Based on whether they take you to places you don’t want to end at, which is an incomplete measure but quite a pragmatical one. E.g. if your set of axioms end at “erase half of the population by force”, then perhaps revisit your axioms.
That's what soulofmischief is saying. If your reasoning ends at somewhere you don't like emotionally, then your axioms are bad i.e. your actual axioms are emotional. Which is fine!