1) THE STRENGTH OF "ROV"
QUESTION: The Gemara discusses a case in which nine frogs and one Sheretz were mixed together, and a person touched one of them but does not know which one he touched. If his doubt occurred in Reshus ha'Yachid, he is Tamei. If his doubt occurred in Reshus ha'Rabim, he is Tahor. If he found one of the creatures apart from the others and he touched that one (and he does not know what it was), he may rely on the fact that the majority are frogs, and he is Tahor even in Reshus ha'Yachid.
The Gemara's ruling that the person is Tahor even in Reshus ha'Yachid implies that when Rov is used to resolve a doubt, the case is no longer considered a Safek (that is, the case is no longer one of Safek Tum'ah b'Reshus ha'Yachid).
However, the Gemara in Bava Metzia (6b) discusses the Halachah that a person is exempt from the obligation to separate every tenth animal from his herd as Ma'asar Behemah when there is a doubt about whether the obligation to do so applies in that situation. That is, the animal being taken as the tithe must come from a group of animals that are definitely obligated to be tithed ("Asiri Vadai v'Lo Asiri Safek"). Accordingly, if one was counting the animals in his herd in order to designate the tenth animal as Ma'asar Behemah, and one of the animals that was already counted jumped back into the herd, all of the remaining animals are exempt from Ma'asar Behemah.
TOSFOS there asks that the animal that jumped back into the herd should become Batel b'Rov. It should become like the majority of animals, which are still obligated to be counted for Ma'asar Behemah. When each animal exits the corral, Rov dictates that this animal is not the one that was already counted. The SHITAH MEKUBETZES in the name of the ROSH answers that the Torah requires that the tenth animal be definitely obligated in Ma'aser, and the principle of Rov does not determine that each animal is definitely obligated. Rather, a degree of Safek still remains. An obligation based on a Rov is not sufficient. (See Insights to Bechoros 57:2.)
The words of the Rosh imply that Rov does not resolve a question for certain, and the situation still remains a Safek. Rov merely permits us to act one way when in doubt, but it does not resolve the question. Why, then, in the case of the Gemara here, is a person Tahor in Reshus ha'Yachid? Even though there is a Rov that tells us that he most likely touched a frog and not a Sheretz, there is still a Safek, and thus he should be Tamei because he is in Reshus ha'Yachid.
ANSWER: REBBI AKIVA EIGER explains that there are three levels of certainty: Safek (50% chance that it is one way, 50% chance that it is the other), Rov (51% chance or more that it is one way, 49% chance or more that it is the other), and unquestionable certainty (100%). When the verse teaches that a Safek Sotah is considered Tamei, it means that only an actual Safek is Tamei in Reshus ha'Yachid. If the likelihood of one of the possibilities is greater than 50%, then it is no longer in the category of Safek, and thus the principle that a Safek Tum'ah in Reshus ha'Yachid is Tamei does not apply.
With regard to Ma'asar Behemah, the Torah teaches that the animal of Ma'aser must certainly be obligated in Ma'aser ("Asiri Vadai v'Lo Asiri Safek"); that is, it must be obligated according to the highest level of certainty (not a Safek, and not a Rov). Therefore, when a Rov dictates that the animal is obligated in Ma'aser, it is not considered to be certainly obligated, and, therefore, it is exempt from Ma'aser. This is also the approach of HA'GAON RAV YISRAEL ZEV GUSTMAN zt'l.

