The Moral Status of the Embryo

Anne Dickinson, John Kleinsman, Michael McCabe
Issue 5, November 2001

Across the world the application of new technology at the beginning of life is giving rise to profound ethical questions. How individuals and nations respond to these questions depends primarily upon how they view the moral status of the human embryo.

Stem cells, cloning, frozen embryos and related technologies have moved out of the laboratory into the political arena, with competing and often opposing demands being made for a legislative response to these technologies. In New Zealand the Government is currently drafting such legislation, a difficult task for any government to undertake given the divisions in society about the moral status of the embryo.

The debate in the community centres on whether human life should be accorded unconditional or conditional respect. Belief in the sanctity of life from the moment of fertilization gives rise to unconditional respect, according the embryo the same rights that children and adults have. The right to life is foremost among these rights.

Conditional respect arises from the view that the early embryo is simply a ball of cells, which cannot yet be accorded the status of a person. In this view human rights are contingent upon when the embryo becomes a person, before which time it is considered not to have the same right to protection as children or adults. Because the ball of cells is recognized as being human in nature, some respect is accorded the embryo, with the level of that respect increasing as the embryo develops. However this perspective does not accord the human embryo an absolute right to life.

Debate about the moral status of the embryo has arisen from technological developments, which have sought to address different forms of human suffering. The desire to have children is deep-seated, emotionally and biologically. The anguish and suffering of couples who have difficulties in having children is very real, and medicine has sought to provide alleviation of that suffering for some couples through in vitro fertilization. However the use of IVF has resulted in thousands of spare embryos being frozen and stored around the world, bringing a new form of anguish and conflict as couples, scientists and governments ponder how to deal with the situation. In some countries moves have been made to allow adoption of frozen embryos, but the number of embryos already in existence far outstrips the number of potential adoptive parents. Allowing frozen embryos to perish after a defined period of time, with the consent of their parents, has been seen by legislators as the only practical option, a step taken reluctantly and with discomfort given the different perspectives in the community about the moral status of the embryo.

In the last few years the development of stem cell research has provided hope that there may be a treatment even cure for intractable conditions such Alzheimer's and Parkinson's diseases. These conditions, and others, which may be treatable by stem cell therapy, cause deep suffering to those affected by them. Embryos are one source of the stem cells needed for this research, which has introduced a new context to the debate about the moral status of the embryo.

Embryo Development

An embryo is formed from the union of an egg and sperm. The egg and sperm are referred to by scientists as gametes, a term which identifies them as each having half the number of chromosomes (23) found in other body cells (46). The process of fertilization begins when the sperm enters the egg, and results in a cell, which contains 46 chromosomes. This cell is called the zygote, and has a genetic complement that is different to that of either the father or the mother.

By the second day the process of cell division has begun. The zygote is now called an embryo, and rapidly becomes a cluster of cells. By days 5 and 6 the cluster has become a hollow ball of cells called a blastula. A particular group of cells in the blastula develops into the foetus, while the other cells become the placenta, umbilical cord and other supporting structures for the embryo-foetus.

Until around day 12 the possibility of twinning exists, with the embryo able to split and grow into two separate individuals. This is, for many, a significant biological factor in determining the moral status of the embryo

Ensoulment and Personhood

Central to the debate about ethical issues associated with human embryos is the question of whether or at what point in its development the embryo should be accorded person status. Personhood is a philosophical concept, and there are many schools of thought as to where it fits in the biological development of a new human being.

In the Catholic tradition the language employed has in the past made use of the concept of 'ensoulment' to describe what definitively sets humans apart from other life. There have been many theories about when ensoulment occurs in the development of the embryo or foetus. While terminology may differ, the question being asked is essentially the same as the question about personhood.

Past Catholic theories about ensoulment, now untenable, drew on the best scientific knowledge of the day. The current position of some scientists, moralists, philosophers and others, who argue for legitimate experimentation on embryos within a certain and limited period of time can be seen, in part, as more nuanced attempts to answer the same questions about ensoulment and personhood. Just as past theories about ensoulment were influenced by the science of the time, more contemporary secular approaches centred on personhood may also be seen to be the product of developments in scientific knowledge.

Theories of Personhood

Among philosophers the arguments about when personhood begins are complex. According to Patrick O' Mahony in his book, A Question of Life, the debate falls into five schools of thought: the Genetic School, the Developmental School, the Relational School, the Social Consequences School, and, the Potentiality School.

