The basic halakhic principle governing abortion practices is recorded in the Mishnah, Oholot 7:6, in the declaration that when "hard travail" of labor endangers the life of the mother an embryotomy may be performed and the embryo extracted member by member. This ruling is cited as definitive by Rambam, Hilkhot Rotzeaḥ 1:9, and Shulḥan Arukh, Hoshen Mishpat 425:2. The halakhic reasoning underlying this provision is incorporated in the text of the Mishnah and succinctly couched in the explanatory phrase "for her [the mother's] life has priority over its [the fetus'] life." In the concluding clause of the Mishnah, a distinction is sharply drawn between the status of the fetus and that of a newly born infant. The Mishnah stipulates that from the moment at which birth, as halakhically definied, is considered to have occurred, no interference with natural processes is permitted, since "one life is not to be set aside for the sake of another life."

Most interesting is the sharply contested view advanced by R. Elijah Mizrachi, in his commentary on Exodus 21:12, that in principle feticide and murder are indistinguishable. The biblical ban on murder extends equally to all human life, including, he claims, any fetal life which, unmolested, would develop into a viable human being. In theory, continues Mizrachi, feticide should be punishable by death since the majority of all fetuses will indeed develop into viable human beings. In practice it is technically impossible to impose the death penalty because punishment may be inflicted by the Bet Din only if the crime is preceded by a formal admonition. Since some fetuses will never develop fully, a definite admonition cannot be administered because it cannot be established with certainty that any particular fetus would develop in this manner. Noachides, on the other hand, require no such admonition. Therefore, since the major number of fetuses are viable, feticide is to be punished by death under the Noachide dispensation.

Differing from these various views are the opinions of the many scholars who have espoused the diametrically opposite position that the prohibition against feticide is rabbinic in origin. There is evidence that as early an authority as Rabbenu Nissim is to be numbered among the latter group. R. Chaim Ozer cites Rabbenu Nissim's explanation of the reason for the ruling of the Mishnah (Erukhin 7a) that the execution of an expectant mother must not be delayed in order to allow the delivery of her child. Rabbenu Nissim (commentary on Hullin 58a) fails to offer the explanation adopted by other commentators; namely, that the fetus is regarded as but an organic limb of the mother having no inherent claim of its own to inviolability and hence considerations of its welfare cannot interfere with the statutory provision for immediate execution of the condemned in order to avoid subjecting the convicted criminal to agonizing suspense between announcement of the verdict and execution of the sentence. Rabbenu Nissim offers a simple explanation to the effect that the fetus has not yet emerged into the world and therefore we need not reckon with its well-being. Since Rabbenu Nissim's remarks certainly cannot be construed as sanctioning wanton destruction of a fetus, R. Chaim Ozer infers that it is Rabbenu Nissim's opinion that the prohibition against taking fetal life is of rabbinic origin. If considered as a rabbinic edict, it is understandable that the Sages suspended their ban in order to mitigate the agony of the condemned woman, giving considerations of her welfare priority over the well-being of the unborn child.

There are a number of latter-day authorities who are explicit in their opinion that feticide is a rabbinic rather than a biblical offense. Perhaps the most prominent of these is the renowned seventeenth-century scholar, R. Aaron Samuel Kaidanower, author of the famed commentary on Seder Kodshim, Birkhat ha-Zevaḥ. His views regarding this matter are recorded in his collection of responsa, Emunat Shmu'el (Frankfort-am-Main, 5443), no. 14. This position is also espoused by R. Chaim Plaggi, Teshuvot Hayyim ve-Shalom (Smyrna, 5632), I, no. 40, and forms the basis for a number of decisions issued by the contemporary halakhic authority, R. Eliezer Yehudah Waldenberg. The rulings issued by R. Waldenberg, who serves as head of the Jerusalem Bet Din, are recorded in his voluminous work, Ẓiz Eli'ezer.

A tentative distinction between the stringency of the prohibition against abortion involving direct physical removal of the fetus and abortion induced by chemical means is found in a responsum bearing the signature of R. Jacob Schorr and included in the Teshuvot Ge'onim Batra'i (Prague, 5576), a compendium edited by Sha'agat Aryeh. While the author of this responsum makes no pertinent halakhic distinction between these two methods, he does draw attention to the fact that Maimonides found it necessary to state definitively that in cases of danger "it is permitted to dismember the fetus in her [the mother] womb, whether by chemical means or by hand." The implication is that, if not explicitly obviated, a theoretical distinction might have been drawn between physical dismemberment of the fetus and abortion by indirect means (gerama), such as imbibing abortifacient drugs in order to induce the expulsion of the fetus. Such a distinction is in fact made by R. Judah Eiyush, Teshuvot Bet Yehudah (Livorno, 5518), Even ha-Ezer, no. 14, who maintains that abortion induced by chemical potions is of rabbinic proscription, whereas direct removal of the fetus is forbidden on biblical grounds. On this basis, R. Eiyush grants permission to induce an abortion in a woman who became pregnant while still nursing a previous child in order that the life of the nursing infant not be endangered.

