or your own preconceptions to back you up.

Yes, as I said, many more people know that wind is a real phenomenon than know that ghosts are a real phenomenon, but you shouldn't assume that everyone knows that wind exists or that no one knows that ghosts exist.  Granted, no one's likely to believe that wind doesn't exist because those people that are not in a position to have experienced wind are likely to know so little as to not have an opinion on the matter.  Regardless, ghosts are partially explained as spirits of the dead that linger around the places where they died.  Whether or not ghosts are real doesn't affect the fact that there is a common understanding of what it means to be a ghost.

Also, you're claiming knowledge beyond what you have if you're saying that no one knows anything about them and that no one knows if they exist.  You don't know anything about them, and probably most people don't know anything about them, but you can't know that no one knows anything about them.  Just because no one has ever managed to get a ghost to perform on demand so that people can repeatedly and consistently observe the ghost's behavior doesn't mean that no one has ever seen any evidence of a ghost.

Okay, you have a point here.  The more well-known an explanation is, the more opportunities there are for someone to refute it.  But then, that raises questions about whether or not the refutation would be able to spread through the population as quickly as the initial explanation would... which would appear to depend on how the members of the population approach the process of seeking and spreading ideas.  Oy, what a can of worms.  But thank you for calling my attention to an interesting question.

There are many issues that someone considering attempting James Randi's challenge (and actually qualified to pass it) would have to weigh.  Of course, before they could even get to that point, they would first have to know that the challenge exists... and I managed to go through the vast majority of my life without ever hearing about it, so I'm sure there are plenty of people that don't even know it exists.  Granted, this is probably not an issue in Chris Angel's case.  But, once that's out of the way, the next major issue is whether or not the person in question considers it worth becoming famous for.  Granted, this is definitely not an issue for Chris Angel, because he's already famous... but a close examination of the JREF website reveals that there are a lot of people who ask if they can take the challenge anonymously (and are denied, of course, as it would be impractical for a number of reasons).  An extension of the fame issue is the issue of everyone knowing that they have a rare skill.  There's probably not going to be any agreement about how much, if at all, that would be a problem... but I'm pretty sure there are religions out there that advocate killing witches, and power-hungry people that would wonder how they could profit from a rare commodity.  Finally, the question has to be asked, how would it change the way people think?  Maybe there are people out there that would like to share the information but worry that if word got out that James Randi's challenge had been passed, cases of people fraudulently claiming to have supernatural abilities to prey on those who lack critical thinking skills would vastly increase.

Well, yes, in general... but also in this case specifically.  I don't know of any case where this principle wouldn't apply, actually.  Okay, so you assume that the performer just tricked you somehow.  That's good.  It means you're admitting that you don't know how he did it.  You said yourself that every event that actually happens must have a legitimate explanation.  Well, if you don't know what that explanation is, the rational thing to do is admit you don't know what the explanation is, just like you're saying you'd do here.

Yes, that's the problem, isn't it?  You can't know that people are telling the truth.  There are people who lie, falsify evidence, etc. for their own selfish reasons.  How do you know who to trust?  Should you trust anyone?  But, you're missing something as well.  You can trust yourself.  Similarly, other people can trust themselves.  That's why I say that watching the video isn't sufficient evidence to justify belief in my explanation.  I don't even believe it's true myself, I just accept that I don't know that it's not true.  The problem I have is if someone says that the people who are right there either seeing it happen or making it happen would be irrational to believe my explanation solely because that explanation is not currently considered to be possible by the average person.  They're in better positions to know than we are.

In theory, I think that all claims should be treated with skepticism... that people shouldn't accept any claims unquestioningly, regardless of how well they fit into our existing world views.  In practice, I realize that we don't have time to investigate every claim we hear that thoroughly, if at all.  Even in light of that dilemma, though, I still have a problem with people accepting claims as true without scrutiny.  I don't, however, see a problem with people accepting claims as possibly true or even likely to be true, and attempting to apply the unverified claims for practical purposes.  I do see a problem with people assuming so much confidence in a claim that they say that others are wrong to disagree with them when they haven't seen sufficient evidence to justify that level of confidence.

I've met people who say they have a major problem with willful ignorance, but I don't see it as a bad thing... by choosing to remain ignorant about one subject, we allow ourselves more time to learn about another.  But, if we choose to believe that things are true without having seen evidence to back them up, we run the risk of believing things are true when they aren't.  That's what religious people do, and we criticize them for it.

I don't know about Islam and Judaism, but it seems to me that many flavors of Christianity wouldn't allow for the possibility of ghosts.  If you die and believe in God, you go to heaven.  If you die and don't believe in God, you go to hell.  If God is all powerful and all knowing, you shouldn't be able to escape your fate.  So, what room does that leave for the spirits of the dead to hang around where they died?

In any case, I mean popular opinion within the subset of people who's opinions you'd actually respect.  Obviously, people don't generally base their conclusions solely on the opinions of people who's methods of determining truth they consider faulty.

That's irrelevant as far as I'm concerned.  Whether he believes that they can or believes that they can't, he doesn't claim that they can't.  He allows for the possibility that someone could surprise him and display a genuine ability that he thought to not exist, and he goes about the process of investigating claims in a fair, practical, and scientific manner.

Of course.  Was there some disagreement about that?

Ah, yes, them... but I was only thinking of the people in this thread.