Li-zchus R' Aharon Yisrael ben R' Moshe Mordechai Feit
for much success in EVERYTHING for him and family!!
A fetus that was born after 8 months was not considered halachic viable in the time of the Gemara but rather was considered a נפל - stillborn [see Shabbos 136a]. [Today we treat a baby born after 8 months as a completely living being. Here is one article on the topic].
The Tosefta says [Shabbos 16-4]:
So what is the halachic status of an 8 month old fetus that was born? On one hand it seems to be considered dead and therefore it is not מטמא and is not considered a viable fetus with regard to Yibum etc. On the other hand it is considered alive and therefore its limb is אבר מן החי and its flesh is בשר מן החי. Which one is it - alive or dead? The Tosefta concludes that as long as it is alive it is neither alive nor dead. Whaaaaaat? Which one? [עי' בשו"ת זכר יצחק סי' ס"ו]
Writes Rabbeinu [הלכות יבום וחליצה עמ' ל"א]:
וצ"ל הגדר שכתבו התוס' חולין דף ע"ה וכ"מ בזה דכל היכי שיש שם פרטי - בן ח' לא הוה.
An 8 month old fetus has חיים כלליים - general life, but lacks חיים פרטיים a specific, personal life. We can't say that he is dead because he is breathing but we also can't attribute to him life because in his very essence he will not live much longer.
In order to absolve from Yibum, the baby needs a צורה פרטית of חיים - a personal form of life. Since he lacks this, he does not absolve from the mitzva. On the other hand, in order to be מטמא he needs to lack all life - even in the general sense - and that he still has as long as he breathes. And so with regard to the other laws. When חיים פרטיים is necessary, he doesn't count. But when all we need is חיים כללים [such as for the law of אבר מן החי], he counts.
Rashi writes [Chullin 72b]:
"בן שמונה חי שנולד מבהמה חיה אין לנו במה לטהר אפילו נשחט לפי שאינו בכלל בקר וצאן"
One has a name only when they have a חיים פרטיים - independent viability and vitality. Since an 8 month old fetus lacks this component, it also lacks the name בקר וצאן and is thus not טהור even when properly shechted.
Elsewhere [מה"ת נ"ו, מובא שם בהערה] he writes the same idea:
"וכה"ג כתבו התוס' בחולין דף קכ"ו ע"ב גבי ביצת השרץ וגבי חלב דכל היכא דפרט לנו רק מינים אז י"ל דכל זמן שאין הצורה שלו כמו שהוא אין עליו זה השם וכה"ג כתב רש"י בחולין ע"ב דלכך לא מהני שחיטה לולד בן ח' משום דעדיין אין עליו שם בקר וצאן ואף דבשבת דף קל"ו אמר הטעם משום דהוי כמת ר"ל דהצורה הפרטית שיש עליו מתה דהרי אינו מטמא ויש בו דין אבר מן החי וכמבואר בתוספתא דשבת".
The Gemara in Shabbos [135b-136a] says as follows:
Rabban Shimon ben Gamliel says: With regard to people, any child that remains alive thirty days after birth is no longer suspected of being a stillborn, and is assumed to be a regular child who will go on living.... If so, with regard to circumcision, how can we circumcise him? Perhaps he is a stillborn and one may not desecrate Shabbos for his circumcision.
Rav Adda bar Ahava said: One may circumcise him whichever way you look at it, based on the following calculation: If he is a child who will live, the circumcisor may well circumcise the child, and if not, if the child is a stillborn and the circumcisor is merely cutting flesh, one who cuts the flesh of a corpse or the flesh of one with the legal status of a corpse is not considered to have made a wound, and therefore has not performed a prohibited labor.
The Gemara raises a difficulty: And however, with regard to that which was taught in a baraita: If there is uncertainty whether he was born after seven months of pregnancy, and uncertainty whether he was born after eight months, one does not desecrate Shabbos on his behalf and circumcise him. The Gemara asks: Why? Let us circumcise him on Shabbos, as whichever way you look at it, that is appropriate. If he is a child that will live, the circumcisor may well circumcise the child, and if not, he is merely cutting the flesh of a corpse, which does not violate any Shabbos prohibitions.
תניא רבן שמעון בן גמליאל אומר כל ששהה שלשים יום באדם אינו נפל ... מימהל היכי מהלינן ליה
Rabban Shimon ben Gamliel says: With regard to people, any child that remains alive thirty days after birth is no longer suspected of being a stillborn, and is assumed to be a regular child who will go on living.... If so, with regard to circumcision, how can we circumcise him? Perhaps he is a stillborn and one may not desecrate Shabbos for his circumcision.
אמר רב אדא בר אהבה מלין אותו ממה נפשך אם חי הוא שפיר קא מהיל ואם לאו מחתך בבשר הוא
Rav Adda bar Ahava said: One may circumcise him whichever way you look at it, based on the following calculation: If he is a child who will live, the circumcisor may well circumcise the child, and if not, if the child is a stillborn and the circumcisor is merely cutting flesh, one who cuts the flesh of a corpse or the flesh of one with the legal status of a corpse is not considered to have made a wound, and therefore has not performed a prohibited labor.
