Why the embryo is a human being

Published 02 Jun 2017

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The embryo is the beginning of the life of a human being. It results from the fusion of a male and a female gamete known as sperm and ova respectively at the time of fertilization until about 8 weeks after fertilization where it becomes a foetus. At this point, the embryo has undergone various stages of development. The issues of abortion and embryo research which result in the death of embryos have created much debate regarding whether the embryo is a human being or not. Arguments concerning biological development and the time when ensoulment occurs have been put forward to explain the status of the human being.

This explanation is dependent on the time at which life begins which varies for most pro-choice groups and medical practitioners and pro-lifers. This is due to various definitions of the beginning of human life such as at the time when the fetus is viable or at birth. For pro-life groups life begins at conception and this too is the start of pregnancy. Due to their different definitions the morality and ethics surrounding abortion and embryo research have found different explanations.

Arguing that the embryo is not a person, indicates that there is specific time when the embryo becomes a human being. The embryo does not have the ability to act; neither does it look like a full grown person. This however cannot be used to defend the argument that it is not a human being. This would mean then, that a grain of corn by looking different from the full grown corn stalk ceases to be corn. The grain of corn therefore has the potency to mature into a stalk of corn. This is the concept of potency which enables the explanation of developmental changes in the embryo. These changes result in different appearances but the subject (the embryo) remains the same individual (0’Rourke, 2005)

Boethius defines a person as having characteristics of individuality and rationality. St. Thomas Aquinas went further to elaborate this definition by commenting that individuality stems from the fact that a person has some degree of separateness from another. Rationality according to Thomas Aquinas indicates control over one’s actions and the ability to have initiative and act rather than being acted upon (0’Rourke, 2005). The term person here is used to refer to human beings, creatures who are made up of matter and form (body and soul). John Locke on the other hand defines a person slightly differently. His definition forms the basis of most present day philosophers. This definition has elements of Aquinas’s definition. Locke did not deny the presence of substance rather; he put emphasis on the activities of a person.

In Locke’s definition, a person thinks, can identify pleasure, pain, happiness, misery and is capable of feeling them. A person also has concern for himself to the degree permitted by consciousness (0’Rourke, 2005). According to Locke’s definition it is therefore possible to be a human being and not be a person. This is especially so with a focus on the aspect of consciousness. Consequently, infants, fetuses, people in comatose states are human beings but non-persons (O’Rourke, 2005). Embryos would therefore seem to fall into this category of human non-persons. They are non-persons because at the time of their existence they have no consciousness and are not capable of pain, pleasure, happiness and misery.

This definition of person seems to create a gap with the one of potency. However it seems that the theory of potency is more fundamental since the agreement is that the attributes of personhood are developed over time. This therefore means that a bridge can be created between the two definitions. The person who did not have consciousness may develop consciousness meaning that not having the ability to carry out activities of a person does not translate to an entire absence of personhood. Further, the adult human being progressed from once being a fetus, then an infant, a child and finally, an adult. With this progression, development of consciousness occurred with time.

The development of the human embryo begins with a radical change of simple human being parts to form a new individual. These simple parts are the sperm and ova. For a human being to exist there has to be a specific number of chromosomes. This is true for all living organisms and the number of chromosomes varies with the species. When the number varies significantly, the organism is unable to survive, human beings included. For those human beings who have a varying number of chromosomes, the number does not vary much, for instance in individuals with Downs or Turner’s syndrome where the chromosomes are increased and decreased by one respectively.

The germ cells, sperms and oocytes cannot be considered human beings, they only have 23 chromosomes. It is necessary for them to have half the number of chromosomes required for existence of a normal human being as this facilitates the fertilization process which results in an embryo, a human being with 46 chromosomes. Sperms and oocytes therefore have human life and are the result of a process of gametogenesis (maturation of germ cells), while the embryo results from fertilization (O’Rahilly and Muller, 1994). The sperms and oocytes possess human life by virtue of the fact that they are a part of a human being and are not wholly living humans. This is similar to the way the liver or the lung and kidneys are parts of humans and therefore have human life.

A sperm and an oocyte can only have the ability to produce sperm and oocyte enzymes and protein respectively, unlike a human being that can produce a myriad of proteins and enzymes. Further, neither sperm nor oocyte itself can produce a human (Irving, 1999). This therefore makes the term ‘fertilized egg’ a misnomer. Often the term oocyte and egg have been used interchangeably. To describe the product of fertilization as a fertilized egg is wrong simply because the egg/oocyte has 23 chromosomes and following fertilization it is a new entity with 46 chromosomes, hence the term fertilized egg becomes incorrect since a human being is already in place with a whole new set of chromosomes different fro those in the oocyte.

