A couple of
weeks ago, I wrote a post describing how some critics of Christianity
use demands for “evidence” as a way of dodging tough questions
rather than dealing with them. In that post, I described a
hypothetical example of two strangers: one tells me he has a pet dog
and the other tells me he has a pet sloth. In these cases, I would
be apt to believe the claim to own a dog but be skeptical of the
claim to own a sloth.
A few
people have tried to point out to me that my heightened suspicion of
the claim to own a sloth actually contradicts a point I made later in
my post. Carl Sagan made a famous claim that, “Extraordinary
claims require extraordinary evidence.” By me being
more critical of the claim to own a sloth than a dog, they say I'm
engaging in exactly the kind of skepticism Sagan said was necessary
before believing an extraordinary claim. I don't think so, but since
a few people have accused me of the same thing, I thought I'd use
this as an opportunity to expound my earlier point.
First off,
Sagan's claim is self-contradicting. If it were true, then where is
the evidence for Sagan's claim? I'm not even asking for
extraordinary evidence, mind you. I mean any scientific
evidence whatsoever to justify the claim
that claims require evidence? If Sagan were here and I asked him to
present the evidence for his claim, I'm sure he would resort to logic
and reason which proves my point. Through logic and reason, we can
make judgments about the truthfulness of a claim – even a claim
for which there may be no scientific evidence!
In my example about the sloth, you will notice that not once did I
demand to see the sloth. My point in asking more questions was so
that I might judge the truthfulness of the claim using only my skills
of logic and reason.
But
let's examine that a little but further. What if I were an especially
stubborn skeptic and demand to see a picture of the sloth? If he
pulled out a photo of him holding his sloth, that really still
wouldn't prove anything. How do I know he didn't have that picture
taken some exotic petting zoo somewhere? How do I know it's not a
Photoshop? Maybe he could take me to his home and show the sloth in
person. It's still not enough because, if I were especially
bullheaded, I could ask for proof that this was his home. You say he
has the deed? So what?! Maybe he's leasing part of his property to
someone else who actually owns the sloth! No matter what evidence he
shows me, I could sit cross armed and skeptical saying, “That's not
enough evidence!”
This
is my frustration with many unbelievers. I try to give reasoned
arguments and ask they consider them objectively yet they respond
only with a demand for more evidence.
For some people, I could say that it would take God appearing to
them personally to make them believe but I know even that wouldn't be
enough because they could still dismiss God's appearance as a
hallucination. For someone who truly doesn't want to believe, no
amount of evidence – not even extraordinary
evidence – is sufficient.
Now
back up a minute. Remember about the person claiming to own a dog?
If I were just as skeptical of his claim, what evidence might he
produce that is different than the evidence that I demanded from the
owner of a sloth? In other words, how is the evidence that proves
someone owns a dog substantially different than the evidence that
proves someone owns a sloth? If I am truly a “blank slate” and
will never believe something unless I have evidence for it, then the
evidence necessary to prove someone owns a dog need not be any
different than the evidence necessary to prove someone owns a sloth.
To
prove conclusively a person owns a dog or a sloth or even a
stegosaurus, it would take roughly the same evidence: 1) look at his
address on his ID, 2) drive to that address, and 3) see if the animal
is there. One claim may seem more extraordinary than another, but
the evidence to prove any of the claims is rather ordinary. The
critic might ask, “what if he doesn't really own the animal? Maybe
he's caring for a friend's or relative's pet.” Regardless,
whatever could be said of a pet sloth could also be said of a pet
dog. The evidence to prove either is still the same.
What
if I claimed to own a Big Foot? Simple – drive to my house and see
it for yourself. What if I claimed to own a unicorn? Drive to my
house and see it for yourself. What if I claimed to have a flying
saucer in my backyard? Drive to my house and see if for yourself.
What if I claimed to have created a to-scale model of the Grand
Canyon in my backyard? Drive to my house and see it for yourself.
What is so “extraordinary” about the evidence that could prove
any of these extraordinary claims?
Besides
the famous quote we've discussed here, Carl Sagan also left us the
analogy, The
Dragon In My Garage. In that story, he pretended to have dragon
in his garage and invited his skeptical friend to see it. Of course,
the garage appeared to be empty. Sagan explained the dragon was
invisible. The friend thought of ways to see if the dragon was
there: spray paint the dragon to make it visible, sprinkle powder on
the floor to see its footprints, or use a sensor to detect its
flames. One by one, Sagan explained why none of these would work. A
subtle irony here is that the skeptic only seems to be looking for
ordinary evidence: he wants to see the dragon! Owning a dragon is an
extraordinary claim. According to Sagan, it should require
extraordinary evidence to substantiate that claim but in this
analogy, merely seeing the dragon seems to be enough. So even Sagan,
who made this famous quote, seems to understand that the proof for
owning a dragon really isn't any different than the proof for owning
a dog.
