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Human Nature: An Oxymoron?
David Heyd
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# Swets & Zeitlinger
Human Nature: An Oxymoron?
David Heyd
Department of Philosophy, The Hebrew University of Jerusalem, Israel
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ABSTRACT
The concept of human nature played an important role in the Aristotelian attempt to
characterize the specific difference of humans from other animals and serves as a normative
guide. But with the positivistic turn in the modern conception of nature and the denaturalization
of reason (typically since Kant), the essential characteristic of human beings can no more
be thought of as ‘‘natural’’. The idea of human nature is more commonly conceived as openended, and is associated, since Pico della Mirandola, with the human power of self-shaping or
transcendence of one’s nature. This rift between the human and the natural undermines the
coherence of the traditional concept of human nature. Since the concept of human nature is
often used in the debates about the moral legitimacy of contemporary genetic technologies, the
critical analysis suggested in the first part of the article is used in the second part to assess the
force of the argument from human nature in the context of germ line genetic manipulation,
genetic engineering, eugenics, and cloning.
Keywords: genetics, human nature, identity
I. MODERN CONCEPTIONS OF HUMAN
NATURE AS OPEN-ENDED
The use of the term ‘‘human nature’’ in contemporary bioethical rhetoric is
often surrounded by an aura of sanctity. Indeed, with the declining force of
traditional theological arguments regarding the immutability of the essential
character of human beings, ‘‘human nature’’ has regained its more secular
Aristotelian role in the discussion of the normative limits to what can be done
with and to humans. The term ‘‘nature’’ effectively serves the purpose of its
modern users, combining two complementary senses or dimensions: on the
Address correspondence to: David Heyd, Ph.D., Chaim Perelman Professor of Philosophy,
Department of Philosophy, The Hebrew University of Jerusalem, Israel. E-mail: msheyd@
mscc.huji.ac.il
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one hand, it refers to the world as it is given (rather than artificially contrived);
on the other, it means the essential aspects or properties of human beings.
‘‘Human nature’’ draws both on our commitment to a positivistic view of the
world as the value-free object of scientific investigation and on our search for a
metaphysically stable perspective able to serve as a normative guide. Like its
close epistemological associate, ‘‘natural kind’’, the term ‘‘human nature’’
attempts to ground our classification of the world in a typically nonconventionalist way. Human nature, accordingly, becomes a necessary
assumption for any meaningful discussion of what human beings are, and
more pertinent to our present concern, what they ought to be.
This tension between the ‘‘is’’ and the ‘‘ought’’ in the concept of human
nature has characterized much of its philosophical analysis since Aristotle.
Human beings, according to Aristotle, are a separate biological species,
having unique natural properties defining them as different from all other
animal species, and these properties are fixed and eternal. However, the
differentia specifica of human beings does not consist merely of biological
features, and the natural distinctions between man and animal are of a kind
other than those between animal species. Humans have the unique power of
self-perfection, that is, of becoming something different from what they
(initially) are. In other words, their development is partly self-induced and
self-directed, which means that it is not necessary or deterministically fixed.
The process of perfection is directed to the goal, the telos of humanity, which
is exactly the essential nature towards which humans ought to aim.
This duality of the given physical and mental structure and the end which
one should attempt to realize does not, in Aristotle, involve the naturalistic
fallacy, since it lies within the realm of the natural. In other words, the norm of
what human beings ought to be is grounded in the nature of humans, their
essential properties. The faculty of reason, in its theoretical and practical uses,
is thus no less natural than the biological and psychological faculties and
properties which characterize humans in contradistinction to other animals.
The telos of a human being is not to become something else than she naturally
is, but to come closest to what she essentially is in her nature. Selftranscendence does not mean overcoming one’s nature but only one’s current,
unfulfilled condition. Moral development consists of the perfection of natural
inclinations rather than their suppression by reason or will.
However, when we come to modern accounts of human nature, reason is no
longer seen as part of nature. Human nature becomes a problematic concept
because what is specifically human in homo sapiens is that which is not
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natural. Rousseau is rightly associated with this modern self-awareness of the
gap between nature and reason with all its moral and political implications.
When he turns from the discussion of ‘‘physical man’’ to his ‘‘metaphysical
and moral side’’ in the Second Discourse, Rousseau traces the distinction
between man and animal: animals act ‘‘by instincts’’; human beings choose
‘‘by an act of freedom.’’ Animal nature is deterministic and forces the animal
to act by the laws prescribed to it even if it would be advantageous for it not to
do so. But ‘‘dissolute men abandon themselves to excesses which cause them
fever and death, because the mind depraves the senses and because the will
still speaks when nature is silent.’’ According to Rousseau, the philosophical
basis for the polar distinction between ‘‘the will’’ and ‘‘the senses’’ lies in the
fact that while ‘‘physics explains in some way the mechanism of the senses
and the formation of ideas,’’ the power of free will or choice is found in
‘‘purely spiritual acts about which the laws of mechanics explain nothing’’
(Rousseau, 1964, pp. 113–114). Thus, the uniqueness of man among the
animals consists of his being partly free from the subjection to nature.
