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Genomic Metaphysics
doi:10.1016/S0022-2836(02)00348-0 available online at http://www.idealibrary.com on
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J. Mol. Biol. (2002) 319, 957–962
Genomic Metaphysics Alex Mauron Bioethics Research and Teaching Unit, Faculty of Medicine, University of Geneva, Centre Me´dical Universitaire, Rue Michel-Servet 1 CH-1211, Geneva 4, Switzerland
A modest proposal Recently, the famous physicist Steven Hawkins, author of the best-seller “A brief history of time”, made a rather provocative proposal about the human genome. He called for an extensive program of genetic modification of humans in order for mankind to remain competitive in the race with machines and computers. Hawkins proposes a program of human self-engineering and wants our species to take responsibility for its genome, lest we could be outperformed by intelligent machines. “We should follow this road if we want biological systems to remain superior to electronic ones”.1 Whether this somewhat bizarre proposal make sense or not is not my concern here. I merely mention it because it represents a radical break from the common humanistic intuitions concerning the genome and human nature. Steven Hawkins’ proposal presupposes that the genome of homo sapiens can and ought in principle to be subjected to the will and the projects of homo faber. For traditional humanism, the biological nature of humans is a given, whereas the human spirit is changeable, mostly for the good thanks to humanistic education. As the German philosopher Peter Sloterdijk argues, both views are challenged in our post-modern times.2,3 Granted, the noble malleability of our mind makes us accessible to education and spiritual improvement, but it also makes totalitarian ideologies and sectarian fanaticism possible. On the other hand, the very assumption that the human species is defined by an immutable biological nature embodied in the genome is necessarily challenged the very moment the human genome is sufficiently well known and the tools to manipulate its structure exist. As Francis Bacon said, knowledge is power, and the sequencing of the complete human genome necessarily opens up the possibility of changing it. However, there is still an extremely strong feeling today that the genome is the stable basis layer of human nature since it is unchangeable and should remain so. In my country, Switzerland, the untouchability of the human genome is even proclaimed by the Constitution (art. 119, adopted by
popular vote in 1992) which prohibits interventions in the genetic material of germ cells. In the imaginaire social that inspired this constitutional amendment, the genome is still a very powerful metaphor of human nature, embodying its stable and permanent character and underpinning both the nature of the individual person and of the human species. In a sense, the genome symbolises the inertial force of nature resisting human contrivances and opposed to the constructivist drive of the human will. The genome is a powerful “intuition pump”,4 that generates metaphysical metaphors such as stability, identity, determinism, resistance to change. It is this “genomic metaphysics” which I discuss here and elsewhere,5,6 both in terms of its present popularity and of its forthcoming decline, as heralded by Hawkins’ Promethean vision. The ethical Self However, I should firstly declare the basis for my interest in these issues, which is not that of a philosopher of biology, but of a bioethicist. There are two motives for this. The first is that in bioethical debates on genetics and genomics, notions of “genetic reductionism” or “genetic determinism” figure prominently. These labels are often used to refer to a naive ideology in which all complex traits of human nature are explained by the genes. Thus these terms are basically derogatory. To be branded a genetic reductionist is hardly a compliment. Nevertheless, the concepts of genetic reductionism or determinism are rarely analysed as such. They rather function as rhetorical operators of moral disapproval, such as the related label of eugenics. To clarify these concepts is therefore useful in order to understand the bioethical controversies that lie downstream. My second motivation relates to the necessarily complex and controversial relationship between the genome and the Self. Some understanding of this relationship is an implicit part of the theoretical basis of bioethics. Folk theories of the Self are indeed part and parcel of philosophical ethics in general. The most obvious example is the
0022-2836/02/$ - see front matter q 2002 Elsevier Science Ltd. All rights reserved
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deontologist tradition originating from Kant. In this tradition, there exists an autonomous and sovereign Self which asserts itself in separation from the reign of nature, necessity and heteronomy. This autonomous Self is itself closely related to the notion of person, to the distinction between persons and things, and to the concept of human dignity (Ref. 7, pp. 348– 355). It is true, however, that the practical implications of the triad: person-autonomy-dignity is not without major difficulties in contemporary bioethical debates. Consider for instance the current discussions on human embryonic stem cells. Is the notion of human dignity applicable to an embryo of a few days which, after all, is just a clump of a few dozen undifferentiated cells? The centrality of implicit theories of the Self is no less evident in Kantianism’s major rival in bioethics, namely utilitarianism. Its basic principle calls for maximising the welfare and/or the satisfaction of the preferences of everyone (Ref. 7, pp. 340 –348). This is only meaningful if one assumes a principle of equality, where “everyone” counts as “one”. But who are the “ones”, the moral atoms, whose preferences and interests are thus accounted for? The limits of “moral citizenship” is a central question for utilitarianism. To paraphrase Jeremy Bentham, the basic question is not whether the moral atoms think, but whether they suffer. This provides the basis for the typically utilitarian search for a moral standing of non-human animals. A consideration of the human genome is not without relevance in this context because it pursues a move that is typical for biology ever since Darwin, namely the revelation of our uncomfortably close kinship with other living things. The fact that our genome is more than 98% similar to the genome of the chimpanzee is perhaps the most glaring and, to some, the most shocking expression of this evolutionary me´salliance. But let us go back to the place of the genome and of “genetic reductionism” in contemporary controversies about the genetics of behaviour, especially in their popular form. These pit a simplistic geneticist ideology against an equally simplistic anti-genetic sentiment. From the latter point of view, it is more or less OK that genes exist, provided that their importance lies way down in the chain of command of human nature, in the engine room where proteins are made, metabolism regulated, and such lowly alimentary tasks are performed. Otherwise, genes are asked to keep quiet and not to mess with personality, intelligence or behaviour, as these noble realities belong to the spirit. Of course, these two visions are mirror images of each other. Both believe in a linear, hierarchical structure of human nature. For the naive genetics enthusiast, instead of the mind, it is the genes that are in command. For instance, in the popularised and simplistic deformation of the selfish gene theory, all human characteristics such as behaviour and the basic traits of psychological and social life are mere instruments serving the
Genomic Metaphysics
