the.com/principle
The thing you swear by until it costs you something inconvenient.
means A fundamental rule, belief, or truth that guides how something works or how a person decides to behave.
from From Latin principium, meaning 'a beginning' or 'foundation,' built on princeps, 'first' or 'chief' (literally the one who takes first place — primus, 'first,' plus capere, 'to take'). It reached English via Old French principe, carrying the sense of a starting point from which everything else follows. Note the family resemblance to 'prince' and 'principal,' all sprung from that same idea of being first.
latin rootFrom principium, meaning first or beginning.
vs principalOne's a rule, one signs your paycheck.
physicsPauli's exclusion keeps your atoms from collapsing.
famous lineGroucho offered to swap his if you disliked them.
the costA principle untested is just an opinion.