I suppose that
those who take an interest in tracing their family tree would
like to be able to prove the correctness of every
linkage they report, every date, every statement about an
individual. They would like to have personally verified
evidence in sufficient quantity that they can say "yes, I'm
certain!" about every claimed fact in the tree. But exactly how
much evidence is that? It is easy enough to accept that proof
derives from evidence, and evidence must be verified as to its
existence and nature before it "counts." What is the role of
authority in all this? Is an official document
irrefutable evidence?
"The proof of
the pudding is in the eating." That old saying sums it up
perfectly. "Proof" is subjective. It takes a certain amount of
evidence to convince you of something, but a different amount
of evidence to convince your brother. One argument may be
highly convincing to you, but leave someone else completely
skeptical. Some people are highly accepting of authority; they
will believe something or not depending on who said it (or
published it, or endorsed it.) "Well, she ought to know if
anyone does!" can be heard in most discussions of matters of
opinion. At the other extreme you have people who will say "You
found his tombstone? All that proves is that there's a stone
there. Did you dig up the coffin and have the DNA analyzed?"
(Even then, it would have to be compared to DNA taken when he
was alive, and correctly identified and labeled at the time.
Can you prove it wasn't mislabeled?)
In short,
there is no such thing as absolute proof. There is evidence,
adequate to convince. That is as close as one can come to the
imaginary concept "proof." One can "have ones mind made up"
such that no amount of contrary evidence will ever convince him
to change it; in that case it is easy to see that the concept
of "proof" is simply that, a theoretical concept. We also speak
of "the burden of proof", a legal concept. In this case, a
statement is made that describes something possible, even
probable. We can say "the burden of proof" is on those who
would refute it. They must produce evidence indicating that,
probable or not, it is in fact wrong. I will return to this
"burden of proof" concept, as it seems to be to be highly
relevant to genealogical research.
First, let us
look at the issue of evidence . Evidence is worthless if
you don't know for sure that it really exists, or can't
demonstrate to someone else that it really exists. You can say
"Here's what it said on the church record ..." and give some
words that you read from your notes. What is your evidence that
you didn't misread the record, or make a copying error? For
that matter, how do we know you didn't make up the whole story?
Before duplicative copiers (photography, Xerox, scanners),
people tried to provide this evidence by having more than one
person make independent pen-and-ink copies, then comparing
them. This is an effective system, if the two copies are indeed
independent. The principle is, there is only one way to get it
right and an infinite number of ways to make a mistake, so if
two versions agree, the odds are they got it right. We would
find that method unendurably tedious today; fortunately we have
faster methods available.
You will hear
much about primary and secondary evidence. Once
again, this is a transfer of a legal concept into the research
arena. Primary evidence is the testimony of an "eye witness",
someone who was present at the event and in a position to know
the facts. Secondary evidence is everything else.
Unfortunately, there is a tendency to imply that if evidence is
primary, it must be reliable. Ever listen to the testimony of a
dozen eye witnesses to the same event at a trial? No two will
agree. Ever have your own words quoted back to you by someone
who heard them directly? Was it a match? Probably not. People
are not recorders and cameras. Our perceptions and what gets
stored in memory are colored by everything else happening
around the same time, guesses we made to fill in portions of
the event we didn't see, and our emotions at the time. The real
reason why we should place more confidence in primary than in
secondary evidence is simply that it has a higher
probability of being correct. There is no certainty,
just a higher probability. Even that has no scientific or legal
basis beyond the fact that, through the years, we observe it to
be the case. "Seeing is believing." Believing, yes. Knowing for
sure, no.
"Weigh the
evidence." Good advice. There are two implications there;
first, that what is presented as evidence must itself be put to
some sort of test to see if it is valid or not.
Secondly, there is "weighty" evidence, evidence of a kind that
is usually found to be reliable when tested, and there is
"light" evidence, evidence of a kind that experience shows
often turns out to be spurious and misleading. Whenever there
is a simple choice to be made between two possibilities, one in
effect adds together the weight of each item of evidence on the
side of each possibility. The side with the "heavier" total of
supporting evidence is the side that ought to be accepted as
most probably true. In law, this concept is the "preponderance
of evidence" that decides who wins a civil court case.