The early seventeenth-century scholar, R. Joseph Trani of Constantinople, author of Teshuvot Maharit, also endeavors to show that the taking of fetal life, while forbidden, nevertheless cannot be considered as constituting a form of homicide. The Mishnah, Erukhin 7a, indicates that an expectant mother who has been sentenced to death, as long as she has not already "sat on the birth stool," must be executed without delay in order to spare her the agony of suspense. Whereupon the Gemara in its comments on this Mishnah exclaims "Peshita!—Of course!" R. Joseph Trani argues that if destruction of the fetus is tantamount to the taking of human life the amazement registered by the Gemara is out of place. The Gemara provides that the mother be struck on the abdomen against the womb in order to cause the prior death of the fetus. This is done in order to avoid the indignity which would be inflicted upon her body as a result of an attempt on the part of the fetus to emerge after the death of its mother. An act of murder certainly would not be condoned simply in order to spare the condemned undue agony or to prevent dishonor to a corpse. R. Joseph Trani then advances an alternative basis for this stricture. In his opinion, the destruction of an embryo is within the category of unlawful "wounding," which is banned on the basis of Deuteronomy 25:3. This consideration is, of course, irrelevant in the case of one lawfully sentenced to death, and hence the Gemara raises an objection to the need for specific authorization for the execution of a pregnant woman sentenced to death. A more recent authority, Rabbi Joseph Rosen expresses a similar view.

The dispute concerning the classification of the nature of the stricture against feticide is of more than mere speculative interest. It will be shown that various halakhic determinations regarding the permissibility of therapeutic abortion in certain situations hinge directly upon proper categorization of this prohibition. This issue is also the focal point of an intriguing problem discussed by Rabbi Isser Yehudah Unterman, the former Ashkenazic Chief Rabbi of Israel. Writing in No'am, VI, 52, Rabbi Unterman refers to an actual question which arose in the course of the German occupation of Poland and Lithuania during World War I. A German officer became intimate with a Jewish girl and caused her to become pregnant. Becoming aware of her condition, the officer sought to force the young woman in question to submit to an abortion. The German officer ordered a Jewish physician to perform the abortion. Upon the doctor's refusal to do so, the officer drew his revolver and warned the physician that continued refusal would result in the latter's own death. If the prohibition against taking the life of a fetus is not subsumed under the category of murder, thereby constituting one of the avizraiya, or "appurtenances," of murder, there arises no question of an obligation on the part of the physician to forfeit his own life; on the contrary, he is halakhicly bound to preserve his own life since preservation of life takes precedence over all other considerations. If, however, feticide is considered to be among the avizraiya of murder and akin to homicide, which is one of the three grave offenses which dare not be committed even upon threat of death, then the principle "Be killed but do not transgress" is germane.

Another argument in support of the contention that the admonition "Be killed but do not transgress" does not apply to an act of feticide was advanced at a much earlier date by R. Joseph Babad in his magnum opus, Minḥat Hinukh. He reasons that this principle, as enunciated with regard to homicide, is based upon an a priori principle propounded in the Gemara's rhetorical question, "How do you know that your blood is sweeter than the blood of your fellow man?" The import of this dictum is to emphasize the intrinsic value of every human life and graphically to underscore the fact that no man dare consider his existence to be of higher value than that of his fellow. For in the sight of God all individuals are equally "sweet" and all alike are of inestimable value. Since, however, a fetus is not accounted as being a full-fledged nefesh, or "life," and since, as an outgrowth of the unborn child's inferior status, Jewish law exempts its killer from the death penalty, the fetus' "blood" is quite obviously assessed as being "less sweet." Therefore, reasons the author of Minḥat Hinukh, when confronted by the impending loss of either one's own life or of the life of the fetus, the killing of the unborn child is to be preferred as constituting the lesser of two evils. This conclusion is inescapable, argues Minḥat Hinukh, since the Mishnah specifically authorizes the sacrifice of a fetal life in order to save its mother. The mother's life is of no greater intrinsic value than that of any other individual. If destruction of the fetus is sanctioned in order to preserve the mother, then it must be permitted in order to save the life of any other person.