The Genetic School

In this school of thought O'Mahony places all who argue that the human person comes into existence at fertilization. Development is a process of becoming the one she or he already is. He quotes a proponent of this school, Teresa Iglesias, who says that human beings are one entity and not a composite of two. They are not human organisms first and persons later when the advent of the soul or consciousness takes place. If we can attain self-consciousness at some stage we must already be the kind of beings that can attain it Whatever capacities we have now, have developed from the beginning. These abilities, like self-awareness and choice, are only explicable if there was always the presence of the inherent capacity for those abilities from fertilization. [1]

While there is a vast amount of medical literature to support this view there are two main objections to this perspective, namely, the high percentage of fertilized ova that do not implant and the phenomenon of twinning. During the first week of its development an embryo can divide into two and each then continues to develop separately. It is then argued that it is not possible to attribute personhood to the embryo until the possibility of twinning has passed.

The Developmental School

The proponents of the Developmental School require further development of the embryo before it can legitimately be called an individual human being. Accordingly, some place the beginning of the human individual after the point where twinning can no longer occur. Others require a later stage of development such as the formation of the cerebral cortex because human life manifests its nature through consciousness. According to this School, the presence of the brain coinciding with the onset of the human person parallels the phenomenon of brain death being a criterion for the death of the person. [2]

The Relational School

This School is unwilling to accept merely physical criteria and argues for what is called more personalistic criteria. In other words this School holds that the beginning of human life and personhood cannot be based on biological evidence alone, and is contingent upon the ability to develop relationships with others.

The Social Consequences School

The proponents of this School base their theory about the beginning of human life on psychological or moral factors. For this School life is sacred because of the consequences to society of destroying it. However at the same time those who argue from this perspective tend to see the sacredness of life and the reasons for protecting it as increasing with the development of the embryo-foetus, rather than being absolute from conception. That people feel differently towards zygotes and children is taken as sufficient indication that zygotes are not to be considered human beings.

The Potentiality School

This School is closely linked to the development of biotechnology. Proponents of this School contend that their case does not rest on the view that the embryo is a person from the moment of fertilization. Yet, they argue, there is no doubt that the life of the human embryo begins at fertilization. Their case is based on the embryo having the potential to become a human person.

Implications of the Schools of Thought

Most proponents of embryonic experimentation rely on scientific knowledge to establish that 'person status' cannot possibly be present in the earliest stages of the development of the fetus. It is on this basis that they would allow experimentation on what is simply a blastocyst, a ball of cells, rather than human life. From this perspective human rights are not being violated because the person does not yet exist. Their argument allows experimentation up to the point in time where it is considered that personhood clearly must exist. There is general acceptance that experimentation should not occur after 14 days, because at this point, (a) there is certainty that the embryo will develop into one individual as opposed to two individuals, and (b) cell differentiation has begun to occur. It is clear which cells will form the embryo and which will form the placenta and other supporting structures, thus making the embryo an identifiable entity.

To a greater or lesser degree this thinking does not take into account the continuity of human existence, with a consequent fragmentation of the earliest stages of human existence. This stance includes the idea that freedom, knowledge, decision-making and the ability to relate, etc, are able to be separated from the capacities in which they are rooted. The resulting fragmentation is not consistent with the genetic continuity which begins with the formation of the zygote, a cell with a genetic complement which is different to that from its mother and father, and different from that of any other individual. It would also seem to ignore the fact that our abilities to make choices, think, act and relate are the outcome of the continuous presence of capacities present at the beginning of the embryo's existence when fertilization occurs.

Others argue for allowing research on the spare embryos resulting from treatments for infertility. Their argument is a purely pragmatic one: spare embryos already exist, and cannot be stored indefinitely. The real choice is between destroying the embryos by allowing them to perish, or using their cells for useful research which will ultimately be of benefit to other human beings. Framed in such a pragmatic way, the argument for the use of frozen embryos appeals to those who are uncomfortable with the creation of embryos for research, or for activities such as the development of stem cell lines from embryos. The logic appealed to places some value to a life which appears to have none as an unwanted frozen embryo.

In these approaches moral evaluation of the use of frozen embryos for research involves the weighing up of two possible outcomes. In the first of these the embryo is allowed to perish, considered to be a life of no value because it is unwanted. In the second outcome the embryo is destroyed during research, and in this act gives its life for the sake of others, thus making its short existence meaningful and of value. This second outcome appeals as the moral choice because it confers a reason for existence on the embryo, and casts its death as an altruistic and salvific act. This moral choice is utilitarian in its premise, because the value of a human life is presented as depending upon its usefulness to others.