But Rousseau proceeds to describe a second quality, which is specific to
human beings, perfectibility. Animals do not develop: on the individual level,
an animal reaches its ‘‘end’’ soon after its birth; on the species level, animals
are the same as they were ‘‘a thousand years’’ ago. But human beings have the
faculty of ‘‘self-perfection’’, which helps other faculties to develop. Rousseau
refers to this faculty as ‘‘almost unlimited’’, a striking anticipation of the
modern awareness of the human power of self-transformation, going far
beyond the Aristotelian view of human perfectibility. But he holds the power
of self-perfection also as the source of misfortune, of misery, of the decline of
old age, of vice as well as of virtue. This modern view of the perfectibility of
man operates on both the individual and the species levels (Rousseau, 1964,
pp. 114–115). Natural (savage) man is contrasted to rational (civil) man, and
in contrast to Aristotle’s view that man is by nature a social being, Rousseau
views social existence as exactly the alienation of human beings from (their)
nature. The perfectibility of man is none other than the power to ‘‘raise him far
above nature.’’1
Now, both choice and perfectibility, as the two distinguishing features of
human beings among other animal species, introduce a deep factor of
instability or an open-ended quality into the traditional idea of human nature.
It is not so much ‘‘understanding’’ as such (a mere extension of ‘‘sense’’
according to Rousseau) which is the mark of humanity, but rather freedom of
choice which extricates humans from nature. Perfectibility makes humanity an
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ever-changing, evolving species, breaking the eternally rigid boundaries
of the Aristotelian view. The direction of human development, either on
the personal or the species levels, is not deterministically fixed. Human
beings and societies can become virtuous or vicious, enlightened or
backward.
However, this does not mean that the operation of human will and the
faculty of self-change are not constrained by nature, or that reason and choice
are completely independent from their natural basis. The primary driving
force behind the development of language, art, technology, and civil society is
the better management of human natural needs and passions. But the passage
from savage to civil life also creates new needs and passions, and here is
exactly where the ‘‘open-ended’’ character of the modern concept of human
nature lies. And as in modern evolutionary theory, the unfixed character of the
development of humanity is partly due to the role of external (environmental)
circumstances.
Thus, concluding his discussion of the passage from natural state to civil
state, Rousseau says
[The reader] will explain how the soul and human passions, altering
imperceptibly, change their nature so to speak; why our needs and our
pleasures change their objects in the long run; why, original man vanishing
by degrees, society no longer offers to the eyes of the wise man anything
except an assemblage of artificial men and factitious passions which are the
work of all these new relations and have no true foundation in nature.
(Rousseau, 1964, p. 178)
Politics is the realm in which human beings typically ‘‘arise above their
nature,’’ that is subject themselves to principles of behavior (laws) which are
grounded not in human nature but in reason. Rationality becomes the ultimate
normative, non-natural guiding principle. The will, that distinguishing quality
of humanity, in its universal operations as volonte generale, becomes the
ultimate non-natural basis of the characterization of humanity.
Kant, a true disciple of Rousseau particularly on these issues, elaborates the
nature-reason distinction in his critical metaphysical system. From the
theoretical point of view, nature is the product of human cognition, rather than
purely ‘‘given’’. From the practical point of view, nature is the sphere of
biological and psychological impulses and drives (‘‘inclinations’’), which in
themselves lack value. Reason is completely independent of nature and
operates spontaneously or autonomously on a priori principles and laws. The
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term ‘‘human nature’’ is accordingly pushed to the margin, since human
beings are said to be citizens in two totally distinct worlds – reason and nature.
Indeed, this dual citizenship is the best description of the uniqueness of human
beings (in contradistinction to both angels and animals). Human nature is split
into two senses: the given psychological constitution of members of the
human species, on the one hand, and the faculty of reason in both its
theoretical and practical manifestations, on the other. The given constitution
cannot capture anything essential in human beings, nor can it serve as the
grounds for normative guidance. And reason cannot be referred to as
that quality ‘‘in the world’’ which defines the specific difference of human
beings.
Rather than looking back to that point in history when human beings lived
according to their pure nature, Kant is concerned with the non-natural ends at
which humans should aim, both as individuals and as a race. In words, which
are reminiscent of Rousseau,
[Man] has a character which he himself creates, insofar as he is capable of
perfecting himself according to the ends he himself adapts . . . . As such he
first preserves himself and his species; secondly, he trains, instructs, and
educates his species. (Kant, 1974, p. 183)
But note that Kant dissociates the principles of (self) perfection from the
natural basis of human existence much more sharply than Rousseau does.
