When Does Human Life Begin?
The question of when a human life begins is a profoundly intricate one, with widespread implications, ranging from abortion rights to stem cell research and beyond. A key point in the debate rests on the way in which we choose to define the concepts of humanity, life and human life. What does it mean to be alive? What does it mean to be human? Is a zygote or an embryo alive? Is a zygote or an embryo a human being? These are intricate philosophical questions that often incite intense debate, for their answers are used as evidence in the answers to questions about the moral status of a zygote, embryo or fetus. The question of when human life begins has been pondered throughout history and in a multitude of cultural contexts. The "answer" is fluid, in that it has been changing throughout history, because any answer about when human life begins is deeply integrated with the beliefs, values and social constructs of the community or individual that drew the conclusion. Throughout history there have been several "answers" to the question of when human life begins, but the only consistency among the answers is that they are always changing as social contexts change, religious morals fluctuate, or new knowledge about the process of embryo development is obtained. A particularly interesting aspect regarding the question of when human life begins is how the answer to the question is obtained. As the criteria and social contexts change, what methodology or fundamental principles did people use to answer this complicated and convoluted question? Historically, the answer has been coupled with the issue of abortion. As people tried to determine what stage abortion was acceptable, they often confronted the question as to when abortion should be considered destruction of a human life. While abortion is also a complicated issue with many confounding political, social and cultural factors, historically one of the fundamental determinants of the moral consequences of abortion, stemmed from what stage people viewed the embryo as a human being. The moral acceptance of abortion extended from the question as to whether abortion was the destruction of tissue, or whether it was an act of homicide. An analysis of the historical controversy over abortion issues can lead to an understanding of how communities and individuals throughout history were able to address the question of when human life begins.Historical Views of When Human Life Begins
At times, the distinction as to when human life begins was based on a community's need to regulate its population flux. In ancient Sparta, abortion was frowned upon because it ran counter to the desire to raise strong males for military struggles. Yet in Sparta, the practice of leaving a child to die of exposure on a hillside was not considered murder if the child was judged to be unsuitable for some reason (Morowitz and Trefil 1992). It is unclear whether Spartans believed that one obtained personhood after birth, and the regulation on abortion was purely for political reasons, or whether they believed that personhood was obtained prior to birth, and that it was a status unattainable by deformed infants. Plato contended that the human soul does not enter the body until birth, and this was determinative for legal science in ancient Roman society (Buss 1967). In his Republic, Plato writes that abortion should be compelled in any woman who becomes pregnant after forty. Plato, in the ideal state detailed in his Republic, laid it down as a matter of eugenic policy that parents should bear children for the state for a defined period of years. After that period sexual intercourse would be permitted, but the couple involved would make every effort to prevent any children conceived from seeing light and dispose of the newborn child only if the former course proved impossible (Bonner 1985). While Ancient Romans may not have openly approved of the practice of abortion, it was not considered a serious offence. Indeed, Seneca disapprovingly states, that it was common practice for a woman to induce abortion in order to maintain the beauty of her figure (Tribe 1990). The Stoics held that the fetus was no more than a part of the women's body during the entire duration of pregnancy and was ensouled only at birth by a species of cooling by the air, which transformed a lump of flesh into a living and sentient being (Tribe 1990). Pythagoreans stressed that the human soul was created at the time of conception and this is reflected in the Hippocratic oath. Hippocrates was of seemingly a minority position in ancient Greece, in that he disapproved of abortion. The Oath expressly forbids giving a woman "an instrument to produce abortion," and it has been interpreted to forbid inducing abortion by any other method (Tribe 1990). Hippocrates outright disapproval of abortion stemmed from his belief that conception marked the beginning of a human life (Tribe 1990). Aristotle formulated a view on abortion and the beginning of human life that was widely accepted, and even acknowledged and practiced for some time in the Catholic Church. Aristotle believed that the state should fix the number of children a married couple could have, and while Aristotle held the common Greek view that deformed children ought not to be reared, he objected to the exposure of healthy infants merely as a method of population control. In his view, the size of the family should be determined by the state, and if children were conceived in excess of the permitted number, an abortion should be procured at an early stage of pregnancy "before sensation and life develop in the embryo" (Bonner, 1985). Aristotle detailed the notion of the "animation" of the fetus, and associated individuality, life, and form as those features for which the "soul" was responsible at a certain point in gestation. Aristotle asserted that when soul was added to the matter in the womb, a living individuated creature was created, which had the form and rational power of a man (O'Donovan 1975). This process of formation or animation, manifested by the movement of the fetus in the womb, took place, in Aristotle's opinion, on the fortieth day after conception in the case of a male child and on the ninetieth day after conception for a female child (Bonner 1985). Aristotle explained this difference in animation times, for males and females, based on his perceived fundamental differences between men and women. Aristotle believed that males were more active than females, thus he believed that they were quicker to develop, obtain a soul, and become animated within the womb. Females on the other hand were viewed as physically and intellectually inferior to men; therefore, their process of ensoulment took a longer time to complete (Bonner 1985). The Catholic Church, including both Thomas Acquinas and Augustine of Hippo, held the view that fetuses were animated (i.e., ensouled) around day 40. The Jewish interpretation of when human life begins is extracted predominantly from three sources: the Torah, the Jewish Talmudic Law, and the rabbinical