I'm trying my best to understand Della Rocca's article "PSR", which I believe convincingly shows that that one cannot reasonably hold that some facts are brute while others are not without a specific reason for drawing the line somewhere. My example below is a heuristic simplification of his main argument, which I think draws out the main intuition, and I'd like to know if there are any good responses to this argument:
A brute fact is a contingent fact with no further reason as to why that contingent fact is true. Suppose I were to ask you:
"What percentage of contingent facts are brute?"
If you were to answer with a percentage above 0%, and you maintain that this percentage being above 0% is simply a brute fact itself, then you run into a conundrum: By your own admission, there exists a brute fact (that the true percentage is in fact above 0%). But by you maintaining that there exists a brute fact, you've provided a reason for the percentage to be set above 0%. Hence it is contradictory that the percentage being above 0% can itself be a brute fact.
In other words, somebody who maintains that some facts are brute while others are not should be able to give clear reason why Fact X is brute whereas Fact Y is not. If we were to apply this standard, say, to the existence of the universe itself, then it seems that the burden of proof lies on the individual who maintains that the existence of the universe is a brute fact. "It just is" simply does not work.