First of all, I thank you all for your warm welcome to this newbie in my other thread about Nostradamus. We know-it-all nerd geeks have to stick together.
After all, who is going to tape our glasses, hem our pants up above our ankles and buy us new pocket protectors to hold our pens when we get old? 
But as some of you have correctly pointed out, I am preaching to the converted in debunking Nostradamus in a forum like this one. Since we are all on the same ignorance-fighting team, perhaps it would make more sense to discuss our tactics in challenging all claims of this kind.
So if you will allow me, I would like to start a new thread to discuss our need to stick to scientific principles in debating such issues with the “outside world”.
I note that one person said that he found Nostradamus’ alleged prediction about the death of Henri II and the other prediction supposedly about 9-11, hard to dismiss. Personally, I find both easy to dismiss. But of course, we are missing the main point if we let that particular poster get away with that comment about “hard to dismiss”.
He who asserts must prove. It is not up to us to prove that Nostradamus did not predict the death of Henri II because he wrote one lousy reference to someone getting their eyes (note the plural) pierced while in a golden cage.
Similarly, the believers in Bigfoot (Sasquatch) have come up with a cute aphorism which is now used also by UFO buffs and others. “Absence of proof does not constitute proof of absence.” Whenever they say this in debate, people nod as if they just heard a pearl of great wisdom.
But wait a damned minute! Since when is it up to us to prove that Bigfoot does not exist? In science, it is up to the person who asserts that something exists to prove it.
How on earth would one prove absence of something anyhow? How do you prove a negative? It is generally impossible.
I say “generally” because you can prove the non-existence of something in a very limited space. For example, I could prove that the shoe box in my closet does not contain a full-grown elephant.
But how could I prove that there are, say, no Leprechauns in Ireland? Ireland is about 83,000 square km. Nobody can see every bit of it at once. Not to mention the fact that the “little people” could live underground. Luckily, scientific principles state that I do not have to prove that they do not exist.
Besides the “You can’t prove they don’t exist” fallacy, there is another trap to watch out for. The old “Why can’t you have an open mind on these subjects?”
At first, this sounds like a perfectly fair request. But our answer is that an open mind is not an open sewer. An open mind is a mind that is willing to sift new facts and new evidence and accept new conclusions that derive from those facts.
I have never declared that Bigfoots do not exist. Nor am I certain that there cannot be UFOs that contain visitors from another planet. My mind is still open to receive evidence. Nor am I certain that there is no such thing as extra-sensory abilities to predict the future outside our normal ability to look at our environment and make reasonable guesses about the future.
But as any rational person would, I must prioritize the credence I give to such claims, based on initial evidence or lack of same, probabilities, and obvious conflicts of the allegation with known facts. For example, do you know of ANY primate, including humans, who can live naked in the climate of the Rocky Mountains in Washingtom State and British Columbia?
For example my mind is not 100% shut to the possibility that Leprechauns exist or that my mother was impregnated by an alien (and that my real father is Vartog of Alpha Centauri). They are just VERY VERY low on my credibility meter. If anyone has evidence of either of those hypotheses, bring it to me and I will examine it. My mind remains open, at least a small crack. Hard evidence would open it wider, I assure you.
I would prefer that the presenter of such evidence NOT be emailing me from a psychiatric hospital, but even this person’s ideas would merit at least a quick look.
So, my mind is open to the possibility of a hitherto undiscovered, elusive form of great ape called Bigfoot in the Pacific Northwest. Or to UFOs from another planet. In fact, both of these rate a good deal higher in credibility in my mind than the Leprechauns or alien daddy hypotheses
But if my mind is open, it must remain open to a whole range of factors that affect Bigfoot credibility. It must remain open to the possibility that tourism promoters and hoaxers like to amaze people with stories about big apes. It must remain open to the fact that historically, humans have believed in flying, fire-breathing dragons and a host of other monsters that are very unlikely to have ever existed.
My mind must remain open to the possibilty that authors often make lots of money by cobbling together a lot of dubious “evidence” about mysterious beasts. My mind must be open to the fact that we love the idea of giant apes and mosters and want to read about them. There have been half a dozen major movies about King Kong, son of Kong, and Mighty Joe Young.
Google search books about the Loch Ness monster or Bigfoot, then try and tell me human beings are not fascinatd by monsters and strange beasts.
But as the years turn into decades and nobody is able to produce a bigfoot skelton, a skull, or a piece of fur that is not identified as bear or another animal, then I begin to wonder. Absence of proof is not proof of absence, but what am I supposed to suspect when proof remains absent for decade after decade?
So may we never lose sight of those two principles: He who asserts must prove by producing evidence, and yes, our minds are perfectly open. They are open to being convinced by rational evidence. So let’s see it!