writings. Since the Torah does not make any direct references regarding the beginning of human life, the inferences as to when human life begins has stemmed from the Torah's stated position on the issue of abortion. In the Torah, there is not an explicit prohibition directed against a voluntary abortion. The legislation in the Torah makes only one reference to abortion, and it is through implication (Jakobovits 1973): And if men strive together, and hurt a woman with a child, so that her fruit depart, and yet no harm follow, he shall be surely fined, according as the woman's husband shall lay upon him; and he shall pay as the judges determine. But if any harm follow, then shalt thou give life for life... (Exodus 21: 22-23; as cited by Jakobovits 1973). According to the Jewish interpretation, if "no harm follow" the "hurt" to the woman resulting in the loss of her fruit refers to the survival of the woman following her miscarriage; in that case there is no capital guilt involved, and the attacker is merely liable to pay compensation for the distress that the miscarriage may cause the family (Jakobovits, 1973). "But if any harm follow," i.e., the woman is fatally injured), then the man responsible for her death has to give "life for life"; in that event the capital charge of murder exempts him from any monetary liability for the aborted fetus (Jakobovits 1973). From the interpretation of this passage it can be concurred that the killing of an unborn child is not considered murder punishable by death in Jewish law. What is explicitly stated in the Jewish text, is that murder is an offense that is punishable by death: "He that smiteth a man, so that he dieth, shall surely be put to death" (Exodus 21:12; as cited by Jakobovits 1973). The Rabbis had to reconcile the contexts of these two passages, and reached the conclusion that the capital charge of murder should be used for death of "a man, but not a fetus" (Mekhilta; as cited by Jakobovits 1973). In reaching this conclusion, the fetus was designated a status that was below that designated for a human. In essence, the interpretation of the Torah led the Rabbis to come to the conclusion that human life does not begin at the fetal stage of development. The Jewish Talmudic Law assumes that the full title to life arises only at birth. According, the Talmud rules: If a woman is in hard travail {and her life cannot otherwise be saved}, one cuts up the child within her womb and extracts it member by member, because her life comes before that of {the child}. But if the greater part {or the head} was delivered, one may not touch it, for one may not set aside one person's life for the sake of another (Talmud, Tohoroth II Oholoth 7:6; as cited by Jakobovits 1973). This is the sole reference to abortion in the principles of Jewish law, and it is more explicit in emphasizing the belief that human life begins once the head of a full term baby emerges, because once the head emerges the infant is given the same status of human life as the mother. Yet even in this context abortion is only considered acceptable if the birth of the child threatens the life of the mother. The fetus must maintain some form of perceived life, otherwise the destruction of the fetus would be acceptable under any circumstances, rather than only under the conditions of a mother's imitable health. Also, an argument has been put forth that declares the child as being in "pursuit" of the mother's life; therefore, it may be destroyed as an "aggressor" following the general principle of self-defense (Jakobovits 1973). The need for this argument indicates that abortion may have been considered the destruction of a human life, and this belief had to be reconciled with the practice of abortion to save the mother's life. Generally, it can be viewed that the fetus is granted some recognition of human life, but it does not equal that of the mother's, and can be sacrificed if her life is in danger. While the Talmud gives the full status of humanness to a child at birth, the rabbinical writings have partially extended the acquisition of humanness to the thirteenth postnatal day of life for full-term infants (Jakobovits 1973). This designation is based on the viability of the infant, so the acquisition of humanness occurs later for premature infants, because the viability of premature infants is still questionable after thirteen days (Buss 1967). Rabbinical writings have established that viability of a child is not fully established until it has passed the thirteenth day of its life. Extending from this idea is that if two lives are at stake, the one that is certain and established, the mother, overrides the infant's life, which is still in some doubt (O'Donovan 1975). Under these circumstances, it may be that the sacrifice of the child must result to save the life of the mother (Jakobovits 1973). This slight inequality in value is too insignificant to warrant the deliberate sacrifice of the child for the sake of the mother if, without such sacrifice, the child would survive; but it is a sufficient factor to tip the scales in favor of the mother if the alternative is the eventual loss of both lives (Jakobovits 1973). The sense that priority belongs to the weaker and younger of the two claimants is balanced, and in most peoples judgment overruled, by a strong sense that the self conscious humanity of the mother, who has already established pattern of relationships, demands more attention than the yet unconscious humanity of the infant (O'Donovan 1975). Some of the Christian interpretations on abortion, and thus indirectly when human life begins, are influenced by the writings of the Old Testament. Under Greek influence the Septuagint version of Exodus 21:22-23 came to make a distinction between an unformed and a formed fetus, the latter was considered an independent person (Buss 1967). This Christian tradition that disputes the Jewish view apparently resulted from a mistranslation in the Septuagint, where the Hebrew for "no harm follow" was replaced with the Greek for "imperfectly formed" (Jakobovits 1973): And if two men strive together and smite a woman with child, and her child be born imperfectly formed, he shall be forced to pay a penalty: as the woman's husband shall lay upon him he shall pay with valuation. But if it be perfectly formed, he shall give life for life (Exodus 21:21-23; as cited by Bonner 1985). Tertullian and later church fathers accepted this interpretation, distinguishing between an unformed and a formed fetus and branding the killing of the latter as murder. The formed fetus was to be accorded full human status, and this distinction was subsequently embodied in canon law as well as in Justinian Law (Jakobovits 1973). The distinction between a formed and an unformed fetus, in Exodus, generated the question as to whether biblical writers understood parts of embryonic development, and had designated a temporal period that marked the formation of a fetus. While the Old Testament gives several passages in which the growth of the unborn child is described, these passages are