Reason does not exist to serve humanity to adapt to changing circumstances,
nor to assist it in satisfying its needs, but ultimately to regulate life according
to universal laws. Human nature (if we mean by this anything beyond the
scientific study of human biology and psychology) is a vacuous and redundant
concept, even an oxymoron. The real (noumenal) self is exactly that which
consists of no natural properties.2 Furthermore, human history, in the sense of
the long-term blueprint for the development and progress of humanity, is a
perpetual effort to invest the natural world with reason, primarily in the
cultivation of the moral life of the individual but equally of enlightened
political institutions and rational legislation. To put it in slightly metaphorical
terms, humanity is the point of intersection of reason and nature. As such it
cannot have ‘‘a nature’’. Reason cannot be naturalized, though nature can be
partly rationalized.
In light of our concern with contemporary discussions of the normativity of
human nature in the context of genetic practices, it is important to add that
Kant by no means denies that human nature in the narrow, positive, biological
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and psychological sense, constrains the progress of humanity towards its
rational goals. But these constraints are merely empirical, and hence of no
moral weight. If technology, medicine and science can manipulate the
‘‘natural’’ constitution of human beings in a way that would make human
beings better equipped to lead a moral life, there is no Kantian reason to
prohibit this. There are no traces in Kant of Rousseau’s romantic commitment
to some primordial natural state.
However, Kant does not rest content with the sharp duality of reason and
nature. Both in his ethics and in his metaphysics he makes a great effort to
somehow reconcile the two, even if not fully unite them in one system. In the
Critique of Judgement, he points out that man as a free agent, a noumenon, is
the only being in nature that acts on ends which are independent of nature.
Although we have no critical epistemological basis for ascribing any value to
nature (and to human nature), we cannot escape a teleological perspective
under which nature has a goal and human history is a rationally directed
process.3 In more radical terms, Kant explicitly says that from the teleological
point of view we should treat man
As not merely a physical end, such as all organized beings [organisms] are,
but as the being upon this earth who is the ultimate end of nature, and the
one in relation to whom all other natural things constitute a system of ends
(Kant, 1928, p. 92).
Kant, in effect, makes a paradoxical (antinomial) statement according to
which human beings can give nature rational structure only because they lack
nature. They both belong to and are detached from nature. Therefore, the
only source of meaning of the very existence and identity of humanity is
internal to it, constituted by human intelligence and will. This was to prove
crucial for present debates on the kind of constraints which bind us in
various genetic practices and policies. Whatever our views on the limits to
genetic intervention in human beings, we cannot appeal to the idea of
‘‘human nature’’ but only to ‘‘rational will’’. In non-Kantian terms we may
conclude that human essential nature lies in the capacity to transcend human
nature.
An even more striking example of the open-ended conception of human
nature, predating modern attempts to escape the Aristotelian essentialist view,
is given by Pico della Mirandola in his 1487 Oration on the Dignity of Man.
After completing the creation of the world, ‘‘the Divine Artificer’’ looked for
someone able to appreciate the grand enterprise (who, in Kantian terms, would
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be able to give it meaning and value). But in order to be able to comprehend
and admire nature, created man could not be assigned any particular
‘‘archetype’’, but had to be given an ‘‘indeterminate image’’. In the only direct
speech passage in Pico’s essay, God says to Man
We have given you, Oh Adam, no visage proper to yourself, nor any
endowment properly your own, in order that whatever place, whatever
form, whatever gifts you may, with premeditation, select, these same you
may have and possess through your own judgment and decision. The nature
of all other creatures is defined and restricted within laws which We have
laid down; you, by contrast, impeded by no such restrictions, may, by your
own free will, to whose custody We have assigned you, trace for yourself
the lineaments of your own nature . . . We have made you a creature neither
of heaven nor of earth, neither mortal nor immortal, in order that you may,
as the free and proud shaper of your own being, fashion yourself in the form
you may prefer (Pico, 1956, p. 7).
This is an extremely bold statement, transforming fixed human nature into
something of a self-shaping, voluntary character. Man is not only placed half
way between the earthly, ‘‘natural’’ world and the divine, super-natural one,
but he is spared the fixed essence which defines all natural kinds
(‘‘archetypes’’). Judgment (Kantian intelligence) and decision (Kantian will)
are the wherewithal for the exercise of human radical discretion about ‘‘human
nature’’ itself.