In
Isaiah 1:18, God says, “Come now, and let us reason
together.” To have the
clearest picture of reality requires that we employ our God given
gifts of reason and deduction. For someone to set the ridiculously
high standard of evidence before believing anything is a guarantee to
have a distorted view of reality.
The
word “extraordinary” is enormously subjective. It describes more
about the person hearing the claim than the nature of the claim
itself. When a claim is labeled, “extraordinary,” it means the
person hearing the claim has a hard time believing it. Maybe he just
doesn't want to believe it. But even extraordinary claims require
only ordinary evidence. To say one claim requires “extraordinary”
evidence simply means the skeptic is likely to reject most of the
evidence you present because of his own incredulity.
Further
reading:
3 comments:
As I've noted a few times before, I'm not sure how you'd go about adducing any evidence for the proposition that "evidence is a reason to believe something." After all, if you dispute it, would all the evidence in the world suffice to show you wrong?
If you don't dispute that evidence is relevant, then I think that the answer to the question, "why should extraordinary claims require extraordinary evidence," lies in Bayesian probability. You can look that up, but basically, Bayesian probability asks us to estimate the probability that a given claim is true, given everything else we know about how the universe operates.
If a person claims to own a unicorn, we must weigh that claim not only against our background knowledge of pet ownership and the person's usual honesty, but against our background knowledge that all evidence suggests that unicorns don't exist and never did. He's asking us not merely to accept that he owns an extremely exotic (and hence unlikely) pet, but that our entire knowledge about whether it is even possible to own unicorns is wrong. Which is more likely: that mountains of evidence for the non-existence (and even the biological impossibility of) unicorns is wrong, or that the various evidences he adduces for his ownership of the unicorn (his word, photographs, videos, actually presenting the animal for our inspection and our inability to see obvious signs that it is some possible pet whose appearance has been altered to resemble a unicorn) is faked?
Obviously, for a claim that would require such a massive shift in our background knowledge, we're going to require more evidence, because the evidence against it -- that all needs to be countered -- starts out so strong. The evidence against ownership of a sloth is obviously weaker, but still stronger (given that even as an exotic pet, sloths are unlikely) than the evidence against ownership of a dog (most people don't own dogs, but obviously a large minority do).
Bayesian probability also asks us to consider two separate questions about the evidence.
First, how likely are we to have this evidence if the hypothesis or claim is true?
You've heard, surely, about the "imperfection of the fossil record;" just because an organism existed, it does not follow that a fossil of it is likely to exist. A suspect can burglarize a house, and leave no fingerprints useful to police. It does not seem at all likely that Jesus' birth certificate would have survived, showing that he was born in Bethlehem in the last year of Herod's reign, even if he was.
Second, how likely is the hypothesis or claim to be true, given that we actually do have the evidence in question?
There's a well-known photo of Steven Spielberg posing next to a dead or injured Triceratops, but is this sufficient evidence to show that he hunted and shot this extremely endangered animal? It might seem to be reaching to suggest that the dinosaur is an expensive and elaborate fake (although knowing that he made a highly-profitable movie using expensive and elaborate fake dinosaurs would of course reduce the unlikelihood of that explanation), but even without knowing that Jurassic Park was made we might reasonably prefer it to the hypothesis that Triceratops still exists and that Spielberg found and shot one.
If you'll allow me an example from fiction, the plot of the film Jack Reacher turns, in part, on his realization that a particular piece of evidence against a suspect, a coin recovered from a parking meter with the suspect's fingerprints, is insanely unlikely to have been looked for and found even if the suspect were guilty -- the idea that the evidence was planted is actually more probable than the idea that it was not only left, but found in a normal police search.
If your neighbor shows you a Bigfoot, the odds that it is fake (e.g. animatronics or a really good costume), or even that you're outright hallucinating, must be regarded as more reasonable that would be the case if he merely showed you a dog, because dogs are very commonly seen and Bigfoot has escaped detection for decades, despite the number of people traipsing through his supposed habitat and finding the carcasses of other animals supposed to live there.
Steven J,
Yes, there is the question of epistemology. I started to explore that in my post but it started to become so unwieldy that I felt it distracted too much from my main point. I feel my closing paragraph addresses your point: to label something as an “extraordinary claim” simply means the hearer is going to reject whatever evidence you may have for your claim.
What we believe to be true really has no bearing on what is true. Even if I refuse to believe someone owns a pet sloth, it isn't proof that he really doesn't. Conversely, me believing he does isn't proof that he does. What it takes to convince us is a measure of our skepticism, not the incredibility of the claim.
Thanks for your comments. God bless!!
RKBentley
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