On Wed, 1 Mar 2000, gordon wrote:

> one strong argument against logical positivism is similar to that to
> which Todd Moody alluded: the statement "Statements which cannot
> be verified empiricially are meaningless" cannot itself be verified
> empirically. This would seem to undermine logical positivism
> in that logical positivism appears to fail its own test. However upon
> closer inspection one sees that this objection is itself an ineffective
> argument unless we first accept the truth of logical positivism! It makes
> no difference to the veracity of logical positivism that its central
> statement cannot be verified, unless we first assume that statements
> must be verifiable to be true.

Logical positivism does fail its own test.  More correctly, if we
assume the Verification Principle to be true, the assumption
turns out to be undermined.  This means that LP is incoherent.
We "accept the truth" of the VP only provisionally, in order to
demonstrate that incoherence.  In short, it's a *reductio ad
absurdum* argument.  We assume something to be true and then show
that it leads to a contradiction, after which we infer that the
assumption was false.  The initial assumption is provisional, not
an actual epistemic commitment.

> Therefore the central principle of logical
> positivism is like the paradoxical "true but unverifiable statement" which
> must exist in every formal system of logic according to Godel's theorem
> (but that theorem is another juicy nugget upon which we could waste a
> few thousand messages, so let's not).

Goedel's theorem applies to formal truths, not empirical truths,
but it does demonstrate that LP does not work in the realm of
mathematics either.

> I once used arguments from the philosophies of metaphysical idealism
> and rationalism to attack empiricism and materialism and logical positivism
> in order to defend my faith in a supreme being. However I have over time
> come to believe  that we need empiricism/logical positivism to separate the
> wheat from the chaff, in the field of health care and diet and nutrition and
> health supplements (especially!) as well as philosophy. I suppose I'm just
> tired of all the unsubstantiated unscientific balderdash that I see being
> promulgated as "true knowledge" on the internet.

Logical positivism is as decisively refuted as any philosophical
position has ever been, and moreso than most since it has the
advantage of being clear enough to refute decisively.  I agree
that more attention to should be paid to questions of what counts
as evidence and what does not in these (and other) fields.  Also,
some evidence is stronger than other evidence, even when not
rising to the level of "proof."

Todd Moody
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