A fundamental thing: how we think about meaning. This boils down to how we think about rules and rule following.

One way to think about rules is an authority / submission model. When we want to know whether something is in accord with a rule, we look to a source of authority which answers the question. This is simple enough.

Consider rule-following paradoxes like 0, 2, 4, 6, … plus vs quus

Phlogiston vs oxygen

Negation of Classical logic vs negation of Intuitionistic logic

  • We have a choice whether or not to consider them the ‘same’ negation