machiavellian, yet blind, self-reproductive drive of the genes. A clash of gene views A couple of years ago, I came across a cartoon showing a group of scientists in white coats, with posters on the wall showing the “gene of intelligence, of homosexuality, of violence” and so on. The picture shows a colleague triumphantly marching into the lab: “I discovered the gene that makes us believe that everything is in the genes”. In this pleasantly paradoxical vision, the gene is clearly conceived as a command post installed at the very core of the individual and conditioning broad aspects of his or her behaviour (typically, the phenotype involved remains rather fuzzy and poses more less intractable semantic and epistemological difficulties). In this view, the genome is the real “ghost in the machine”.8 Within human nature, the genome is considered the innermost locus of being, while all other characteristics are, in some sense, more peripheral. It is also thought to be the most stable element, the most strictly determined and the most inflexible. In other words, in contemporary popular representations, the genome has a privileged connection with human nature, to the extent that the latter is seen as an unchanging given, both by common experience and by the philosophia perennis of the Western tradition. Another part of this conceptual baggage is the dualistic discourse of “genes versus the environment”. Both terms come with strings attached. For better or for worse, genes carry with them the notions of determinism, nature, fatality, stability. Rightly or wrongly, environment is supposed to mean freedom, culture, will, change. It is conventional wisdom that if something is “in the genes”, you can’t do anything about it. You’ve got to accept it, it is a matter of fate; or if you want to change it, that’s bad, because it is eugenic. If it’s “in the environment” however, you can influence and change it.† The whole point of culture for instance is environmental change by education, based on the premise that progress is possible. Translating this conventional wisdom in admittedly naive political terms, you could say that the genes vote for the right and the environment votes for the left. Today, such views are energised by the powerful exposure of the public to biology and genomics, but they are not completely new. People who nowadays say “it’s all in the genes” would have said “it’s all in the glands” 60 or 70 years ago. Go † Geneticists know well that this conventional wisdom is false. Phenylketonuria is a monogenic disease and as such qualifies as a human trait that is entirely “in the genes” in popular language, yet its phenotypic expression is controlled by nutrition, i.e. the environment, and therefore “you can do something about it”. In fact, this is one of these important examples where forestalling the phenotype depends on knowing what’s wrong with the genotype.9
Genomic Metaphysics
back 250 years and they would have said “it’s all in the balance of humours, or in the traits of the human face”. The 18th century German diarist Georg Lichtenberg once commented on Lavater’s physiognomony, a theory that claimed to deduce the essential characteristics of a person by analysing its facial features. He remarks that if this view is correct, we shall hang children for crimes they would have committed as adults (Ref. 10, aphorism F521). Issues of biology, destiny and free will have troubled us for a long time. The pervasiveness of a “metaphysics-heavy” language in genomics and related topics is especially obvious considering the increased popularity of “-ome” words.9 Genome, transcriptome, proteome, metabolome… The conceptual trick of hypostatising a collection of genes into a single entity, namely the genome, seems to be easily replicated for collections of other biological objects. One could say that the suffix “-ome” is a kind of ontological operator that transforms a purely pragmatic and operational notion into a “strong” material entity. It provides it with metaphysical bite. As regards the genome, this is the conceptual move I have called “genomic metaphysics”. One even occasionally reads the word “environome”. This is troubling, since the very notion of an environment seems to imply some object, some thing of which the environment is, so to speak, the surroundings. It seems strange to speak of the environment as such, independently of whose environment it is, as it were. Thus placing the genome and the environment on the same conceptual level appears to be a category error. It seems to imply that there is “environment stuff” in the same way as there is “gene stuff”, namely DNA. But “environment stuff” can be DNA as well, as geneticists have known for a long time, because from the point of view of one particular gene, the rest of the genome is the environment. Genomic metaphysics and personal identity Genomic metaphysics is the belief that the genome is the ontological hard core of an organism, defining its distinctive traits, its individuality, as well as underpinning its membership in a particular species. Common metaphors, which refer to the genome as a blueprint or as a program whose execution consists in putting together a particular living thing, link up with an old tradition of Western metaphysics. In this line of thinking, every living thing has a soul, an eidos in Aristotle’s sense. This is the individual and specific organising principle that causes the organism to become what it is meant to be. This remarkable analogy between the vocabulary of molecular biology and the essentialist tradition of Aristotelian and scholastic origin has been noticed by several biologists with philosophical interests, in particular Ernst Mayr11 and Max Delbru¨ck.12 More recently, these insights have been revisited in the context of cell biology by Jean-Jacques Kupiec.13,14 These authors have
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criticised genetic essentialism from various perspectives. Nevertheless, this view remains powerful and influential today, as I shall now examine. In this metaphysical perspective on the human genome, the genome becomes the “secular equivalent of the soul”,5 although the latter term must be understood in the rather special sense of Aristotelian and scholastic hylomorphism. The identity between the genome and the soul is actually taken rather literally by some religious discussants in debates on abortion, human embryo experimentation, and similar topics. The conservative position on these issues takes for granted that a new human person arises at the moment of fertilisation, often adding that any other criterion for the beginning of personhood would be arbitrary. Theologians attached to the scholastic tradition are often genuinely impressed by modern biology and it is rather natural for them to believe, explicitly or implicitly, that the formation of a novel diploid genome at fertilisation marks the moment when a new personal soul is created. This interpretation of the diploid genome as the material signature of the soul fails however, for reasons related to the logical properties of personal identity. The Cambridge dictionary of philosophy defines personal identity as “the (numerical) identity over time of persons. The question of what personal identity consists in is the question of what it is (what the necessary and sufficient conditions are) for a person existing at one time and a person existing at another time to be one and the same person” (Ref. 15, s.v. “personal identity”). Thus, the very idea of personal identity entails an element of constancy amid the drift of time and change. The task becomes one of discovering this element and at first sight, the diploid genome emerges as a hopeful contender. In ontogeny, fertilisation is indeed a rather revolutionary event that gives rise to a novel genome that will not change (much) afterwards. It is tempting then to map the timeline of personhood onto to timeline of “genomehood” and to conclude that zygotes are persons, identical to the grown human persons they are destined to become. This is what I will refer to as the zygote-as-person thesis. There is fatal flaw in this line of reasoning, however, as evidenced by the existence of monozygotic twins. The problem with twins must be analysed carefully because proponents of the zygote-asperson thesis offer purported refutations of the argument that miss its point entirely. Let us assume (Figure 1) that a particular zygote Z eventually gives rises to two born persons called Arthur and Bob. Two statements about Arthur and Bob are uncontroversial: (a) they are persons, (b) they are separate persons. Nobody ever suggested that monozygotic twins should have a single passport or a single voting ballot. But if we consider zygote Z to be a person as well, it cannot be simultaneously identical to Arthur and to Bob (Figure 1, bottom right). However, this destroys the basis for
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Figure 1. The logical inconsistency of the zygote-asperson thesis.
