Re: Descriptions, Presuppositions, Liar,...

On 23 Apr 2007 07:10:28 -0700, Newberry <newberry@xxxxxxxxxx> wrote:

On Apr 23, 5:42 am, David C. Ullrich <ullr...@xxxxxxxxxxxxxxxx> wrote:
On 22 Apr 2007 15:47:23 -0700, Newberry <newbe...@xxxxxxxxxx> wrote:

On Apr 22, 12:27 pm, "Jesse F. Hughes" <j...@xxxxxxxxxxxxx> wrote:
Newberry <newbe...@xxxxxxxxxx> writes:
[...]

It is a matter of opinion. But since "All round squares are large"
does not describe any imaginable state of affairs it is meaningless.

No, most people, in particular anyone dealing with standard
logic, would say it's true. The phrase "vacuously true" is
used to refer to this sort of thing.

Let's make one thing clear. We are not talking about classical logic.
The entire post about the logic of presuppositions. We are exploring
where it may lead us. Do you understand that? Do you find such a logic
inconceivable? If not what is the point of saying it is not the same
as classical logic?


Your notion of meaningfulness would have some very curious
consequences. For example, let's say that n is "bad" if
(i) n is an even integer, (ii) n > 2, (iii) n is not the
sum of two primes.

Note that at present nobody knows whether or not a bad
integer exists. Now let P be the following statement:
"Every bad integer is greater than 10".

In any system of logic I've ever seen P is simply
_true_ (proof: 4 = 2+2, 6 = 3+3, 8 = 5+3, 10 = 7 + 3.)
According to your definition of meaningfulness we
need to first determine whether there _exist_ any
bad integers _before_ we can decide whether
P is even _meaningful_. This is very curious (also
definitely _not_ what people mean by "meaningful";
this P is an example of why. Note that if in fact
there are no bad integers that's true for the
same sort of reason as why there are no round
squares, just more complicated - if in fact there
are no bad integers then this follows just from
the definitions.)

So a logic of presuppositions IS conceivable after all.

Who said such a thing was inconceivable? There are
journal articles on "the logic of suppositions" -
not having read any I don't know whether this has
anything to do with what you're talking about.

You have just
stated what consequences it would have.

I gave one consequence of one of the silly things
you've said, yes. The word "meaningful" has a
standard meaning - according to you in this
"logic" certain meaningful (and in fact _true_)
statements are not meaningful. At the very least
you should use a different word - "meaningful"
already means something. It is a _fact_ that
every bad integer is greater than 10 - insisting
that that statement is not meaningful is simply
bizarre. Say it's not newberryfull instead...


I.e. if F means round square then (1) cannot possibly be true.

************************

David C. Ullrich



************************

David C. Ullrich
.

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