written in poetry, and it cannot be determined whether they represent what the biblical writers actually thought was happening inside the womb (Rogerson, 1985). Job 10:10 states the rhetorical question: "Didst thou not pour me out like milk and curdle me like cheese"? It continues: "Thou didst clothe me with skin and flesh and knot me together with bones and sinews" (Rogerson 1985). The reference to curdling may reflect the fact that as a result of miscarriages and premature births, the biblical writers were aware of the difference between the fetus in an undeveloped state, and in a state where the outward form of the child was already complete. Psalm 139: 13-16 stresses again upon the growth of the child from something formless to something developed and complete, but there is not a clear distinction indicating when the fetal body obtains form, and whether this acquisition of form designates an acquisition of humanness (Rogerson 1985). Yet there is reference to the involvement of God in the process of growth and development of the embryo, and some theologians argue that there is no need to distinguish between a formed and an unformed fetus, because embryonic development is a divine process that should not be interrupted by human intervention (Rogerson 1985). The involvement of God in determining the beginning of human life is further expanded upon in the New Testament. The New Testament offers the belief that it is the love of God, which makes possible the Christian life. The passage that comes nearest to saying this explicitly is Galatians 2:20 "... the life I now live in the flesh I live by faith in the son of God, who loved me and gave himself to me" (Rogerson 1985). If the love of God marks the beginning of human life, then the point at which God extends his love to a fetus must be determined. Does God's love extend to include potential life, or is there a point in development where the soul is infused with an embryo, which is the point that God extends his love to mark the beginning of a Christian life? While there are references in the New Testament to God's love rejuvenating life, there is not any mention of God's role in loving a developing fetus. For example, in the New Testament it was the fact that the Good Samaritan in the parable was "moved with compassion" that saved from certain death the man who had been robbed and beaten (Rogerson 1985). In the parable of the Prodigal Son it was the love of the father that make possible the renewed life of the son who had been "dead, and is alive again" (Luke 15:24; as cited by Rogerson, 1985). The very possibility of Christian life may depend on the fact that God commends his love towards Christian followers "in that while we were yet sinners Christ died for us" (Romans 5:8; as cited by Rogerson 1985). It has been stated that it is the love of God, which makes life in a relational sense possible, consequently Christians should resist any degradation of the life of a human being who is potentially a son or daughter of God (Rogerson, 1985). ... can we, at one and the same time, be under the imperative of love, and be satisfied with a society that denies to the unborn the possibility of living (Athenag., Supplicatic; as cited by Rogerson 1985)? Yet it is still unclear as to whether denying the ability for God to love a fetus represents taking away a human life or a potential human life. Some Christian theologians argue that humanness is acquired on a continuum, and the state of humanness is reached through the acts of birth and baptism. It has been argued, that the true acquisition of humanness cannot be obtained until after a baptism or at least birth, because miscarried fetal material is usually not accorded the signs of recognition with which some Christians note human birth and death: baptism, burial and weeping (Rogerson 1985). Tertullian, a prominent Christian theologian, opposed contraception and early abortion, because he regarding them as "proleptic murder"- the prevention of a birth that should occur (Buss 1967). In his Apology (A.D. 197) Tertullian denounces infanticide and abortion: As regards infanticide, however—although I grant that murder of a child, if it is your own, differs from killing somebody else!—it make no difference whether it is done willfully or as part of a sacred rite. I will turn to you now as a nation. How many of the crowd standing round us, open-mouthed for Christian blood, how many of you, gentlemen, magistrates most just and strict against us, shall I not prick in your inner consciousness as being the slayers of your own offspring? There is, indeed, a difference in the manner of death; but assuredly it is more cruel to drown an infant or expose it to cold and starvation and the dogs (than to sacrifice it, as you allege that we do)—even an adult would prefer to die by the sword. But for us, to whom homicide has been once for all forbidden, it is not permitted to break up even what has been conceived in the womb, while the blood is still being drawn from the mother's body to make a new creature. Prevention of birth is premature murder, and it makes no difference whether it is a life already born that one snatches away or a life that is coming to birth that one destroys. The future of man is a man already: the whole fruit is present in the seed (Tertullian, Apology; as cited by Bonner 1985). Tertullian observes that infanticide, usually accomplished by exposure, was generally accepted in Roman society. He contends that it was only eventually banned due to the influence of Christianity. The notion that a child, once born, was a human being enjoying the same right to life as an adult, was very far from being generally accepted by Roman society (Bonner 1985). The survival of the child during the first few days following birth depended to a great degree upon the decision of the father who thus retained, in an attenuated form, something of the power of life and death enjoyed by the head of the family in early Roman society. This residual patriarchal power perished with the instillation of Christianity; but the notion that parents had a right over the fate of the newly born was retained (Bonner 1985). While Tertullian regarded infanticide and abortion as forms of homicide, indicating that he believed the fetus had acquired a status of humanness, he did recognize the need for abortions when necessary to save the life of the mother. So while Tertullian considered the embryo a human being, he did not designate it the same status of personhood as that held by the mother (Buss 1967). Tertullian's views on abortion were reinforced by St Basil the Great, writing in 374, when he declared that abortion was murder, and that no distinction between the formed and the unformed fetus was admissible in Christian morality (Buss 1967). In 1140, when Gratian compiled the first collection of canon law that was accepted as authoritative within the church, he concluded that "abortion was homicide only when the fetus was formed." If the fetus was not yet a formed human being, abortion was not homicide. Throughout history, even the