We find a declaration of Rav Chisda (Yevamot 69b) to the effect that the daughter of a kohen widowed shortly after marriage to an Israelite may partake of terumah during the first forty days following consummation of her marriage despite the fact that she has become a widow in the interim. Permission to eat terumah is a privilege accorded an unmarried daughter of a kohen or a widowed daughter who has no children. The concern in the case presented to Rav Chisda is that the widow, unknown to herself, may be pregnant with child, in which case terumah would be forbidden to her. Rav Chisda argues, if the widow is not pregnant there is no impediment to her partaking of terumah; if she is pregnant the embryo is considered to be "mere water" until after the fortieth day of pregnancy. Therefore she may continue to eat terumah for a full forty days after her marriage. The ruling of Rav Chisda indicates that fetal development within the initial forty days of gestation is insufficient to warrant independent standing in the eyes of Halakhah. Another source for this distinction is the Mishnah (Niddah 30a), which declares that a fetus aborted less than forty days following cohabitation does not engender the impurity of childbirth ordained by Leviticus 12:2–5. Similarly, according to Mishneh le-Melekh, Hilkhot Tumat Met 2:1, the defilement associated with a dead body is not attendant upon an embryo expelled during the first forty days of gestation. Furthermore, in the opinion of many authorities, a fetus cannot acquire property prior to the fortieth day of development.

The result is that the status of an embryo's claim to life during the first forty days following conception is not entirely clear. Is the prohibition against feticide operative during this early stage of fetal development during which the embryo is depicted as "mere water"? It would appear that according to the grounds advanced by Havot Ya'ir no distinction can be made between the various stages of fetal development since, according to this opinion, feticide is prohibited, not because it is tantamount to the the taking of a human life, but because it is a form of "destroying the seed." The fact that no specific reference is made in Havot Ya'ir to the status of the embryo during this period in no way vitiates this conclusion. In the absence of a distinction there is no reason for such reference. Yet the considerations advanced by Havot Ya'ir can explain only the nature of the ban against feticide under the Sinaitic covenant. Feticide, a capital offense in Noachide law, may well be viewed as a form of homicide under that code, leaving the possibility of such a distinction with regard to the conduct of Noachides an open question.

There is further evidence pointing to a prohibition against destroying the life of a fetus during this early period. Nachmanides notes that according to the opinion of Ba'al Halakhot Gedolot the Sabbath may be violated even during this forty-day period in order to preserve the life of a fetus. The author of Havot Ya'ir, citing Tosafot, Niddah 44b, shows that the right to violate the Sabbath for the sake of saving a prenatal life is incompatible with permission to kill it deliberately. It follows that, according to Ba'al Halakhot Gedolot, induced abortion during this period is forbidden. Responding to a specific inquiry, R. Plocki grants permission for termination of pregnancy within this forty-day period only when the life of the mother is threatened.

Distinctions pertaining to the early period of gestation are echoed by numerous other authorities. R. Chaim Ozer (Teshuvot Aḥi'ezer, III, no. 65, sec. 14) writes, "It appears that a Noachide is not put to death for this and perhaps even with regard to an Israelite there is no biblical prohibition." Torat Hesed, Even ha-Ezer, no. 42, sec. 33, states explicitly that the prohibition against destroying an embryo within the first forty days following conception is rabbinic in nature. R. Joseph Rosen, Ẓofnat Pa'aneaḥ, no. 59, comments, "Before the fortieth day there is not such a stringent prohibition according to many authorities." In an earlier collection of responsa, Teshuvot Bet Shlomoh, Hoshen Mishpat, no. 162, R. Shlomoh Drimer of Skole concludes that there is no prohibition against destroying an embryo less than forty days old and notes that in punishment for performing such a deed "even a Noachide is not put to death." An even more permissive view is cited by Rabbi Waldenberg. He quotes a responsum included in Teshuvot Pri ha-Sadeh (vol. IV, no. 50) which extends this distinction to the entire first three months of pregnancy. Relying upon this opinion, Rabbi Waldenberg Ẓiz Eli'ezer, IX, 236, permits the performance of an abortion within the first three months when there are definite grounds to fear that the child will be born deformed or abnormal. Rabbi Waldenberg, however, denies such permission even within this period once fetal movement is perceived. Rabbi Weinberg, in his original responsum (No'am IX, 213 f), also concluded that it is permissible to induce abortion prior to the fortieth day of pregnancy, but later added in a note (Seridei Esh, III, 350, note 7) that having seen a contrary opinion expressed by Rabbi Unterman in No'am (VI, 8f), he reserves decision pending consultation with other halakhic authorities. The late Rabbi Moshe Yonah Zweig of Antwerp, writing in No'am (VII, 48), concurs in the view which forbids abortions even during the first forty days of pregnancy other than on medical grounds.

