My son pointed out to me in interesting line in the Birchas Shmuel at the end of Kiddushin which discusses the parameters of the mitzvah of talmud Torah. The gemara (Brachos 35) records a machlokes between R' Yishmael and RSHB"Y whether one must learn at all times or whether one is permitted to take time off for planting, plowing, harvesting, etc. R' Baruch Ber writes that he asked R' Chaim how we pasken and R' Chaim answered that we pasken like RSHB"Y. The proof: The Rambam (Shemita 13:13 ) writes that anyone who desires can emulate sheivet Levi and devote themselves completely to talmud Torah to the exclusion of all other pursuits.
ולא שבט לוי בלבד, אלא כל איש ואיש מכל באי העולם אשר נדבה רוחו אותו והבינו מדעו להיבדל לעמוד לפני ה' לשרתו ולעובדו לדעה את ה', והלך ישר כמו שעשהו האלוהים, ופרק מעל צווארו עול החשבונות הרבים אשר ביקשו בני האדם--הרי זה נתקדש קודש קודשים, ויהיה ה' חלקו ונחלתו לעולם ולעולמי עולמים
This seems a bit difficult,as the Rambam himself in Hil Talmud Torah (1:12) describes how a "ba'al umnos" should split his time between his learning and his profession:
כיצד: היה בעל אומנות--יהיה עוסק במלאכה שלוש שעות ביום, ובתורה תשע
Later in Hil Talmud Torah (ch 3) the Rambam extols the value of work:
מעלה גדולה היא למי שהוא מתפרנס ממעשה ידיו, ומידת חסידים הראשונים היא
The gemara itself concludes that many people tried to emulate the path of RSHB"Y and failed. It seems clear that for the masses, R' Yishmael's approach is correct. What was R' Baruch Ber's safeik? Was he perhaps wondering whether there is a heter to follow RSHB"Y? Were that the case it would turn the whole machlokes on its head -- R' Yishmael and RSHB"Y are not arguing about whether there is a heter to work, but whether there is a heter not to work! This would be quite a chiddush -- maybe its just me, but I never read the sugya that way.
Interestingly, R' Ahron Soloveitchik writes that there really isn't any machlokes RSHB"Y and R' Yishmael in the first place. Elsewhere (Menachos 99) the two Tanaim seem seem to reverse positions. To reconcile the sugyos R' Ahron suggests that everyone agrees that for the masses, a balance between talmud Torah and secular pursuits is needed, but Torah-only is OK for the elite. The Tanaim offered different advice depending on whom they were speaking to. I guess R' Aharon did not hear from R' Chaim the psak R' Baruch Ber refers to, because if there is no machlokes, there can't be a question of psak.