Acarina, pycnogonids, Permian ticks?

[Thomas DiBenedetto]

-----Original Message-----
From: Kirk Fitzhugh [mailto:kfitzhug at NHM.ORG]
...
>The problem with Popper is that he wanted to
>relegate all of the arena of hypothesis formation to the level of
>psychologism, which immediately removes most of cladistics from the realm
>of science since most of what we do is devise, non-deductively, sets of
>causal hypotheses.

I think this seriously misrepresents Popper. Even if it were true (and I
dont see it) that Popper wished to "relegate all of the arena of hypothesis
formation to the level of psychologism", this would not lead to the
exclusion of cladistics (your view of cladistics) from the realm of science.
For Popper was quite explicit that the issue of hypothesis formation was not
the relevant issue when deciding if something was to be considered
scientific or not. To repeat the point I made yesterday, the demarcation
between science and non-science is the testability of hypotheses, not the
process used in their formation.

> Popper is in the minority among philosophers on this
>point. While there might be some creative/serendipitous aspects to some
>hypothesis formation (Darwin's reading of Malthus is a good example), much
>of it does follow far more rigorous rules grounded in the relevant
>covering theories.

Once again, I dont believe that Popper was all that concerned with the
process of hypothesis formation. So basically, we should not particularly
care what proportion of creativity or "rule groundedness" Darwin's
hypotheses manifest. The only issue is how they stand up to tests.

>There is no real creativity in the inference of cladistic hypotheses,

I agree. All possibile phylogenetic hypotheses, including the "true" one,
are already known - they are the set of alternative trees of life.
Creativity is a wonderful thing, but not necessary. It does characterize
many hypotheses, but, once again, it is only testability that makes a
hypothesis scientific, and it is only success at passing tests that enhances
its value.

>I won't comment on the immense difficulties that actually exist in the
>actual testing of historical hypotheses by the criteria mandated by Popper

No doubt that testing historical hypotheses is difficult - we seem to be
restricted to mining the same evidentiary base from which we made our
initial selection - i.e. to discover new characters and to test their
congruence with our preferred hypothesis.