Authority for performance of an embryotomy in order to preserve the life of the mother is derived from the previously cited Mishnah, Oholot 7:6. Virtually all authorities agree that the Mishnah does not merely sanction but deems mandatory that the life of the fetus be made subordinate to that of the mother. At the same time the Mishnah expressly forbids interference with natural processes after the moment of birth, which is defined as the emergence from the womb of the forehead or the greater part thereof. In the ensuing talmudic discussion (Sanhedrin 72b), the child is described as being in effect an aggressor "pursuing" the life of its mother. As such, its life is forfeit if necessary to save the innocent victim so pursued. At this point the question is raised, why should an embryotomy not be performed in such circumstances even in the final stages of parturition? It is answered by pointing out that the law of pursuit does not apply when the mother is "pursued by Heaven," i.e., her danger is the result of natural occurrences rather than malevolent human activity. The apparent inference to be drawn from this discussion is that there is no need for resort to the law of pursuit in order to justify destruction of the fetus prior to birth. On the contrary, were there need for such justification, the law of pursuit would be of no avail since it cannot be validly applied in cases where such "pursuit" arises as a result of the processes of nature. Rashi (ad loc.) explains that the fetus is sacrificed in order to spare the life of the mother because even though the fetus has a claim to life and is sufficiently human to render its destruction a moral offense, neither this claim nor its status as a human life is equal to that of the mother: "As long as it [the fetus] has not emerged into the light of the world, it is not a human life."

Maimonides codifies the law emerging from this discussion in the following manner: "This also is a negative precept: not to have compassion on the life of a pursuer. Therefore the Sages ruled [regarding] a pregnant woman in hard travail that it is permitted to dismember the fetus in her womb, whether by chemical means or by hand, for it [the fetus] is as one pursuing her in order to kill her; but if it has already put forth its head it may not be touched, for [one] life may not be put aside for the sake of [another] life. This is the natural course of the world" (Hilkhot Rozeah 1:9). This formulation is problematic in that Maimonides invokes the law of pursuit as justification for the performance of an embryotomy in the early stages of labor, whereas the Gemara implies that the deliberate sacrifice of the unborn child is permitted simply because its life is subservient to that of the mother. Furthermore, the explanation offered seems to be contradictory in nature since Maimonides, in his concluding remarks, follows the Gemara in dismissing the applicability of the law of pursuit on the grounds that nature, not the child, pursues the mother. The question of proper interpretation of Maimonides is of the utmost halakhic relevance because in this instance his phraseology is adopted verbatim by the Shulḥan Arukh, Hoshen Mishpat 452:2.

In an attempt to resolve these difficulties, R. Yechezkel Landau points out that the killing of a fetus, while not constituting an act of homicide, is nevertheless an odious offense. Just as there is no justification for the sacrifice of a person suffering from a fatal injury—the killing of whom does not technically constitute murder—for the purpose of preserving the life of a normal person, so also destruction of the embryo in order to safeguard the life of the mother would not be condoned if not for its being, at least in measure, an aggressor. R. Ya'ir Bachrach and Rabbi Chaim Soloveitchik employ similar reasoning in explaining Maimonides' position. A somewhat different explanation is offered by R. Isser Zalman Melzer in the name of R. Chaim Soloveitchik. Rabbi Unterman, in his work Shevet me-Yehudah, attempts a further clarification of Maimonides' position by explaining that the ban against destroying the life of a fetus stems not from an actual prohibition against the act of feticide per se, but from an obligation to preserve the life of the fetus. Since the killing of a fetus is antithetical to its preservation, embryotomy is permissible only when the fetus is, in point of fact, an aggressor. Once the child is born, the prohibition against homicide becomes actual and since, technically, it is nature which is the pursuer, the law of pursuit is not operative.

Resolution of the difficulties surrounding Maimonides' ruling and the reasoning upon which it is based is of great significance in terms of practical Halakhah. According to the explanations offered by R. Yechezkel Landau, R. Chaim Soloveitchik and others following in the same general mode, therapeutic abortion would be permissible only in instances where the "pursuer" argument may be applied, i.e., where the threat to the life of the mother is the direct result of the condition of pregnancy. R. Chaim Ozer and Rabbi Weinberg both contend that a pregnancy which merely complicates an already present medical condition, thereby endangering the life of the mother, does not provide grounds for termination of pregnancy according to such analyses of Maimonides' position. In these cases the fetus cannot be deemed an aggressor since the mother's life is placed in jeopardy by the disease afflicting her. It is this malady, rather than her pregnant condition, which is the proximate cause of impending tragedy. An identical conclusion was reached much earlier by R. Isaac Schorr (Koaḥ Shor, no. 20) who points out that the law of pursuit encompasses only cases where the pursuer seeks to perform an overt act of homicide. If the act only leads indirectly to the death of the pursued, e.g., when the pursuer merely seeks to incarcerate the victim so that he die of starvation or seeks to cut off the intended victim's supply of oxygen in order to cause asphyxiation, the law of pursuit is not applicable, for "we have not heard that the pursued may be saved by taking the life of one who is desirous of preventing a benefit necessary for the life of his fellowman." A fetus, which itself is not the cause of danger but whose presence thwarts the efficacy of medical remedies, clearly falls within this category. At least one other authority, R. Isaac Lampronti, the author of Paḥad Yizḥak (Erekh Nefalim, 79b) states unequivocally that danger caused by an extraneous disease does not warrant performance of an abortion in order to save the mother. Rabbi Schorr emphasizes that (according to Maimonides) it must be known with certainty that the pregnancy per se constitutes this danger. This rules out abortion in instances where there is doubt as to whether the pregnancy is the actual case of danger or whether the pregnancy merely complicates a previously existing condition.

