Why is the bat kol concerning Rabbi Elazar ben dordaya accepted but the bat kol concerning Rabbi Eliezer is dismissed by Rabbi Yehoshua and even more so, rabbi Eliezer was put into cherem! How can this be?
David Levkovich, Montreal, Canada
We do not rely on a Bas Kol for Halachic matters, since we have a rule (Bava Metzia 59b) "Lo ba'Shamayim Hi", this means that once the Torah was given to mankind, it is in their hands to rule on Halachic matters. The Bas Kol of Rabbi Elazar Ben Dordaya was not in connection with any Halachic matter, and therefore is not covered by this rule.
Furthermore, Tosfos (Eruvin 6b) says that where the Bas Kol is not contradicting the majority, it is believed. Alternatively, Tosfos says that the rule only applies to the Machlokes between Rebbi Eliezer and Rebbi Yehoshua. However, Rebbi Yehoshua himself was of the opinion that we never rely on a Bas Kol for Halachic matters. See also Rav Nissim Gaon Berachos 19b.