Yevamot

between one halachah and the other. Said Abaye: Whence do I infer that R. Eliezer b. Jacob treats any doubtful case as a certainty? — [From] what was taught: R. Eliezer b. Jacob said, 'Behold, when a man has intercourse with many women and does not know with which particular woman  he had intercourse, and, similarly, when a woman with whom many men had intercourse does not know to which particular man her conception is due, the consequences are that a father will be marrying his daughter and a brother his sister, and the whole world will be filled with bastards,  and concerning this it was said, And the land became full of lewdness'.  And Raba?  — He can answer you: It is this that was meant, 'What might be the result'? More than that  was said by R. Eliezer b. Jacob: A man shall not marry a wife in one country and then proceed to marry one in another country, since [their children]  might marry one another and the result might be that a brother would marry his sister. But, surely, this could not be [the accepted ruling], for Rab, whenever he happened to visit Dardeshir,  used to announce, 'Who would be mine  for the day'! So also R, Nahman, whenever he happened to visit Shekunzib,  used to announce, 'Who would be mines for the day'!  — The Rabbis came under a special category since they are well known. But did not Raba say: A woman who had an offer of marriage and accepted must allow a period of seven ritually clean days to pass!  — The Rabbis sent their representatives and these presented the announcements to the women.  And if you prefer I might say: The Rabbis only had them  in their private rooms;  for the Master said, 'He who has bread in his basket cannot be compared to him who has no bread in his basket'. A Tanna taught: R. Eliezer b. Jacob said: A man must not marry a woman if it is his intention to divorce her, for it is written, Devise not evil against thy neighbour, seeing he dwelleth securely by thee. If the 'doubtful son'  and the levir came to claim a share  in the estate of the deceased,  the 'doubtful son' pleading, 'I am the son of the deceased and the estate is mine', while the levir pleads, 'You are my son and you have no claim whatsoever upon the estate', it is a case of money of doubtful ownership,  and money the ownership of which is doubtful must be divided. Where the 'doubtful son'  and the sons of the levir came to claim their share  in the estate of the deceased, the 'doubtful son' pleading, 'I  am the son of the deceased and the estate is mine while the sons of the levir plead, 'You are our brother and you have only a share equal to ours', it was the intention of the Rabbis to submit to R. Mesharsheya that this was a case [identical with that] of a Mishnah wherein we learned, 'He  does not inherit from them  but they inherit from him',  since here the case is just the reverse:  There they tell him, 'produce proof and take [your share]'  while here he tells them, 'produce proof and take your share'.  R. Mesharsheya, however, said to them, 'Are [the two cases] equal? There, their claim is a certainty  while his is doubtful,  while here both are doubtful!  If, however, a case is to be compared to a Mishnah it is to the following: That of a 'doubtful son'  and the sons of the levir who came to claim  shares in the estate of the levir himself, where they can say to him: produce proof that you are our brother and take your share'. If a 'doubtful son'  and the sons of the levir came to claim  their shares in the estate of the levir after the levir had received his share in the estate of the deceased, the sons of the levir pleading, 'produce proof that you are our brother and you will receive [your share]', the 'doubtful son' can tell them, 'Whatever you wish: If I am your brother, give me a share among you;  and if I am the son of the deceased, return to me the half which your father received when he shared the estate with me'. Said R. Abba in the name of Rab: The judgment must stand.  R. Jeremiah said: The judgment is to be reversed. May it be suggested that they  differ on the same principle as that which underlies the dispute between Admon and the Rabbis? For we learned: If a man went to a country beyond the sea and [in his absence] the path to his field was lost,  he shall, Admon said, use the shortest cut;  but the Sages said: He must purchase a path even though it will cost him a hundred maneh or else fly in the air.  And in discussing this [Mishnah it was pointed out] against the Rabbis that Admon was perfectly right; and Rab Judah replied in the name of Rab that here it is a case where [the fields of] four persons surrounded it on its four sides.  But [it was asked] what is Admon's reason? And Raba replied: Where four persons  derive their rights of possession from four persons  or where four persons derive it from one  all agree that these  can refuse  him; the dispute only concerns one person who derived his rights from four. Admon is of the opinion that he  can tell him, 'At all events  my path is in your fields',  while the Rabbis hold that the other can answer him, 'If you will keep quiet, well and good;  and if not, I will return the deeds to their original owners whom you will have no chance to call to law'.  May it, then, be suggested that R. Abba  holds the view of the Rabbis  and R. Jeremiah  that of Admon?  R. Abba can tell you: I may even hold the view of Admon; he made his ruling there  only because he  can say to him,  'Whatever you wish to plead,