Like Rousseau and Kant, Pico emphasizes the freedom of human beings
from deterministic natural laws, but he opens an even wider spectrum of
possibilities of self-development: God bestowed upon man ‘‘the germs of
every form of life’’ (Pico, 1956, p. 8). We are getting close to contemporary
consciousness of the tremendous potential of genetic intervention in future
people. Pico describes man as a ‘‘chameleon’’ and as ‘‘Proteus’’ (Pico, 1956,
p. 9), alluding to the infinite power of assuming different shapes. ‘‘Man is a
living creature of varied multiform and ever-changing nature’’ (Pico, 1956,
p. 11).4
The context of Pico’s conception of the dignity of man is, as we have seen,
theological. God’s created world was already ‘‘filled’’ before the creation of
man, so that there was no ‘‘space’’ left for him in the natural order. Pico notes
that ‘‘it was not in the nature of the power of the Father to fail in this last
creative elan’’ (Pico, 1956, p. 6). Rather than create yet another creature, God
creates man as a creator, or at least as self-creator, endowing him with the
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power of an ‘‘artificer’’, even though not a divine one. This idea takes us back
to the biblical version of the creation of man in Genesis:
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And God said, ‘‘Let us make man in our image, after our likeness. They
shall rule the fish of the sea, the birds of the sky, the cattle, the whole earth,
and all the creeping things that creep on earth’’. And God created man in
His image, in the image of God He created him; male and female He
created them. God blessed them and God said unto them, ‘‘Be fertile and
increase, fill the earth and master it; and rule the fish of the sea, the birds of
the sky, and all the living things that creep on earth’’ (Genesis 1: 26–28).
This passage led to an extensive exegetical literature in both the Jewish and
the Christian traditions.5 As I have suggested elsewhere, the close textual
association of the idea of creating man in the image of God and the
commandment to be fertile and increase (which is the first commandment)
suggests that procreation itself constitutes the image of God (Heyd, 1997).
According to this reading, the world without human beings has no value, since
there is no one (but God) for whom the world is good. Human beings serve as
the end of creation, its teleological point (as in Kant). This is why after every
day of creation God is satisfied with the product as ‘‘good’’, but after the
creation of man God describes the end result as ‘‘very good’’.
However, human beings are not just part of nature, destined to remain in
their pre-ordained place or function. Unlike animals, for whom fertility is a
blessing, for human beings it is a commandment, that is, a matter of choice.
They do not act by instinct, but by self-conscious awareness of their
(pro)creative power. They rule nature, rather than belong to it, in the double
sense of dominating the natural environment, on the one hand, and controlling
their own reproduction, on the other. There have been many interpretations of
the way in which humans should master the animal and inanimate world, and
even more of the way they should mold themselves. Indeed, in the first ten
generations, all the way down to Noah, the commandment to increase is taken
literally, i.e., by simply securing the future existence of human beings in the
world (Genesis, chap. 5). But the abuse of sexual power in Noah’s generation,
which leads to God’s reappraisal (of creation) and reprisal (the deluge), raises
the wider issue of the kind of principles which should govern the exercise of
human procreative power. The Bible does not envision the capacity to mold
human identity, but rather focuses on the value of the number of offspring (the
covenant with Abraham) and the duty of human beings to perpetuate
humanity. It would be interesting to consider the question whether Man is the
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exploiter or the custodian of nature (which is the issue in recent
environmentalist debates) reflexively: do we have a duty to preserve human
nature as it is, or are we allowed to use it for our own purposes by changing it?
But in any case, the biblical conception of human control over the future of
humanity as the essential trait of male and female may be useful in the attempt
to deal with contemporary problems of genetic practices.6
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II. THE GENETIC CONTROL OF HUMAN NATURE
Much of the objection to genetic engineering is based on the idea of its
unnaturalness. Both popular intuition and philosophical argument resort to the
claim that radical intervention in the genetic make-up of future people is
unnatural in two senses: being artificial, on the one hand, and transgressing
human nature, on the other. The two senses are closely related. Human nature,
like other natural kinds, is not a product of convention, nor is it a mere
construct. It is independent of an act of choice or intention. Even if it changes
or evolves, it does so through impersonal, non-intentional processes. Even if
we believe that human nature is a culturally constructed idea, its meaning or
content consists of that aspect of humanity which is given rather than invented
or constituted by agreement. In contrast, the artificial is that which is the
outcome of human will, scheme, or design. Now, insofar as humanity is
considered as essentially natural, it cannot and should not be treated as an
artifact.
The recent revolution in genetic technologies has, however, posed the
philosophical problem of this widely shared conception of human nature.
Whereas we cannot hope to change the chemical structure of natural kinds like
gold or water, we are close to getting a large measure of control over the
genetic constitution of plants, animals, and human beings. To the extent that
genetic structure is at least partly constitutive of properties that belong to
‘‘human nature’’, human beings are becoming masters of their own nature. But
being master of one’s nature is a contradiction in terms, at least according to
the analysis suggested above. Nature is no more what we essentially are but
the product of what we want or choose. Nature becomes artifice, the product of
human voluntary design.