believing in the zygote-as-person thesis, because to assert that the embryo is a person is equivalent to asserting that an “uncontroversial person”, for instance a human child or adult, is necessarily (numerically) identical to the embryo it once was. The very existence of monozygotic twins makes this assertion demonstrably false. In other words, it shows that there is no automatic congruence between genomic identity as established at fertilisation and personal indentity. Whatever event is biologically connected with the emergence of personal identity, it cannot be definitionally identical with fertilisation. Although some traditional thinkers have seen the seriousness of the problem, others have thought to salvage the zygote-as-person thesis by construing twinning as an abnormal form of procreation. For instance: “twinning is an unusual way of being generated; the relationship between the earlier and the later generated individuals is an unusual form of parentage”.16 In this view, the zygote is a person and twinning is the creation of an additional person. In a way, the zygote would seem to be even more precious since it is simultaneously a person and several potential persons. Figure 2 shows why this line of reasoning cannot stand. Let us assume again that zygote Z is a person. It eventually grows into “uncontroversial” person Bob salva identitate, i.e. without change in personal identity. Early on, however, it also undergoes parthenogenesis to beget the other person, Arthur, who is in some sense the grandchild of the two
Genomic Metaphysics
individuals who initially produced the fertilised egg. But if one believes in that special parthenogenetic event, one has to conclude that it does not correlate with the formation of any new genome. In twinning, the initiation of personhood appears to be a stochastic bifurcation for which no specific underlying biological event can be discerned. The supposed objection presented by Finnis and others merely reinforces the conclusion that personal identity is distinct from genomic identity. Furthermore, it suggests that the origination of a new person is not something that can be pinpointed to coincide with some obvious and instantaneous biological event. Although personhood ought in principle to be related to the possession by a human organism of certain empirical properties (such as sentience, or the neural substrate of an individual biography, or some level of self-awareness), it is typical of these properties that they have fuzzy, illdefined beginnings. Defenders of the zygote-asperson thesis often assert that it would be arbitrary to consider any other stage of development as the beginning of a new person equipped with human rights, and that it would be equivalent to ascribing or denying basic rights to people by capricious fiat. The problem is that, in determining personhood in early life, some degree of arbitrariness is the name of the game, no less so for those who stick to the fertilisation criterion. In fact, deciding that a new person must start at fertilisation is not just arbitrary, it is plainly wrong. It is worth noting that this logical inconsistency is present even if one accepts the substantialist metaphysical framework in which these discussions usually arise. It does not necessarily mean that this framework is wrong in itself. The most cogent opponents of the zygote-as-persons thesis have sometimes been scholars who broadly accept a Thomistic worldview and its characteristic description of organic development in terms of substance and form, such as the catholic theologian Norman Ford.17 In fact, one could argue that they are the better Thomists. In contrast, defenders of what has become the semi-official Catholic position have unwisely embraced “immediate animation” (the notion that a new soul arises at conception), in part out of a faulty understanding of biology, and have thus sacrificed the self-consistency of the traditional Thomist account of the pre-natal origination of persons. Is there a pilot in the plane?
Figure 2. Twinning illustrates the necessary distinction between genomic and personal identity.
But it is not obligatory to be a Thomist in the 21st century and one need not even be convinced that the classical metaphysical self-understanding of man will eventually survive. A detailed examination of its future demise is very much beyond the scope of this paper, but two small hints should be given here. The first is related to the scope of biotechnological interventions on humans that are thinkable, if not presently feasible. The received bioethical treatment of gene therapy, for
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Genomic Metaphysics
instance, is to distinguish somatic therapy, which is analogous to standard medical treatment, and germline therapy and/or enhancement, which are thought to be unacceptable.18 This disapproval was once strong, but never unanimous.19 It is much less powerful nowadays and several thoughtful authors are ready to contemplate germline engineering.20 Another related distinction is sometimes made between genetic interventions that heal people without “essential” change and those that alter them rather than cure them.21,22 This stems from a long-standing philosophical line of inquiry about how alternative courses of action cause alternative persons to exist.19,23 However, this classical distinction between curing people salva identitate on the one hand, and producing substitute healthy persons on the other, is also open to criticism and may ultimately be a distinction without a difference.24,25 It is based on the unspoken premise that to engineer the genome of future persons in such a way that the genome of every cell is affected (by germline engineering) somehow has more ontological clout than to effect some indirect phenotypic change. There we have it again: genomic metaphysics. However, at the end of the day, it is phenotypes that really matter and whether you causally influence phenotypes by way of the genome or otherwise is, in an important sense, irrelevant.26 The second reason for doubting that the traditional ontological view, as expressed by genomic metaphysics, is here to stay, is that it fits badly with the implicit overall view of human functioning coming from the life sciences in general, and not just genomics. This view of human functioning does not imply a hierarchical command structure with either “the genes” or “the mind” at the top. In the current picture, it rather looks like gene regulatory networks, metabolic regulations, mental processes, neuro-endocrine feedback loops, synaptic plasticity and so forth all have a part of the action. Biological discourse seems to invoke causal explanations in an opportunistic way, from which a circular picture of internal causation emerges. To quote Matt Ridley, who discusses the particularly illuminating example of stress: You are not a brain running a body by switching on hormones. Nor are you a body running a genome by switching on hormone receptors. Nor are you a genome running a brain by switching on genes that switch on hormones. You are all of these at once (Ref. 27, p. 152). It becomes difficult and perhaps illusory, to produce a metaphysically robust understanding of Self from such an account, where internal causation has no beginning or end, and where one cannot cleanly parse causal connections between organic cause and behavioural effect (or vice versa ). However, the problem is with our philosophical habits rather than with science. Progress may come from alternative accounts of personal
identity that emphasise less the permanence of an unchanging and causally efficient Self than the narrative continuity of a more or less coherent biography.
