Todd,

> > Consider the statement "The unicorns on the moon prefer to
>> eat carrots".
> >
> > I reject that statement as meaningless on positivist grounds. The
> > statement cannot be verified because unicorns do not exist on the
> > moon or elsewhere.
>
> You are mistaken.  Even according to positivism this statement
> is meaningful, but false.

I think you are mistaken. A false but meaningful statement would be
"Unicorns exist".

However the statement in question is "The unicorns on the moon prefer to eat
carrots".

>The verification principle only requires
> that we be able to say what observations would, in principle,
> verify it.

Exactly. And there are no observations would could in principle measure the
eating preferences of lunar unicorns. Therefore the statement is meaningless
nonsense on positivist grounds.

> It's not nonsense.  It's just false.

It could be false (or true) only if lunar unicorns were observable in
reality. It would be false if lunar unicorns were non-imaginary creatures
who preferred something other than carrots.

Without logical positivism, there is no reason to avoid arguments about the
habits of unicorns or about the number of angels that can dance on the head
of a pin. I could assert that 1,000 angels can dance on a pin and then you
could argue as above that my statement is "false" rather than meaningless.
We would then each be forced to invent elaborate theories about the size and
dancing abilities of angels in order to defend our positions.

Fortunately most scientists take a positivist approach and nip such
arguments in the bud before they waste everyone's time. This is why
mainstream physicists, for example, will not suffer through arguments about
the correct interpretation of quantum mechanics. To a logical positivist
there is no point to hypothesizing about the nature of subatomic reality
prior to its observation, since such hypotheses can never in principle be
tested. Neils Bohr's non-mystical no-nonsense Copenhagen interpretation of Q
M is the accepted mainstream interpretation because it is a *positivist*
interpretation. Far from being "dead", logical positivism is alive and well
in modern science.

-gts