In arguing that embryos should not be created for research, but that it is morally acceptable to use frozen embryos for this purpose, a second-class status is conferred upon frozen embryos as far as protection is concerned. Embryos created by cloning also have this second-class status, despite the fact that all embryos have the same biology. From a Catholic perspective these arguments ignore the intrinsic value each human life has by its very nature.

Catholic Teaching

In recent years the moral status of the embryo has been made abundantly clear in official Church documents. The 1987 document Donum Vitae [The Gift of Life] stated that the respect due to all persons is to be accorded to the human embryo from the first moments of fertilization:

The human being must be respected - as a person - from the very first instant of his or her existence ... From the time that the ovum is fertilized, a new life is begun which is neither that of the father nor of the mother; it is rather the life of a new human being with his or her own growth. [3]

Contrary to what many people think however, the current Catholic position does not accord 'person status' as such to the embryo in its very earliest stages of development.

Regarding this question, although the Magisterium has not expressed itself in a binding way by a philosophical affirmation, it has still taught constantly that from the first moment of its existence, as the product of human generation, the embryo must be guaranteed the unconditional respect which is morally due to a human being in his or her spiritual and bodily totality. [4]

This view is echoed in the writings and teachings of Pope John Paul II. When writing on abortion in Evangelium Vitae he says:

Some people try to justify abortion by claiming that the result of conception, at least up to a certain number of days, cannot yet be considered a human life. But in fact, from the time that the ovum is fertilized, a life is begun which is neither that of the father nor the mother; it is rather the life of a new human being with his or her own growth. It would never be made human if it were not human already. This has always been clear, and modern genetic science offers clear confirmation. It has demonstrated that from the first instant there is established the programme of what this living being will be: a person, this individual person with his or her characteristic aspects already well determined.

what is at stake is so important that, from the standpoint of moral obligation, the mere probability that a human person is involved would suffice to justify an absolutely clear prohibition of any intervention aimed at killing a human embryo. Precisely for this reason, over and above all scientific debates and those philosophical affirmations to which the Magisterium has not expressly committed itself, the Church has always taught and continues to teach that the result of human procreation, from the first moment of its existence, must be guaranteed that unconditional respect which is morally due to the human being in his or her totality and unity as body and spirit: the human being is to be respected and treated as a person from the moment of conception. [5]

Over time philosophical ideas about personhood and the embryo have changed with scientific advances. The teaching of the Church, as re-stated by Pope John Paul II, does not depend upon apportioning personhood to the embryo at a particular point in the continuum of development. This frees it from dependence on scientific knowledge for its authenticity. Because the human being is to be respected and treated as a person from the moment of conception all human rights, which attach to living children and adults, are accorded to the embryo and to the foetus, prime among those rights being the right to life. The origin of the embryo does not affect this status, and so embryos resulting from cloning or IVF have the same rights as an embryo conceived through sexual intercourse.

The teaching of the Church illuminates with great poignancy on the situation of the thousands of frozen embryos which exist in clinics around the world, and who some consider are a morally acceptable source of stem cells for research. If they are to be treated as persons then experimentation on them is an immoral choice, which is not consistent with the unconditional respect morally due to the human being in his or her totality and unity as body and spirit. Rather than giving value to their existence, experimentation adds indignity to their death.

Amid the sea of shifting philosophies on the moral status of the embryo, Catholic teaching offers sound principles for the ethical and moral analysis of issues arising from the use of new technology at the beginning of life. In their application these principles help to provide protection for the most vulnerable members of humanity. The provision of such protection is a key criterion for society to use in analysing the morality of its decisions and actions.


[1] Patrick O'Mahony A Question of Life: Its Beginning and Transmission London: Sheed and Ward, 1990: 9-10.

[2] O'Mahony 1990:18.

[3] Congregation for the Doctrine of the Faith, Instruction on Respect for Human Life in its Origin and on the Dignity of Procreation [Donum Vitae]Vatican translation. Boston: Saint Paul Books and Media, 1987:12-14.

[4] The Problems of Threats to Human Life. Vatican City: Vatican Polyglot Press, 1991: 11-12.

[5] Pope John Paul II, The Gospel of Life [Evangelium Vitae] Vatican City: Vatican Polyglot Press, 1995: 60-61.


Anne Dickinson, John Kleinsman, Michael McCabe