References 1. Walsh, N. P. (2001). Alter our DNA or robots will take over, warns Hawking. The Observer, September 2. 2. Sloterdijk, P. (2000). Re`gles pour le parc humain: Une lettre en re´ponse a` la Lettre sur l’humanisme de Heidegger (French transl. from German by O. Mannoni), Mille et une nuits, Paris. 3. Sloterdijk, P. (2000). The Operable Man: On the Ethical State of Gene Technology. Enhancing the Human: Genomics, Science Fiction, and Ethics Collide, Goethe Institute, Los Angeles URL: http://www.goethe.de/ uk/los/symp/enindex.htm. 4. Dennett, D. C. (1984). Elbow Room: The Varieties of Free Will Worth Wanting, MIT Press, Boston. 5. Mauron, A. (2001). Essays on science and society. Is the genome the secular equivalent of the soul? Science, 291, 831– 832. 6. Mauron, A. (1996). The human embryo and the relativity of biological individuality. In Conceiving the Embryo: Ethics, Law and Practice in Human Embryology (Evans, D. & Pickering, N., eds), pp. 55 – 74, Martinus Nijhoff, The Hague. 7. Beauchamp, T. L. & Childress, J. F. (2001). Principles of Biomedical Ethics, 5th edit., Oxford University Press, New York and Oxford. 8. Oyama, S. (1985). The Ontogeny of Information: Developmental Systems and Evolution, p. 73, Cambridge University Press, Cambridge. 9. Scriver, C. R. (2001). Work, the clinician-scientist and human biochemical genetics. Clin. Invest Med. 24, 179 –195. 10. Lichtenberg, G. C. (1968). Schriften und Briefe, Carl Hanser, Mu¨nchen. 11. Mayr, E. (1982). The Growth of Biological Thought: Diversity, Evolution and Inheritance, The Belknap Press of Harvard University, Cambridge, MA. 12. Delbru¨ck, M. (1971). Aristotle-totle-totle. In Of Microbes and Life (Monod, J. & Borek, E., eds), pp. 50 – 55, Columbia University Press, New York. 13. Kupiec, J.-J. (1999). L’influence de la philosophie d’Aristote sur l’e´laboration de la the´orie de l’e´volution et sur la ge´ne´tique. Revue Europe´enne de Sciences Sociales, 37, 89 – 116. 14. Kupiec, J.-J. & Sonigo, P. (2000). Ni Dieu ni ge`ne. Pour une autre the´orie de l’he´re´dite´, Seuil, Paris. 15. Audi, R. (ed.) (1999). The Cambridge Dictionary of Philosophy, 2nd edit., Cambridge University Press, Cambridge. 16. Finnis, J. (1994). Abortion and Health Care Ethics II. In Principles of Health Care Ethics (Gillon, R., ed.), pp. 547 –557, Wiley, Chichester. 17. Ford, N. M. (1991). When Did I Begin? Conception of the Human Individual in History, Philosophy and Science, Cambridge University Press, Cambridge. 18. de Wachter, M. A. M. (1993). Ethical aspects of human germ-line gene therapy. Bioethics, 7, 166–177. 19. Glover, J. (1984). What Sort of People Should There Be?, Penguin, London. 20. Stock, G.; Campbell, J. (eds) (2000). Engineering the Human Germline: An Exploration of the Science and
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21. 22. 23. 24.
Ethics of Altering the Genes We Pass to Our Children, Oxford University Press, New York. Zohar, N. J. (1991). Prospects for “genetic therapy”— can a person benefit from being altered? Bioethics, 5, 275– 288. Kahn, J. P. (1991). Genetic harm: bitten by the body that keeps you? Bioethics, 5, 289–308. Kripke, S. (1981). Naming and Necessity, Blackwell, Oxford. Elliot, R. (1993). Identity and the ethics of gene therapy. Bioethics, 7, 27 –40.
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25. Holtung, N. (1997). Altering humans—the case for and against human gene therapy. Cambridge Quarterly of Healthcare Ethics, 6, 157 –174. 26. Mauron, A. (2000). The question of purpose. In Engineering the Human Germline: An Exploration of the Science and Ethics of Altering the Genes We Pass to Our Children (Stock, G. & Campbell, J., eds), Oxford University Press, New York. 27. Ridley, M. (1999). Genome. The Autobiography of a Species in 23 Chapters, Fourth Estate, London.
Alex Mauron is a Professor of Bioethics at the University of Geneva’s Medical School. He holds a PhD (Lausanne, 1978) in molecular biology, with research experience in molecular genetics and neurobiology. His professional interests shifted to the field of bioethics in the late 1980s. Since then, his scholarly interests have included ethical issues in human genetics such as gene therapy, genetic diagnosis, and the social implications of genetic data. He has also had a long-standing involvement with issues concerning the human embryo, including the transplantation of fetal tissues and human embryonic stem cell research. Other topics of interest include biological concepts in ethics, teaching bioethics, and clinical ethics (futility, end-of-life issues). He has published widely on the ethical issues of genetics and reproduction, as well as on clinical ethics. He has been heavily involved in public debate on genetic engineering and reproductive technologies, and participated in the formulation of ethical guidelines and/or other policy documents on several bioethical issues. In addition, he is a regular columnist on bioethics in the French language Swiss daily Le Temps. After several years service in the Federal Ethics Commission on genetic engineering, he is now a member of the Swiss National Advisory Commission on Biomedical Ethics. He is also a member of the Central Ethics Commission of the Swiss Academy of Medical Sciences, and several other ethics committees.
