1 Whether those categories reflect natural categories or are socially constructed is a question for a different article.

2 Babylonian Talmud, Yoma 85a.

3 Mishnah, Ohalot 1:6; Babylonian Talmud, Hullin 20–21.

4 The human respiratory system consists of a series of organs that take in oxygen and expel carbon dioxide. The respiratory system is part of a larger system that includes the circulatory system, where the two work to circulate blood and oxygen throughout the body.

5 The psychological process of how a person incorporates mechanical assistance or foreign biomaterial into their identity and personhood is the subject of a different essay.

6 With respect to the difference between activity and function, see, for example, Rabbi Shlomo Goren's distinction between cardiac activity and cardiac function. He writes, “With regard to the heart, we need to distinguish between two types of activity, functional activity and physio-biological activity. From the perspective of function, once the brain has ceased any activity, when it no longer receives any oxygenated blood from the heart, the heart has died functionally as well [i.e. lost its function]. For the heart is considered a [functioning] heart only when it functions as a heart, meaning it pumps oxygenated blood to all limbs of the body, including the brain. For that is the functional purpose of the heart, to send deoxygenated blood to the lungs and to take oxygenated blood from the lungs and send it to the brain and other organs. But when the heart ceases to perform its function in the body, even if it is still beating on its own, it cannot be considered a heart from that point on, but rather an individual organ.” Goren, Shlomo, Torat ha'Refuah: meḥḳarim hilkhatiyim be-noś'e refu'ah [The Torah/teaching regarding medicine: Halakhic studies on the topic of medicine], ed. Tamari, Yisrael (Jerusalem: Ha-Idra Rabba, 2001), 57–78, at 63Google Scholar. All translations from the Hebrew are the authors’. Our interpolations (marked in square brackets) provide a comprehensible reading of the passage in English; the additional information (marked in parentheses) provides context or clarification for ease of understanding.

7 The idea of head transplants is not new. For a review of the history of the procedure, see Lamba, Nayan, Holsgrove, Daniel, and Broekman, Marike L., “The History of Head Transplantation: A Review,” Acta Neurochirurgica 158, no. 12 (2016): 2239–47CrossRefGoogle ScholarPubMed.

8 See Brian Wang, “First Human Head Transplant Will Still Happen Soon Based upon Millions in Sunk Costs,” nextBIGFuture (blog), July 19, 2018, https://www.nextbigfuture.com/2018/07/first-human-head-transplant-will-still-happen-soon-based-upon-millions-in-sunk-costs.html.

9 Many (in truth, almost everyone) have criticized the HEAVEN team for not considering the social, legal, and ethical ramifications and potential harm this research would entail. For example, with transplants in general there are ethical concerns, such as who is entitled to a transplant, how organs or body parts should be procured and distributed, if transplantation should be voluntary or whether donors or their families can be compensated, as well as determining the probability of success or rejection of a particular transplant and the medical consequences it may have on the particular recipient. Also, the clinical consequences, in terms of whether the recipient of the “new” body would accept the transplant psychologically and physiologically are simply unknown. Moreover, given the proportions of what is donated and who is considered the recipient, the procedure raises social and moral questions regarding the limits of personal identity and legal conceptions of personhood.

10 See Paul Root Wolpe, “A Human Head Transplant Would Be Reckless and Ghastly. It's Time to Talk about It,” Vox, June 12, 2018, https://www.vox.com/the-big-idea/2018/4/2/17173470/human-head-transplant-canavero-ethics-bioethics.

11 Bernat, James L., Culver, Charles M., and Gert, Bernard, “On the Definition and Criterion of Death,” Annals of Internal Medicine 94, no. 3 (1981): 389–94CrossRefGoogle ScholarPubMed.

12 The President's Commission on Bioethics originally conceived of neurological criteria to determine death as an alternative criterion that would uphold the same physiological definition of death as that based on cardiopulmonary criteria. However, in light of findings of brain-dead patients who still demonstrated certain integrative functions, such as normal function of the liver, kidneys, cardiovascular and endocrine systems, wound healing and fighting of infections, successful gestation of a fetus, and sexual maturation of a child, among others, the commission changed its definition of death to maintain the validity of death based on neurological criteria. Instead of maintaining a physiological definition of death, in order to affirm that a person, who has lost neurological functioning to the point that meets the criterion of brain death, should be considered dead, the commission defined death as losing that which is essentially significant to the human species. See President's Council on Bioethics (US), Controversies in the Determination of Death: A White Paper of the President's Council on Bioethics, 2008, https://bioethicsarchive.georgetown.edu/pcbe/reports/death/.

