Biological self-government of the embryo from fertilization

embryo person category based in he latest findings embryo from fecundation The continuing advances of science in the area of embryology leave little doubt about the human nature of the embryo of our species. Biologically, there is no other definition of this entity which, from its single-cell phase, manifests as an individual of the human family with the characteristics – already defined but not yet developed – of the particular human being that it will be until its death. In the process of perfect vital unity, continuous and uninterrupted, which continues from the fertilized egg to the newborn, there is nothing to suggest the idea of an evolutionary leap that implies the beginning of a genomic reality different to the previous one[1] (see Biological status of the embryo).

Nevertheless, there is no unanimity as regards whether the species, as such, is more than merely matter and is relevant for the recognition of the “personhood” of the human individual. In fact, there are several studies that address this question. Thus, very recently, Linacre Quarterly [2] reopened the discussion on the possible ontological distance between the human being, as a mere biological entity, and the person as a moral subject (Personhood Status of the Human Zygote, Embryo, Fetus. The Linacre Quarterly, May 1, 2017). Hence, in what follows, we offer philosophical anthropology’s response to the question regarding the personal status of the nasciturus. Because when one states that human embryonic life has the “potential” to become a person, but is still not one, an anthropological assumption is accepted that might be wrong.

Two hypotheses:

embryo from fecundation The question of the embryo person category (anthropological status) of the human embryo is reduced, in the end, to two hypotheses:

  1. A person is the one who the embryo will become when it develops certain qualities, mainly rationality “in the strict sense”, autonomy and self-awareness.
  2. A person is the one who, precisely because he is, may one day manifest those qualities.

The first hypothesis has taken the concept of person, paraphrasing José Luis del Barco, to play a fundamental role “in the destruction of the idea that all men, for the mere fact of being men, have rights in the presence of their fellow men”[2]. Because when personhood is reduced to a qualitative inventory, it accepts that for those who do not possess the qualities described, even if they are human, personal status is not recognized.

Can some humans not be persons?  

H. Tristram Engelhardt Jr. (American philosopher and editor-in-chief of The Journal of Medicine and Philosophy and Christian Bioethics)  denies the condition of person to certain humans:

Not all humans are persons. Fetuses, infants, the profoundly mentally retarded and the hopelessly comatose provide examples of human non-persons. They are members of the human species but do not in and of themselves have standing in the secular moral community. One speaks of persons in order to identify entities one can warrant blame or praise. For this reason, it is nonsensical to speak of respecting the autonomy of fetuses, infants or profoundly retarded adults who have never been rational. They are not prime participants in the secular moral endeavor. Only persons have that status.[3]

Philosophical approach to the category of embryo as a person

The philosophical deconstruction of the person in all his accidents allows, in effect, the relegation of the human embryo to the condition of “pre-person” being with a legally irrelevant life, thus opening the process of transferring its rights from Family Law to the Law of Things[4]. Not only the embryo and the fetus, though; young children are not self-aware, nor autonomous, nor do they reason. Norbert Hoerster[5] has had to accept this objection, and for this reason, has set four months after birth as the beginning of the person. Nevertheless, he has not explained why four months and not any other time limit, but merely suggested that the reasons for which the date of birth is generally established for the recognition of the child as a person — with the rights inherent to such condition — are of a practical and not a philosophical nature[6]. One of these is the need to protect premature infants who are born before showing the first signs of “personal” life; the other, the lesser willingness of parents to procure the death of their already-born child than to kill the unborn[7].

embryo from fecundation biological self-governance Both reasons, however, seem too tenuous to warrant the womb becoming an unsafe place for the unborn child. It does not seem reasonable, indeed, that based on these, those born prematurely at seven months would have more rights than those who remain in the womb[8], any more than embryos conceived extracorporeally and still not implanted receive better protection than those sheltered in the womb, where there is a law on time limits to regulate abortion[9]. But there is yet another aspect to consider: the fact that the embryo depends functionally on its mother’s body does not contradict its capacity for biological self-governance. What is more, the newborn also depends on its mother until it reaches a certain feeding maturity. In fact, persons never stop being dependent. Alasdair MacIntyre explains it thus:

