Devil's advocate for why ontology is meaningless and vacuous.

[RoadRunner79]

I would think, that you can know your own values, as well; you could know the values of another (if they tell you) objectively; even if they are by nature subjective.

The former is untrue because of the nature of human irrationality, human infallibility and human inability to fully understand and know themselves.

The later is untrue for the more obvious reason that when someone tells you something there's no way you can know for sure that they're telling you the truth or a truth. They may be lying or honestly mistaken.

And if you can't know for sure how can you know for sure that you even know a little. And how can you know a little that you even know a little? It's rather self-collapsing and self-invalidating.

There is logical proof, there is mathematical proof and there is self-referential proof (I must exist and be experiencing this whatever the nature of "I" is and regardless of what the "this" that I am experiencing is). Other than that there is no knowledge unless you define knowledge differently.

It sounds as if you are saying, that there is no objective or subjective knowledge... There is only you, and you cannot even know what "you" is or holds to, accept for this one caveat.

I would agree, that it is self-collapsing and self-invalidating. And I don't think that we are on the same page concerning knowledge.