(n.) A platitude; a statement which is plainly true; a proposition needing no proof or argument\; -- opposed to falsism.

a priori truth abstraction aphorism apothegm axiom banality brocard bromide cliche commonplace dictate dictum formula general idea generalization generalized proposition glittering generality gnome golden rule gospel hackneyed expression law lieu commun locus communis maxim moral platitude postulate principium principle proposition prosaicism prosaism rubber stamp rule self-evident truth settled principle shibboleth sweeping statement tag theorem tired cliche truth universal truth verity