ואלא הא דתניא ספק בן שבעה ספק בן שמונה אין מחללין עליו את השבת אמאי נימהליה ממה נפשך אם חי הוא שפיר קא מהיל ואם לאו מחתך בבשר הוא
The Gemara raises a difficulty: And however, with regard to that which was taught in a baraita: If there is uncertainty whether he was born after seven months of pregnancy, and uncertainty whether he was born after eight months, one does not desecrate Shabbos on his behalf and circumcise him. The Gemara asks: Why? Let us circumcise him on Shabbos, as whichever way you look at it, that is appropriate. If he is a child that will live, the circumcisor may well circumcise the child, and if not, he is merely cutting the flesh of a corpse, which does not violate any Shabbos prohibitions.
[The Gemara answers the question. Then the Gemara says]
Abaye said: The issue of whether a child who has not yet survived thirty days from his birth is considered viable is parallel to a dispute between the tanna’im with regard to the interpretation of the verse: “And if any animal of which you may eat shall die, one who touches its carcass shall be impure until the evening” (Leviticus 11:39). The verse is interpreted as coming to include offspring of eight months. Large domesticated animals typically give birth after a gestation period of nine months. If an animal of that sort gives birth after eight months, its offspring is deemed to be not viable and its slaughter does not purify it. Rather, it assumes the status of an unslaughtered animal, which is not only prohibited to be eaten, but also transmits ritual impurity to those who touch or move it. Rabbi Yosei, son of Rabbi Yehuda, and Rabbi Elazar, son of Rabbi Shimon, say: Its slaughter purifies it, and it does not assume unslaughtered animal status.
What, is it not that this is the matter with regard to which they disagree? That this Master holds that the animal is considered alive and therefore its slaughter is effective, as is the case with regard to all pure animals, while this Master, the first tanna, holds that it is considered dead.
Rava said: If so, instead of disagreeing over the issue of impurity and purity, let them disagree over the issue of eating, i.e., whether it is permitted to eat this offspring after it is slaughtered. Since they did not dispute this point, their disagreement must revolve around a different factor.
Rather, it must be that everyone agrees that it is considered dead and may not be eaten.
Writes Rabbeinu [צ"פ מהד"ת עמ' מט, ועיין מפענח צפונות, עמ' נו]:
אמר אביי כתנאי וכי ימות מן הבהמה אשר היא לכם לאכלה להביא בן שמנה שאין שחיטתו מטהרתו רבי יוסי ברבי יהודה ורבי אלעזר ברבי שמעון אומרים שחיטתו מטהרתו
Abaye said: The issue of whether a child who has not yet survived thirty days from his birth is considered viable is parallel to a dispute between the tanna’im with regard to the interpretation of the verse: “And if any animal of which you may eat shall die, one who touches its carcass shall be impure until the evening” (Leviticus 11:39). The verse is interpreted as coming to include offspring of eight months. Large domesticated animals typically give birth after a gestation period of nine months. If an animal of that sort gives birth after eight months, its offspring is deemed to be not viable and its slaughter does not purify it. Rather, it assumes the status of an unslaughtered animal, which is not only prohibited to be eaten, but also transmits ritual impurity to those who touch or move it. Rabbi Yosei, son of Rabbi Yehuda, and Rabbi Elazar, son of Rabbi Shimon, say: Its slaughter purifies it, and it does not assume unslaughtered animal status.
מאי לאו בהא קא מיפלגי דמר סבר חי הוא ומר סבר מת הוא
What, is it not that this is the matter with regard to which they disagree? That this Master holds that the animal is considered alive and therefore its slaughter is effective, as is the case with regard to all pure animals, while this Master, the first tanna, holds that it is considered dead.
אמר רבא אי הכי אדמיפלגי לענין טומאה וטהרה ליפלגי לענין אכילה
Rava said: If so, instead of disagreeing over the issue of impurity and purity, let them disagree over the issue of eating, i.e., whether it is permitted to eat this offspring after it is slaughtered. Since they did not dispute this point, their disagreement must revolve around a different factor.
אלא דכולי עלמא מת הוא
Rather, it must be that everyone agrees that it is considered dead and may not be eaten.
Writes Rabbeinu [צ"פ מהד"ת עמ' מט, ועיין מפענח צפונות, עמ' נו]:
"ר"ל דהצורה שיש בו דשייך בה שחיטה מתה ממנו ונתבטלה וכך גבי מילה שם ר"ל דתואר של זכר נתבטל ממנו"
An 8 month old animal lacks the general form of an animal for which shechita is effective because it lacks viability. And so regarding Milah, an 8 month old fetus lacks the תואר של זכר or שם זכר - the nomenclature of a male, because of his impending demise. He is strictly speaking "alive" but only in a general sense but not in a specific way that would give him the status of an animal for whom shechita is possible or a baby who is considered a unique male.
This reality of an 8 month old is not connected to the short amount of time that he will survive. According to Rashi [יבמות פ] a stillborn can live up to 20 years and yet is still not considered viable. This is because in his very essence he is a reality of העדר - lacking true life which is defined as a continuum. With this we can understand the Rambam [הלכות אבל א-ו] who says that we don't have laws of mourning for a stillborn. We only mourn a מציאות פרטית and this stillborn lacked that quality. All he had was a generic form of life.