Re: The principle of non-contradiction re-assessed

On Jun 10, 2:36 pm, John Jones <jonescard...@xxxxxxx> wrote:
I want to illuminate in my own way the nature of a law or principle. I
will use a popular example to do this - the principle of non-contradiction*:

There can be no arguments for, no convincing us of the truth of, the
principle of non-contradiction*. Argument cannot ratify the
self-evident. We can never come to "believe" in the principle of
non-contradiction - there are ... no alternatives.

We know that the principle of non-contradiction is applicable simply
because we see immediately that it encapsulates the rules we employ in
our every-day life in the empirical world. Knowledge itself, empirical
knowledge that is, is built on it.

It follows, in fact, that there can be circumstances in which the
principle does NOT apply. These are not hard to find. A universe
constituted of a solitary object cannot provide us with an instantiation
of the principle of non-contradiction. The solitary, monad object, call
it A, cannot be distinguished from not A.

Self-evident truths, like the principle of non-contradiction, are always
'true' in a trivial sense, though they may apply or not apply. Graham
Priest argues in Beyond the Limits of Thought that "dialetheia" (which
holds that the principle is not always true) arise at the borders of
expressibility. Priest here confuses the application or instantiation of
the principle with its truth or even with its absolute truth.

*(one cannot say of something that it is and that it is not in the same
respect and at the same time", Aristotle)

Those logics that go by the name of "paraconsistent" are ones in which
the principle of non-contradiction fails and certain contradictions
can be "true" (whereby "true" I mean satisfied in the appropriate kind
of model). Graham Priest is one of the people who've worked in the
area of paraconsistent logic and argued in favor of it. If you
bothered to read what he's written on the subject, or bothered to read
what anyone else has written on the subject, you'd know about how this
sort of thing works.

So ... but, oh, that's right. You don't believe you actually have to
read or learn anything about logic ... which leaves everyone puzzled
about why you continuously post to sci.logic.
.

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