The aforementioned discussions concern themselves only with cases in which failure to terminate pregnancy will indubitably result in the loss of life to the mother. The question of termination of a pregnancy which, while jeopardizing the life of the pregnant mother, will not necessarily result in imminent loss of life again centers around Maimonides' invocation of the law of pursuit. Citing Rashi, Sanhedrin 72b and Pesaḥim 2b, Rabbi Schorr demonstrates that the law of pursuit cannot be invoked in cases of doubt. Hence abortion may be permitted only when there exists incontravertible medical evidence that the pregnancy per se will result in the loss of the life of the pregnant mother. R. Shlomoh Drimer (Bet Shlomoh, Hoshen Mishpat, no. 120), however, reaches the opposite conclusion, at least in theory. Following the authorities who maintain that a fetus is "not a life" and hence its destruction does not constitute an "appurtenance" of homicide, Rabbi Drimer concludes that feticide is no different from other transgressions which may be violated even in cases of possible or suspected danger. Nevertheless, in practice, Rabbi Drimer, on the basis of other considerations, withholds permission in cases of merely possible danger to the life of the mother. The Gemara (Yoma 82a) specifies that a pregnant woman who becomes agitated at the smell of food on the Day of Atonement may, if necessary, partake of the food which causes this excitement lest she suffer a miscarriage and her fetus be spontaneously aborted. Maimonides, Rabbenu Asher and Rabbenu Nissim interpret this provision as being based, not on a concern for the preservation of the unborn child, but on a concern for the life of the mother. According to their view, expulsion of the fetus ipso facto constitutes a threat to the life of the mother. Accordingly, reasons Rabbi Drimer, even if continuation of pregnancy jeopardizes the life of the mother, this consideration is counterbalanced by the fact that termination of pregnancy in itself constitutes a parallel jeopardy. Therefore, a course of "sit and do not act" is preferable. Even if physicians advise that there is no danger involved in the performance of the abortion, their advice is to be disregarded, just as medical opinion is ignored when it fails to recognize cases of "danger" which are delineated by Halakhah as constituting a threat to human life. Halakhah specifies that a woman's life is in jeopardy for a minimum period of three days following childbirth and hence during this time she is permitted to partake of food on the Day of Atonement, the Sabbath is violated on her behalf, etc. Since Halakhah defines childbirth as a "danger," medical opinions to the contrary or protestations of well-being on the part of the patient are disregarded. Rabbi Drimer reasons that the same considerations should apply to the conditions surrounding abortion.

A very different conclusion is reached by R. Mordecai Leib Winkler (Levushei Mordekhai), who finds reason to distinguish between miscarriages and abortions performed by medical practitioners. Since there is no explicit reference to the latter, those authorities who state that abortion per se constitutes a threat to the life of the mother may not have intended their remarks to encompass therapeutic abortion surrounded by medical safeguards. Levushei Mordekhai also introduces the notion of comparative danger and seems to indicate that, while abortion may itself constitute a danger in the opinion of these authorities, this danger may not be acute since dispensation for violation of Shabbat and Yom Kippur is granted for even the slightest threat to life. Abortion should therefore be sanctioned in order to obviate a more acute danger. Furthermore, the remarks of these authorities fail to demonstrate that miscarriage per se jeopardizes the life of the mother. Their pronouncements are consistent with the conclusion that danger will result only if the woman fails to receive proper care pursuant to the expulsion of the fetus. Since such care would involve desecration of Yom Kippur in any event, the woman may break her fast in order to prevent the necessity for such later violations. Levushei Mordekhai concludes that there is, then, no evidence that a therapeutic abortion performed under proper medical conditions and with provision for proper convalescence constitutes a jeopardy to the life of the mother.

