dgary@ecsvax.UUCP (07/24/84)
<>
This was prompted by several recent postings on free will, mind and
brain, psi phenomena, Shirley MacLaine and other odds and ends.
I believe it was Carl Sagan who observed (in connection with the
existence of extraterrestrials) that "absence of evidence is not
evidence of absence."
Whenever someone declares a belief in flying saucers, pyramid power,
handwriting analysis, or the S A T, you can bet a righteous host
will respond with a cascade of prose pointing out all holes in the
argument bigger than a proton, and I'm right there cheering them on
... up to a point.
I quite agree that the evidence offered so far (offered where I can see
it, anyway) is pretty lousy for any of these things. So I don't believe
in flying saucers or spooks or bermuda shorts. Leprechauns, well...
I further believe in the NON-existence of some things. I don't believe
that vampires are a large and active segment of the population, because
if that were true we would expect to see some evidence (bat craps, I
suppose). I disbelieve in ROUTINE psi phenomena because if they
were going on all around me I think I'd notice, and anyway someone would
have come up with solid demonstrations by now, right?
But I think a few posters have been carelessly implying that if there
is no evidence for the existence of something, that something does not
exist.
Sometimes people ask me if I believe in life on other planets. I tell
them I don't know. I certainly would like to think it is possible
for such life to exist - perhaps even probable. But I don't know either
way. I'm probably not as consistent and sensible on this as I'd
like to think, but it strikes me as good policy.
D Gary Grady
Duke University Computation Center, Durham, NC 27706
(919) 684-4146
USENET: {decvax,ihnp4,akgua,etc.}!mcnc!ecsvax!dgarygwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) (07/26/84)
I think the point is rather that if there is no evidence for something, then it is not proper to believe in it. That is different from saying that it does not exist. Maclaine is hopeless. Read her upcoming Playboy interview (I used precognition to determine what it was going to say).
laura@utzoo.UUCP (Laura Creighton) (07/29/84)
This ``absence of evidence is not evidence of absence'' bit: I think that it is only one way of stating that it is not possible (in the general case) to prove a negative. The best way to try to prove a negative is to set something up which goes: p implies not-q q therefore not-p (Try to prove that my class is not full of 7-up. glass full of 7up implies glass not full of coke glass full of coke, therefore glass not full of 7up) Now the way that you would like to set this up to prove that PSI does not exist is: existence of PSI implies some sort of physical evidence no physical evidence therefore no PSI You notice that the form of the argument, (Denial of the Consequent) is the same. However, in the first example I could point to the existence of something and conclude from that. Here I am stuck with trying to prove ``no physical evidence'' which is a tougher proposition. Even if there has been no evidence whatsoever, there is always the possibility that there will be some tomorrow. However, we cannot all make like the Red Queen and believe 7 impossible things before breakfast. At some point you need to set a threshhold and say ``unless there is more than this much evidence I am going to assume for the moment that not only is there none but there isn't going to be any either.'' Of course, having done this you have to remember why it is that you are disbelieving something so that if somebody comes by with a heck of a lot of evidence that goes over the threshhold then you will reexamine the evidence. This is necessary. Otherwise I will have to keep thinking that ``there might be a big hairy monster in my sock drawer that eats my socks -- even though I haven't seen it (yet)'' and anything else I could possibly imagine. To balance this problem is the generally accepted claim that the people who are trying to present a new theory have to provide the evidence. And if the claim is extrodinary, then then evidence had better be extrodinary as well. It may be that there is extrodinary evidence for PSI that we either don't know how to recognise yet, or haven't found for some other reason. But, until the people who are interested in such things actually present this evidence, there is no more reason to believe in PSI than there is to believe in my sock monster. Laura Creighton utzoo!laura
dave@garfield.UUCP (David Janes) (08/01/84)
[die hobbit!] | From: laura@utzoo.UUCP (Laura Creighton) | Newgroups: net.sci,net.philosophy,net.misc | Subject: Re: science and belief | | ... But, until the people who are | interested in such things actually present this evidence, there is | no more reason to believe in PSI than there is to believe in | my sock monster. | | Laura Creighton | utzoo!laura Wrongo Laura. Since many of my socks have vanished, and many others have been affected by this also, i'd say the sock monster is a lot more believable than this PSI stuff. dave ------- David Janes | allegra \ "Is There Anybody Out There?" | inhp4 - !garfield!dave | utcsrgv /