daf bit: Rosh Hashana 14
The g'mara relates a story of Rabbi Akiva following stricter interpretations from both Beit Hillel and Beit Shammai. The g'mara then challenges this: is it right to adopt the harder rule from each side? If you follow Hillel, follow Hillel for both strict and lenient rulings! And if you follow Shammai, follow Shammai! One who adopts the lenient positions of both is a bad man, while one who adopts the more stringent rulings of both, about him it is said: "but the fool walks in darkness" (Eccl. 2:14). The g'mara then clarifies that R. Akiva was uncertain of how one of them ruled, but that he was in fact following only one of these traditions. (So he was mistaken, not walking in darkness.) (14b)
(There's more to the story than this; the g'mara goes on to discuss other sources R. Akiva might have been following, so maybe it wasn't even Hillel or Shammai to begin with.)

no subject