Catholic Church has held varying declarations about the beginning of human life. For most of the history of the Catholic Church, its thinkers viewed immediate animation/ensoulment as impossible, and under the traditional Catholic doctrine, a male fetus became animated—infused with a soul at forty days after conception, and the female fetus became animated at eighty days after conception (Tribe 1990). In 1588, Pope Sixtus V mandated that the penalty for abortion (or contraception) was excommunication from the Church. However, his successor, Pope Gregory IX, returned the Church to the view that abortion of an unformed embryo was not homicide. This was largely the view until 1869, when Pope Pius IX again declared that the punishment for abortion was excommunication. (Much of the support for this view was based on the idea that since we cannot know with certainty the time at which human life begins, it should have protection from the earliest possible time, that of conception. This view does not actually insist that fertilization is the time when human life begins. Rather, it is a statement that we don't know the time of ensoulment. Pope Pius IX was also responsible for canonization of the notion that Mary was without sin and that the pope was infallible). The current Catholic Church doctrine maintains the belief that immediate animation, the instant at which the zygote is endowed with life including a soul from God, is concurrent with the moment of fertilization (Shannon and Wolter 1990). Later Catholic theologians argued that the rational human soul began at the time of conception, because such an infusion was a divine act. This designating established that ensoulment occurred at conception, and the fetus should be designated a status independent of its parents. The fetus was considered a separate entity; no longer an automatic derivative of its parents, hence it had obtained a status of humanness as early as conception (Buss 1967). Catholicism traditionally forbade even early abortion in that it held that these acts interfered with the procreative purpose of sexual activity; but a fetus was not considered a person early in pregnancy, and early abortion was not deemed homicide (Tribe 1990). By the Catholic doctrine, firmly enunciated by Saint Augustine and other early Christian authorities, the unborn child was included among those condemned to eternal perdition if he died un-baptized (DeMarco 1984). The movement to remove the distinction between animate and inanimate fetuses from the Catholic doctrine was initiated by Thomas Fienus, who argued in 1620 that the soul must be present immediately after conception in order to organize the material of the body (DeMarco 1984). In the late nineteenth century, following the discovery of fertilization, the debate about abortion within the church tipped in favor of its now familiar position that human life begins at conception. This view was enhanced by the theological acceptance of the Immaculate Conception of Mary. In 1701 Pope Clement XI declared the Immaculate Conception a feast of universal obligation, and in 1854 Pius IX incorporated into Catholic dogma the teaching that Mary was without sin for the moment of her conception (Tribe 1990). These beliefs did not coincide with the prior view that the fetus did not acquire a soul until later in pregnancy, so the church had to unite its doctrine so that the act of conception coincided with the beginning of human life. This belief that life begins at conception is maintained to the present day, and it assumes that potential life, even in the earliest stages of gestation, enjoys the same value as any existing life. Some Catholic theologians even reject medical indication, considering abortion the destruction of a potential human being and an outright refusal of a divine gift from God (Buss 1967). The current catholic view of abortion concerning medical indication strays from that of Tertullian and Augustine, who accepted the use of abortion when the mother's life was threatened as the Church maintains the view that "two deaths are better than one murder" (Jakobovits 1973). Debate over the beginning of human life and abortion practices is not limited to ancient civilizations or Judeo-Christian religions. That abortion was known, practiced and punished in the ancient Near East is evident from the Middle Assyrian Laws, where we read: If a woman has had a miscarriage by her own act, when they have presented her (and) convicted her, they shall impale her on stakes without burying her. If she died in having the miscarriage, they shall impale her on stakes without burying her. If someone hid that woman knowing when she had the miscarriage (without) informing (the king).... (Meek, The Middle Assyrian Laws; as cited by Rogerson 1985). There may have been a political aspect to the foundation of Assyrian Law. The state may have penalized abortion because it regarded it as destruction of human life, but the state also needed to increase the number of healthy males so that there could be more warriors to carry out the state's military aims (Buss 1967). Certain Persians, Hindu and Buddhist texts applied ritual penalties to abortion on the level for those of homicide. Buddhism opposed the destruction of any form of life. Abortion violated the Buddhist ideal of self-sacrifice; its price is the woman's entrapment in the perpetual cycle of birth and rebirth (Tribe 1990) The Japanese Buddhists have a number of devotional practices that demonstrate their opposition to abortion. As early as the Tokugawa period, an aborted fetus came to be known as Mizuko (water child or unseeing child). It was believed that the soul of the aborted child is sent back to a children's limbo, whence it might later be reborn into the family that earlier rejected it (Tribe 1990). Throughout the Vedas, the classical Hindu religious texts, pejorative references to abortion abound. It has been called embryo murder and an act inimical to the very principle of creation. (Tribe 1990) Islamic law regards the fetus as a possible heir that can have his own heirs, but abortion is only punishable when it is done without the fathers consent (Buss 1967). Arabs practiced certain forms of contraception, particularly withdrawal, during the early Islamic era, and Muhammad apparently condoned these acts (Tribe 1990). In 1937 the grand mufti of Egypt issued a fatwa (opinion) that declared birth control permissible. In 1964, the grand mufti of Jordan declared that it is permissible to seek an abortion as long as the embryo is "unformed," that is, within 120 days of conception. Islam appears to espouse a view that strictly forbids abortion after the embryo has acquired a soul; something said to take place any time between 40 and 120 days after conception (Tribe 1990). The abortion laws in Britain originally roughly coincided with the belief of when human life begins, but gradually the multifaceted political aspects of abortion resulted in the abortion laws deviating from the general opinion of when human life begins. English common law located the beginning of a human