1. (n.) A self-evident and necessary truth, or a proposition whose truth is so evident as first sight that no reasoning or demonstration can make it plainer; a proposition which it is necessary to take for granted; as, The whole is greater than a part; A thing can not, at the same time, be and not be.

2. (n.) An established principle in some art or science, which, though not a necessary truth, is universally received; as, the axioms of political economy.

a belief a priori principle a priori truth absolute fact accepted fact actual fact adage admitted fact affirmation ana analects aphorism apothegm apriorism article of faith assertion assumed position assumption bald fact bare fact basis brocard brutal fact byword canon catchword categorical proposition center circumstance cold fact collected sayings conceded fact conjecture core current saying data datum demonstrable fact dictate dictum distich doctrine dogma elixir empirical fact epigram essence essential established fact expression fact fact of experience first principles flower focus formula foundation fundamental gist given fact gnome golden rule golden saying gravamen ground guesswork hard fact heart hypostasis hypothesis hypothesis ad hoc indisputable fact inescapable fact inference inner essence kernel law lemma major premise marrow matter of fact maxim meat minor premise moral mot motto naked fact not guesswork not opinion nub nucleus nuts and bolts oracle philosopheme philosophical proposition phrase pith pithy saying plain position positive fact postulate postulation postulatum precept premise prescript presumption presupposal presupposition principium principle proposition propositional function provable fact proverb proverbial saying proverbs quid quiddity quintessence rule salient fact sap saw saying self-evident fact self-evident truth sentence sententious expression set of postulates settled principle significant fact simple fact sloka sober fact soul spirit statement stock saying stubborn fact stuff substance sumption supposal supposing supposition surmise sutra teaching tenet text the case the nitty-gritty theorem thesis truism truth truth table truth-function truth-value undeniable fact universal truth verse well-known fact wisdom wisdom literature wise saying witticism word words of wisdom working hypothesis