We human beings are vulnerable to many kinds of afflictions and most of us are at some time afflicted by serious ills. How we cope is only in small part up to us. It is most often to others that we owe our survival, let alone our flourishing, as we encounter bodily illness and injury, inadequate nutrition, mental defect and disturbance, and human aggression and neglect. This dependence on particular others for protection and sustenance is most obvious in early childhood and in old age. But between these first and last stages, our lives are characteristically marked by longer or shorter periods of injury, illness or other disablement, and some among us are disabled for their entire lives[10].

Having said that: according to the second hypothesis, the “person” would not be a qualitative inventory, but a modus existentiae, the specific individual realization of man[11]; it would not be “something” that can be understood as the casual consequence of one or all of its predicates, among which is consciousness, but “someone” on whom those predicates will be made in a given moment. Because the substance is not all of its accidents, but what gives the being to the accidents. Hence, as the authors of the aforementioned study in Linacre underline, “A human being does not become a person at a particular stage of development following fertilization” but the person is “inherent in a human being at all stages of development” see HERE).

embryo person category from fecundation When does the category of person of the human embryo begin?

Attempts to disassociate the human individual from its category of person (personal status) are contrary to what we intuitively consider obvious and we express simply in our day-to-day language. Thus, when a mother addresses her child, she usually does so in terms such as: “When I was pregnant with you”, or “When I gave birth to you”, but never saying: “When I carried an organism in my womb that then was you” [12].

Nonetheless, what we know intuitively is not always easy to explain with philosophical arguments. For this purpose, we will use the most synthetics accurate definition of person of all that have been proposed throughout history[13]: that defined by Boethius and later reprised by Thomas Aquinas: Persona est rationalis naturae individua substantia[14],[15] (person is an individual substance of a rational nature). The issue before us will lead us to ask ourselves if the three elements included in the definition – individuality, substantiality and ability to reason – occur in the human embryo, particularly the latter because we know that it will fully develop well after birth.

1. Substantiality and individuality

biological individual is the abse of embryo person category Genetic studies show irrefutable evidence: the zygote contains, from the genes derived from the sperm and the egg, its own genome, different to its father and mother, which give it its unique and unrepeatable individuality that essentially will not undergo any changes until its death. It is not a mere appendage of its mother’s body. Furthermore, although the changes that it will undergo as a result of its maturation will give it a different appearance at each of the different times during its life, the individual that it is will always remain the same over the course of time. The radical individuality of a person — and consequently his incommunicability[16] — reaches all the dimensions of his being as personal, making even accidents his own[17].

In this sense, Sgreccia makes a very enlightening comparison between the maturation of the person and the construction of a house. It is as follows: “Imagine that we have to build a house. We need the architect who carries out and oversees the project, the building contractor who implements the project and the construction workers who execute it according to their different specialities. The zygote would be the planner, the building contractor and the worker who arranges the construction materials as appropriate. These activities are found in it and are activated from within. The zygote, as in the example of the house, already manifests its complete structure as an individual; the mother provides only the environment that contains it and the materials needed for construction”[18]. In a similar sense, Spaemann distinguishes between progress that makes sense thanks to the achievement of an end and progress that constitutes “improvements” in an end given in advance. An example of the first type would be the progress that takes place in the construction of a house, because none of it would make sense if it is never finished. In the second type of progress, the maturational, the telos of the process has already been accomplished when the improvement begins. Neither successive mitoses nor the formation of organs and tissues implies the production of a whole or the achievement of a final state, but the mere service to an already existing final end[19].

When empiricism — as far back as Locke[20] — distinguishes between men and persons, it does so on the basis of an erroneous philosophical argument. It is as follows: To recognize something that we find in different times and places as identical, it needs to be attributed to a single beginning not shared with anything else. Even so, there are things that change so much over the course of time that, despite having a single beginning, they allow us to feel that we are dealing with two different identities[21]. In these cases, we should define when the new beginning has occurred.