Pico della Mirandola intentionally refers to God as the ‘‘Divine Artificer’’.
The enterprise of the creation of the world is thus understood as a feat of
invention, of an intentional production according to a particular design or
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plan. Nature itself is, accordingly, a work of art. From our human perspective,
though, nature is given. Although it may be used and exploited by man,
according to the biblical account, it cannot be essentially changed. But
Pico’s radical interpretation, which we have seen is in line with a possible
reading of Genesis, points out the unique ‘‘nature’’ of man, namely his
freedom from natural necessity. Man is creative in the deep sense of being
an ‘‘artificer’’ of his own nature. Genetic manipulation, in contrast with
less essential interventions in human life (like medical therapy, education,
social conditioning), makes human nature itself the object of artificial
design.
Why should we be morally concerned about such radical self-creation,
which seems to be but a biological extension of Pico’s spiritual interpretation
of self-formation? Why should ‘‘human nature’’ (whatever it specifically is)
be protected from any intentional (human) change? Why accept changes in
human beings that occur in the long-term course of biological evolution and
prohibit any rationally contrived, ‘‘artificial’’ changes of the kind offered by
genetic technologies? A group of scientists has recently announced that in the
near future we will be able to order roses of almost any color we wish and
select scents for these roses from a rich menu. What is the status of such
genetic manipulation of flowers? It is certainly an artificial procedure in the
sense that it is developed and exercised by human beings working on the basis
of knowledge and will. But it is not clear to what extent the product of this
procedure is more artificial than the (few) flower species left in the wilderness,
or hybridized roses grown in hothouses. A genetically modified rose is not
artificial in the same sense as a paper rose (appropriately called ‘‘artificial
flower’’). Yet, despite the greater similarity to ‘‘natural’’ flowers than to paper
flowers, we feel ill at ease about the genetic modification of roses in a way
which we do not with regard to artificial flowers.
The common preference for natural flowers over both genetically
engineered flowers and artificial ones expresses the double meaning of
‘‘unnatural’’ to which we referred above. Flowers that do not grow in nature,
in their natural environment, are artificial, that is, a product of human art and
skill; and flowers which are genetically engineered are violations of the
essential (real) nature of flowers, an intervention in the way the world is given
to us. Artifacts are often considered less valuable if they serve as substitutes
for natural objects. The unnaturalness of genetically produced flowers consists
in the interrelated exercise of an artificial technique and the violation of the
human-independent ‘‘nature’’ of botanical entities.
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But it is not easy to show why the violation of the genetic integrity of
flowers is worse than the destruction of a rocky landscape or the obstruction of
the natural flow of rivers. And it is no less tricky to demonstrate why the
genetic manipulation of human beings is morally worse than the engineering
of roses. Again, the artificiality of the genetic intervention in the constitution
of individuals cannot be wrong as such, since all medicine consists of artificial
intervention in natural processes. It is rather the depth of this intervention
which causes moral concern, that is to say, the alleged transgression of the
protected zone of ‘‘human nature’’. This zone is considered to be the source of
the identity of human beings, not merely of the conditions and circumstances
of their life.
But why is the identity of humanity a sacred sphere, an object of awe, a
protected given fact which should not be meddled with? The natural identity
of roses, like the integrity of the natural landscape, can be defended on
theological grounds (that is the way God created the world and wanted it to
look like), ecological (we are only part of nature, not its rulers), or aesthetic
(real beauty lies in what is natural rather than artificial). But the opposition to
messing around with human nature goes beyond these arguments. Human
nature is paradoxically more sacred than flowers and rocks exactly because
humans are not merely part of nature! This is exactly the lesson learnt from
Kant’s view of reason as constituting the dignity of man, its inner priceless
worth.
If that is the case, then only that aspect which constitutes the dignity of
human beings, their essential identity, or their true nature should be protected
from intentional manipulation and alteration. It is an interesting question
whether Kant would have been opposed to genetic engineering or cloning.
Although from his conservative views about sexuality and reproduction it
seems he would have been truly horrified at recent (and future) techniques of
assisted reproduction, it is not clear whether he could have grounded his
reluctance in his theory of double citizenship. For genetic engineering seems
to be operating merely on the natural level of our biological and possibly
psychological constitution. Genetically engineered people will not necessarily
lack any of the rational features of intelligence and will and hence would have
the same source for their inner worth and dignity as we, ‘‘natural’’ humans,
possess. And the same argument applies to any philosophical view which
considers essential human nature to lie in non-natural features like the faculty
of free choice, the existence of a soul, the capacity for language or the ability
to lead a contemplative life. Insofar as genetic engineering does not affect
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these powers and features, it is immune from the critical argument from
human nature.
