Based on the verse in Deuteronomy Ch. 11, v. 26,27: “R’ei onochi nosein lifneichem ha’yom brochoh ukloloh, Es habrochoh asher tish’m’u” –
There are two levels of faith. One is acquired by intellectual pursuit, an attempt at understanding to the fullest of one’s capacity. This is called “r’ioh,” seeing.
A second level is that of “emunoh f’shutoh,” simple faith, based on accepting the values transmitted by our parents and teachers, acquired through hearing what they teach us. This is called “shmioh,” hearing.
Although there is a blessing in the intellectual approach in that it gives one a grasp of understanding, it is likewise fraught with the danger of possibly denying, since it is based on intellect, since there is the possibility of counter-logic, rebuttal, that might seem sounder. Hence “r’ei” has in it “brochoh ukloloh [blessing and curse],” while “asher tish’m’u [that you will hear]” only has “brochoh.”
(Rabbi Chaim Mayer of Vizhnitz in Ahavoh M’shuleshes, astrasmitted byZvi Akiba Fleisher via the Shma Yisroel Torah Network. )