Evidently, the question is complicated when that “something” whose origin we question is a living being and, in particular, when it comes to a person. Given that the empiricist principle only accepts the empirical data of the senses as ontologically originating, it understands that all synthesis — including the identification of a being as a continuous existence in space and time — is an external principle, a constructive ingredient of the observer and not an inner perspective. Hence, it does not conceive of personal identity as an integral unit of a process of motion. The person who is today, for empiricism, was not in its embryonic phase.

This is so because it understands motion as a succession of infinitely short events — each occurring in a certain place at a certain time — which can only be reconstructed mathematically through infinitesimal calculus. Motion as life – that is, as potency or “act of the possible”[22] – does not exist for it. And on dissolving motion into a sequence of infinite separate and instantaneous events, it also dissolves the very being of the living, because, in accordance with Aristotle, life itself is motion[23]. Empiricism, in short, understands that the identity alone can be affirmed by the invariance of a structure after the exchange of material parts.  But these structures exist in both living beings and in machines, with the only difference being that the former commence their teleological organization before their final finishing. Based on this, empiricism distinguishes between the conditions of identity of men and persons: men would be a certain type of organism; persons, a series of combinations of states of awareness defined by memory, though which they attribute to themselves the performance of certain actions. For Locke, for example, the term “person” would designate the thinking being that reflects on itself as the same thing in different times and places. The identity of consciousness would not rest, therefore, on the identity of its possessor, but the other way around: the “person” himself is consciousness of identity[24].

However, this argument does not adequately distinguish between the concepts of substantial change and accidental change. Substantial change implies an ontological discontinuity; it is genesis and not alloeosis (qualitative change). Both the beginning of life and death are substantial changes. Thus, the zygote is not the continuation of its parents, but rather its being “in itself” (Selbst ein is the original term) founds a new nature and is distinguished from the being of those who have made it possible[25]. However, as opposed to substantial change, accidental change is that which occurs in a being that exhibits its own qualities and performs its own operations. This change is compatible with the Selbst ein. Thus, the emergence of qualities that people cherish is not a substantial change, but an accidental one.

Embryonic biological self-governance is founded on the latest embryological studies

 2. Rationality

In line with what we have said, we find that rationality and self-awareness do not manifest immediately or spontaneously when human life begins. They do not even always manifest. This is because, as noted, their appearance and loss are not substantial changes, but accidental ones. We shall explain below.

Personal life is motion in the sense of potency, of “act of the possible”. Therefore, saying that the “to be” of the person is “to live a rational life” means that it is “to live a life susceptible to the awakening of reason”. Being a person is not a state, a situation that we enjoy on some occasions and on others no, but rather reason belongs from the start to the endowment of the human being whose animality, as human, constitutes the substrate on which the person unfolds. “Who” we are, in short, does not identify with “what” we are, as “whatever a man is, what matters is that that does not determine ‘who’ that man is”[26].

embryo person category by Saint Thomas of Aquinas Reason in the strict sense and in the broad sense

Where is the embryo person category when he has not the faculty of reason in the act?

This is something that is better understood by Thomas Aquinas, who distinguished between reason in the strict sense and reason in the broad sense. In the strict sense, “reason” is the function of the intellect that is implemented through thought and discourse; in the broad sense, it is the set of intellective powers, i.e. of all those faculties independent of matter. While the first sense allows unborn children to be denied estatus personae, the second includes them, since they possess the structure or functional unit of the intellective powers that Aquinas called mind or spirit, and which we identify with the soul or substantial form[27]. The spirit – reason in the broad sense – is the higher power of the soul, i.e. the substantial form of the person.

Mens non est una quae dam potential praeter memoriam, intelligentiam et voluntatem; sedest quoddam totum potentiale comprehendens haec tria[28].