We may conclude from these considerations that, contrary to our intuitive
response, the violation of the nature of roses by genetic manipulation is greater
than that of ‘‘human nature’’ by genetic engineering, since only humans have
a ‘‘nature’’ which is not susceptible to change through genetic intervention.7
All, of course, depends on our conception of human nature and whether it is in
any way based on genetic characteristics. Thus, when critics oppose the use of
genetic engineering to increase the height of human beings, they may argue
that such a change would be ‘‘unnatural’’ in the sense of deviating from
average human height, the outcome of biological evolution; but height is
hardly a constituent of human nature in the traditional (essential) sense. Even
the artificial creation of psychological and mental dispositions (like courage,
or higher I.Q.) cannot be rejected on the basis of their going against human
nature, although these could change human beings in important features. Only
intervention in what makes human beings, for instance, able to make
autonomous choices or cooperate with others on a fair basis could be
considered as an infringement of human nature. And at the present stage of
genetic technology this seems to be quite a remote possibility.
However, human dignity (reason, freedom, and autonomy) does not exhaust
the identity of human beings, neither on the individual nor on the species level.
Even if the power of self-molding is, as Pico suggests, the source of the dignity
of man, his identity is the ultimate constraint on the exercise of that power. As
individuals we want to shape our lives, sometimes making radical choices and
changes. But we are always bound by the logic of deciding what is good for us,
that is to say, we are committed to maintaining our identity throughout those
changes. There is logically no sense in planning our life if it is not going to be
we who are the subjects of that life. Human beings are the kind of entities
whose identity is not just given to them but projected by them into the future.
The same concept of identity operates on the collective (social, species) level.
The whole point of our communal life, of the creation of social frameworks,
search for scientific truth, development of technology and the whole collective
enterprise called ‘‘civilization’’ is that our descendants enjoy, appreciate, and
continue that process. For any long-term human project there must be people
who are sufficiently similar to us, sharing our identity.
The concept of identity is therefore a constraint on the rationality of genetic
engineering. But unlike the traditional definitions of human nature, which are
clear and fixed, the concept of human identity is typically vague and
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gradational. It does not relate to the immutable ‘‘nature’’, that is essential
properties, of human beings in general, but to the way we conceive who we are
or want to be. For instance, on the individual level, I might define myself as an
artist, parent or a religious believer, although I do not regard these features as
pertaining to my (human) ‘‘nature’’. But I would be distressed by the thought
of losing those properties, as if without them I would not be the same person
anymore. On the collective level, a group of people might consider themselves
as a people, a tribe or a nation, willing to make almost unlimited sacrifices to
make this identity endure (this is the fundamental force behind national
movements, for example). Again, no appeal to any metaphysical, ‘‘natural’’
properties of the group is necessary for the formation of such collective
identities. But in both the individual and the collective cases, the projective
aspect of the notion of identity is crucial: we do what we can to perpetuate it
into the future, either of our own individual lives or those of our descendants.
We have a deep wish that our children be similar to us in those features held by
us as constitutive of our identity.
Now, beyond the personal and group identities, modern genetic practices
force us to consider the identity of the human race. This is the largest group to
which we belong and whose particular identity is a matter of moral concern to
us. (The class of all rational beings or that of all sentient beings was taken as
morally significant by Kant and Bentham, respectively, but only to
demonstrate particular criteria or moral principles rather than to describe
our self-shaped identity, which for both philosophers remained ‘‘the human’’).
But once we reach that level of generality, is there any difference left between
human nature and human identity? Are there any features we wish to maintain
as human beings in ourselves and our offspring? And are these features selfdefined as they are in our individual life and our tribal or national identities, or
do they belong to what we believe to be the essential and unchangeable
properties?
Adopting the modern view running from Pico through Rousseau and Kant
to Marx, Darwin and Nietzsche, we can answer these questions by saying that
human nature, in the philosophical and moral sense, is the power humans have
to define their identity, both individual and collective, to decide what they are
and would like to be. But as we have argued, this power of self-definition itself
is not a natural power but an exercise of choice and rationality, and hence
cannot be regarded as purely ‘‘given’’ or immutable. Unlike Aristotelian
species or ‘‘natural kinds’’, human beings decide or construct what they
‘‘essentially’’ are, and the exercise of their power to do so is itself a matter of
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choice. Kant was very perceptive and deep in characterizing humans in terms
of their power to make a radical choice between leading a rational life or
choosing to live by natural inclination. This power, he said, is ‘‘inscrutable’’,
but this may ultimately be his way of articulating the idea of a ‘‘human
nature’’ in the light of its inner contradiction (Kant, 1960, Book I).