When we
consider evidence we must also be careful about exactly what it
is evidence of ! You may say "I have seen a letter from
his 8th grade teacher saying he was very
intelligent." Then you say where this letter can be found. Four
other people, none of them your close relatives or in your
employ, go there and also report that they saw the letter, and
that it says what you said it says. Now we have justification
for believing this evidence. But we have no particular reason
to believe he actually was intelligent, merely that his 8
th grade teacher thought he was. Now we
need evidence that the teacher (a) always expressed her opinion
bluntly and honestly, and (b) was a good judge (by some
objective standard) of a student's intelligence. This is an
easy error to make – evidence that someone actually said
something is not evidence that what they said was true. This is
the difference between verified evidence and
validated evidence. When you verify evidence, you show
that it exists as originally claimed. When you validate it, you
show that what it claims is in fact correct and
accurate; that is, you provide supporting evidence .
Valid evidence is not contradicted by other, equally
strong evidence, and violates no rules of logic.
Let me return
to the "burden of proof" concept. All scientific research is
based on the Principle of Hamlet and the Principle of Laplace.
The former says "All things are possible." The latter says "The
more improbable something is, the stronger the evidence you
need before you should believe it." If there is general
acceptance of some statement about one of your ancestors, no
one has ever proposed a contrary statement, and in general
there is no dispute, then very little evidence is needed to
justify your belief in that statement. The situation could
change in the future if someone eventually presents a contrary
view, but "sufficient unto the day is the evil thereof" – it
seems to me you are justified in saving your finite time and
energy for research on those issues that already have
conflicts. Let "the burden of proof" be on that imaginary
future person who decides to deny what is presently accepted.
In fact, you have no choice, since you do not know what
arguments this person (who may never exist) will put forth. In
short, your efforts at collecting evidence must depend on the
probability that what is currently believed or claimed actually
occurred.
If the claim
at hand is that Archibald's parents were Theobald and Minerva,
and Minerva would have been 60 years old when Archibald was
born, you need strong ("weighty") evidence to support that
claim before you should believe it, as it is not very probable.
I suggest as a definition of "improbable", "likely to be quite
rare." We're not into advanced math here. I have seen family
trees on the Internet that reported a marriage occurring in
1768, and in the same record, stating that the "groom" died in
1767. I find this sufficiently improbable (especially since
they proceeded to have a child in 1769, according to those
reports) that I can't really visualize the weight of evidence
it would take to convince me that it was all true. I do not
feel that I have the "burden of proof" that there is at least
one error in this report – in cases like this, the "burden of
proof" is on the person who is claiming something that on the
face of it is highly unlikely (improbable.)
Finally, I
want to say something about official documents. I could
use the example of my father's official birth certificate from
the state. The birth record provided by the hospital does not
agree with the one provided by the state. The disagreement
happens to involve the middle name. Is the official birth
certificate "weightier" evidence than the hospital document,
because the former is what would count the most in court,
toward getting a passport, etc.? The hospital record happens to
match what both my father and his parents wrote on every
relevant document throughout his life. There are two possible
viewpoints – (a) the birth certificate has his "real" name
because it would be the version accepted by the law, and (b)
the other version is his "real" name because it is how he was
known all his life, even by himself. Keep in mind that the
intent is to record on a birth certificate the name assigned by
the parents; but while the hospital certificate is in fact
filled out by the parents, the official birth certificate is
not. The attending physician, if any, may be the sole arbiter
of what appears there. I would point out that any "official"
document can certainly be refuted in court, and can be declared
invalid if a sufficient "weight of evidence" is brought forth
opposing it. That it was "official" simply identifies who has
"the burden of proof", namely those who would refute it.
The bottom
line is, think about who has the "burden of proof" in
genealogical issues. I suggest that it is the person or
authority who is making the least probable claim. I have seen
genealogical researchers dedicate a lifetime to the
accumulation of more and more evidence for what was never in
contention in the first place, or for what needed very little
evidence because it was so highly probable. This serves no
useful purpose, and limits what can be accomplished.
~~~~~~~~~~~~~~~~~~O~~~~~~~~~~~~~~~~~~~
Note about the author: Phil Albro is a retired research
biochemist who has replaced biochemical research with research
into his ancestry. He has published approximately 140 articles
in research journals, and sees no fundamental difference
between valid biochemical research and valid genealogical
research. He teaches at a state university, and his course
includes the difference between scientific evidence and legal
evidence. He works in a bona fide dungeon, and has a lifelong
love of science fiction. He believes that excessive credulity
and excessive skepticism can both be detrimental to any kind of
research. He invites disagreement, and values the willingness
to express it.