The beginning of this week’s parshah discusses the halachos of a parah adumah (red heifer). The red cow is shechted and burnt, and its ashes are sprinkled on one who is tamei meis. The individual thereby becomes pure.
The Gemara in Chullin 11a asks: Where in the Torah is the source for the halacha that one may follow a majority found in nature or tendencies (ruba d’lessa kaman). One answer that the Gemara suggests is that it is derived from the parah adumah. The Gemara explains that the pasuk says, “veshachat vesaraf – and you shall slaughter and burn it,” from which we learn that just as a cow must be whole and intact when it is slaughtered, so too the cow must be whole and intact when it is burnt. The Gemara says that since the Torah refers to the parah adumah as a chatas, it must not be a traifa. The Gemara asks: How can we be certain that the cow is not a traifa, since if it must be intact we cannot check its insides to determine whether it is a traifa. This is proof that the Torah intended for us to rely on the fact that the majority of cows are not traifes.
Tosafos (Chullin 11a, d”h minah) quotes from the ba’alei Tosafos Rabbeinu Chaim that we learn from parah adumah another halacha concerning following a majority (rov). He says that we draw from this that in a situation where there is a rov and a chazakah that states the opposite, we follow the rov. This is known as ruba v’chazakah, ruba adif. We see this because there is a chazakah here that stands against the rov, yet the Gemara says we follow the rov. The chazakah is that the individual was certainly tamei prior to the sprinkling of the ashes, but now a doubt arises as to whether the cow was a traifa and fit to be a parah adumah. The chazakah of the person indicates that he should remain in his current status, namely to remain tamei. However, since there is a rov that says that the animal is not a traifa, we follow the rov – and the person is tahor.
Tosafos uses the opinion of Rabbeinu Chaim to answer the following question (after a quick review) that he has on the Gemara: The Gemara asked for the Torah source on the issue of following a rov. Tosafos asks why the Gemara did not derive this from the pasuk that teaches us that we may follow a chazakah? Since ruba v’chazakah, ruba adif indicates that a rov is better than a chazakah we certainly may follow a rov. Tosafos at first answers that according to one opinion in the Gemara, we do not obtain the halacha that we may follow a chazakah from a pasuk. So in his view the Gemara is asking what the source is for the halacha that we may follow a rov.
Tosafos then says that according to Rabbeinu Chaim the question does not apply. This is because according to Rabbeinu Chaim we do not logically know that a rov is better than a chazakah; rather, we only know it after we learn from the pasuk that we can follow a rov. Therefore the Gemara is justified when asking what the source for following a rov is, even if we know the source for the halacha that we may follow a chazakah. This is so because we do not know that a rov is better than a chazakah until we know that we can follow a rov.
It seems clear to me that the two answers in Tosafos disagree as to whether the rule that we follow a rov over a chazakah is based on logic or if it is a divine decree that exists out of logic. The explanation in logic as to why we would follow a rov over a chazakah is because the two halachos work entirely differently. A rov is a tool that can be used to clarify the unknown. For example, in the case of whether the animal is a traifa, the rov can clarify that it is not a traifa. Chazakah, on the other hand, is not a clarifying tool but rather states that things must remain in place until we know for certain that they have changed. The Torah only said that we should rely on a chazakah when we do not know how to determine the unknown. But where a clarifying tool is available, i.e. a rov, we know the unknown and have no need to remain in the status quo. This is what Tosafos held in his question and first answer, when he said that the Gemara is only asking based on the view of the one who said that there is no pasuk from which we derive the halacha that we may follow a chazakah. Tosafos held that this logic dictates that a rov is better; thus if there was a pasuk to teach us that we may follow a chazakah, we would then be able to conclude that we can certainly follow a rov.