13 Genesis 7:22; Babylonian Talmud, Yoma 85a.

14 Numbers 19:13; Mishnah, Ohalot 1:6; Mishnah, Shabbat 23:5.

15 See Rabbi J. David Bleich, who writes, “The traditional view is that death occurs upon the separation of the soul from the body. Of course, the occurrence of this phenomenon does not lend itself to direct empirical observation.” Bleich, J. David, “Establishing Criteria of Death,” Tradition: A Journal of Orthodox Jewish Thought 13, no. 3 (1973): 90–113Google ScholarPubMed.

16 Also, according to halakha, death of a human being is not conceived as different than death of an animal, as seen by the many Talmudic sources which juxtapose questions of knowing when a human or an animal is dead for the sake of clarity and analysis.

17 The terms physical and physiological both refer to bodies; however, physical refers to the body itself while physiological refers to the body's functions.

18 Rabbi Shlomo Zalman Auerbach demonstrated this perspective in his decision to have Dr. Avraham Steinberg conduct an experiment to see whether a decapitated pregnant sheep can give birth to a healthy lamb. This experiment was meant to test whether the Talmudic passage in Babylonian Talmud, Arakhin 7a, which states that when a pregnant woman dies her fetus will die before her, still applies when medical intervention is used on the dead woman for the sake of delivering a healthy fetus.

19 This is the position of the Israeli Chief Rabbinate, Rabbi Moshe Feinstein, and R. Gedalia Dov Schwartz, among others.

20 This is the position of Rabbi Bleich, Rabbi Shlomo Zalman Auerbach, Rabbi Yitzhak Yaakov Weiss, Rabbi Shmuel ha-Levi Wosner, and Rabbi Eliezer Waldenberg, among others. However, Rabbi Shlomo Zalman Aurbach held that if every cell in the brain were definitively dead, the patient should be considered dead.

21 This is the position of Rabbi Moshe Feinstein. See Igrot Moshe, Yoreh Deah 2:174.

22 Because head/body transplants assume that neurological function would be maintained, the position of Rabbi Moshe David Tendler—that brain death constitutes death according to halakha—would not be a relevant position to examine directly, since it assumes loss of neurological functioning rather than its continuance. However, as we analyze the various sources that are relevant to the discussion, the reader may investigate how our position might be in conversation with Rabbi Tendler's position. For Rabbi Tendler's view, see Rosner, Fred and Tendler, Moshe David, “Definition of Death in Judaism,” Journal of Halacha and Contemporary Society, no. 17 (1989): 14–31Google Scholar.

23 See Chia-Yi Hou, “Circulation and Cell Function Revived in Dead Pigs’ Brains,” Scientist, April 17, 2019, https://www.the-scientist.com/news-opinion/circulation-and-cell-function-revived-in-dead-pigs-brains-65751; John D. Loike and Alan Kadish, “Opinion: Test Brain-Reviving Technology in Infants First,” Scientist, July 9, 2019, https://www.the-scientist.com/news-opinion/opinion--test-brain-reviving-technology-in-infants-first-66110.

24 Rabbi Moshe Sofer (1762–1839) was one of the leading Orthodox rabbis of European Jewry in the first half of the nineteenth century.

25 Hatam Sofer, Yoreh Deah 338.

26 Hatam Sofer, Yoreh Deah 338.

27 In a separate article, we discuss the validity—conceptually and hermeneutically—of the concept of vital motion, most often associated with the position of Rabbi Bleich. In that article, we intend to show that vital and non-vital motion are not distinct halakhic categories. Rather, physical or physiological activity is understood in context as either meaningful or not, depending on whether it is assumed that the person or animal will continue living or not.

28 Babylonian Talmud, Yoma 85a.

29 See Igrot Moshe, Yoreh De'ah 2:146.

30 A heart can be removed from a body, placed in saline solution, given oxygen, and still continue to beat.

31 This is not the only place in the Talmud where Rav Pappa limits disagreement regarding signs indicating life and death to a disagreement over whether one checks starting from the feet or from the top of the head. See Babylonian Talmud, Nidda 23b–24a.

32 See Rashi, s.v. “amar Rav Papa,” who explains the two positions as follows: “For one says, ‘One can distinguish by the heart if there is life in him, since his soul beats there.’ And one says ‘Until the nose since there are times when life is not clear[ly indicated] in the heart, but it is clear through the nose.’”