soul at "quickening," believed to be the stage when the soul enters the body and the embryo could be felt moving within the uterus, which occurs at about four months. Abortion laws became more stringent in 1803, when abortion was criminalized. Punishment for abortion before quickening was set at exile, whipping, or imprisonment. Post-quickening abortion was punishable with death (Tribe 1990). In 1838 the concept of quickening was subtracted from British legal calculations on abortion. At the same time punishment by death was also eliminated. Under the Offenses Against the Person Act of 1861 anyone procuring an "unlawful" abortion, including the woman herself, could be punished with three years in prison. In 1929 Parliament passed Infant Life (Preservation) Act, which states that a termination of pregnancy, particularly with a viable fetus, is unlawful except when proved to have been done in good faith to preserve the life of the woman (Tribe 1990). In 1966 the House of Commons voted to legalize abortions performed for medical reasons including health. The British Abortion Act of 1967 permits abortion until infant viability outside the womb, as long as two doctors' certify that the risk to the life or mental or physical health of the woman, or to her existing children, would be greater if the pregnancy were to continue than if it were to be terminated. The line of viability is provided by the still valid Infant Life (Preservation) Act, which has been interpreted to restrict abortion after twenty-eight weeks of gestational age (Tribe 1990). The first soviet abortion decree, issued in 1920, was cast solely in terms of public health. Calling abortion a necessary "evil," the proclamation alluded to the pervasiveness of illegal abortion in a country torn by famine and civil war and suggested that abortion was a symptom of the social illnesses that lingered from the Czarist regime and for which Socialism would soon find a cure (Tribe 1990). Those opposed to legalized abortion argued not in terms of the right to life of the unborn child but in terms of the duty of the mother to perform her "natural" role in society, that of bearing children. The socialist state, they believed, had a right to the "natural" increase in the labor force occasioned by this role (Tribe 1990). In 1936 Joseph Stalin outlawed abortion. He proclaimed that socialism had solved the underlying problems that had caused abortion and he exhorted soviet women to fulfill their natural role and "give the nation a new group of heroes" (Tribe 1990). Two decades later after Stalin's death, abortion was re-legalized, again for public health reasons (Tribe 1990). The United States does not have a set definition of when human life begins. Many of the historical and contemporary abortion laws are based on either the opinion that life begins at conception, quickening, or the viability of the fetus outside the womb. Abortion was also permitted as a matter of public health in America, in an attempt to prevent the loss of lives of women who would be injured when trying to obtain illegal abortions. In 1821 Connecticut first enacted abortion laws though abortions of a non-quickened fetus were often permitted, or treated more leniently than others, and were generally permitted to save the life of the mother. The decision of Roe vs. Wade in 1973 was based on the survivability of the fetus outside of the womb. There are several different contemporary cultural views regarding when a person acquires humanness. In rural Japan, personhood is obtained when an infant utters first cry (Morowitz and Trefil 1992). In Northern Ghana a child is said to acquire humanness seven days after birth, while for some Ayatal aborigines personhood is not obtained until the child is named which occurs two to three years after birth (Morowitz and Trefil 1992). For several Native American tribes in the Mojave, human life begins for children who live long enough to be put to the mother's breast (Morowitz and Trefil 1992).Current Scientific Views of When Human Life Begins
Current perspectives on when human life begins range from fertilization to gastrulation to birth and even after. Here is a brief examination of each of the major perspectives with arguments for and against each of the positions. Contemporary scientific literature proposes a variety of answers to the question of when human life begins. Metabolic View: The metabolic view takes the stance that a single developmental moment marking the beginning of human life does not exist. Both the sperm and egg cells should individually be considered to be units of life in the same respect as any other single or multicellular organism. Thus, neither the union of two gametes nor any developmental point thereafter should be designated as the beginning of new life. Another slightly different though similar position maintains that the argument over when a new human life begins is irrelevant because the development of a child is a smoothly continuous process. Discrete marking points such as the fourteen day dividing line between a zygote and an embryo are entirely artificial constructions of biologists and doctors in order to better categorize development for academic purposes. This position is supported by recent research that has revealed that fertilization itself is not even an instantaneous event, but rather a process that takes 20-22 hours between the time the sperm penetrates the outermost layers of the egg and the formation of a diploid cell (Kuhse 1988).Genetic View:
The genetic view takes the position that the creation of a genetically unique individual is the moment at which life begins. This event is often described as taking place at fertilization, thus fertilization marks the beginning of human life. During this developmental event, the genes originating from two sources combine to form a single individual with a different and unique set of genes. One of the most popular arguments for fertilization as the beginning of human life is that at fertilization a new combination of genetic material is created for the first time; thus, the zygote is an individual, unique from all others. Although the opinion that life begins at fertilization is the most popular view among the public, many scientists no longer support this position, as an increasing number of scientific discoveries seem to contradict it. One such discovery in the last twenty years is that research has shown that there is no "moment of fertilization" at all. Scientists now choose to view fertilization as a process that occurs over a period of 12-24 hours. After sperm are released they must remain in the female reproductive tract for seven hours before they are capable of fertilizing the egg. Approximately ten hours are required for the sperm to travel up to the fallopian tube where they find the egg. The meeting of the egg and the sperm itself is not even an instantaneous process, but rather a complex biochemical interaction through which the sperm ultimately reaches the inner portion of the egg. Following fertilization, the chromosomes contained within the