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> The basic question is are mathematicians fundamentally discovering mathematics (Platonism) or creating mathematics (non-Platonism)? My main issue with mathem
by zajio1am 5y ago
> The basic question is are mathematicians fundamentally discovering mathematics (Platonism) or creating mathematics (non-Platonism)?
My main issue with mathematical platonics is not whether we are discovering or creating mathematic (which seems to me as semantically empty question), but whether existence of matematical object is an absolute property, or a property relative to a specific model/structure, and whether some models are metaphysically exceptional, or all models are metaphusically equal, only some are more convenient to use, so they are more worth studying.
Consider some poly-platonist, who thinks that both natural-number-structure and non-standard-number structure (and both models of ZFC+CH and models of ZFC+non-CH) exist and are "real" and "tangible", and we discover internal relations in these structures as mathematical knowledge.
> Or to put it another way, the abstract notion of "counting" seems to exist objectively and outside of our formal mathematics theories, and our formal theory of natural number is really trying to describe "counting" rather than create the notion of "counting" from scratch.
I can say that we all have clear informal concept of what are natural numbers, just limitations of logic prevent us to formalize that.
But i cannot see how such argument can be extended to set theory, where are plenty of arbitrary choices how to axiomatize that (e.g. ZFC vs. New Foundations).
- dwohnitmok 5y agoTo keep my Platonist hat on... Well if you accept that there is an objective truth to the natural numbers, the set theory axioms you choose will have ramifications for the natural numbers. (Elsewhere in these threads a commentator brings up that Not(Con(ZFC)) will tell you a Turing machine terminates when in our universe it doesn't) Put another way there will always be a purely arithmetical statement of the natural numbers that is independent of your set theory axioms. What is the truth value of that statement? If you think you have a clear and absolute conception of the natural numbers it seems like you should believe that an arithmetical statement has an objective truth value, and if that's true, then that seems like your objective benchmark to decide on how to accept a new axiom (does it prove or refute this true arithmetical statement?). There's your absoluteness.