The main difference between mathematics and most other works of fiction is that mathematics is based on what you can derive when you follow certain sets of rules. The sets of rules are in principle just as arbitrary as any artistic creation, but some are very much more interesting in their own right or useful in the real world than others.
As I see it, the sense in which 2+2 “really” equals 4 is that we agree on a foundational set of definitions and rules taught at a very young age in today’s cultures, following those rules leads to that result, and that such rules have been incredibly useful for thousands of years in nearly every known culture.
There are “mathematical truths” that don’t share this history and aren’t talked about in the same way.
The main difference between mathematics and most other works of fiction is that mathematics is based on what you can derive when you follow certain sets of rules. The sets of rules are in principle just as arbitrary as any artistic creation, but some are very much more interesting in their own right or useful in the real world than others.
As I see it, the sense in which 2+2 “really” equals 4 is that we agree on a foundational set of definitions and rules taught at a very young age in today’s cultures, following those rules leads to that result, and that such rules have been incredibly useful for thousands of years in nearly every known culture.
There are “mathematical truths” that don’t share this history and aren’t talked about in the same way.