sperm and the chromosomes of the egg meet to form a diploid organism, now called a zygote, over a period of 24 hours. (Shannon and Wolter 1990). Thus, even if one were to argue that life begins at fertilization, fertilization is not a moment, but rather a continuous process lasting 12-24 hours, with an additional 24 hours required to complete the formation of a diploid individual. The most popular argument against the idea that life begins at the moment of fertilization has been dubbed the "twinning argument." The main point of this argument is that although a zygote is genetically unique from its parents from the moment a diploid organism is formed; it is possible for that zygote to split into two or more zygotes up until 14 or 15 days after fertilization. Even though the chances of twinning are not very great, as long as there is the potential for it to occur the zygote has not completed the process of individuation and is not an ontological individual. Proponents of this view often propose the following hypothetical situation: Suppose that an egg is fertilized. At that moment a new life begins; the zygote gains a "soul," in the Catholic line of thought, or "personhood" in a secular line of thought. Then suppose that the zygote splits to form twins. Does the soul of the zygote split as well? No, this is impossible. Yet no one would argue that twins share the same "soul" or the same "personhood." Thus, supporters of this view maintain that the quality of "soul" or "personhood" must be conferred after there is no longer any potential for twinning. (Shannon and Wolter 1990) The argument that human life begins at the moment that chromosomes of the sperm meet the chromosomes of the egg to form a genetically unique individual is also endangered by the twinning argument because genetic uniqueness is not a requirement for an individual human life. "Genetic uniqueness" can be shared by multiple individuals, particularly indentical twins. Thus, this argument continues, the moment at which a unique individual human forms is the not the moment when its genetic code is determined, but rather the moment when the zygote can no longer split into multiple individuals. In addition to twinning, there are other complexities that further confound the idea of the moment of conception. Just as it possible for a zygote to form two or more individuals before it is implanted in the uterus, it is also possible for it to not continue to develop at all, but rather just become a part of the placenta. (Shannon and Wolter 1990). It is estimated that more the 50% of the fertilized eggs abort spontaneously and never become children (see Gilbert 2003). Or, if the zygote splits into multiple zygotes, it is also possible for these to recombine before implantation. All of these possibilities are examples of the ways in which the individuation of the zygote is incomplete until it has been implanted in the uterus.Embryological View:
In contrast to the genetic view, the embryological view states that human life originates not at fertilization but rather at gastrulation. Human embryos are capable of splitting into identical twins as late as 12 days after fertilization resulting in the development of separate individuals with unique personalities and different souls, according to the religious view. Therefore, properties governing individuality are not set until after gastrulation. This view is endorsed by a host of contemporary scientists such as Renfree (1982), C. Grobstein (1988) and McLaren. This view of when life begins has also been adopted as the official position of the British government. The implications of a belief in this view include giving support to controversial forms of contraception including the "morning after" pill and contragestational agents as long as they are administered during the first two weeks of pregnancy. One of the most popular positions among philosophers is the perspective that life begins at the point of gastrulation, that point at which the zygote is an ontological individual and can no longer become two individuals. Gastrulation commences at the beginning of the third week of pregnancy, when the zygote, now known as an embryo is implanted into the uterus of the mother. The cells are now differentiated into three categories that will give rise to the different types of body tissue. (Shannon and Wolter 1990). After gastrulation the zygote is destined to form no more than one human being. The philosophers who support this position argue that there exists a difference between a human individual and a human person. A zygote is both human and numerically single and thus a human individual. However, because individuality is not certain until implantation is complete, and because individuality is a necessary condition of personhood, the zygote is not yet a human person. (Ford 1988; Shannon and Wolter 1990; McCormick 1991). Catholic scholars Shannon and Wolter (1990) describe this eloquently saying, "An individual is not an individual, and therefore not a person, until the process of restriction is complete and determination of particular cells has occurred. Then, and only then, it is clear that another individual cannot come from the cells of this embryo." Some supporters of the fertilization position find fault in this argument by claiming that the potential of twinning is a technicality and not strong enough to support the claim that human life does not begin until gastrulation. Alan Holland puts forth the view that just because a zygote has the possibility to divide into multiple individuals does not mean that it is not an individual before it divides. As an analogy, he presents the case of the worm that is clearly a single individual worm until it is cut into two when it becomes two individual worms. (Holland 1990). Some would also argue that in the discussion of when human life begins the question of whether a zygote will eventually become one individual or multiple individuals is irrelevant. The key point is that at least one human life may begin as the result of the zygote, and thus human life began at the creation of the zygote, fourteen days before gastrulation.Neurological view:
