1) THE LOGIC OF "KOL D'ALIM GEVAR"
OPINIONS: The Gemara teaches that in a case in which two litigants argue over the ownership of an object (such as a boat) which neither one of them is holding in his possession, the rule of "Kol d'Alim Gevar" applies, and whichever disputant overpowers the other prevails and may keep the object.
How is the ruling of "Kol d'Alim Gevar" to be understood? It seems strange and unjust that Beis Din should allow the two disputing parties to fight against each other, and rule that whoever overpowers the other may keep the object in dispute.
(a) The RASHBAM (end of DH Hasam) explains that when it is possible that one litigant will bring proof to support his case, Beis Din does not rule "Yachloku" or "Shuda d'Dayanei," because Beis Din might need to retract its ruling at a future time when proof is brought. Therefore, Beis Din does not get involved, but rather Beis Din leaves the case alone and lets the litigants contend with each other, and whoever is stronger and overpowers the other may keep the object until either one presents to the court proper proof of ownership.
The Rashbam's words imply that "Kol d'Alim Gevar" is not a Halachic ruling that Beis Din issues based on an analysis of the case. Rather, "Kol d'Alim Gevar" is a mechanism wherein Beis Din withdraws from the case and issues no ruling.
(b) The ROSH here (3:22), in Bava Metzia (1:1), and in Teshuvos (77:1) writes that there is some logic to the principle of "Kol d'Alim Gevar." He explains that it is logical to assume that the true owner probably will bring proof to his ownership soon, as the Gemara explains, and therefore even if one overpowers the other, justice eventually will prevail. Moreover, it is probable that the true owner will overpower his opponent because he will put more effort into claiming the object since he knows that it is truly his. The claimant who is not the true owner will not put forth so much effort to get the object, because he is afraid that the court will take it away from him later and give it to the other party based on proof of ownership that the other party will bring.
The Rosh adds that once one person overpowers the other, Beis Din no longer allows the two of them to physically seize the object from each other without sufficient proof of ownership, in order that they not continually be fighting with each other.
The SHITAH LO NODA L'MI (cited by the Shitah Mekubetzes) questions the Rosh's explanation. According to the Rosh, why should Beis Din get involved with the case and protect the rights of the first person who seizes the object? The Gemara teaches that Beis Din prefers to stay uninvolved with the quarrel and not pass judgment, and thus even when one litigant seizes the object, Beis Din still should stay uninvolved and not pass judgment! The Shitah therefore rules that Beis Din will not protect the seizure of the object by either party, and even after one party has seized the object the other can grab it back and take it for himself.
It seems that the Rosh, who argues with the Shitah's view, understands the principle of "Kol d'Alim Gevar" differently. "Kol d'Alim Gevar" is not a way for Beis Din to withdraw from the case. Rather, Beis Din indeed issues a ruling on the case. As the Rosh explains, Beis Din rules that the one who overpowers his opponent is the true owner. Therefore, after one overpowers the other, Beis Din is entitled to become involved in order to uphold its ruling.
Based on this explanation, the CHASAM SOFER and CHIDUSHEI RABEINU MEIR SIMCHAH present a new way of understanding the Machlokes (on 34b) regarding whether Beis Din is allowed to return the object to the public domain, and allow the litigants to fight over the object, after Beis Din has appropriated the object in order to give time to the true owner to bring proof of ownership. Rav Yehudah, who says that Beis Din may not remove the object from the domain of Beis Din, maintains (like the Rashbam) that "Kol d'Alim Gevar" means that Beis Din withdraws from the litigation. Beis Din has no right to withdraw, however, once it has already taken the object into its custody, as the Rashbam explains there. Rav Papa, who argues and says that Beis Din can return the object, maintains that "Kol d'Alim Gevar" is also a form of justice, and therefore Beis Din may take the object out of its custody and say "Kol d'Alim Gevar," being assured that justice will be done.
However, there are some questionable points on this understanding of the Rosh. First, the Poskim cite the Rosh's ruling l'Halachah, even though they also rule that "Lo Mafkinan" -- once the object is in the custody of Beis Din, Beis Din may not take it out of its custody and say "Kol d'Alim Gevar."
Second, if the Rosh indeed is proposing a logical reason to explain why the one who grabs the object is probably the true owner, then why should that logic not apply after the first time the object is seized by one of the disputants? If the second disputant later overpowers the first and takes the object from him, then it should show that he is the true owner and not the first one!
Third, the Rosh himself in Teshuvos (loc. cit.) seems to contradict his explanation. Although he repeats what he writes here, he adds that "Kol d'Alim Gevar" is not a "Din," a formal ruling of Beis Din, but rather it is merely the withdrawal of Beis Din from the case ("Histalkus"), whereby Beis Din declines from issuing a ruling! He proves this from the Gemara here which says that the reason why Beis Din rules "Kol d'Alim Gevar" is that one defendant might eventually bring proof, and therefore it is not necessary for Beis Din to pass a ruling. This implies that "Kol d'Alim Gevar" is a method of refraining from issuing a ruling. (See also KOVETZ SHI'URIM who asks this question without citing the Teshuvah of the Rosh.)
Moreover, RABEINU CHANANEL (cited by Tosfos and Rashbam, 34b) writes that "Kol d'Alim Gevar" does not apply when the disputants are holding the object, because Beis Din has no right to take the object out of someone's hands when it does not know who owns the object. This also implies that "Kol d'Alim Gevar" does not determine the identity of the true owner of the object. The Rosh, based on these proofs, therefore rules that when one party overpowers the other, the losing party is entitled to force the winning party to swear with a "Shevu'as Heses" that the object is his.
Based on the words of the Rosh in Teshuvos, it seems that the Rosh here should be understood differently. The Rosh agrees that "Kol d'Alim Gevar" is a means by which Beis Din withdraws from the case. However, the Rosh is bothered by a question: how can Beis Din -- the role of which is to maintain peace and order in the community (Bava Metzia 96b) -- remove itself from the case and refrain from maintaining the peace, and allow chaos to prevail? The Rosh therefore proposes two complementary suggestions. First, the court will stop the free-for-all after the first seizure of the object, and consequently peace will be restored. Second, even the first seizure has some logical basis in determining the ownership of the object, since it is likely that the one who prevails over his opponent is the true owner. (M. Kornfeld)