Bob Barber [does God exist?]

by James C

The scientific method involves nothing more than a systematic application of common
sense. For example, suppose I told you about a friend named Bob Barber who lives in
certain distant city. I describe him in detail - physical appearance, age,
education, religious beliefs, occupation, and so on. Then I ask you a rather strange
question - "Does Bob Barber really exist?"




At this point, if you are wise, you will be agnostic, because you just don't know
the answer. You have never met the person I described, and you don't know me well
enough to estimate the probability that I might have invented an imaginary friend
named Bob Barber. However, if you consider the possible existence of Bob Barber to
be important enough to justify at least a cursory investigation, then you might look
for his name in the telephone directory of the city in which I told you he lived, or
do a Google search on his name (maybe he is either famous or notorious), or try one
of the numerous internet sites that offer (for a fee) to do a complete investigation
of anyone you might care to name.

Let us supposed that although you have searched diligently, you have failed to
discover any evidence whatever that a Bob Barber lives in the city in question. This
is a suggestive finding, but it is by no means conclusive proof that no Bob Barber
lives in that city.
Negative evidence is intrinsically less valuable than positive evidence, because
logically there must always be a possibility that we did not consider all possible
explanations for the observed negative results. Such a possibility will continue to
exist whether or not we can imagine it. In our example, Bob Barber might have an
unlisted telephone, or he might always use cell phones or telephone cards, or he
might live with friends and use their telephone, or he might not have a telephone
(he didn't pay his bill? - it happens!), or he might be living incognito, or he
might be in a witness protection program, etc.

It has often been stated that " Absence of proof is not proof of absence". A
scientist might claim, quite truthfully, to have failed to extract even a trace of
compound X from substance Y, using techniques A, B, C, D, R, and F. However, such
negative evidence will lose much of its significance if some other scientist can
truthfully state, "I used a quite different technique, and was able to extract a
very substantial amount of compound X from substance Y". With science, as with many
other processes in life, it is very important to use a technique that works.
Techniques that don't work will always produce negative data.

Does Bob Barber really exist? If we try to answer this question using techniques
that don't work, inevitably we will obtain negative data.
Moreover, we can never be completely certain that we have considered and eliminated
every possible explanation but one for such data.
Philosophers of science claim that it is logically impossible to prove a universal
negative. Somehow, I suspect that it would be a much simpler and cleaner experiment
if we arranged to meet Bob Barber. Once we got to know him and saw him in action, we
would have no further doubts about his existence. A single item of positive evidence
("I have met him, and I know him") outweighs any amount of negative evidence from a
multitude of witnesses who have not yet met him or seen any other convincing
evidence that he exists.