The Incredibly Lucky JTEM wrote:
> Ray Martinez wrote:
>
>> Wallace ended up concluding that an invisible spirit world does indeed exist.
>
> So you're a mental case, huh?
>
> Because it was Wallace, not Darwin, that worked out
> natural selection. Darwin couldn't even manage to
> describe it, while his attempt at explaining how it
> worked resulted in embarrassing pseudo science:
>
> "Pangenesis."
>
>
>
Might look like this to people who have the scientific understanding of
a ten year old, and an understanding of the history of evolution of a
five year old, sure.
Pangenesis wasn't offered as an explanation for natural selection, it
was offered as a hypothesis for the creation of variation on which
natural selection then can work. He correctly identified this as an
as-yet-missing element of this theory, and in the absence of an
explanation that adequately explained all that was available in term so
of observations at the time, made a suggestion of how such a theory
could look like, while knowing full well that is was highly speculative.
But when no other theory lends itself for incremental modification, such
as "bold hypothesis" (in Popper's terminology) is exactly what moves
science along: it results in testable ideas (in this case Francis
Galton's rabbit blood experiments e.g.) , which then lead to a refined
undertanding of the problem, better hypothesis etc etc .
Darwin saw this very clearly, and explicitly justified his method with
reference to the prevailing conception of scientific methodology at the
time:
"I am aware that my view is merely a provisional hypothesis or
speculation; but until a better one be advanced, it will serve to bring
together a multitude of facts which are at present left disconnected by
any efficient cause. As Whewell, the historian of the inductive
sciences, remarks:—”Hypotheses may often be of service to science, when
they involve a certain portion of incompleteness, and even of error.”
Under this point of view I venture to advance the hypothesis of
Pangenesis[..]"
perfectly sound approach. Ironically, seeing that you reply to Ray, some
of the reasons Panspermia did not work out was that it was both too
Aristotelian, and too Newtonian. In particular, it adopted the
Aristotelian idea of mixing fluids during procreation (again in line
with the science at the time), and the determinism of Newton that
required that ever causal account has to be ultimately reducible to a
deterministic and mechanistic explanation (again, pretty much standard
for the time).
So randomness and chance are only shortcomings of our knowledge ad can
be eliminated:
“I have hitherto sometimes spoken as if the variations so common and
multiform in organic beings under domestication, and in a lesser degree
in those in a state of nature had been due to chance. This, of course,
is a wholly incorrect expression, but it serves to acknowledge plainly
our ignorance of the cause of each particular variation”
While a perfectly sound position epsitemologically, from a pragmatic
perspective it meant he could not exploit the (at the time) modern
tools of probability theory to the extend that a proper genetic theory
required.