[FOM] Question on the number line

Steven Ericsson Zenith steven at semeiosis.com
Tue Nov 15 21:25:50 EST 2005

Dear Dean,

Dean Buckner wrote:
> Forgive me if this is a naïve question.  It occurs in the chapter in
> Suarez (the 16C philosopher & mathematician) that I mentioned in a
> previous posting.  Suppose one takes a line segment of length 1 and
> break it in half (assuming we can break it "in half").  Intuitively, you
> would imagine you get two identical segments of length 0.5.  But if you
> "identify" that line segment with the reals from 0.0 to 1.0, you have to
> ask what happens to the point at 0.5 -- which "half" does it belong to?

In the first case you specify the reals are a function of the points on 
the line - and points have no magnitude so the divided segments at the 
respective end points each have 0.5 as a map since they are the same 
point with respect to the original length.

The second case you specify is a contradiction to the first and 
describes a different mapping.  In that case the line you describe is a 
function of the reals - and therein lies the problem, the number line is 
not a geometric line in the world.  The number line has epistemology, 
but no ontology - it can be known, but it does not exist.

With respect,

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