33 Rabbi Shlomo Yitzchaki (1040–1105), was a medieval French rabbi and author of a comprehensive commentary on the Bible and Talmud.

34 Rashi, Babylonian Talmud, Yoma 85a, s.v. “ad hotmo.”

35 This is not always the case, and it depends on the type of trauma incurred. Breathing can also cease before cardiac activity has stopped.

36 Even through this interpretation, cardiac activity may not be a primary indicator in and of itself but rather it should be seen as an indirect indicator because it implies circulation of oxygenated blood. See articles by Rabbi Hershel Schachter, who writes that circulation is the definition of life: Schachter, Hershel, “Determining Death,” Journal of Halacha and Contemporary Society, no. 17 (1989): 32–40Google Scholar; Hershel Schachter, “B'dine Met v'Gavra Katila [Regarding the laws of a dead person and a person certain to die],” Assia, no. 49/50 (5750/1989–1990): 119–37.

37 The Jerusalem Talmud records the debate differently. “[If a person is buried under rubble,] until what point does one check [to clarify whether the victim is still alive]? There are two positions. One said: [One clears] until [the victim's] nose. The other says: [One clears] until [the victim's] navel (tibburo). According to the person who says, ‘Until his nose,’ the reason is that he is kayyam. According to the person who says, ‘Until his navel,’ the reason is that he is rabun/rakin.” Jerusalem Talmud, Yoma 8:5. Rabbi Moshe Margalit explains the difference between kayyam and rabun/rakin as follows: “They are not arguing. The one who says, ‘Until his nose,’ is referring to a person who is kayyam, meaning he is strong and firm and one can sense through the nose whether the person has life. And the one who says, “Until the navel,” refers to someone who is soft (rakin), meaning that he is soft to the touch and one cannot sense through the nose. So, one checks until the navel for perhaps one can still sense if he has life. See Moshe Margalit, Pnei Moshe, Jerusalem Talmud, Yoma 8:5.

There are two major points to gain from the Jerusalem Talmud. First, the spot to check is the navel (tibburo) and not the heart. This difference has led some to argue that the debate is not about cardiac activity versus respiratory function, since checking the navel would be for indications of respiration and not for a heartbeat in particular. However, one can also reason that the Jerusalem Talmud and the Babylonian Talmud are in disagreement as to what constitutes a realistic indication of life, movement of the torso or cardiac activity.

Second, there seems to be no reference to the direction from which the victim is uncovered; the disagreement is to the condition of the body and the ability to check specific parts of the body. In this light, it seems that any movement that one can detect should be seen as an indication of life. Rashi may have understood the passage in the Babylonian Talmud in a similar way as the Jerusalem Talmud. The disagreement is based on where one can effectively check for signs of life or not. If this were the case, however, the disagreement would still only have occurred in a situation where the person was kayyam (firm), since it would difficult to perceive a heartbeat or movement in the person's navel, when the person was uncovered feet first. It would not have applied when the person was rabun/rakin and one could detect signs of life from movement in the navel. Because Rashi does not make that distinction, it is difficult to understand his commentary as taking the Jerusalem Talmud's disagreement into account. Moreover, the major post-Talmudic halakhic authorities who ruled on this passage did not account for the passage in the Jerusalem Talmud in their decision.

38 Mishne Torah, Hilkhot Shabbat 2:18–19. Unless otherwise noted, citations to Maimonides are to the Mishne Torah.

39 Maimonides, Commentary on Mishna, Yoma 8:5.

40 Maimonides, Commentary on Mishna, Yoma 8:5. He affirms this ruling in his Commentary on Mishna, Shabbat 23:5.

41 Hilkhot Avel 4:5.

42 Hatam Sofer, Yoreh Deah 338.

43 Rabbi Yoseph ben Ephraim Karo (1488–1575) is the author of the Shulhan Arukh, which is considered one of the most authoritative halakhic codes.

44 Shulhan Arukh, Orakh Hayyim 329:4.

45 Rabbi Shlomo Zalman Auerbach (1910–1995) was a renowned Orthodox Jewish rabbi who lived in Jerusalem.

46 Minhat Shlomo 86:5.

47 Minhat Shlomo 86:5.

48 The comparisons between humans and animals in these discussions demonstrate that even while the Jewish tradition maintains that humans are qualitatively different from animals, death for both humans and animals occurs in the same ways.