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III. HUMAN NATURE AND THE ETHICS
OF GENETIC PRACTICES
The genetic revolution has raised the issue of human nature in a particularly
sharp manner. For even if human nature is not constituted by our biological
features, these features constrain the means and chances to realize that nature.
Genetic intervention may thus create new means or even criteria for achieving
human excellence. The argument from human nature plays a major role in
both public and professional debates on the morality of new genetic practices.
The analysis of the concept of human nature proposed in this article provides a
tool for the critical examination of four main issues in the contemporary
debate: the distinction between screening and intervention, the distinction
between therapy and enhancement, the distinction between somatic cell and
germ line interventions, and the practice of cloning.
Screening vs. engineering: There is a widespread belief that genetic
screening is much less problematic, morally speaking, than active genetic
interference. The term ‘‘engineering’’ connotes artificial human intervention
in the ‘‘natural course of events’’. Screening is considered non-invasive; it
consists of mere, passive, inspection. It provides prospective parents with
crucial genetic information regarding their future children and enables them to
make decisions about marriage, conception, the selection of fertilized ova for
implantation in IVF procedures, and abortions. Engineering, on the other
hand, is an active manipulation of natural phenomena, the genes, and
accordingly is seen as typically violating the integrity of human nature.
However, neither the distinction nor its alleged ethical implications are
clear cut. Screening is not purely passive, since its purpose is an active
intervention in the ‘‘natural course of events’’. Traditional matchmaking (e.g.,
of the sort suggested by Plato in the Republic) directly affects the genetic
make-up of future individual children and in the long run the genetic pool of a
whole society. The point of screening is not mere inspection but active
changes in procreative behavior using human knowledge. Genetic screening
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may become a form of social engineering which in principle is no different
from genetic engineering in going against nature. This has been exactly the
basis for the opposition to Plato’s ideas about pre-scientific eugenic policies.
Therapy vs. enhancement: A slightly less conservative appeal to the
argument from human nature is often raised in the distinction between
therapeutic uses of genetic technologies and eugenics. Therapy, even if it
involves invasive intervention (engineering), is considered ethically justified
since its purpose is the correction of a defect, the prevention of an illness.
What is natural to human beings is judged here in terms of a certain standard
of normalcy, health, the removal of dysfunction. Therapy, even when it
consists of gene replacement, is the restoration of human nature rather than a
violation of its integrity. However, enhancement of the properties and powers
of future human beings is suspected as an interference with the natural
development of the human species, an attempt to ‘‘play God’’. The aversion to
eugenics is nowadays almost universal, partly due to the horrific history of the
idea in the twentieth century and partly because of the deep reservation about
the legitimacy of making changes in human nature. Enhancement is rejected
because it implies the refusal to accept the given natural properties of
humanity and a presumptuous endeavor to create a new kind of beings (which
might turn out to be not human).
Yet, critical analysis of the idea of human nature has shown that it can
hardly serve as a basis for the rejection of genetic enhancement. There is no
set of fixed properties (either of the ideal human being or the average or
‘‘normal’’) which forms what humans essentially are, and the open-ended
character of human nature only supports a reasoned choice of selftransformation. The argument from potentiality may work on the individual
level (the embryo’s trajectory of development being naturally innate to it,
genetically fixed from conception); but it does not apply on the species level,
because evolution lacks direction, is partly decided by random factors, and in
that sense is completely open. Of course, there may be good reasons for
restricting genetic enhancement (like social distributive injustice), but the
argument from human nature cannot serve as one of them. Even the above
mentioned principle of human identity does not speak against most forms of
enhancement, since by promoting and strengthening in our children certain
physical and mental features, which we find appealing, we by no means lose
the sense of identity and continuity.
Somatic cell vs. germ line interventions: This is yet another distinction
which splits conservatives and liberals in the ethics of genetic practices. Even
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if engineering is allowed and even if its purpose is enhancement, these should
be strictly confined to the treatment of individuals. Germ line interventions in
the human gene are closely associated with the manipulation of human nature
itself. Their irreversibility is awesome because it is permanent in the same
sense as ‘‘human nature’’ is conceived. By making radical changes in the longterm evolutionary processes of human beings, we damage the human genetic
heritage. The concept of a genetic heritage is derived from its cultural
counterpart, namely a cumulative achievement or record that we are obliged to
pass on from our ancestors to our descendants. It reflects a commitment to
natural evolution (or divinely created nature) which should be protected from
willful transgression.
Again, there are many valid arguments against the highly risky practice of
germ line manipulation, which this article by no means wishes to
underestimate. But the invocation of the idea of human nature is of little
help. Future people have no rights against us to have a particular genetic
make-up, since they are merely possible people and as such do not have rights
of any sort (Heyd, 1992). And it is difficult to show that there is an
‘‘impersonal’’ value in maintaining the present genetic character of human
beings, especially if the germ line changes are oriented towards enhancement,
that is, the creation of better adapted individuals. The argument from human
nature as a limitation of germ line engineering appears to be powerful because
it is concerned with the human species rather than with individuals, but its
validity is dubious.