Following the process of fertilization, the embryo that results is able to direct its own growth and development. The embryo has the characteristic of individuality common to all human beings as it is separate from its mother. It is also genetically unique and different from its mother though there may be similarities. The genetic difference and/ or uniqueness lies not in the number of chromosomes but in the content carried in these chromosomes. The uniqueness arises from the combination of chromosomes from different individuals (the mother and father).

Following fertilization, the embryo differentiates not into another organism rather, its complexity and consciousness continues to increase. The embryo divides and becomes bigger and it goes through various stages named differently by scientists. These are a morula (at 4 days, a blastocyst during the 5th -7th day, a two layer (bilaminar embryo in the second week and a tri-laminar embryo in the third week (Moore and Persaud, 1998). A human embryo is therefore not a potential human being rather it is a human being with the potential to develop and grow into a person with consciousness and the ability to perform different activities.

As per Boethius and Aquinas’s definition of person it already has individuality though it may lack rationality due to the fact that it is totally dependent on its mother and it has not developed the structures necessary for initiating action by itself. The theory of potency however comes into play here because the characteristic of rationality can be developed and is actually developed with time. More fundamentally to the definition of a human being, the embryo has substance and form evident from the fact that it can be detected by various techniques of visualizing in the mother’s womb such ultrasound scan.. Inability to perform certain activities does not make the embryo any less human than a human being in a comatose state or one with certain physical disabilities like paraplegia.

The tendency to call an embryo and/or fetus, ‘it’ also perpetuates the idea that the embryo being neither boy nor girl is not a human being. This is however untrue since the product of fertilization can be either of the two. It is actually one of the two (boy or girl) depending on whether it was fertilized by an XX sperm or XY sperm. The difference is that the external genitalia and even internal organs that would make the difference obvious have not yet developed during the 8 week period. The idea that an embryo is neither male nor female is therefore a mistaken one. Adding a gender to the embryo adds more to the evidence of individuality and therefore to the evidence of being a human being.

Attribution of rationality is often used as a means to describe the embryo as not being a human being. Rationality is physiologically supported by the brain. Development of the brain is a process that continues after birth, way into young adulthood. Irvin points out that apart from the brain, other physical features continue to develop after birth, these include the teeth and the breasts. The weight of the brain continues to increase up to 3 fold in the period between birth and the child’s sixteenth birthday with the process of development being complete at around 25 years (Irvin, 1999). To therefore claim that the inability to be rational causes the embryo to cease being a person is to say that many young people have not yet become persons.

Brain birth is explained to be a gradual process through which the human being acquires the functions of the neural system that can provide support for thinking and feeling. The concept of brain birth was put forward to run parallel to brain death where there is loss of function of the brain. Brain birth however does not adequately explain the bridge from incapacity to capacity for consciousness (Irvin, 1999). The neural system that is supposedly developing during the process of brain birth is not a brain and thus the claim that a human person starts at brain birth is invalid. To ascribe to this theory would mean that the brain birth and brain death have an almost equal level of symmetry and that one is more or less the opposite of the other which is untrue.

An embryo is thus a human being with all the rights that human beings have. Definitions of human being and person have been applied to many issues concerning the embryo from abortion, item cell research, abortifacients, cloning, human embryo, and research and chimera formation. In having all these discussions, it is necessary to isolate myth and especially scientific myth from objective scientific facts. Many philosophical ideas have been used to explain human being and human person. All these ideas have an effect on public policies and individual choices, making it necessary for philosophy and science to bridge the gulf that is created by illegitimate impositions of one field’s idea on another. This will lead to incorporation of sound ideas and accurate science in policy making and decision making.

Works Cited

  • D. Gareth Jones, Brain birth and personal identity, Journal of Medical Ethics 15:4, 1989, p. 178.
  • Keith L. Moore and T.V.N. Persaud, The Developing Human, Philadelphia: W.B. Saunders Company, 1998
  • O’Rourke, Kevin, The Embryo as Person, International Congress on Bioethics, University of Santo Thomas, Manila, The Philippines,
  • Ronan O’Rahilly and Fabiola Müller, 1994, Human Embryology & Teratology New York: Wiley-Liss,
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