Although most cultures identify the qualities of humanity as different from other living organisms, there is also a universal view that all forms of life on earth are finite. Implicit in the later view is the reality that all life has both a beginning and an end, usually identified as some form of death. The debate surrounding the exact moment marking the beginning of a human life contrasts the certainty and consistency with which the instant of death is described. Contemporary American (and Japanese) society defines death as the loss of the pattern produced by a cerebral electroencephalogram (EEG). If life and death are based upon the same standard of measurement, then the beginning of human life should be recognized as the time when a fetus acquires a recognizable EEG pattern. This acquisition occurs approximately 24- 27 weeks after the conception of the fetus and is the basis for the neurological view of the beginning of human life. These principles of the neurological view of the beginning of human life are presented in The Facts of Life, a book written by Harold Morowitz and James Trefil in 1992 concerning the abortion controversy. An electroencephalogram (EEG) is a simple medical procedure in which electrodes are attached to different locations on a patient's head and the voltage difference over time is measured between the two points. The voltage data is plotted against time to produce "brain waves" with up and down voltage oscillations that are representative of the organized electrical activity of the brain (Morowitz and Trefil 1992). Medical professionals use a patient's EEG pattern to identify a broad spectrum of mental states. Although EEGs are often used as a diagnostic tool, the exact mechanism behind how an EEG pattern is linked to an individual's cerebral neuron activity remains a mystery (Morowitz and Trefil 1992). Despite lacking a precise explanation for the connection between the EEG and neural activity, there is a strong argument that the unique and highly recognizable EEG pattern produced by a mature brain is a defining characteristic of humanity (Morowitz and Trefil 1992). Therefore, the moment that a developing fetus first exhibits an EEG pattern consistent with that of a mature brain is indicative of the beginning of human life. It is from this point and onward during development that the fetus is capable of the type of mental activity associated with humanity (Morowitz and Trefil 1992). Because the state of modern technology still prohibits EEGs in utero, brain activity data for humans at various stages of development has been gathered using premature infants. Observations to date have led to the conclusion that 25 weeks of gestation is required for the formation of synapses needed for recognizable neural activity. At this point in development, the recognizable signals exist only as intermittent bursts that interrupt periods of random activity (Morowitz and Trefil 1992). This conclusion is summarized by Donald Scott who in his book Understanding the EEG wrote, "Attempts have been made to record cerebral activity of premature infants and they have succeeded (only) if the gestational age was 25 weeks or more (Morowitz and Trefil 1992)." Such claims, as well as arguments that endorse an opposite argument, are for many the foundation for any dispute over defining the inception of human life. Consequently, the principles of the neurological view are tenets in the debate over another controversial subject: abortion. Champions for a fetus's right to life often claim that the brain of a human fetus begins to show electrical activity at a remarkably early age. A key moment in the history of the abortion debate is the production and release of "The Silent Scream," an influential abortion film that graphically depicts the fetal response to its termination. The video accompanies the abortion of a 12-week-old fetus with the words "Now this little person at twelve weeks is a fully formed absolutely identifiable human being. He has had brain waves for at least six weeks..." (Morowitz and Trefil 1992). Although such arguments appeal to both the emotion by depicting an infant, though still developing, in a moment of pain and crisis and the intellect by presenting a scientific line of reasoning, the position presented by the film conflicts widely accepted developmental theory. For instance, the film contends that a fetus has brain waves after 12 weeks and suggest, even in the title "The Silent Scream," that it reacts to its termination with fear and pain. These contentions contradict scientific evidence that indicates neural connections in the cerebral cortex have yet to develop in a 12-week-old fetus. Lacking these basic neural networks, the developing fetus is incapable of feeling the emotions recognized as fear or pain (Morowitz and Trefil 1992). The film's position is further contrasted by evidence that suggests a 12-week-old fetus is not yet capable to take direct actions in response to a thought. The developing fetus is therefore incapable of recognizing potential danger and unable to either be fearful of it or actively evade it through movement or any other willful activity (Morowitz and Trefil 1992). In addition to presenting 25 weeks as a critical developmental landmark, other proponents of the neurological view believe that events of the eighth week of human gestation represent the key moments marking the beginning of human life. Contemporary philosophical arguments for designating week 8 as the beginning of human life proceed in accordance with the following format: humanness requires rational thought and rational thought requires a brain and a nervous system. Philosophers who present such arguments contest that an embryo is not a human being until it has a rudimentary nervous system. At week 8, the embryo has completed organogenesis, meaning it has simple, undeveloped versions of all the basic organ systems, including the nervous system (Shannon and Wolter 1990) Philosophers who subscribe to this perspective pay close attention to the progressively increasing complexity of the nervous system or the first weeks and months of pregnancy. At week 5 the first neurons begin to appear, at week 6 "the first synapses ... can be recognized," and at 7.5 weeks the embryo displays its first reflexes in response to stimulus. (Shannon and Wolter 1990). Thus around week 8 the embryo has a basic three-neuron circuit, the foundation of a nervous system necessary for rational thought. (Shannon and Wolter 1990). It should come as no surprise that this contemporary philosophical debate also consists of a second argument, which is in direct opposition to the aforementioned position. There are philosophers who believe that the capacity for rational thought is indeed a prerequisite of humanness, but that an 8-week-old embryo does not have the capacity for rational thought. At 8 weeks an embryo displays reflexes that are the result of its budding nervous system, but it does not yet have the structures necessary to engage in true rational activity in contrast to mere reflex motivated movement. (Shannon and Wolter, 1990) A third developmental landmark presented by proponents of the neurological view occurs at 20 weeks. Some advocates of the philosophy that a prerequisite for humanness is the capacity for rational thought believe that the existence of a primitive nervous system after 8 weeks, with the ability to respond by reflex to stimulation, does not amount to rational thought. The embryological landmark of 20 weeks marks the completion of the development of the thalamus, a region of the brain, which enables the integration of the nervous system. Philosophers who support this view therefore believe that only after 20 weeks of gestation can the embryo be said to have the capacity for rational thought. The precept at the heart of the neurological view of the beginning of human life is the significant development of neural pathways that are critical for characteristic human brain activity. The formation