> >Chris: (to my question of how anyone could determine why a paramecium
> >turns right or left)
> >Examine it's molecular structure down to a
> >sufficient level of detail. Or disable various molecular mechanisms and
see
> >which way it turns both with and with out them. Start from the act of
> >turning right or left and back up from there, gradually eliminating things
> >that don't cause it to turn the way it turns.
>
> Bertvan:
> You know a way to do that?
>
There are a number of rather simple molecular biological techniques that
allow you to remove or disable genes or exons within genes, to shut down
various metabolic pathways, provided you know the organism's genome well
enough, which we do for a number of species. They are used in higher animals
(such as mice) to investigate metabolic and developmental activity. In a
protist like paramecia it can be used to investigate your question using the
protocol Chris outlined. In fact, experiments like this have been done, and
they demonstrate that bacteria and protists respond entirely to external
environmental signals. In other words, there is no evidence that bacteria or
protists "choose" by some form of free will where they wish to go.
>
> >Chris: (in answer to my question of how can we know
> >what determines when a particle leaves the nucleus of an atom?)
> >Again, in principle, we would do this by positing possibilities
eliminating
> >everything else except the right one(s). Right now, of course, we don't
> >have
> >the means (YET) to examine the nucleus and its environment closely enough.
>
> Bertvan:
> How about waiting until we DO have the means to examine the nucleus and
its
> environment closely enough, before declaring the method a success?
>
That's just the point, though. Chris' protocol is theoretically feasible;
whether it will ever be practically feasible is another matter. Being
theoretically feasible, however, there is no _a priori_ reason why we should
not expect it to work.
>
> You are
> describing determinism, Chris, where everything has a predictable,
physical
> cause.
>
Scientifically speaking, this is a perfectly valid point of view. In fact,
if you abandon this point of view, you abandon the scientific method.
>
> I doubt determinism can ever be proven.
>
Technically, neither can the law of conservation of matter, energy and
momentum, nor the principle of inertia, nor principle of relativity (I don't
mean the theory of relativity), nor the Third of Thermodynamics (the entropy
of any substance at absolute zero is zero), nor any of a number of other
basic, fundamental working assumptions that scientists use. However, that
does not invalidate them either. They are the assumptions that form the
basis of the scientific method; you don't have to accept them as true, but
you do need to accept that science considers them to be valid.
>
> Surely you will allow that
> an unprovable belief system should not be compulsory-- or declared to be
> more "scientific" than other belief systems.
>
Again, that's just the point. Science is defined by the method it uses,
which is in turn defined by its underlying assumptions. One of those
assumptions is methodological determinism. No scientist is required to
believe in philosophical determinism (I certainly do not), but to be a
working scientist he must accept that one of the assumptions of science is
that specific physical events have specific physical causes that can in
principle be investigated and eventually understood. To reject this is in
essence to reject the scientific method.
Kevin L. O'Brien