Rubah Dlesah Lekaman

Gavra_at_work,

thanks for starting this thread! I just looked quickly at that gemara, not be’iyun, so if I’m wrong I’d appreciate someone correcting me.

There seems to be 2 separate things, a rubah d’leisah kaman and a statistical proof. The latter is called a chazaka or an umdena. The camel case is a chazaka not a ruba d’leisa kaman. Also, to answer squeak’s question, the case was that this particular camel was next to the dead camel so between the fact that it was right there and the fact that camels during that time normally get violent there is an umdena that this camel killed the other one.

A ruba d’leisa kaman is by definition a statistical majority, i.e. more than 50%, not a statistical certainty.

The gemara starts out on 92b with a machlokes between rav and shmuel if by financial issues we go by rov to force someone to pay. The case there is a ruba d’leisa kaman – when someone bought a cow which turns out be a gorer and the buyer says its a mekach ta’us and wants his money back. The seller says he doesn’t have to return the money because it is fit for shechita and that’s what he was selling it for (even though he never said so prior to the sale). Rav says the seller has to return the money because there is a rubah dleisah kaman that most people who buy cows are buying it to use it and not for slaughter, so if this cow was only suitable for slaughter the seller should have said so. Shmuel agrees that there is such a rov but says that the seller doesn’t have to return the money anyway because we don’t go by rov in dinei momenos.

Then on 93a the gemara wants to compare this to the case of the camels where its more than a ruba d’leisa kaman, instead its a statistical certainty.

The gemara wants to say though that the 2 cases would have the same halacha as each other, but then the gemara says that this is not necessarily the case. One can hold of ruba and still not go by chazaka in the camel case because over there there is also a rov that says not like the chazaka, namely squeak’s rov – that there are many camels in the world that could have done it so why say it was this one. Or you can not hold of rov and still go by chazaka because chazaka is more of a certainty than a rov.

gavra,

I am very rusty so shkoyach to you for getting me into it. You’re right I was talking about ruba d’alma. Ouch, it hurts to realize how rusty you are, no? although you seem less rusty than me.

First of all, Rusty’s full name is Rustowitz, and he prefers to be addressed that way.

Second, in probability there is a priori and a posteriori probability. Given A, what are the chances that B will occur is a priori, sometimes called conditional probability. Given B, what is the chance that A has occurred is a posteriori. If Bayes rule sounds familiar, you will remember what I mean. I havenb’t had time to look up the sugya in Bava Kamma, but I believe that you need to keep the above in mind.

Third, on a related topic, I thought of a simple hesber for the din of kol deparish meruba parish, kol kavua kmechtza al mechtza. When a piece of meat is on the ground, and their are ten butcher shops of which 9 are kosher, we have an objective, physical leidas hasafek in front of us. We therefore use the rov. However, when a person forgot which butcher shop he went to, the leidas hasafek is in his own mind. It is not an objective physical reality. If he remembered, then it is kosher, but if he didn’t remember, then we don’t use rov, since remembering and forgetting are only in this person’s head, and the rest of the world doesn’t know what is really going on in his mind. However, I seem to recently have come across a din which doesn’t fit with this hesber. Let me know what you think.

thanks for finding that shmaytsa, gavra. (I like your roaming_gavra user name 🙂 )

I looked up the shmaytsa it starts in perek vov and continues into zayin. He brings down a tosfos like you said in sanhedrin 3b which says that shmuel only says we don’t go basar rov by momoin in the case of ruba l’radia – a majority buy for the purpose of using cows, not shechting them, but by other cases of rov then shmuel will agree to rav that we do use rov even by momoinos. Tosfos doesn’t explain why this is so. The shmaytza brings down 2 sevaros, one from the bach which is similar to squeak’s tayna. I didn’t look inside the bach but I think he quoted him as saying that more cows are bought for shechita but more buyers are buying to use the cows alive. The Ramban and the Ritva say a different sevara which the shmaytsa wants to use to explain tosfos – which is gavra’s sevara above – that a rov which is based on a person’s decision (ruba l’radia) is weaker than a rov which is based on nature (giving birth after 9 months).

However, I think both are called ruba d’leisa kaman, just there is a halachic difference between them by momoin according to those rishonim. The rashbam clearly calls the ruba l’radia a ruba dleisa kaman.

The shmaytsa asks on tosfos from your camel case. In that case it is a rov based on nature so according to tosfos shmuel should agree there that one does go basar rov, so why does the gemara say that shmuel could agree there because its gufo muchzak, instead the gemara should say that shmuel agrees by the camel because its a rov based on nature, not based on a decision.

On the answer that gemara gives, that gufo muchzak, I’m not sure what that means. Does it mean the camel is a muad? The rashbam in the hava ameina clearly says this camel has never done this before and that is itself the chidush of the camel case. Is the maskana changing that assumption or does it mean something else?

oh, and squeak, the rashbam says clearly that the camel was next to the dead carcass.

I’ll just add with an agreement to gavra that I have not gone through the entire sugyah, so there may be more.

Please feel free to add or refute, Torah He VLilmod Ani Tzarich.

Yasher Koach to all those who post here.

gavra,

I agree with you what the shmaytza’a raya from the camel case is. I was trying to say the same thing but you said it clearer.

blahblah,

The others on this thread seem very much to be but I definitely am not unfortunately. And that is really truly not just modesty, it is a fact. But hopefully one day I will be one.