I'm looking for a word that describes something that is not yet a scientifically proven fact, but people intuitively think to be true. The word is not "hypothesis" as I'm not describing The Scientific Method. Also hypothesis implies something that is potentially disprovable. I'm looking for a stronger term. Is there such a word or a phrase?
Here is an example:
"Hard work does not guarantee success".
People think (or know) this to be true even though it's not yet scientifically provable or disprovable. It's a general truth, not a hypothesis or a theory.