Former Secretary of Defense Donald Rumsfeld was in the news last week with the release of his memoir "Known and Unknown." The title stems from a comment he made in February of 2002: "because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns - the ones we don't know we don't know."
This statement is very clear and straightforward. I would like to use his statement to describe a difference between the philosophy of the shiurim of Rav Ahron Soloveichik and his brother Rav Yoshe Ber Soloveitchik.
For a year I was in the shiur of a very well-known talmid of the Rav, and I still distinctly remember him at times, summarizing a sugya, saying "What we still don't know is how Tosfos learns this Tosefta," and things like that. When he was leaving a sugya, he mentioned the known unknowns, the items we were not able to figure out while studying the sugya. (Some might call it the glass half-empty approach, but I don't agree with that.) However, after completing a sugya with Rav Ahron, I always had a feeling "now I understand this Rishon, that shita...," a focus on the known knowns. I was happy knowing what I learned - or should I say what I knew.
And yes, I think I can even give an example of unknown unknowns from their grandfather Rav Chaim Brisker (though in at least one place I heard it attributed to their uncle Rav Velvel). Rav Chaim is quoted as saying "you cannot say a chiddush until you have gone through Shas." I think there is a lot in that statement, but one point definitely is that there is a lot in Shas, and until you know it, you cannot speculate with new ideas. Because you'll find that some are really old ideas. Some might be good and some might be bad; some are true and some are false. Until you reduce your unknown unknowns, you shouldn't be speculating.