Quote:
Originally Posted by bunny
This premise doesnt rely on intuition - it relies on understanding the properties of an actual infinite. You claim some distinction between infinity and infinite which eludes me, however until that is made explicit why not defer to the experts (ie the mathematicians)?
I've been looking quite far, though haven't yet found Hilbert's initial reference to his hotel - so far, nobody other than Craig and those citing him make the following claim:
As I mentioned earlier, this isn't the point of Hilbert's hotel. Do you have any reference which doesn't involve someone ultimately citing Craig? Mathematical textbooks, and mathematicians don't support this claimed purpose. (I've done three separate maths courses where Hilbert's Hotel was discussed - needless to say none of them were remotely concerned with an 'actual infinite'.
The purpose of Hilbert's Hotel is to point out that our finite intuitions fail when trying to comprehend infinite sets, the lesson being to rely on definitions, theorems and proofs - not on what "seems reasonable". This, in fact, undermines any argument along the lines of "doesn't this consequence of an actual infinite strike you as absurd?" since the point is to illustrate that our intuitions are decidely fallible when it comes to infinite sets.
Suppose we have a line segment we can divide into infinite segments. Can we really say we're recognizing an infinite set of actual segments that already exist, or are we simply creating segments by dividing the line? If the latter, can we really say what we're talking about is an actual infinite, or isn't more just a potential infinite?
I'd argue that the set of natural numbers, (1,2,3, . . .n, n+1, . . .) is a potential infinite, not an actual infinite, because we're just creating the numbers with 'n+1' in a similar manner as we create an infinite set of segments by dividing the line.
So I'd distinguish infinites by saying a potential infinite is created by adding, dividing, etc., whereas with an actual infinite the segments are actual existents that aren't created but simply labeled through an infinite labeling process.
If the Hilbert Hotel is an actual infinite, then rooms aren't created (n+1) as a new guest arrives as with a potential infinite. The rooms are actual existents and what we're doing is an infinite labeling process for room numbers. However, creating a new label would not seem to create new room.