kriyas shema and its brachos

We usually assume that missing a bracha is not a fatal defect in the performance of a mitzvah; the mitzvah as a Biblical command stands by itself separate from the Rabbinic obligation to recite a bracha before its performance. However, R’ Hai Gaon (Quoted in Rosh sima 1 in 2nd perek of Brachos) opines that the mitzvah of kriyas shema is fulfilled only if the brachos of kriyas shema are also recited. A similar distinction between kriyas shema and other mitzvos may be inferred from the Rambam. If one has a doubt whether one fulfilled a mitzvah, the mitzvah is repeated but not the bracha – the weighty Biblical obligation demands that we strive for certainty, but the Rabbinic obligation of bracha does not. However, the Rambam writes (hil keriyas shema 2:13) that if one has a doubt if one has fulfilled the mitzvah of kriyas shema, not only must one recite shema, but one must also recite the brachos as well. R’ Chaim Brisker assumed that the brachos said before keriyas shema are not the same as other birchos hamitzvah that stand independently from the mitzvah itself, but are part and parcel of the fulfillment of the mitzvah of shema itself. Shema recited without its brachos is an incomplete fulfillment of the mitzvah of kriyas shema. So much for the lomdus - I bring this up for another reason, which I will get back to…