49 The indication that one has died when flayed like a fish and cut in half from one's stomach can be explained by the fact that it would constitute such a breach in the physiological integrity of the body that without medical intervention proper functioning of the body for the purpose of maintaining life would cease. Whether from exsanguination or irreversible termination of circulation of oxygenated blood or something else makes no difference; the key factor is that the functioning of the person's organ systems necessary to maintain life have ceased. The interest in discussing the indication of death when a person's backbone is broken together with most of the surrounding flesh, on the other hand, is because it is not as obvious that proper functioning of the body for the purpose of sustaining life has ceased. Our interest in discussing decapitation is because the article is about head/body transplants.

50 A nevelah is any dead animal that has died as a result of any process other than valid ritual slaughter.

51 Babylonian Talmud, Hullin 20b; Rashi, Babylonian Talmud, Hullin 20b, s.v. “nevelah.”

52 Babylonian Talmud, Hullin 21a.

53 Babylonian Talmud, Hullin 21a.

54 Babylonian Talmud, Hullin 19b; Hilkhot Maaseh Korbanot 6:23; Hilkhot Shehita 1:7; Shulhan Arukh, Yoreh Deah 20:1.

55 See Tosafot, Hullin 32b, s.v. “ve'lihshov”; Taz, Yoreh Deah 27; Pleiti, Yoreh Deah 27; Responsa Yehuda Ya'aleh, Yoreh Deah 70.

56 There are those who do not interpret Zeiri's and Rav Yehuda's ruling as referring to severing the spinal cord through breaking the cervical spinal column. Maimonides, Hilkhot Shehita 3:19, and Tur, Yoreh Deah 27, refer simply to breaking the back of an animal's neck, including the majority of the flesh surrounding the spinal column, without mentioning the spinal cord. This may lead one to infer that Zeiri's case is one where the spinal cord is either intact or only partially damaged. See Teshuvot Hakham Tzvi, 28. Also, Aruch HaShulhan, Yoreh Deah 27, brings both the interpretation that the spinal cord has been severed and the interpretation that it has not.

57 Rabbi Bleich interprets these cases as either severance of the spinal column in the thoracic area together with severance of the trachea and the esophagus in their entirety or severance of the spinal column in the thoracic area coupled with perforation of the major portion of both the trachea and the esophagus. Bleich, J. David, “Of Cerebral, Respiratory and Cardiac Death,” Tradition: A Journal of Orthodox Jewish Thought 24, no. 3 (1989): 44–66, at 61n4Google ScholarPubMed.

However, it is difficult to conclude that this is a proper interpretation of Zeiri's claim for two reasons. First, physiologically, it would be difficult to contend that Zeiri is referring to damage to the thoracic area rather than the cervical area, since the trachea and esophagus are only present in the upper part of the thoracic spine. Lower down, the esophagus transitions to the stomach, and the trachea divides into the left and right bronchi and then branch further. It would therefore be very unlikely that a severance of the thoracic spine would also lead to severance or perforation of both the trachea and the esophagus.

Second, hermeneutically, Zeiri's comment does not seem to indicate that severance of the trachea and esophagus are also required. Even though the Talmudic passage initially equates Zeiri's statement with that of Rabbi Hisda, “We have also learnt the same: If one nipped off [the head of a consecrated bird] with a knife, the carcass, whilst in the gullet [of the person eating the dead bird], renders clothes [of the person eating the bird] unclean,” the ensuing Talmudic passage disregards this assumption. The passage continues:

Rabbi Bleich interprets the debate about whether one cuts through both organs or the majority of both organs as referring to the statement of Zeiri. However, Zeiri's statement should be compared to the statement “He cuts [with his finger-nail] the spinal cord and the neckbone without cutting through the major portion of the surrounding flesh, until he reaches the gullet or the windpipe.” For Zeiri, if this occurs, and the majority of the neck's flesh was also torn, the animal is rendered nevelah. Otherwise, Zeiri's answer to the question, “Why proceed with the nipping if it is already dead?” does not make sense. As such, Zeiri's position has no reference to severing the trachea or esophagus.

