Positivism vs Realism

[Byron Adams]

Re: the thread of realism vs positivism:

        In Ghiselin's recent book, "Metaphysics and the origin of species"
is a gem about how positivism, and the school of logical positivism in
particular, tries to remove metaphysics from science by inventing a science
based on logic and language.  Criticising this approach, Ghiselin goes on
to say, "One can no more have science without metaphysics than a drink
without a beverage: the only choice is that between good metaphysics and
bad metaphysics, good science and bad science."

        I thought this was a clever way of illustrating the suboptimal
position of trying to divorce science from metaphysics.  But isn't this
what one of you is accusing some research programs of doing?

        I get lost trying to keep track of who is saying what on taxacom as
I follow the threads - but it seems to me that either James or Tom is
accusing a particular research program of relying on the tenets of logical
positivism (or something other than realism) as a part of its discovery
operations.  In order to do this, it would be helpful if they (again, I
can't remember who is accusing who of being a positivist) could show that a
particular research program defies realism in some critical aspect of it's
methodology or interpretation.  This means that you should be able to show
that at some point, the discovery operations employed behave as if what is
true is not independent of what we know, do, or believe as scientists.

        For example, I am now trying to recover the evolutionary
relationships among some insect parasitic nematodes.  My *opinion* of what
happened is independent of the reality that cladogenetic events millions of
years ago produced the diversity and relationships among nematodes I am
trying to recover.  Or, as Ghiselin points out in his defense of realism,
"How could any scientist's beliefs or opinions possibly affect whether or
not chordates have a more recent common ancestor with echinoderms than they
do with flatworms?"

        It seems reasonable to me that any scientific research program or
methodology employing discovery operations subservient to positivism should
be exposed as such.  I think this is a very clever and valid way to
criticise a research program or methodology, and I would like to see it
continue.  So far (from reading the threads) I am not convinced that this
argument has been clearly made or defended.


Byron J. Adams
Department of Plant Pathology
406 Plant Sciences Hall
P.O. Box 830722
Lincoln, NE 68583-0722
lab (402) 472 5598
fax (402) 472-2853
http://ianrwww.unl.edu/ianr/plntpath/nematode/badams.htm