|Axiom: principle or rule for linking elements of a theory that is not proven within the theory. It is assumed that axioms are true and evident. Adding or eliminating axioms turns a system into another system. Accordingly, more or less statements can be constructed or derived in the new system. > System.|
Books on Amazon
Axioms/Hacking: mass ratios can be incorporated into axioms. E.g. The mass of the myon is 206,786 times the mass of the electron - HackingVsPutnam: but this cannot be reinterpreted according to Loewenheim because of a bundle of consistent calculations and many relationships to natural constants - these are experimentally confirmed, not just sentences.
Einführung in die Philosophie der Naturwissenschaften Stuttgart 1996