Returning to our central problem, many authorities take a different view with regard to embryotomy in cases where pregnancy endangers the life of the mother by complicating an already present medical condition. Rabbi Weinberg (No'am IX, 204; Seridei Esh, III, 343 f.) offers a radically different approach to the resolution of the complex difficulties surrounding the previously cited statements of Maimonides, Hilkhot Rozeaḥ 1:9, in light of the latter's remarks in Hilkhot Hoveil u-Mazik 8:4. Maimonides rules that although property belonging to others may be appropriated in order to preserve one's own life, compensation must nevertheless subsequently be paid to the lawful owner. Rabbi Weinberg notes that the provision is modified in the event that the property itself is the source of danger (Nizkei Mamon 8:15). The paradigm case is that of the threat to the lives of the passengers sailing on an overly laden ship which is in danger of sinking. One who lightens the load by throwing cargo overboard is absolved from payment of property damages since the cargo itself is deemed to be "a pursuer." Rabbi Weinberg opines that Maimonides invokes this provision in his exposition of the law surrounding danger arising from pregnancy. Maimonides does not resort to the law of pursuit, argues Rabbi Weinberg, in order to justify sacrifice of the life of the fetus; this is warranted on the basis of Rashi's explanation that it is not fully "a human life." Rather, continues Rabbi Weinberg, Maimonides invokes the pursuer argument in order to provide a basis for exemption from satisfaction of the husband's claim for monetary damages normally incurred as a result of destruction of a fetus as provided by Exodus 21:22.

R. Chaim Ozer, in another responsum (Aḥi'ezer, III, no. 72), points out that Maimonides' phraseology refers specifically to a woman in "hard travail." As previously noted, the Talmud regards a fetus which has "tom itself loose" from the normal uterine position as a separate body. According to R. Chaim Ozer, Maimonides deems it necessary to rely upon the law of pursuit only because he refers to a fetus which, although yet unborn, is already a separate body. The Gemara speaks of earlier stages of pregnancy and hence has no need for recourse to this line of reasoning. According to this interpretation, Maimonides recognizes that prior to the mother's "sitting on the birth stool" the fetus is but an organic limb of her body. It is of course not merely permissible, but mandatory, to amputate a limb in order to save a life. Therefore, concludes R. Chaim Ozer, even according to Maimonides, it is permissible to perform an abortion in cases involving danger to the life of the mother, irrespective of the source of such danger, provided this procedure is performed before the fetus has "torn itself loose." R. Chaim Ozer adds the stipulation that the physicians advising this medical procedure be highly expert and certain in their opinion that the operation itself does not constitute a danger.

A further ramification of these diverse analyses of Maimonides' views relates to the permissibility of therapeutic abortion in situations deleterious to the health of the mother, but not endangering her life. The most permissive ruling with regard to therapeutic abortion, one to which later authorities take strong exception, is that of R. Jacob Emden, who permits performance of an abortion not only when the mother's health is compromised but also in cases of "grave necessity," such as when continuation of the pregnancy would subject the mother to great pain. Such abortions are sanctioned by R. Emden when performed before the onset of labor at which time the fetus has "torn itself loose" from the uterine wall. Citing Havot Ya'ir's explanation that the basis of the law against feticide is the prohibition against destroying the seed, R. Emden maintains that destroying the seed is forbidden only when such emission or destruction is without purpose, but may be permitted when it serves a medical function. It should, however, be noted that Havot Ya'ir himself quotes Rashi's commentary, Sanhedrin 72b, "a woman who is in hard labor and whose life is in danger," from which Havot Ya'ir deduces that other than in cases of actual danger to maternal life abortion cannot be sanctioned.

R. Joseph Trani, in a somewhat more restricted ruling (Teshuvot Maharit, I, no. 99), sanctions abortions when performed in the interests of maternal health. This decision follows logically from his thesis that feticide is not a form of homicide but is forbidden because removal of the fetus constitutes an act of "wounding." It, of course, follows that any wound inflicted for purposes of healing is not encompassed by this prohibition.

Rabbi Weinberg (No'am IX, 215; Seridei Esh III, 350) observes that according to the previously cited explanations of Hilkhot Rozeaḥ 1:9 by R. Yechezkel Landau and R. Chaim Soloveitchik, abortion would not be sanctioned by Maimonides except when there exists an imminent threat to the life of the mother. Rabbi Weinberg adds, however, that in view of the fact that many authorities dispute Maimonides' position, "perhaps" the lenient ruling of R. Jacob Emden may be relied upon if continuation of pregnancy until term would be detrimental to the health of the mother.

In a similar vein, Rabbi Waldenberg notes (Ẓiz Eli'ezer, IX, 239) that "there is room for leniency" if the state of maternal health is very precarious or if necessary in order to secure relief from severe pain. As noted earlier, Rabbi Moshe Yonah Zweig (No'am, VII, 48) rules that abortion on these grounds is permissible within the first forty days of gestation.

Among the authorities not previously cited who forbid destruction of the fetus other than in face of a definite threat to the life of the mother are: Koaḥ Shor, no. 21; Levushei Mordekhai, Hoshen Mishpat, no. 36; Bet Shlomoh, Hoshen Mishpat, no. 132; Pri ha-Sadeh, IV, no. 50; Binyan David, no. 47; Avnei Ẓedek, Hoshen Mishpat, no. 19; Afarkasta de-Anya, no. 169; and Ẓur Ya'akov, no. 141.