(Received and Accepted 11 April 2002)
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J. Mol. Biol. (2002) 319, 957–962
Genomic Metaphysics Alex Mauron Bioethics Research and Teaching Unit, Faculty of Medicine, University of Geneva, Centre Me´dical Universitaire, Rue Michel-Servet 1 CH-1211, Geneva 4, Switzerland
A modest proposal Recently, the famous physicist Steven Hawkins, author of the best-seller “A brief history of time”, made a rather provocative proposal about the human genome. He called for an extensive program of genetic modification of humans in order for mankind to remain competitive in the race with machines and computers. Hawkins proposes a program of human self-engineering and wants our species to take responsibility for its genome, lest we could be outperformed by intelligent machines. “We should follow this road if we want biological systems to remain superior to electronic ones”.1 Whether this somewhat bizarre proposal make sense or not is not my concern here. I merely mention it because it represents a radical break from the common humanistic intuitions concerning the genome and human nature. Steven Hawkins’ proposal presupposes that the genome of homo sapiens can and ought in principle to be subjected to the will and the projects of homo faber. For traditional humanism, the biological nature of humans is a given, whereas the human spirit is changeable, mostly for the good thanks to humanistic education. As the German philosopher Peter Sloterdijk argues, both views are challenged in our post-modern times.2,3 Granted, the noble malleability of our mind makes us accessible to education and spiritual improvement, but it also makes totalitarian ideologies and sectarian fanaticism possible. On the other hand, the very assumption that the human species is defined by an immutable biological nature embodied in the genome is necessarily challenged the very moment the human genome is sufficiently well known and the tools to manipulate its structure exist. As Francis Bacon said, knowledge is power, and the sequencing of the complete human genome necessarily opens up the possibility of changing it. However, there is still an extremely strong feeling today that the genome is the stable basis layer of human nature since it is unchangeable and should remain so. In my country, Switzerland, the untouchability of the human genome is even proclaimed by the Constitution (art. 119, adopted by
popular vote in 1992) which prohibits interventions in the genetic material of germ cells. In the imaginaire social that inspired this constitutional amendment, the genome is still a very powerful metaphor of human nature, embodying its stable and permanent character and underpinning both the nature of the individual person and of the human species. In a sense, the genome symbolises the inertial force of nature resisting human contrivances and opposed to the constructivist drive of the human will. The genome is a powerful “intuition pump”,4 that generates metaphysical metaphors such as stability, identity, determinism, resistance to change. It is this “genomic metaphysics” which I discuss here and elsewhere,5,6 both in terms of its present popularity and of its forthcoming decline, as heralded by Hawkins’ Promethean vision. The ethical Self However, I should firstly declare the basis for my interest in these issues, which is not that of a philosopher of biology, but of a bioethicist. There are two motives for this. The first is that in bioethical debates on genetics and genomics, notions of “genetic reductionism” or “genetic determinism” figure prominently. These labels are often used to refer to a naive ideology in which all complex traits of human nature are explained by the genes. Thus these terms are basically derogatory. To be branded a genetic reductionist is hardly a compliment. Nevertheless, the concepts of genetic reductionism or determinism are rarely analysed as such. They rather function as rhetorical operators of moral disapproval, such as the related label of eugenics. To clarify these concepts is therefore useful in order to understand the bioethical controversies that lie downstream. My second motivation relates to the necessarily complex and controversial relationship between the genome and the Self. Some understanding of this relationship is an implicit part of the theoretical basis of bioethics. Folk theories of the Self are indeed part and parcel of philosophical ethics in general. The most obvious example is the
0022-2836/02/$ - see front matter q 2002 Elsevier Science Ltd. All rights reserved
958
deontologist tradition originating from Kant. In this tradition, there exists an autonomous and sovereign Self which asserts itself in separation from the reign of nature, necessity and heteronomy. This autonomous Self is itself closely related to the notion of person, to the distinction between persons and things, and to the concept of human dignity (Ref. 7, pp. 348– 355). It is true, however, that the practical implications of the triad: person-autonomy-dignity is not without major difficulties in contemporary bioethical debates. Consider for instance the current discussions on human embryonic stem cells. Is the notion of human dignity applicable to an embryo of a few days which, after all, is just a clump of a few dozen undifferentiated cells? The centrality of implicit theories of the Self is no less evident in Kantianism’s major rival in bioethics, namely utilitarianism. Its basic principle calls for maximising the welfare and/or the satisfaction of the preferences of everyone (Ref. 7, pp. 340 –348). This is only meaningful if one assumes a principle of equality, where “everyone” counts as “one”. But who are the “ones”, the moral atoms, whose preferences and interests are thus accounted for? The limits of “moral citizenship” is a central question for utilitarianism. To paraphrase Jeremy Bentham, the basic question is not whether the moral atoms think, but whether they suffer. This provides the basis for the typically utilitarian search for a moral standing of non-human animals. A consideration of the human genome is not without relevance in this context because it pursues a move that is typical for biology ever since Darwin, namely the revelation of our uncomfortably close kinship with other living things. The fact that our genome is more than 98% similar to the genome of the chimpanzee is perhaps the most glaring and, to some, the most shocking expression of this evolutionary me´salliance. But let us go back to the place of the genome and of “genetic reductionism” in contemporary controversies about the genetics of behaviour, especially in their popular form. These pit a simplistic geneticist ideology against an equally simplistic anti-genetic sentiment. From the latter point of view, it is more or less OK that genes exist, provided that their importance lies way down in the chain of command of human nature, in the engine room where proteins are made, metabolism regulated, and such lowly alimentary tasks are performed. Otherwise, genes are asked to keep quiet and not to mess with personality, intelligence or behaviour, as these noble realities belong to the spirit. Of course, these two visions are mirror images of each other. Both believe in a linear, hierarchical structure of human nature. For the naive genetics enthusiast, instead of the mind, it is the genes that are in command. For instance, in the popularised and simplistic deformation of the selfish gene theory, all human characteristics such as behaviour and the basic traits of psychological and social life are mere instruments serving the
Genomic Metaphysics
