tdib at UMICH.EDU
Tue Dec 9 07:21:41 CST 1997
On Tue, 9 Dec 1997 08:57:10 -0800, Richard Zander wrote:
>There are two approaches to viewing hypotheses and theories, realism and
>anti-realism. These are much the same, since the first posits a reality,
>then says it is correctable,
what does that mean,,,,correctable?
> and the second has all the trappings of the first, but denys the reality (acting "as >if").
What exactly are you denying the reality of? Taxa, homologies,
organisms? What, if anything, is real? Quarks?
>They are both liable to
>generating statistical nonsense. Realism, however, in positing the
>reality of patterns, species, synapomorphies, opens the door to low
>standards of hypothesis construction.
I dont think your standards are any higher simply because you imagine
that you can calculate a probability for something.
>Because realists feel that there
>is a truth and that data converge to the truth, hypotheses that maximize
>explanation or minimize falisification are presented as "approximately
>the truth" even with they are of low probability.
Low probability according to what? You keep repeating that as if it
were some holy grail. There is no calculation of probability relative
to truth; only to theory. So what if a minimally falsified hypothesis
is adjudged to have low probability in light of some theory,,why does
this indicate that it is false? Maybe the theory underlying the
probability calculation is false.
> Yes, the correct hypothesis (if it could be determined with a time
>machine) is one of the hypotheses of low probability, but it is the
>ability to choose which low probability hypothesis is the true one that
>is the problem. Maximizing synapomorphies and maximizing likelihood only
>narrows the field by eliminating grossly unreasonable trees.
How can you say that? By what procedure do they eliminate only
grossly unreasonable trees, but fail to eliminate all the rest,
excepting one. Because you independently calculate a probability
which indicates that a set of trees is "reasonable"? What if I were
to say that your calculations are irrelevant or meaningless?
> Thus, reification associated with realist attitudes introduces
>idealist attitudes into realism, which is supposed to be its
>philosophically exact opposite.
I dont think there is any idealism involved. And it seems that you
are the one who is engaged in some sort of a dance with the notion of
truth. You seem to beleive that you can calculate the probability of
something being TRUE. How can an anti-realist hold such a position?
Tom DiBenedetto http://www-personal.umich.edu/~tdib/
Fish Division tdib at umich.edu
University of Michigan Museum of Zoology
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