[...]
>WR>Popper's recantation --
>>Sir Karl Popper said Darwinism is not science because it is not testable
>>(i.e. falsifiable) -- and in return he received scathing criticism from
>>Darwinians. Later he made a mild (and unconvincing to Micheal Ruse)
>>recantation of the point. Since then evolutionists sight Popper's
>>recantation as definitive evidence that their theory is scientific.
>
I have only seen Popper's recantation cited as definitive evidence
that Popper recanted ;-).
>WR>But the reasons Popper gave in his recantation are inadequate, and
>>fall down on inspection. I dismantle his recantation in an appendix
>>of my book, _The Biotic Message_.
>
SJ:========================
>Indeed. I am still plowing through Walter's excellent (but heavy) book,
>"The Biotic Message". I hadn't yet reached his Appendix which discussed
>the Popper "recantation"
>
>I found Popper's actual words illuminating:
>
>"In its most daring and sweeping form, the theory of natural selection
>would assert that all organisms ... have evolved as the result of
>natural selection; ... If formulated in this sweeping way, the theory
>is not only refutable, but actually refuted. For not all organs serve
>a useful purpose: as Darwin himself points out, there are organs like
>the tail of the peacock, and behavioural programmes like the peacock's
>display of his tail, which cannot be explained by their utility, and
>therefore not by natural selection. Darwin explained them by the
>preference of the other sex, that is by sexual selection..It seems far
>preferable to admit that not everything that evolves is useful, though
>it is astonishing how many things are; ... In other words it seems to
>me that like so many theories in biology, evolution by natural
>selection is not strictly universal, though it seems to hold for a
>vast number of important cases. (Popper K., 1978, "Natural Selection
>and the Emergence of Mind," Dialectica, Vol. 32, No. 3, p 339-355,
>in (ReMine W.J., "The Biotic Message: Evolution Versus Message
>Theory", St. Paul Science: Saint Paul, 1993, p486)
>
Following the quote above, skipping one paragraph, Popper
writes:
I may now briefly sum up what I have said so far about Darwin's
theory of natural selection.
The theory of natural selection may be so formulated that
it is far from tautological. In this case it is not only
testable, but it turns out to be not strictly universally
true. There seem to be exceptions, as with so many biological
theories; and considering the random character of the variations
on which natural selection operates, the occurrence of exceptions
is not surprising. Thus not all phenomena of evolution are
explained by natural selection alone. Yet in every particular
case it is a challenging research programme to show how far
natural selection can possibly be held responsible for the
evolution of a particular organ or behavioural programme.
-- Karl Popper, <reference given above>
It seems clear to me that Popper is using an extreme form of a theory
of NS to illustrate how it can be tested. He finds that the sweeping
claim that all of evolution can be accounted for by NS is false.
But this is just an exageration for purposes of illustration. I doubt
too many Darwinists hold that NS explains all of evolution.
SJ:============================
>Agreed. Walter's criticism is valid. By not really retracting
>what he originally said, Popper by default has conceded
>his earlier point that "Darwinism", is not testable:
>
"Nevertheless, I have changed my mind about the testability and
logical status of the theory of natural selection"
Why is this not a retraction?
>"I have come to the conclusion that Darwinism is not a testable
>scientific theory, but a metaphysical research programme-a possible
>framework for testable scientific theories....it is therefore
>important to show that Darwinism is not a scientific theory but
>metaphysical...." (Popper K., "Unended Quest", Fontana, Glasgow,
>1976, in Sunderland L.D., "Darwin's Enigma: Fossils and Other
>Problems", Master Book Publishers: El Cajon CA, Revised Edition 1988,
>p29).
>
Compare the wording above to that below:
I mention this problem because I too belong among the
culprits. Influenced by what these authorities say,
I have in the past described the theory as "almost
tautological", and I have tried to explain how the
theory of natural selection could be untestable
(as is a tautology) and yet of great scientific
interest. My solution was that the doctrine of natural
selection is a most successful metaphysical research
programme. It raises detailed problems in many fields,
and it tells us what we would expect of an acceptable
solution of these problems.
-- Karl Popper, _Dialectica_
It seems to me that "Darwinism" in the quote you give means
"Darwins theory of natural selection". I suspect that this
choice of words led to some confusion so Popper was much more
careful this time to define exactly what he meant.
Now, the above paragraph is followed by this one:
I still believe that natural selection works this way as
a research programme. Nevertheless, I have changed my mind
about the testability and logical status of the theory of
natural selection; and I am glad to have an opportunity
to make a recantation. My recantation may, I hope,
contribute a little to the understanding of the status
of natural selection.
-- Karl Popper, "Natural Selection and the Emergence of Mind",
_Dialectica_, vol. 32, no. 3-4, 1978, pp. 339-355.
How do you get a concession that "Darwinism" is not testable
from: "Nevertheless, I have changed my mind about the testability
and logical status of the theory of natural selection"
Popper changed his mind.
I regret that my earlier comments may have added to the confusion.
Before reading Popper's recantment I was expecting something more
forceful. Instead, Popper changed his mind from "not testable" to
"difficult to test".
SJ:==========================
>Indeed, if "evolution by natural selection is not strictly universal",
>then what has become of the Darwinism that Dawkins espouses:
>
>"It is the contention of the Darwinian world-view that...slow,
>gradual, cumulative natural selection is the ultimate explanation for
>our existence.
> If there are versions of the evolution theory that
>deny slow gradualism, and deny the central role of natural selection,
>they may be true in particular cases.
If mechanisms other than NS "may be true in particular cases" then
NS is not "strictly universal".
> But they cannot be the whole
>truth, for they deny the very heart of the evolution theory, which
>gives it the power to dissolve astronomical improbabilities and
>explain prodigies of apparent miracle." (Dawkins R., "The Blind
>Watchmaker", Penguin: London, 1991, p318)
>
It's hard to say if Popper would agree about NS playing the
"central role" in evolutionary theory. I would guess that he
would say that this claim is possible but has not yet been
firmly established.
If you want to find some individuals who do question the central
role of NS you should try Michael Ho, Peter Saunders, Brian
Goodwin, Stuart Kauffman and other self-organizationalists.
They say rather forcefully that NS plays only a minor role
in macroevolution, especially the origin of novelty.
========================
Brian Harper |
Associate Professor | "It is not certain that all is uncertain,
Applied Mechanics | to the glory of skepticism" -- Pascal
Ohio State University |
========================