The law of pursuit provides that the life of the pursuer is forfeit only if his malevolent intention cannot be thwarted by otherwise disabling the pursuer. Thus, if it is possible to disable the aggressor by maiming or crippling him, his life may not be taken under the law of pursuit. R. Moses Samuel Horowitz and R. Isaac Schorr (Koaḥ Shor, no. 20) both rule that this consideration applies to a fetus as well. Accordingly, when intrauterine amputation of a limb would suffice to save the mother without recourse to an embryotomy, destruction of the fetus cannot be sanctioned. R. Shlomoh ha-Kohen of Vilna, author of the well-known Heshek Shlomoh, deems this conclusion incontravertible and concurs in this ruling.

Indeed, this interesting ramification serves as the basis for a novel reinterpretation of Maimonides' position. Rabbi Horowitz and Rabbi Schorr, apparently without either having seen the other's work, both note the expression "for it is as one pursuing her." They infer that Maimonides does not really intend to invoke the law of pursuit. Instead, he relies on the implicit rationale that the fetus is not "a life." Yet one restrictive aspect of the law of pursuit is applicable; namely, that the fetus, even though it is not deemed to be "a life," cannot be destroyed if it is possible to save the mother by merely crippling her unborn child. This then, they declare, is the intention of the phrase "limb by limb" as used by the Mishnah—first one limb, then another is removed in an attempt to deliver the child. While preservation of maternal life is of paramount concern, care must be taken that no unnecessary harm be inflicted upon the fetus.

Interpreted in a similar manner, the further provision of the Mishnah, "but once the major portion has emerged one may not touch it" (the fetus), implies that even the maiming of a partially born child or amputation of a limb is forbidden in order to save the mother. R. Chaim Sofer (Maḥaneh Hayyim, Hoshen Mishpat, no. 50) draws such an inference and indicates that the rationale motivating the decision is the fact that the physician "cannot guarantee with certainty" that the child will survive the surgical procedure. However, if noninterference will result in the loss of both mother and child, R. Sofer permits maiming of the child in an attempt to save the life of the mother.

The entire area of psychiatric problems and severe emotional disturbances and their bearing upon halakhic questions has as yet not been adequately explored. Guidelines are to be found in isolated references to various forms of mental illness scattered throughout responsa literature. The earliest references to mental disease sufficiently grave to imperil the life of the afflicted occurs in the Issur ve-Heter he-Arukh, attributed to Rabbeneu Yonah of Gerondi. Issur ve-Heter he-Arukh cites a specific query addressed to an earlier authority, Maharam, concerning an epileptic who sought advice concerning the permissibility of partaking of a forbidden food reported to possess medicinal properties capable of curing his disease. The decision, in which Nachmanides acquiesces, is in the affirmative, provided that the efficacy of the remedy has been established. This decision is predicated upon a determination that epilepsy constitutes a danger to life, since at times an epileptic may endanger himself by "falling into fire or water." R. Israel Meir Mizrachi relies upon the decision of Nachmanides in ruling that insanity constitutes a danger to life and accordingly permits an abortion when it is feared that the mother may otherwise become mentally deranged. This position is also adopted by Levushei Mordekhai, Hoshen Mishpat, no. 39, who is cited by R. Waldenberg, Ẓiz Eli'ezer, IX, 327, Similarly, R. Yitzchak Ya'akov Weisz, Minḥat Yizḥak, I, no. 115, and R. Moses Feinstein, Iggrot Mosheh, Even ha-Ezer, I, no. 65, declare that mental derangement constitutes a danger to life.

Other authorities, however, apparently do not regard insanity (at least in all forms) as constituting a hazard to life. Thus when R. Moses Sofer was asked whether it was permissible to have a mentally ill child admitted to an institution where he would be served forbidden foods, he discusses all aspects of the case without at all raising the question of pikuaḥ nefesh (danger to life). Rabbi Unterman, in an article contributed to Ha-Torah ve-ha-Medinah (IV, 27), argues that the instinct for self-preservation is so deeply ingrained, and suicidal tendencies are so rare, that one cannot consider mental illnesses as falling under the category of diseases which imperil life.