Richard of St Victor[29], for his part, defines the person as “Existens per se solum juxta singularem quamdam rationalis existentiae modum” (something that exists by itself in the singular form of rational existence). From this perspective, the rationality that confers the category of person (personal status) would be a mode of existence. And although the essence or “way of being” of persons is to have a rational nature, their condition of possibility of personal recognition is the esse, i.e. the “to be”.  Existence — we stress — and not essence[30]. Because in all reality, as we know, it distinguishes between that “which is” (the ente) [1] and the “being” itself which makes that entity what it is and is given a different name, i.e. its essence.

The present participle of the verb sum (sum, es, esse, fui), is conjugated: ens-entis, i.e. being. Ente is, therefore, what “is”, what is being. All that “is”, all that has to be, is an entity.

There are anthropologies that justify the antagonism between reason and nature by appealing to the first as a natural compensation for the inadequate endowment of our species. However, in humans, there is a “surplus of reason” that is not at the service of self-preservation, which is not instrumental, but allows one to open oneself to unconditionality and to relativize all finite interests[32]. Reason is not, consequently, contingent upon self-preservation, but is a gift, a present “plus”, potentially, in our nature:  The possibility of a progressive awakening to the reality of the real, i.e. to what reality is “in itself” and not only as it is “for the beholder”. It is therefore “nothing other than fully awakened consciousness”[33]. Consciousness, to awaken, must previously exist in a latent or potential state.

Rationality is, in short, a natural feature of our species, of whose privileges every being whose nature is human participates. For this reason, recognizing the embryo as a person means recognizing it in its nature, i.e. as a being whose essence consists of having a rational nature, present from the beginning of its life even if it still does not carry out the operations that its particular nature will one day allow. If we only recognized the other qua rational being, then it would not be him that we recognized as a person, but the rationality criteria realized in him. And as long as we fail to find them, we would feel entitled to deny him personal status, something that could extend from the embryo, not only to minors but also to the demented, the dissident and immoral man[34].

Recognition of the embryo as a person cannot, therefore, respond to practical reasons, but to strictly ontological (metaphysical) ones.  A person does not appear when the community of rational beings observes in it the realization of the rational operations with which it feels identified; rather, the previous recognition of its rational nature is what compels the recognition of the embryo as a person.


Enrique Burguete

Bioethics Observatory – Institute of Life Sciences

Catholic University of Valencia




[1] Aznar, J.  (2014). Estatuto biológico del embrión humano. En Bellver V (Ed.), Bioética y cuidados de enfermería, Vol. 2. Valencia: Consejo de Enfermería de la Comunidad  Valenciana: 47-64.

[2] Del Barco, J. L. (2000). Teoría práctica de la persona. El pensamiento moral de Robert Spaemann. Introducción a la versión española de R. Spaemann, (2000). Personas. Acerca de la distinción entre «algo» y «alguien» (pp. 11-26). Pamplona: Eunsa.

[3] Engelhardt HT. Los Fundamentos de la Bioética. Barcelona: Paidós; 1995.

[4] Silva, J. M. (09 de enero de 2007). Los indeseados como enemigos. La exclusión de seres humanos del status personae. (On line). Revista electrónica de Ciencia Penal y Criminología, pp. 1 – 18 (4). Retrieved from:

[5] Hoerster, N. (1995). Neugeborene und das Recht auf Leben. Frankfurt: Frankfurt / Main, Suhrkamp, p. 23.

[6] Spanish civil law, for example, recognises as person the newborn with human form who survives for twenty-four hours outside its mother’s womb, although the foetus, by legal fiction, is considered newborn for those rights that benefit it in the legal sphere. Thus, if a woman is pregnant and her husband dies leaving an inheritance, the foetus will be taken into account as if it had been born, although if it dies before birth or within twenty-four hours, it will be considered as not born and no-one will be able to inherit its supposed rights as it never existed in the eyes of the law.

[7] Hoerster, N. (1991). Abtreibung im säkularen Staat. Argumente gege den § 218. Suhrkamp, pp. 137-8.

[8] Pérez del Valle, C. (septiembre de 2004). Protección de la vida humana a través del Derecho: argumentos, estrategias y algunas falacias. Valencia: Fundación Universitaria San Pablo CEU.