58 Older individuals are more likely to have low-velocity mechanisms of injury, such as those that occur due to falling (as was the example of Eli), and these types of injury are more likely to result in upper cervical spine injury than lower cervical spine injury. For example, the most common cervical spine injury seen in geriatric patients is an injury at C2, followed by injury at C1. Damage is most severe when it occurs in the high cervical spinal cord, since it typically includes paralysis, such as quadriplegia, and inability to breathe. The higher occurrence of these types of injuries for geriatric patients is due to the higher occurrence of other pathologies, such as arthritic changes and cervical canal stenosis. The elderly are also more likely to have metastatic spinal tumors and decreased bone density related to aging. Rebecca Jeanmonod and Matthew Varacallo, Geriatric Cervical Spine Injury (Treasure Island: StatPearls Publishing, 2019) (last updated March 26, 2020), https://www.ncbi.nlm.nih.gov/books/NBK470375/.

It is possible to understand that Rav Yehudah (in the name of Shmuel), who said that the case of Eli was different because he was elderly, was explaining why Eli in fact died when his neckbone was broken even without the major portion of the surrounding flesh having been cut, without making a categorical distinction between the ways in which elderly versus younger people die. In other words, Rav Yehuda was not establishing the presumption that that elderly die on a regular basis even without major soft tissue damage. He was simply saying that the elderly might be an exception to the general presumption that people who fall and break their neck will survive if the majority of the surrounding flesh is not severed.

59 Babylonian Talmud, Hullin 42a.

60 The subsequent Talmudic discussion on that Mishna concludes by ruling that the halakha follows the opinion that the majority of the spinal cord must be severed to render an animal a treifa, yet the primary concern of the discussion regards whether the majority of the meninges surrounding the spinal cord has been severed rather than focusing on the spinal cord itself. Whether the spinal cord itself has been severed or not is of no concern if the meninges were intact. See Hilkhot Shehita 9:1; Shulhan Arukh, Yoreh Deah 32:1. If the spinal cord has liquefied to the point where it would “pour out like from a jug” if the meninges were punctured, the animal is still only considered a treifa; it would not be a nevelah. See Babylonian Talmud, Hullin 45b; Hilkhot Shehita 9:2; Shulhan Arukh, Yoreh Deah 32:2. The reason why the animal would be considered a treifa, is either the probability that the meninges will eventually become severed as well or because liquefaction is a greater blemish than severance of the spinal cord. See Rashi, Babylonian Talmud, Hullin 45b, s.v. “mipnei kevodo.” Regarding the probability that the meninges will eventually be severed as well, however, is very difficult to contend on a practical basis, since, if the meninges remain intact after the initial trauma, they will not be subsequently severed unless there is a lot of movement between the two edges of the fracture which would cause them to tear, which is unlikely.

61 Lach, Yaakov Dovid, Sefer Ṭemune ḥol/Chullin Illuminated (Brooklyn: Hamesivta Publications, 2003), 157Google Scholar.

62 The innervation to the diaphragm, which is the main muscle of respiration, comes via the phrenic nerve, which in humans exits the spinal cord between C3 and C5, so damage at C5 or above is likely to affect breathing. It is not uncommon for spinal cord damage to ascend after trauma, so that that an injury at C5 could cause delayed difficulty breathing, even if it was not a problem initially.

63 Hilkhot Tumat Met 1:15.

64 Hilkhot Shehita 3:19.

65 Hilkhot Sha'ar Avot HaTumah 2:1.

66 Maaseh Rokeach, Hilkhot Shehita 3:19.

67 Rabbi Yaakov ben Asher (1269–1343) was a well-known rabbi in the Holy Roman Empire and Spain.

68 Rabbi Yechiel Michel ha-Levi Epstein (1829–1908) was a rabbi in Lithuania.

69 Tur/Shulhan Arukh, Yoreh Deah 370; Arukh Hashulhan, Yoreh Deah 370:1.

70 Many have identified “brain death” as “physiological decapitation” or the total destruction of the entire brain. Yet, conceptually, there is a big difference between decapitation and “physiological decapitation,” which can be seen as follows: Physiological decapitation is seen as an analogy to decapitation because in physiological decapitation the brain is destroyed, and thus could be imagined as separated from the body. Yet in normal decapitation the brain is not destroyed, it is actually separated from the body. It may still function on its own accord, even if for only a few seconds (and, through technological means, it may be possible to restore circulation to the brain, and thereby restore both consciousness and function, even if the brain might not have a body for that function to effectuate).

