Comment by andybak

Yes and no. Something can exist as a fact of the universe but still be unknowable. i.e. some hypothetical oracle could measure the quantum states of all human brains and ascertain what true objectivity looks like.

Regular mortals can have any certainty about this dbut espite the logical neccessity that this fact "exists" in some sense.

I think we're essentially also talking about the Overton Window to some degree. But that means you need to be OK with the thought that a sudden rise in extremism on one side of the political spectrum can alter the what you personally have to regard as "neutral and objective".