of these neural connections is often viewed to culminate in the acquisition of humanness, a stage during the third trimester of human gestation when the overwhelming majority of neural pathways in the cerebral cortex are established (Morowitz and Trefil 1992). The contemporary concept of the acquisition of humanness was developed and elaborated during the later half of the twentieth century by theological and biological leaders who emphasized the importance of the cerebral cortex in characterizing humanness. The Jesuit scholar and anthropologist scientist Pierre Teilhard de Chardin presented his belief that the transcendence of humanity was dependant upon the successful maturation of the cerebral cortex. Bernard Haring, a permanent Catholic theologian of the 1970s argued that individuality and the uniqueness of personal characteristics and activities originated from the cerebral cortex. A decade later, the anatomist Paul Glees argued "the (cerebral cortex) represents the signature of a genetically unique person" (Morowitz and Trefil 1992) The contemporary idea of the acquisition of humanness is based on the contemporary theories of developmental embryology. Cerebral nerve cells accumulate in number and continually differentiate through the end of the second trimester of human pregnancy (Morowitz and Trefil 1992). However, it is not until the seventh month of gestation that a significant number of connections between the newly amassed neurons begin to take form. It is only after the neurons are linked via synapse connections that the fetus is thought to acquire humanness. Just as a pile of unconnected microchips is incapable of functioning and is therefore not called a computer, the unconnected neurons of the pre 24-week fetal brain lack the capacity to function, thus the developing fetus has yet to acquire humanness (Morowitz and Trefil 1992).Ecological / Technological view:
Advocates of the neurological view contend that human life begins when a developing fetus acquires humanness, a point designated by brain activity that can be described as characteristically human. But if this developing fetus is separated from its mother at an early stage, regardless of the state of neural development, the fetus will be unable to sustain life on its own. The total dependence of the developing fetus for the majority of gestation catalyzed the formation of another view of when human life begins. The ecological/technological view of when human life begins designates this point when an individual can exist separately from the environment in which it was dependent for development (i.e., its mother's womb). Under most circumstances, the limiting factor for human viability is not the development of neural connections but the maturation of the lungs. However, advances in medical science permit a premature fetus to breathe after only 25 weeks of gestation, a stage in its development prior to the complete formation of functioning lungs (Gilbert 2002). Legislation using the ecological/technological view of when human life begins includes decrees of when a fetus can legally be aborted, mandating that after a fetus is determined to be independent its life can no longer be terminated (Gilbert 2002).Self-Consciosness: Contemporary Philosophical Stands on When Human Life Begins
There are philosophers, although not very many, who would dare to make the stance that a fetus nor an infant is a human being because it does not possess a consciousness of itself. This of course means that neither a zygote nor an embryo is a person either. Michael Tooley is one of these philosophers who describes his perspective in the article "Abortion and Infanticide." Essentially he argues that abortion and infanticide are really no different, if you support one, then you must support the other. His argument is that in order to claim that an adult has the right to live and an embryo or a fetus does not, one must be able to identify some moment where the moral status of the organism in question changes. There is nothing inherent about birth that it should automatically be hailed as this defining moment. A more justified moment, Tooley argues, is the moment at which the human child gains consciousness. At this moment, not at birth, should the child be considered a full fledged person, entitled to all the rights, particularly the right to life, that human adults are entitled to (Tooley 1999). The main problem that most people find with this position on when human life begins is that it condones infanticide, arguing that infants do not have the same right to life as adult humans do. Must people reject this view of when life begins, finding it impossible to support a view that logically leads to the conclusion that infanticide is acceptable. Tooley, however, argues that this rejection of his perspective is based on a purely emotional response to the idea of infanticide and not on logic or reasoning. Historically, the question of when human life begins was answered by a progression that was initiated by edicts on abortion which were governed by the popular notions of moral acceptability. These popular notions were decrees put forth by God, delivered to the populous through religious texts. Modern technological innovations of the twentieth century have reversed the order of this progression; contemporary scholars often address the question of when human life begins by first evaluating scientific data. The conclusions reached via the scientific method become the tools used to create popular standards of moral acceptability. These contemporary notions of moral acceptability then provide the framework for the modern abortion debate. The temporal divergence between the progressions of thought leading to answers of when human life begins reveals a shift in the source of knowledge that is used to answer one of humanity's most puzzling questions. Prior to the twentieth century, God was humanity's source of absolute knowledge. In recent years, however, scholars have terminated the utility of God's omniscience and in its place have raised science and technology as their source of absolute knowledge. This shift is evidence for, perhaps, the most determinant factor of any argument for when human life begins. The reasons governing the variation in both historical and modern views of when life begins is largely due to a variation in moral standards. However, understanding the basis for societal moral standards appears to be the key to discerning how to approach the question of when human life begins. Science has not been able to give a definitive answer to this question. One opinion is that the acquisition of humanness is a gradual phenomenon, rather than one that occurs at any particular moment. If one does not believe in a "soul," then one need not believe in a moment of ensoulment. The moments of fertilization, gastrulation, neurulation, and birth, are then milestones in the gradual acquisition of what it is to be human. While one may have a particular belief in when the embryo becomes human, it is difficult to justify such a belief solely by science.