71 Mishna, Ohalot 1:6.

72 Tumat Okhlin are contracted by food items that become ritually defiled by contact with a dead body and can then defile other food and drink. The reason why it contracts this type of ritual impurity is based on the different legal prohibitions for Jews and non-Jews regarding eating animals. At the moment of slaughter, the animal may not be eaten by the Jew because it is not a kosher animal. For Jews, however, ritual slaughter deems an animal to be dead. For a non-Jew, the animal is prohibited because it is still considered alive, and non-Jews are prohibited to eat live animals according to Noahide law. This animal thus contracted tumat okhlin from itself, given the different status it has due to the different legal norms that categorize it.

73 Mishna, Hullin 9:1; Mishna, Taharot 1:4. See also Babylonian Talmud, Hullin 117b.

74 The Rishonim were the leading rabbis who lived approximately from the eleventh century through part of the fifteenth century.

75 Rashi, Babylonian Talmud, Hullin 21a, s.v. “hutzu.”

76 This is the position of Rabbi Asi in the name of Rabbi Mani in Babylonian Talmud, Hullin 21a.

77 Rabbi Shlomo ben Avraham ibn Aderet (1235–1310) was a rabbi in Spain.

78 Rashba, Babylonian Talmud, Hullin 21a, s.v. “amar leih.”

79 Tosafot are medieval French commentaries on the Talmud.

80 Tosafot, Babylonian Talmud, Hullin 21a, s.v. “hutzu rasheihen.”

81 Tosafot, Babylonian Talmud, Hullin 21a, s.v. “hutzu mamash.”

82 Tosafot, Babylonian Talmud, Hullin 21a, s.v. “hutzu mamash.” This is the position of Reish Lakish.

83 In his commentary on Mishna Ohalot, he writes regarding decapitation, “huvdalu rasheiheim,” in line with the position of Reish Lakish's position of “mamash,” yet see below for discussion and defense of this interpretation.

84 Hilkhot Tumat Met 1:15; Hilkhot Sha'ar Avot HaTumah 2:1.

85 David Shabtai writes, “Rambam, however, in delineating various death-defining injuries for both humans and animals, lists both hatazat ha-rosh [decapitation] as well as shevirat ha-mafreket ve-rov basar imah [breaking of the neck along with removal of the majority of the adjacent flesh], seemingly indicating that they represent different injuries and that both are halakhically meaningful.” Shabtai, David, Defining the Moment: Understanding Brain Death in Halakhah (New York: Shoresh Press, 2012): 130Google Scholar. In trying to explain the need for both examples, Shabtai refers to Rabbi Yonatan Eyebeschutz, who posits that decapitation means severing the front of the neck without severing the spinal cord so as to distinguish it from breaking of the neck along with removal of the majority of the adjacent flesh, which is severing the back of the neck. Pleiti 27:2. However, based on the passage in the Babylonian Talmud, Hullin 121b, Maimonides writes, “When a Jew slaughters a non-kosher animal for a gentile and slits the two—or the majority of the two—signs of ritual slaughter, it imparts the tumat okhlin (impurity associated with food) as long as it is in its death-throes.” Hilkhot Tum'at Okhalin 3:4. See also Babylonian Talmud, Gittin 70b, as it relates to humans. Decapitation, however, imparts tumat nevelah, and not tumat okhlin. Decapitation must therefore be different from simply severing the front of the neck. Shabtai also refers to Rabbi Yosef Te'omin and Rabbi David Pardo, who posit that decapitation refers to severing the esophagus and the trachea along with the spinal cord, but not including the majority of the surrounding flesh. However, Rabbi Karo, in his commentary on Maimonides's code called the Kessef Mishna, argues that Maimonides interprets decapitation as literal, i.e. more extensive than simply severing the spinal cord along with removal of the majority of surrounding flesh. Kessef Mishna, Hilkhot Tumat Met 1:15. He reasons that Maimonides definition of decapitation with respect to animals and humans is consistent with his definition with regard to sheratzim, where he writes, “A sheretz does not impart impurity until it dies. If it has been decapitated, even if the head is still connected to the skin of the body, and it is still in its death throes as happens with regard to the tail of a lizard, it imparts impurity.” Hilkhot Sha'ar Avot Ha'Tumah 4:14. This would also explain Maimonides's wording in Hilkhot Shehita 2:9: “If he drew the knife back and forth until he cut off the head entirely (hatakh ha'rosh v'hetizu), his slaughter is acceptable.” See Babylonian Talmud, Hullin 30b.

86 Note that the insignificance of the moving lizard's tail is different than that of the decapitated person's moving body. The lizard is still alive, even without the moving severed tail. The person, on the other hand, is dead, despite the severed moving body.

