But there is another interesting question that arises from the Bayes explanation at the bottom of the article. If we had all things in the universe available and sufficiently defined to tell what is one thing and what is another, and we found that there are indeed no non-black ravens, that would still leave open the question of whether there could possibly be non-black ravens in the future. They could be born right in this moment, so there would be a race condition between making the statement and the statement being falsified by the event of a non-black raven being born. And I think that's one of the problematic things about purely extensional logic advocated by philosophers like Quine.