[9] Steiner, U. (January-April 1993). Der verfassungsrechtliche Streit in Deutschland über die strafrechlilche Regelung der Abtreibung. (J. Cremades y A. Delgado, Trads). Revista Española de Derecho Constitucional, no. 37, pp. 159-171. (169). Retrieved from:

[10] MacIntyre, A. (2004). Tras la virtud. (2ª ed.). (A. Valcárcel, Trad.). Barcelona: Crítica, p. 15.

[11] Spaemann, R. (2000). Personas. Acerca de la distinción entre «algo» y «alguien». (J. L. Del Barco, Trad.). Pamplona: Eunsa, p.54.

[12] Spaemann, R. [2007]. Quando l’uomo inizia a essere persona? En E. Sgreccia e J. Laffitte (eds.), L’embrione umano nella fase del reimpianto. Aspetti scientifici e considerazioni bioetiche, 214-219 (216). Città del Vaticano: Libreria Editrice Vaticana.

[13] Martí, G. (enero-junio de 2009). Sustancia individual de naturaleza racional: el principio personificador y la índole del alma separada. Metafísica y Persona. Revista sobre Filosofía, Conocimiento y Vida, 1 (1). UMA y UPAEP: 113-129 (113).

[14] Boethius: Liber de persona et duabus naturis: ML, LXIV, 1343.

[15] Thomas Aquinas: Summa theologiae (S. Th.) I, q. 29, a. 1

[16] The person is a substance that exists by itself, sui juris, and is therefore perfectly incommunicable.

[17] Personhood Status of the Human Zygote, Embryo, Fetus. The Linacre Quartely, May 1, 2017

[18] Personalist Bioethics, Ed. National Catholic Bioethics Centre, pág. 433

[19] Spaemann, R. (1980). ¿Bajo qué condiciones se puede hablar todavía de progreso? En R. Spaemann, (2004). Ensayos Filosóficos, pp. 141-160 (142). Madrid: Cristiandad.

[20] Locke, J. (1689). An Essay Concerning Human Understanding. Oxford: Clarendon Press.

[21] This is the case of an originating human cell and the adult individual that it will one day become.

[22] As understood by Aristotle (Physics III, 3).

[23] Spaemann, R. (2000). Personas. Acerca de la distinción entre «algo» y «alguien», op.cit., p. 141.

[24] Spaemann, R. (1991). ¿Son personas todos los hombres? Acerca de nuevas justificaciones filosóficas de la aniquilación de la vida, op. cit. p. 401.

[25] Spaemann, R. (2000). Personas. Acerca de la distinción entre «algo» y «alguien», op.cit., p. 60.

[26] Spaemann, R. (2000). Personas. Acerca de la distinción entre «algo» y «alguien», op.cit., p. 57.

[27] For Thomas Aquinas, the mind distinguishes between the personal sub-positum and inanimate things, although man is not the only personal sub-positum: Homo enim cum Angelis convenit in superiori animae parte, quae mens vocatur (Aquinas, Summa Theologiae, I–II, q.89, a 4, arg. 1). The angel, for example, is fully mens. But there is also the divine mind: Mens vero angeli […] non solum cognoscit materiam in universali directa inspectione, sed etiam in singulari; et simili teretiam mens divina.

[28] De Aquino, De veritate, q.10, a.1, ad.7 (mind is not a single power over and above memory, understanding, and will, but a kind of potential whole including these three).

[29] La Trinidad, 4,6

[30] Spaemann, R. (2000). Personas. Acerca de la distinción entre «algo» y «alguien», op.cit., p. 48.

[31] The present participle of the verb sum (sum, es, esse, fui), is conjugated: ens-entis, i.e. being. Ente is, therefore, what “is”, what is being. All that “is”, all that has to be, is an entity.

[32] Spaemann, R. (1991). Felicidad y benevolencia. (J. L. Del Barco, Trad.). Madrid: Rialp, pp. 135-6.

[33] Idem, p. 139.

[34] Spaemann, R. (1989). Lo natural y lo racional. (D. Innerarity, & J. Olmo, Trad.). Madrid: Rialp, p. 152.



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