R. Ya'ir Bachrach was asked whether a dose of ecbolics could be administered to a Jewess who had become pregnant as the result of an adulterous relationship in order to induce the abortion of her bastard fetus. Noting that the customary prayer "Preserve this child to its father and to its mother" is omitted at the circumcision of the issue of an adulterous or incestuous union because "the proliferation of bastards in Israel" is not desirable, he concludes that while proliferation of such children may not be a social desideratum, and hence there is no obligation to offer prayer on their behalf, nevertheless there is no legal distinction between a bastard and a legitimate embryo which would sanction any overt action which might threaten its life (Havot Ya'ir, no. 31). An identical query addressed to R. Jacob Emden (She'elat Ya'avez, no. 43) elicited a different response. Taking note of the earlier responsum in Havot Ya'ir, R. Jacob Emden finds grounds to differentiate between the seduction of an unmarried maiden and an adulterous relationship with a married woman. The latter, having committed a capital offense, is liable to the death penalty. Were we able to execute judgment in capital cases, the pregnant condition of the condemned would not warrant a delay in administering punishment. This is clearly established by the Mishnah (Erukhin 7a) even with regard to cases in which pregnancy occurs after commission of the crime. Since, in this case, the child was conceived in sin, there is all the more reason for immediate execution of the mother. R. Jacob Emden adds the rather astonishing opinion that, although we no longer administer capital punishment, nevertheless, one who has committed a crime punishable by death may commit suicide without fear of sin. R. Jacob Emden even deems self-immolation to be meritorious in such circumstances. R. Jacob Emden reasons that if the mother may destroy herself completely she may certainly destroy a part of her body. Hence he concludes there can be no prohibition against the destruction of a bastard fetus since its life is legally forfeit. From an observation added in the course of his discussion, it appears that R. Jacob Emden intended his remarks to apply only where formal warning of the nature of the transgression and its punishment was administered prior to the adulterous act, since capital punishment is not inflicted by the Bet Din in the absence of such warning.

Rabbi Unterman voices an obvious objection against the above decision. The Mishnah in Erukhin which provides for the execution of a pregnant woman is understood by the commentaries as having reference to situations where pregnancy was not detected until the verdict was announced; when pregnancy was known beforehand, the trial was delayed until after confinement in order to spare the life of the child. The status of an adulterous woman in our times is always that of a woman prior to trial. Accordingly, there is no justification for the destruction of a fetus illicitly conceived.

R. Moses Yekutiel Kaufman, author of Leḥem ha-Panim (Fürth, 5526), states unequivocally (Kuntres Aḥaron, no. 19, p. 58b) that it is forbidden to give a woman a drug for the purpose of aborting a bastard fetus.

The status of abnormal and malformed human beings is well defined in Halakhah. Physical or mental abnormalities do not affect the human status of the individual. R. Yehudah ha-Chassid refers to the question of terminating the life of a monsterlike child born with the teeth and tail of an animal. Indeed, the interlocutor raises the question only on basis of the fear aroused by reports that the creature would later "eat people." R. Eliezer Fleckeles of Prague rules explicitly that the killing of even a grotesquely malformed child possessing animal features constitutes an act of murder. Challenging the questioner's view that the Talmud's suspension of the usual ritual impurity following the emission of similarly malformed or animal-like embryos indicates that upon birth a child so formed should not be classified as a human being. R. Fleckeles counters that this exclusion is limited to the laws of impurity applicable to miscarriages. The issue of a human mother, no matter how gravely deformed, enjoys human status and may not be destroyed either by overt act or by passively allowing it to die of starvation.

Rabbi Unterman, in dealing with the question of abortion in cases where an expectant mother contracted German measles early in pregnancy, and Rabbi Moshe Yonah Zweig, in discussing the deformities caused by thalidomide, both conclude that there is no distinction in the eyes of the law between normal and abnormal persons either with regard to the statutes governing homicide or with regard to those governing feticide. Rabbi Waldenberg (Ẓiz Eli'ezer, IX, 237) is the only authority who deems abnormality of the fetus to be justification for interruption of pregnancy and even he stipulates that the abortion must be performed in the early stages of pregnancy. Rabbi Waldenberg indicates that the difficulties engendered by the birth of an abnormal child may render abortion a "grave necessity" and therefore permissible according to the previously cited view of R. Jacob Emden. Rabbi Waldenberg permits such termination of pregnancy within the first three months following conception provided there is as yet no fetal movement.

Nevertheless, R. Isaac Schorr finds a basis upon which a non-Jewish physician might be requested to terminate the pregnancy of a Jewish woman. Requesting such aid should normally be discountenanced as a violation of "Thou shall not place a stumbling block before the blind." However, this commandment is no different from other negative prohibitions (excepting the three cardinal sins) which may be ignored when life is at stake. Since R. Moses Isserles (Yoreh De'ah 157:1) rules that this ban may be violated even if the "stumbling block" is the commission of one of the three cardinal sins, there is no barrier to requesting the non-Jewish physician to undertake such a procedure, if he is willing to do so, provided no Jewish physician is available. If a Jewish physician is available, his aid should be sought in order to obviate the necessity of "placing a stumbling block."