Re: Question on Falsification of Common Descent


John Wilkins wrote:
Kent <musquodster@xxxxxxxxx> wrote:

John Wilkins wrote:


2. The existence of some common ancestry is no longer open to
disconfirmation, because it has been confirmed (you can't falsify what
is true, despite what Popper said, although it was disconfirmable at one
time)


I always worry about this arguement that something is so confirmed that
it is beyond falsification. Is this not basically claiming Hume was
wrong or at leat irrelevant. But I keep coming back to 1900 (or perhaps
1885). Newton's laws and Newtonian gravity had been confirmed beyond
all possibility of them being worng. New planets had been predicted and
found. It had survived every test. The geometry of the world was
definitely Euclidean. At one time the idea that geometry could be
anything else was considered absurd. Kant even had Euclidean geometry
as synthetic a priori knowledge. In the end being confirmed beyond
falsifiability was just proof by lack of imagination. I can not imagine
how it can be wrong, therefore it must be correct. At one time the
Ptolmaic system would have been considered confirmed beyond all
falsification. Fixed contenents wold probably also fall in caegory. I
would suggest that your arguement that aspects of evolution have been
confirmed beyond falsification is also proof by lack of imagination.
This has much in common with the arguements for creationism. The
problem with proof by lack of imagination is that a more imaginative
person may come along.

This is always a possibility. But I would suggest that Hume's point is
about the justification of a knowledge claim rather than about attaining
knowledge claims in the first place. Hume certainly accepted that we
*do* make inductive inferences. The question is whether we are justified
in doing so.

Likewise Popper - the test he applies is whether it *could* be
falsified, but he needed more and appealed to verisimiltude, or
truthlikeness. Of course, under his scheme, this is hidden from us, but
as a theory survives repeated attempts at falsification, according to
Popper, it can be treated as more verisimilitudinous. Whether one wants
to adopt Popper's view of science or not, everyone accepts that some
theories are as solidly embedded as they can be.

Common descent can be "verified" in one of two ways - we can observe
that it happens (which we have in limited cases), in which case it is
like one of the positivistic "protocol sentences" that are not subject
to falsification - or it can be shown that all available evidence
supports it so strongly that it is unlikely to be rejected at any time
in the future, and this is what our present position is (with
Interpretation A).

Of course we can *conceive* that there might be ways in which it will be
later challenged, but possible ways in science are like possible
athletes in an actual race. We do not say that the winner of a race
actually isn't, because Superman might have raced against him. We say he
has won. As things stand now, common descent (A) has won the race in
many cases. If a new hypothesis comes up, then, and only then, will
there be another race. Right now, though, the mere formal *possibility*
that there could be a future challenger does not mean that we have not
now confirmed common descent (A). When Superman shows up, then we'll see
(The Flash can beat him in a running race anyway).

I finish with a quote from David Hull, which I have used before:

"Yet another ambiguity constantly crops up in our discussions of
scientific theories. Are they hypotheses or facts? Can they be "proved"?
Do scientists have the right to say that they "know" anything? While
interviewing the scientists engaged in the controversies under
investigation, I asked, "Do you think that science is provisional, that
scientists have to be willing to reexamine any view that they hold if
necessary?" All the scientists whom I interviewed responded
affirmatively. Later, I asked, "Could evolutionary theory be false?" To
this question I received three different answers. Most responded quite
promptly that, no, it could not be false. Several opponents of the
consensus then current responded that not only could it be false but
also it was false. A very few smiled and asked me to clarify my
question. "Yes, any scientific theory could be false in the abstract,
but given the current state of knowledge, the basic axioms of
evolutionary theory are likely to continue to stand up to
investigation."

Philosophers tend to object to such conceptual plasticity. So do
scientists -- when this plasticity works against them. Otherwise, they
do not mind it at all. In fact, they get irritated when some pedant
points it out."

Science as a Process, 1988, p7
--
John S. Wilkins, Postdoctoral Research Fellow, Biohumanities Project
University of Queensland - Blog: scienceblogs.com/evolvingthoughts
"He used... sarcasm. He knew all the tricks, dramatic irony, metaphor,
bathos, puns, parody, litotes and... satire. He was vicious."

Basically you have ignored my point. In the past, models that were
considered absolutely established have been shown to have shortcomings.
This has happened more than once. The problem is that pointed out by
Hume: no number of correct observations can prove a model universally
correct. True, Hume had problems dealing with the implications of his
claim. In science it was largely ignored until classical mechanics
being replaced by quantum mechanics showed the arguement in action. The
failure of induction, like evolution, has now been observed repeatedly.
This had a profound effect on the philosophy of science. Kuhn was
trained as physicists and Popper quotes Max Born. Any reasonable
philosophy of science must deal with physics between 1900 and 1925. Or
geology between 1915 and 1960 ie between Wegener and the acceptance of
continental drift. In science the concept of fact is not useful and
frequently counter productive. A scientific model can no more be a fact
than a road map can be. As for your quote, scientist frequently are too
attached to their own models.

.

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