machiavellian, yet blind, self-reproductive drive of the genes. A clash of gene views A couple of years ago, I came across a cartoon showing a group of scientists in white coats, with posters on the wall showing the “gene of intelligence, of homosexuality, of violence” and so on. The picture shows a colleague triumphantly marching into the lab: “I discovered the gene that makes us believe that everything is in the genes”. In this pleasantly paradoxical vision, the gene is clearly conceived as a command post installed at the very core of the individual and conditioning broad aspects of his or her behaviour (typically, the phenotype involved remains rather fuzzy and poses more less intractable semantic and epistemological difficulties). In this view, the genome is the real “ghost in the machine”.8 Within human nature, the genome is considered the innermost locus of being, while all other characteristics are, in some sense, more peripheral. It is also thought to be the most stable element, the most strictly determined and the most inflexible. In other words, in contemporary popular representations, the genome has a privileged connection with human nature, to the extent that the latter is seen as an unchanging given, both by common experience and by the philosophia perennis of the Western tradition. Another part of this conceptual baggage is the dualistic discourse of “genes versus the environment”. Both terms come with strings attached. For better or for worse, genes carry with them the notions of determinism, nature, fatality, stability. Rightly or wrongly, environment is supposed to mean freedom, culture, will, change. It is conventional wisdom that if something is “in the genes”, you can’t do anything about it. You’ve got to accept it, it is a matter of fate; or if you want to change it, that’s bad, because it is eugenic. If it’s “in the environment” however, you can influence and change it.† The whole point of culture for instance is environmental change by education, based on the premise that progress is possible. Translating this conventional wisdom in admittedly naive political terms, you could say that the genes vote for the right and the environment votes for the left. Today, such views are energised by the powerful exposure of the public to biology and genomics, but they are not completely new. People who nowadays say “it’s all in the genes” would have said “it’s all in the glands” 60 or 70 years ago. Go † Geneticists know well that this conventional wisdom is false. Phenylketonuria is a monogenic disease and as such qualifies as a human trait that is entirely “in the genes” in popular language, yet its phenotypic expression is controlled by nutrition, i.e. the environment, and therefore “you can do something about it”. In fact, this is one of these important examples where forestalling the phenotype depends on knowing what’s wrong with the genotype.9
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back 250 years and they would have said “it’s all in the balance of humours, or in the traits of the human face”. The 18th century German diarist Georg Lichtenberg once commented on Lavater’s physiognomony, a theory that claimed to deduce the essential characteristics of a person by analysing its facial features. He remarks that if this view is correct, we shall hang children for crimes they would have committed as adults (Ref. 10, aphorism F521). Issues of biology, destiny and free will have troubled us for a long time. The pervasiveness of a “metaphysics-heavy” language in genomics and related topics is especially obvious considering the increased popularity of “-ome” words.9 Genome, transcriptome, proteome, metabolome… The conceptual trick of hypostatising a collection of genes into a single entity, namely the genome, seems to be easily replicated for collections of other biological objects. One could say that the suffix “-ome” is a kind of ontological operator that transforms a purely pragmatic and operational notion into a “strong” material entity. It provides it with metaphysical bite. As regards the genome, this is the conceptual move I have called “genomic metaphysics”. One even occasionally reads the word “environome”. This is troubling, since the very notion of an environment seems to imply some object, some thing of which the environment is, so to speak, the surroundings. It seems strange to speak of the environment as such, independently of whose environment it is, as it were. Thus placing the genome and the environment on the same conceptual level appears to be a category error. It seems to imply that there is “environment stuff” in the same way as there is “gene stuff”, namely DNA. But “environment stuff” can be DNA as well, as geneticists have known for a long time, because from the point of view of one particular gene, the rest of the genome is the environment. Genomic metaphysics and personal identity Genomic metaphysics is the belief that the genome is the ontological hard core of an organism, defining its distinctive traits, its individuality, as well as underpinning its membership in a particular species. Common metaphors, which refer to the genome as a blueprint or as a program whose execution consists in putting together a particular living thing, link up with an old tradition of Western metaphysics. In this line of thinking, every living thing has a soul, an eidos in Aristotle’s sense. This is the individual and specific organising principle that causes the organism to become what it is meant to be. This remarkable analogy between the vocabulary of molecular biology and the essentialist tradition of Aristotelian and scholastic origin has been noticed by several biologists with philosophical interests, in particular Ernst Mayr11 and Max Delbru¨ck.12 More recently, these insights have been revisited in the context of cell biology by Jean-Jacques Kupiec.13,14 These authors have
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criticised genetic essentialism from various perspectives. Nevertheless, this view remains powerful and influential today, as I shall now examine. In this metaphysical perspective on the human genome, the genome becomes the “secular equivalent of the soul”,5 although the latter term must be understood in the rather special sense of Aristotelian and scholastic hylomorphism. The identity between the genome and the soul is actually taken rather literally by some religious discussants in debates on abortion, human embryo experimentation, and similar topics. The conservative position on these issues takes for granted that a new human person arises at the moment of fertilisation, often adding that any other criterion for the beginning of personhood would be arbitrary. Theologians attached to the scholastic tradition are often genuinely impressed by modern biology and it is rather natural for them to believe, explicitly or implicitly, that the formation of a novel diploid genome at fertilisation marks the moment when a new personal soul is created. This interpretation of the diploid genome as the material signature of the soul fails however, for reasons related to the logical properties of personal identity. The Cambridge dictionary of philosophy defines personal identity as “the (numerical) identity over time of persons. The question of what personal identity consists in is the question of what it is (what the necessary and sufficient conditions are) for a person existing at one time and a person existing at another time to be one and the same person” (Ref. 15, s.v. “personal identity”). Thus, the very idea of personal identity entails an element of constancy amid the drift of time and change. The task becomes one of discovering this element and at first sight, the diploid genome emerges as a hopeful contender. In ontogeny, fertilisation is indeed a rather revolutionary event that gives rise to a novel genome that will not change (much) afterwards. It is tempting then to map the timeline of personhood onto to timeline of “genomehood” and to conclude that zygotes are persons, identical to the grown human persons they are destined to become. This is what I will refer to as the zygote-as-person thesis. There is fatal flaw in this line of reasoning, however, as evidenced by the existence of monozygotic twins. The problem with twins must be analysed carefully because proponents of the zygote-asperson thesis offer purported refutations of the argument that miss its point entirely. Let us assume (Figure 1) that a particular zygote Z eventually gives rises to two born persons called Arthur and Bob. Two statements about Arthur and Bob are uncontroversial: (a) they are persons, (b) they are separate persons. Nobody ever suggested that monozygotic twins should have a single passport or a single voting ballot. But if we consider zygote Z to be a person as well, it cannot be simultaneously identical to Arthur and to Bob (Figure 1, bottom right). However, this destroys the basis for
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Figure 1. The logical inconsistency of the zygote-asperson thesis.