87 Commentary on Mishna, Hullin 9:1.

88 Rabbi Yaakov ben Asher rules in Tur, Yoreh Deah 27, that an animal whose neck was broken with the majority of its flesh severed is a nevelah. Rabbi Karo in his Beit Yosef questions why he includes it, since the Tur does not usually mention halakhot that are not practiced today (such as tumat nevelah) and there is no practical difference between treifa and nevelah with respect to the prohibition of eating the animal. Rabbi Yehiel Michel Epstein, in Arukh HaShulhan, Yoreh Deah 27:7, explains the practical ramification. He writes that the reason the Tur states that an animal whose neck was broken with the majority of its flesh severed is a nevelah is to inform that one may cut a piece of the animal and give it to a non-Jew even while it is still moving, which would in normal circumstances be considered a limb from a live animal (eiver min ha'chai), and that Rabbi Yaakov needed to make this case explicit since the animal would still be moving, unlike in the other cases.

89 Hilkhot Sha'ar Avot HaTumah 2:1.

90 Hilkhot Tumat Met 1:15.

91 Igrot Moshe, Yoreh Deah 2:174. The reason is because, while there is an obligation of saving a person's life, there is no obligation to resurrect the dead

92 Nishmat Avraham, Yoreh Deah 546.

93 Rabbi Shlomo Zalman Auerbach writes that if a medical intervention is not successful, then time of death is recorded retroactively as at the end of respiration and not at the end of resuscitative efforts. If resuscitative efforts succeeded, then we say that the person was alive the whole time. See Minhat Shlomo 86:5.

94 The exception to this principle is the case in determining the worth of a goses for the sake of making a vow (neder) or for an endowment valuation (arakhim). For these purposes, the principle—since most gosesin will die, he is considered as if he is [already] dead—applies. Babylonian Talmud, Arakhin 6b; Hilkhot Arakhim VaHaramim 1:13. The reason for this exception is that, when it comes to monetary valuation for the purpose of a neder, there is no valuation for a goses, since the majority of them will die in the near future. For arakhim, the Torah states explicitly that the person should “stand before the priest, and the priest shall value him,” Leviticus 27:8, yet the Talmud continues to claim that a goses is unable to stand. As such, these exceptions do not contradict the principle; their distinction is based on other factors.

95 Tosefta, Eiruvin 5:21.

96 Hilkhot Eiruvin 4:12. An eruv encloses an urban area so that the entire area is considered a private domain, thereby permitting activities within it that are normally forbidden in public on Shabbat.

97 Rabbi Shmuel Yitzchak Heilman (1868–1953) was a renowned rabbi who served as a Dayan of the London Beth Din.

98 Ohr HaYashar, Hilkhot Eiruvin 4:12.

99 Ohr HaYashar, Hilkhot Eiruvin 4:12.

100 Babylonian Talmud, Gittin 28a; Hilkhot Gerushin 6:28.

101 Tur, Even HaEzer 141. See, however, Beit Shmuel, Even HaEzer 141:105, who writes that one should distinguish between a goses who can still speak (whose get is a matter of doubt) and one who cannot (whose get would not be valid even doubtfully). If at the time the goses gave the get to the messenger, he was able to speak, one might suspect that he lost mental capacity before the get was delivered, rendering the get invalid. However, we do not suspect this if he remains settled and not mentally agitated. Yet he also cites Rabbi Yoel Sirkes (Bach), who writes that one would suspect a person's mental state if he gave a messenger a get before he became a goses, but the messenger did not deliver it until he became a goses who was unable to speak.

102 Babylonian Talmud, Gittin 28a.

103 Hilkhot Terumah 9:3.

104 Semahot 1:1.

105 Shulhan Arukh, Yoreh Deah 339:1.

106 Hilkhot Avel 4:5.

107 Babylonian Talmud, Shabbat 151b.

108 Rabbi Eliezer Yehuda Waldenberg (1915–2006) was a halakhic decisor in Jerusalem.

109 Tzitz Eliezer 14:81.

110 Rema, Yoreh Deah 339:1. As to how one should remove these impediments so as not to hasten death, see Tzitz Eliezer 13:8; Igrot Moshe, Yoreh Deah 3:132; Avraham Steinberg, “Kelalim Halakhti'im l'Hitnahagot Rofeh b'Yichida l'Tipul Nimratz” [Halakhic rules for physician behavior in the ICU], Assia, no. 63/64 (5759/1999): 18–19.

