On 10/12/2013 10:58 AM, WM wrote:
> On Saturday, 12 October 2013 16:34:12 UTC+2, fom wrote:
>> On 10/12/2013 8:33 AM, WM wrote: > On Sunday, 6 October 2013 02:32:27 UTC+2,
>
>>> If you want to well-order a set you have to index every element, such that every subset has a first element. How do you index uncountably many elements with only countably many numbers/indices?
>
>> Your contradiction arises by imagining something which cannot be to be. The standard view also imagines something which cannot be to be. However, its proponents do not imagine it to be in such a way that it forces contradiction.
>
> Its proponents did know that |R can be well-ordered. Zermelo wrote in 1904: Proof that every set can be well-ordered. Fraenkel in 1923 emphasized that it had *not yet* been possible to find a well-ordering.
> Only after it had been proven that well-ordering of |R is impossible, the addicts of the infinite dropped that belief. They cannot accept a contradiction in their pet theory, because most of them had to recognize that they devoted their whole life to nonsense. Nevertheless, they did. Thousands of mathematicians did nothing but nonsense during their whole life.
>
Accepting a proof of such impossibility requires
a comparable act of imagined knowledge concerning
the continuum.
The issue here is known as independence.
In models of set theory a global well-ordering
implies that all sets are well-ordered. I do
not know enough about models of set theory without
choice, but the possibility certainly exists that
the reals do not have a well-ordering in models
without the explicit assumption of choice.
> Had anybody ever before made axioms in order to show that they are false? Look at these:
>
> For every two points A and B there exists a line a that contains them both.
>
This expresses sufficient knowledge to postulate a
line. It is not, however, the complete determination
of a line.
> For every two points there exists no more than one line that contains them both; consequently, if AB = a and AC = a, where B ≠ C, then also BC = a.
>
This expresses that the sufficient knowledge to
postulate a line also suffices to segregate an
individual line. It is not, however, the complete
determination of a line.
> There exist at least two points on a line. There exist at least three points that do not lie on a line.
>
The first expresses that sufficient knowledge to
postulate a line is universally sufficient. Everything
that can be a line has the property needed to
postulate it.
The second expresses that the universe of lines
is plural.
Neither involves the complete determination of a
line.
> Should the following axiom be of completely different character?
>
> For every two real numbers there exists one and only one relation <, =, >.
>
This statement refers to the complete determination
of real numbers by virtue of the finite quantifier.
> Only those poor matheologians who have wasted their lifetimes with Cantor-nonsense cannot accept the truth. That's a psychological problem, not a problem of mathematics.
>
Well, if it is a psychological problem, the notion of
independence forces it to be symmetrical. It is your
psychological problem as well.
As for what is and what is not mathematics, that subject
has nothing to do with the reply I gave to your previous
post.
You asked a question about imagination -- both yours and
your opponents. That is what I answered.
If ever you wish to introduce me to One or Three, I
will be happy to meet with them. I think that possibility
just as unlikely as Virgil introducing me to Omega.
http://en.wikipedia.org/wiki/Empty_name