believing in the zygote-as-person thesis, because to assert that the embryo is a person is equivalent to asserting that an “uncontroversial person”, for instance a human child or adult, is necessarily (numerically) identical to the embryo it once was. The very existence of monozygotic twins makes this assertion demonstrably false. In other words, it shows that there is no automatic congruence between genomic identity as established at fertilisation and personal indentity. Whatever event is biologically connected with the emergence of personal identity, it cannot be definitionally identical with fertilisation. Although some traditional thinkers have seen the seriousness of the problem, others have thought to salvage the zygote-as-person thesis by construing twinning as an abnormal form of procreation. For instance: “twinning is an unusual way of being generated; the relationship between the earlier and the later generated individuals is an unusual form of parentage”.16 In this view, the zygote is a person and twinning is the creation of an additional person. In a way, the zygote would seem to be even more precious since it is simultaneously a person and several potential persons. Figure 2 shows why this line of reasoning cannot stand. Let us assume again that zygote Z is a person. It eventually grows into “uncontroversial” person Bob salva identitate, i.e. without change in personal identity. Early on, however, it also undergoes parthenogenesis to beget the other person, Arthur, who is in some sense the grandchild of the two
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individuals who initially produced the fertilised egg. But if one believes in that special parthenogenetic event, one has to conclude that it does not correlate with the formation of any new genome. In twinning, the initiation of personhood appears to be a stochastic bifurcation for which no specific underlying biological event can be discerned. The supposed objection presented by Finnis and others merely reinforces the conclusion that personal identity is distinct from genomic identity. Furthermore, it suggests that the origination of a new person is not something that can be pinpointed to coincide with some obvious and instantaneous biological event. Although personhood ought in principle to be related to the possession by a human organism of certain empirical properties (such as sentience, or the neural substrate of an individual biography, or some level of self-awareness), it is typical of these properties that they have fuzzy, illdefined beginnings. Defenders of the zygote-asperson thesis often assert that it would be arbitrary to consider any other stage of development as the beginning of a new person equipped with human rights, and that it would be equivalent to ascribing or denying basic rights to people by capricious fiat. The problem is that, in determining personhood in early life, some degree of arbitrariness is the name of the game, no less so for those who stick to the fertilisation criterion. In fact, deciding that a new person must start at fertilisation is not just arbitrary, it is plainly wrong. It is worth noting that this logical inconsistency is present even if one accepts the substantialist metaphysical framework in which these discussions usually arise. It does not necessarily mean that this framework is wrong in itself. The most cogent opponents of the zygote-as-persons thesis have sometimes been scholars who broadly accept a Thomistic worldview and its characteristic description of organic development in terms of substance and form, such as the catholic theologian Norman Ford.17 In fact, one could argue that they are the better Thomists. In contrast, defenders of what has become the semi-official Catholic position have unwisely embraced “immediate animation” (the notion that a new soul arises at conception), in part out of a faulty understanding of biology, and have thus sacrificed the self-consistency of the traditional Thomist account of the pre-natal origination of persons. Is there a pilot in the plane?
Figure 2. Twinning illustrates the necessary distinction between genomic and personal identity.
But it is not obligatory to be a Thomist in the 21st century and one need not even be convinced that the classical metaphysical self-understanding of man will eventually survive. A detailed examination of its future demise is very much beyond the scope of this paper, but two small hints should be given here. The first is related to the scope of biotechnological interventions on humans that are thinkable, if not presently feasible. The received bioethical treatment of gene therapy, for
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instance, is to distinguish somatic therapy, which is analogous to standard medical treatment, and germline therapy and/or enhancement, which are thought to be unacceptable.18 This disapproval was once strong, but never unanimous.19 It is much less powerful nowadays and several thoughtful authors are ready to contemplate germline engineering.20 Another related distinction is sometimes made between genetic interventions that heal people without “essential” change and those that alter them rather than cure them.21,22 This stems from a long-standing philosophical line of inquiry about how alternative courses of action cause alternative persons to exist.19,23 However, this classical distinction between curing people salva identitate on the one hand, and producing substitute healthy persons on the other, is also open to criticism and may ultimately be a distinction without a difference.24,25 It is based on the unspoken premise that to engineer the genome of future persons in such a way that the genome of every cell is affected (by germline engineering) somehow has more ontological clout than to effect some indirect phenotypic change. There we have it again: genomic metaphysics. However, at the end of the day, it is phenotypes that really matter and whether you causally influence phenotypes by way of the genome or otherwise is, in an important sense, irrelevant.26 The second reason for doubting that the traditional ontological view, as expressed by genomic metaphysics, is here to stay, is that it fits badly with the implicit overall view of human functioning coming from the life sciences in general, and not just genomics. This view of human functioning does not imply a hierarchical command structure with either “the genes” or “the mind” at the top. In the current picture, it rather looks like gene regulatory networks, metabolic regulations, mental processes, neuro-endocrine feedback loops, synaptic plasticity and so forth all have a part of the action. Biological discourse seems to invoke causal explanations in an opportunistic way, from which a circular picture of internal causation emerges. To quote Matt Ridley, who discusses the particularly illuminating example of stress: You are not a brain running a body by switching on hormones. Nor are you a body running a genome by switching on hormone receptors. Nor are you a genome running a brain by switching on genes that switch on hormones. You are all of these at once (Ref. 27, p. 152). It becomes difficult and perhaps illusory, to produce a metaphysically robust understanding of Self from such an account, where internal causation has no beginning or end, and where one cannot cleanly parse causal connections between organic cause and behavioural effect (or vice versa ). However, the problem is with our philosophical habits rather than with science. Progress may come from alternative accounts of personal
identity that emphasise less the permanence of an unchanging and causally efficient Self than the narrative continuity of a more or less coherent biography.