18b----------------------------------------18b

2) A CHILD SITTING NEAR DOUGH
OPINIONS: The Gemara quotes the Mishnah in Taharos (3:8) that discusses the case of a child discovered near a batch of dough with some dough in his hand. Rebbi Meir says that the dough is Tahor. The Chachamim say that the dough is Tamei, because "most children touch." Rebbi Meir's reason for ruling that the dough is Tahor is that there is a Mi'ut (minority) of children who do not touch. Although there is a Rov (majority) of children who do touch, the Mi'ut here is supported by the Chazakah that the dough was Tahor until now. According to Rebbi Meir, the Mi'ut and Chazakah combine and override the Rov. The Chachamim ignore the Mi'ut, and thus the Rov overrides the Chazakah.
What does the Mishnah mean when it says that "most children touch"? What are they touching in this case?
(a) RASHI (DH l'Tape'ach) says that children generally touch Sheratzim, and thus they are Tamei. Since the child sitting near the batch of dough is holding some dough, we assume that he certainly touched the batch of dough, and since most children touch Sheratzim, we must assume that the dough is Tamei. Rashi elsewhere (see Kidushin 80a and Chulin 86a, DH she'Darko) explains that children tend to rummage around the garbage and end up touching Sheratzim and Neveilos, and thus they will be Metamei dough that they later touch.
(b) TOSFOS (DH Rov) cites RABEINU TAM who says that the Mishnah means that children generally touch dough that is in their vicinity. He proves this from other places where the word "Tape'ach" is used, showing that it is always used with regard to touching food and drink.
The RASHBA, who agrees with Rabeinu Tam, asks many questions on Rashi's explanation. One of his questions is that the text of the Yerushalmi in Kidushin (4:10) that quotes this Mishnah reads, "she'Derech ha'Tinok Metape'ach b'Isah" -- "that the way of the child is that he touches the dough." Also, if the question of the Gemara is only whether the child had touched a Sheretz or Neveilah before touching the dough, but there is no question whether the child touched the dough, then Rebbi Meir cannot argue that the dough has a Chazakah that it is Tahor; it was definitely touched by the child! According to the Rashba, Rebbi Meir can say that the dough has a Chazakah that it is Tahor, because it is possible that the dough was never touched and therefore retains its previous status.
Another difficulty that Tosfos and the Rashba have with Rashi's explanation is that the Tosefta in Taharos (3:5) explicitly states that children are assumed to be Tamei, because women who are Nidos are constantly hugging them. How, then, can Rebbi Meir argue that the dough has a Chazakah of being Tahor if the Tamei child definitely touched it?
The RAMBAN agrees with the Rashba and Rabeinu Tam, but he attempts to give an answer for Rashi's explanation. The Ramban says that according to Rashi, the child did not definitely touch the batch of dough, even though he is holding a piece of it in his hand. The Ramban apparently means that the child could have obtained a piece of dough without touching the batch (for example, a piece could have fallen off of the batch).
However, the CHOCHMAS BETZALEL writes that although this explanation is valid for Rashi here and in Kidushin, it is not valid for Rashi in Chulin (86a, DH she'Darko). Rashi there explicitly states that "we saw the child touch the dough." The RAN in Chulin raises this question as well. Nevertheless, the Chochmas Betzalel concludes that the Ramban's explanation is correct here and in Kidushin. When Rashi in Chulin says that the child definitely touched the dough, he is discussing a specific opinion that is discussed in that Gemara (see Chochmas Betzalel at length). (Y. MONTROSE)
3) COMBINING A "CHAZAKAH" WITH A "MI'UT" TO OVERRIDE A "ROV"
QUESTION: The Gemara quotes the Mishnah in Taharos (3:8) that discusses the case of a child discovered near a batch of dough with some dough in his hand. Rebbi Meir says that the dough is Tahor. Although there is a Rov (majority) of children who touch everything around them, there is a Mi'ut (minority) of children who do not touch, and this Mi'ut is supported by the Chazakah that the dough was Tahor until now. According to Rebbi Meir, the Mi'ut and Chazakah combine and override the Rov, and thus we may assume that the dough is still Tahor.
Why does Rebbi Meir need to use the Chazakah of the dough to support the Mi'ut? He should use the Chazakah of the child himself! Every person has a Chezkas Tahor, and thus the Chazakah that the child is Tahor should combine with the Mi'ut that some children do not touch everything around them, and thus we may assume that the child was never Tamei in the first place. (REBBI AKIVA EIGER)
ANSWER: The AYALES HA'SHACHAR answers that a Chazakah cannot be used in all situations to support a Mi'ut (and override a Rov). If the use of a Chazakah will directly conflict with the Rov, then the Chazakah cannot be used. In the case of the dough, if the Chezkas Tahor of the child would be combined with the Mi'ut, then it would follow that no child is ever Tamei. Whenever a doubt about a child arises, we will rule that he is Tahor based on the Chezkas Tahor combined with the Mi'ut. Since this is in direct opposition with the fact established by the Rov (that most children are Metafchin and therefore are Tamei), we cannot apply such a Chazakah. In contrast, the Chazakah that the dough is Tahor does not directly conflict with the Rov that most children are Metafchin. That Chazakah does not address children at all; it deals only with the dough, and therefore it can help us resolve whether a child who was Tamei or who was Tahor touched the dough. (See also Insights to Kidushin 80:2.)

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