WHEN IS BLOOD ASSUMED TO BE TAMEI?
According to Rav Huna, R. Chiya and Rav Katina do not argue. R. Chiya's law applies when the blood was found inside the Lul, and Rav Katina's law is when it was found outside.
Rami bar Shmuel and Rav Yitzchak said that blood found inside is Safek Tamei, and blood found outside is Tahor. This can be like Rav Katina, if he discusses when the blood was found inside.
Suggestion: We must say that they argue with R. Chiya!
Rejection: No. R. Chiya discusses when blood was found on the floor of the Prozdor (the way it normally exits the Cheder), and they discuss when it was found on the ceiling.
FOLLOWING THE MAJORITY
(R. Yochanan): In three places, Chachamim say that something definitely comes from the majority -- blood of the Makor (like we explained), a Shilya (fetal sac), and a piece (of an aborted fetus):
(Mishnah): (If a woman miscarried a Shilya and no child came out,) if the Shilya is in a house, the house is Tamei;
A Shilya is not Metamei because it is considered a (dead) child. Rather, it is always accompanied by a child.
R. Shimon says, perhaps the child was dissolved before the Shilya left the mother (and the house is Tahor)!
(Beraisa): If a woman miscarried a hand or foot in which the fingers or toes are delineated, she is Teme'ah Yoledes. We are not concerned lest it came from an Atum body (the bottom is lacking, like we will explain on 23b).
Question: In other places Chachamim also follow the majority absolutely!
(Beraisa): If nine stores in the city sell slaughtered meat and one sells Nevelah, and a man is not sure from which he bought, the meat is forbidden;
If meat is found, we follow the majority.
Answer: R. Yochanan discusses Tum'ah. (In only three cases of Tum'ah, Chachamim follow the majority absolutely.)
Question: There is another case regarding Tum'ah!
(Beraisa): If one Sheretz was among nine frogs; and Reuven touched one of the ten and is unsure what he touched:
If this Safek arose in Reshus ha'Yachid, he is deemed Tamei;
If it arose in Reshus ha'Rabim, he is deemed Tahor.
If one Sheretz or frog was found and we cannot determine which of these it is, we follow the majority (in that area).
Answer: R. Yochanan discusses Tum'ah of a woman.
Question: There is also the following case!
(R. Yehoshua ben Levi): If a woman miscarried in a river, she brings a Korban (like a definite Yoledes). Kohanim eat the Chatas, for we follow the majority:
Most women give birth to a proper child (for which a Korban is brought).
Answer: R. Yochanan discusses Mishnayos and Beraisos, but not teachings of Amora'im.
Question: Ravin said "R. Yosi b'Rebbi Chanina tried to refute R. Yehoshua ben Levi from the Beraisa (29b) about a woman who errs. I do not see the refutation!"
Suggestion: Rather, the Beraisa supports R. Yehoshua ben Levi! (R. Yochanan should have listed the Beraisa.)
Answer: Perhaps it neither supports nor refutes R. Yehoshua ben Levi.
Question: What did R. Yochanan come to exclude?
Answer #1: When a Chazakah opposes the majority, we follow the majority, but we do not burn Terumah due to it.
Rejection: R. Yochanan already taught this!
(Mishnah - R. Meir): If a (young) child is next to a dough, holding a piece of dough, the dough (next to him) is Tahor;
Chachamim say, it is Tamei, because most children touch. (Rashi - most become Tamei through touching Sheratzim in the wasteheap. Surely, the child touched the dough to take a piece. Tosfos - all children are (Muchzakim to be) Teme'im, for Nidos hug them. Most play with dough. He probably touched it himself. We ignore the minority chance that someone else gave it to him.)
Question: What is R. Meir's reason?
Answer: Most children touch, and a minority do not. The dough has Chezkas Taharah.
We combine the minority of children who do not touch with the Chazakah. This weakens the majority that touch. (We are left with a Safek in which Ein Da'as Lisha'el, i.e. the child is too young to be asked. It is Tahor even in Reshus ha'Yachid.)
Chachamim disagree. We ignore the minority, and we follow the majority against a Chazakah.
(Reish Lakish): We burn Terumah based on such a majority.
(R. Yochanan): We do not burn Terumah based on such a majority.
Answer #2: He excludes R. Yehudah's majority (regarding a miscarriage. Rashi - he teaches that R. Yehudah himself considers it a Safek. Rashba - he rules like Chachamim, who do not follow this majority.)
(Mishnah): If a woman miscarried a piece of flesh:
If blood came out with it, she is Teme'ah. If not, she is Tehorah;
R. Yehudah says, in either case she is Teme'ah.
(Rav Yehudah): R. Yehudah is Metamei (without blood) only if the flesh has the color of one of the four Tamei appearances of blood (Halachah considers the flesh like blood), otherwise he is Metaher.
(R. Yochanan): R. Yehudah and Chachamim agree that if the flesh is one of the four colors, she is a Nidah. If not, she is not;
They argue when we do not know the color of the flesh;
R. Yehudah follows the majority of women. When they miscarry flesh, it is one of the four colors. (Rashi - he is only stringent. She is Safek Nidah);
Chachamim do not follow this majority. (She is Tehorah.)