References 1. Walsh, N. P. (2001). Alter our DNA or robots will take over, warns Hawking. The Observer, September 2. 2. Sloterdijk, P. (2000). Re`gles pour le parc humain: Une lettre en re´ponse a` la Lettre sur l’humanisme de Heidegger (French transl. from German by O. Mannoni), Mille et une nuits, Paris. 3. Sloterdijk, P. (2000). The Operable Man: On the Ethical State of Gene Technology. Enhancing the Human: Genomics, Science Fiction, and Ethics Collide, Goethe Institute, Los Angeles URL: http://www.goethe.de/ uk/los/symp/enindex.htm. 4. Dennett, D. C. (1984). Elbow Room: The Varieties of Free Will Worth Wanting, MIT Press, Boston. 5. Mauron, A. (2001). Essays on science and society. Is the genome the secular equivalent of the soul? Science, 291, 831– 832. 6. Mauron, A. (1996). The human embryo and the relativity of biological individuality. In Conceiving the Embryo: Ethics, Law and Practice in Human Embryology (Evans, D. & Pickering, N., eds), pp. 55 – 74, Martinus Nijhoff, The Hague. 7. Beauchamp, T. L. & Childress, J. F. (2001). Principles of Biomedical Ethics, 5th edit., Oxford University Press, New York and Oxford. 8. Oyama, S. (1985). The Ontogeny of Information: Developmental Systems and Evolution, p. 73, Cambridge University Press, Cambridge. 9. Scriver, C. R. (2001). Work, the clinician-scientist and human biochemical genetics. Clin. Invest Med. 24, 179 –195. 10. Lichtenberg, G. C. (1968). Schriften und Briefe, Carl Hanser, Mu¨nchen. 11. Mayr, E. (1982). The Growth of Biological Thought: Diversity, Evolution and Inheritance, The Belknap Press of Harvard University, Cambridge, MA. 12. Delbru¨ck, M. (1971). Aristotle-totle-totle. In Of Microbes and Life (Monod, J. & Borek, E., eds), pp. 50 – 55, Columbia University Press, New York. 13. Kupiec, J.-J. (1999). L’influence de la philosophie d’Aristote sur l’e´laboration de la the´orie de l’e´volution et sur la ge´ne´tique. Revue Europe´enne de Sciences Sociales, 37, 89 – 116. 14. Kupiec, J.-J. & Sonigo, P. (2000). Ni Dieu ni ge`ne. Pour une autre the´orie de l’he´re´dite´, Seuil, Paris. 15. Audi, R. (ed.) (1999). The Cambridge Dictionary of Philosophy, 2nd edit., Cambridge University Press, Cambridge. 16. Finnis, J. (1994). Abortion and Health Care Ethics II. In Principles of Health Care Ethics (Gillon, R., ed.), pp. 547 –557, Wiley, Chichester. 17. Ford, N. M. (1991). When Did I Begin? Conception of the Human Individual in History, Philosophy and Science, Cambridge University Press, Cambridge. 18. de Wachter, M. A. M. (1993). Ethical aspects of human germ-line gene therapy. Bioethics, 7, 166–177. 19. Glover, J. (1984). What Sort of People Should There Be?, Penguin, London. 20. Stock, G.; Campbell, J. (eds) (2000). Engineering the Human Germline: An Exploration of the Science and
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Ethics of Altering the Genes We Pass to Our Children, Oxford University Press, New York. Zohar, N. J. (1991). Prospects for “genetic therapy”— can a person benefit from being altered? Bioethics, 5, 275– 288. Kahn, J. P. (1991). Genetic harm: bitten by the body that keeps you? Bioethics, 5, 289–308. Kripke, S. (1981). Naming and Necessity, Blackwell, Oxford. Elliot, R. (1993). Identity and the ethics of gene therapy. Bioethics, 7, 27 –40.
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25. Holtung, N. (1997). Altering humans—the case for and against human gene therapy. Cambridge Quarterly of Healthcare Ethics, 6, 157 –174. 26. Mauron, A. (2000). The question of purpose. In Engineering the Human Germline: An Exploration of the Science and Ethics of Altering the Genes We Pass to Our Children (Stock, G. & Campbell, J., eds), Oxford University Press, New York. 27. Ridley, M. (1999). Genome. The Autobiography of a Species in 23 Chapters, Fourth Estate, London.
Alex Mauron is a Professor of Bioethics at the University of Geneva’s Medical School. He holds a PhD (Lausanne, 1978) in molecular biology, with research experience in molecular genetics and neurobiology. His professional interests shifted to the field of bioethics in the late 1980s. Since then, his scholarly interests have included ethical issues in human genetics such as gene therapy, genetic diagnosis, and the social implications of genetic data. He has also had a long-standing involvement with issues concerning the human embryo, including the transplantation of fetal tissues and human embryonic stem cell research. Other topics of interest include biological concepts in ethics, teaching bioethics, and clinical ethics (futility, end-of-life issues). He has published widely on the ethical issues of genetics and reproduction, as well as on clinical ethics. He has been heavily involved in public debate on genetic engineering and reproductive technologies, and participated in the formulation of ethical guidelines and/or other policy documents on several bioethical issues. In addition, he is a regular columnist on bioethics in the French language Swiss daily Le Temps. After several years service in the Federal Ethics Commission on genetic engineering, he is now a member of the Swiss National Advisory Commission on Biomedical Ethics. He is also a member of the Central Ethics Commission of the Swiss Academy of Medical Sciences, and several other ethics committees.
(Received and Accepted 11 April 2002)