Re: Popper (was Re: Argument from authority? (was DIFFICULTIES

Brian D Harper (bharper@postbox.acs.ohio-state.edu)
Thu, 19 Mar 1998 18:56:20 -0500

At 10:46 PM 3/17/98 +0800, Steve wrote:

[...]

plopping into the middle of the Popper quote:
>
>BH>The fact that the theory of natural selection is difficult
>>to test has led some people, anti-Darwinists and even some
>>great Darwinists, to claim that it is a tautology. A tautology
>>like "All tables are tables" is not, of course, testable;
>>nor has it any explanatory power.
>
>SJ>I suspect that Popper was cleverly getting even with his
>Darwinist critics, by continuing his criticisms in the guise
>of a recantation!
>

Right ;-)

Popper:==
>BH>It is therefore most
>>surprising to hear that some of the greatest contemporary
>>Darwinists themselves formulate the theory in such a way
>>that it amounts to the tautology that those organisms that
>>leave the most offspring leave the most offspring. And C.H.
>>Waddington even says somewhere (and he defends this view in
>>other places) that "Natural selection ... turns out ... to
>>be a tautology". However, he attributes at the same place
>>to the theory an "enormous power ... of explanation". Since
>>the explanatory power of a tautology is obviously zero,
>>something must be wrong here.
>
>SJ>Yes indeed!

Yes indeed!, and what was wrong was that NS is not a
tautology no matter what some authorities may have
said. You need to read more carefully [with all due
respect and no offense intended and all that other
nice polite mushy talk ;-)]

Popper:==
>BH>Yet similar passages can be found in the works of such great
>>Darwinists as Ronald Fisher, J.B.S. Haldane, and George Gaylord
>>Simpson; and others.
>
>SJ>That "great Darwinists" like "Fisher", "Haldane", and "Simpson"
>have trouble formulating the theory of natural selection without
>making it a tautology, is good prima facie evidence that it *is*
>a tautology.
>

Again with all due respect, I believe you should evaluate
your criteria for evidence.

I don't know if you were around awhile back when Del and I
debated whether Newton's second law was a tautology. I took
the position that it was not, however, one can make very
reasonable arguments that it is. I'm sure Del would say
they're a lot more than just reasonable :-). Formulating
mechanics so that Newton's second law is not tautological
is very difficult, with people still arguing over it.
This doesn't mean it's not possible.

But suppose Del is right and it is a tautology?
Would mechanics be any less useful, or any less correct
for that matter.

Popper:==
>BH>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.
>
>SJ>So Popper in this "recantation" admits that the theory of natural
>seelction is not "almost tautological", but is in fact "a tautology"!
>How he must have laughed as he wrote this!
>

Please read carefully. Popper is describing his *former* position.

>BH>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.
>
>SJ>Note "*doctrine* of natural selection"! It's no longer a "theory"!
>And it still is a "metaphysical research programme"!
>

Once again, Popper is describing his *former* position.

>BH>I still believe that natural selection works this way as a
>>research programme.
>
>SJ>And again. It is a "research programme".
>
>BH>Nevertheless, I have changed my mind about
>>the testability and logical status of the theory of natural
>>selection;
>
>SJ>Popper is just pulling Darwinist's legs and they don't even
>notice! He hasn't retracted anything what he said about
>"the testability and logical status of the theory of natural
>selection". Indeed, he has confirmed that "really severe tests
>of the theory of natural selection are hard to come by" (read
>"impossible"). And as for "logical status" it has slipped
>further from "almost tautological" to "a tautology".
>

No, you misread.

>BH>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
>
>SJ>What a wit! Indeed Popper's "recantation" has contribute "to the
>understanding of the status of natural selection", ie. that it
>"is not a testable scientific theory, but a metaphysical research
>programme"!
>

How do you arrive at this conclusion when he says the opposite?

"Nevertheless, I have changed my mind about the testability and
logical status of the theory of natural selection;" -- Popper

Oh, I forgot, he was only joking.

>BH>With respect to the claim that macroevolution is not science
>>(according to Popper), consider the following sentence from
>>the above quote:
>>
>>#"The Mendelian underpinning of modern Darwinism has been
>>#well tested, and so has the theory of evolution which
>>#says that all terrestrial life has evolved from a few
>>#primitive unicellular organisms, possibly even from one
>>#single organism." -- Popper
>
>SJ>That "all terrestrial life has evolved from a few primitive unicellular
>organisms, possibly even from one single organism" is a necessary but
>not sufficient test of *Darwinism*. *I* am a creationist and I have no
>problem believing in common descent and nor does Mike Behe. As
>Denton points out, common descent is "compatible with almost any
>philosophy of nature", including some forms of creationism:
>

But the point was Popper's views on macroevolution, whether it
is science. Popper said "...all terrestrial life has *evolved*
from a few primitive unicellular organisms, possibly even from one
single organism." (emphasis added). The evolution of all terrestrial
life from one or a few primitive unicellular organisms must
surely involve some macroevolution along the way :).

[...]

>
>BH>It is also instructive to note why Popper came to his
>>former view that natural selection was "almost tautological".
>>He was "Influenced by what these authorities say..."
>
>SJ>Since Popper was not a biologist, like the rest of us, he had no
>alternative but to be "Influenced by what these authorities say".

It seems to me that he did in fact find an alternative.

>SJ>What do you expect him to do-sail around the world for several years
>making his own observations?
>
>But as a *philosopher* Popper was well qualified to subject Darwinist
>reasoning to established canons of logic, and to conclude that not
>only was the Darwinist theory of natural selection "almost tautological"
>but in fact it *was* "a tautology"!

No, you are quite wrong about this.

Brian Harper
Associate Professor
Applied Mechanics
The Ohio State University

"It is not certain that all is uncertain,
to the glory of skepticism." -- Pascal