Without any agreement to the terms being used in that description, determining whether those "facts" are born out or not is an entirely subjective proposition.
"Without any agreement," the human race is lost. For we no longer have any way of making ourselves intelligible to one another, if we begin by saying that there is no standard by which our statements can be judged, in principle.
Are you sure you want to go there? It seems you are advocating in favor of an infinite causal regression that leads to exactly nothing and nowhere.
As against that proposition, may I advance a notion of Eric Voegelin's, that the human psyche -- assuming it has not been tampered with -- has an innate, "indefeasible integrity" in its contacts with/descriptions of nature.
Meaning: We humans seemingly tend to get things right in our descriptions of the universe. Otherwise, the causes that led to our advanced societies would be utterly unintelligible.
Just ask yourself: Why is that???