111 Rabbi Asher ben Yehiel (1250?–1327) was a famous rabbi who lived in the Holy Roman Empire and in Spain.

112 Commentary on Mishna, Ohalot 1:6.

113 Rashi, Babylonian Talmud, Yevamot 120a.

114 A tzluv is typically translated as someone who is crucified, but it may also mean someone who is hanged.

115 Mishna, Yevamot 16:3.

116 Commentary on Mishna, Yevamot 16:3.

117 Hilkhot Gerushin 13:18. He continues, clarifying where the animal was eating the person, “If, however, we see the vulture eating from a place that would cause him to die—e.g., his brain, his heart or his intestines, one may offer testimony that he died.”

118 Rabbi Shmuel ben Uri Shraga Phoebus (1650–1706) was a Polish rabbi and Talmudist of Woydyslaw.

119 Beit Yosef, Even HaEzer 17; Beit Shmuel 17:94.

120 Hon Ashir, Mishna Ohalot 1:6.

121 This view, however, limits the category of goses to a goses b'yidei Shamayim (goses by the hands of Heaven) even though there is also a category for gosses b'yidei adam (goses because of another person's actions). Though it is possible to conceive of the meguyyad as a paradigmatic example of a gosses b'yidei adam.

122 Rabbi Elijah ben Solomon Zalman (1720–1797), was a Talmudist, halakhist, kabbalist, and the foremost leader of non-Hasidic Jewry of his time.

123 The Vilna Gaon's reasoning is based on Babylonian Talmud, Gittin 70b: “And it was taught in a baraita: If they saw a meguyyad or a man crucified on a cross (tzluv al hatzliva), and he signaled and thereby stated, ‘Write a bill of divorce for my wife,’ then those present should write and give it to her. To what can these cases be compared? There [for a meguyad or a man crucified] his mind is lucid, though he has begun to feel weakness [and will die very soon.]”

124 Eliyahu Rabbah on Ohalot. Rabbi Bleich has argued that consciousness is “nowhere posited as a condition negating otherwise dispositive criteria of death.” Bleich, “Of Cerebral, Respiratory and Cardiac Death,” 58. However, there are those who argue that consciousness is an implied, independent indication of life, citing Babylonian Talmud, Gittin 70b, where Rav Yehuda says that Shmuel says, “One whose throat was slit and his two pipes[, i.e. his trachea and esophagus,] or the majority of the two pipes were severed, and he signaled and thereby stated through his gestures: ‘Write a bill of divorce for my wife,’ then those present should write and give it to her.” The discussion in the passage relates to whether the person can have the legally mandated intention to divorce his wife or not. It is not about whether the person is alive or not. It is presumed as obvious that the person is alive.

125 Rabbi Aaron Soloveichik has argued that brain waves that can be recorded on an electroencephalogram constitute “movement” and should be deemed as halakhically relevant in determining whether one deems a person as alive or not. See a discussion of his position in Bleich, J. David, “Survey of Recent Halakhic Periodical Literature,” Tradition: A Journal of Orthodox Jewish Thought 16, no. 4 (1977): 121–39, at 137Google ScholarPubMed. See also Soloveichik, Ahron, “Death According to the Halacha,” Journal of Halacha and Contemporary Society, no. 17 (1989): 41–48Google Scholar.

126 External assistance means assistance in maintaining the internal functioning of the person, which would include artificial circulation, dialysis, respirators, or transplantation.

127 Mishna, Sotah 9:3; Babylonian Talmud, Sotah 45b.

128 The Talmud provides a reason why Rabbi Eliezer and Rabbi Akiva disagree. “With regard to what do they disagree? [They both agree that he should be buried in the place where he was killed, but] one Sage[, Rabbi Eliezer,] holds that his body fell in its place and the head rolled away. And one Sage[, Rabbi Akiva,] holds that his head fell where it fell, and the body continued onward.” Babylonian Talmud, Sotah 45b. This does not negate the idea that the disagreement is over which body part is primary since in any event both the body and the head will move while falling to the ground. The perspective of what fell in its place and what continued moving depends on which body part serves as the anchoring perspective.

129 Hilkhot Rotzeah uShmirat Nefesh 9:9.

130 Primacy is not determined by amount. For example, see Mishna, Berahot 6:7, regarding making the appropriate blessing for a mixture: “This is the principle: Everything that is primary, and has something secondary with it, he blesses on the primary and [thereby] exempts the secondary.”