Cloning: Cloning is probably considered the most unnatural of all genetic
technologies and hence the most controversial. In the popular mind, clones are
thought to be a kind of robots, artificial products of some mechanical
technique. Unlike the outcome of genetic engineering, the whole point of
which is introducing changes in the future person, clones are exact copies of
an original individual. Paradoxically, this identity is exactly the source of the
common response of alarm towards the possibility of cloning. Human nature
is perceived as the persistent and fixed essence underlying the changes from
parents to children. As we saw earlier, we want to have children who are at
once similar to us in their basic identity but sufficiently different from us to
make them non-identical with us.
As we have noted, the term ‘‘unnatural’’ has two (interrelated) meanings –
what is artificial and what goes against human nature. It seems that the fierce
opposition to cloning arises out of the first rather than the second meaning.
The abhorrent aspect of cloning is connected with the artificial process by
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which a new person is created, rather than with the outcome of that process.
For, paradoxically, the clone maintains the genetic heritage in its purest form.8
If the parent is an exemplification of ‘‘human nature’’, then its clone is equally
so. Indeed, the process of creating a clone is far removed from the standard
(natural!) way of reproducing, but so are – in varying degrees – conceptions by
sperm donations, IVF, and surrogacy (as well as the more common forms of
‘‘assisted’’ reproduction offered by modern medicine). Only if we believe that
human nature amounts to standard sexual reproduction can we say that
cloning is a violation of human nature. But as we have seen from the
interpretation of the first biblical commandment in Genesis, even the natural
way of reproducing is not a ‘‘given’’ or the mere operation of ‘‘nature’’ in the
case of human beings. Their ‘‘nature’’ consists precisely of deliberate control
over what is natural to them. In other words, the very distinction between
natural and artificial, which is applicable in the case of flowers, loses its point
in human beings.
IV. CONCLUSION
The paradoxical quality of the concept of human nature is a deep feature in
ethical thinking, particularly in the modern era in which the idea of nature has
undergone a process of positivistic disenchantment and reason has been denaturalized. Modern ethics is consequently haunted by the naturalistic fallacy.
Human nature means either the biologically (and psychologically) constitutive
properties of members of the human species, or the immutable core of the
ideal human being. In the first case, human nature has no normative
implications; in the second, it is itself a normative concept and hence cannot
serve as the foundation for an ethical system.
However, the tension between the human and the natural that was the focus
of this article is hard to avoid. No ethical theory can completely do without a
conception of what human beings are, what is essential in them and hence can
serve as a guiding principle in the formulation of goals and ideals. The nature
of human beings is the source of stability, predictability, generality, and
trajectory of perfection without which no moral conception can be articulated.
A given basis, which is beyond choice, is a necessary constraint on the
exercise of choice, at least in the sense of securing the identity of the choosing
agent. But the human aspect of freedom, of rational control of the given
natural properties and circumstances, is equally necessary for the moral point
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of view. The unique value of humanity – its dignity – lies in its power of selftranscendence, of being other than the natural given.
So, although modern culture has become suspicious of the idea of human
nature, it cannot dispense with it. The context in which the inner contradiction
in the idea of human nature is most challenging in our times is, not
surprisingly, the genetic revolution. It forces upon us the re-drawing of the
borderlines between given nature and free choice, between the hard core of
what we are and new ways by which we can transform ourselves.
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NOTES
1. Cf. Horton (1997). Horton appeals to Charles Taylor’s notion of the ‘‘moral sources’’
human beings possess, through which they can rise above their natural inclinations and act
in the light of moral principles. The philosopher’s role is to oppose the rationalizations by
which we try to justify our failure to act morally.
2. Thomas Nagel argues that reason (or will) cannot be fully naturalized. The subjective or
personal point of view is irreducible. This irresolvable tension between the personal and the
impersonal is unique to human beings and, as in Kant, is the closest to the tension in the
concept of human nature (although, again, not in the scientific or theological sense of
‘‘nature’’). See Nagel (1997, chap. 9).
3. For a systematic and illuminating discussion of Kant and Rousseau (as well as many of
their modern followers) on human nature, see Bayertz (1994, chap. 6). Bayertz argues that
for Kant, the essence of a human being ‘‘is its responsibility’’ (1994, p. 106). This is a
reading which might mislead in its existentialist overtones. It ignores the teleological
direction of perfectibility (completely absent from Sartre’s conception of the open-ended
nature of freedom and from Pico della Mirandola discussed below).
4. For a contemporary similar view of the open-ended character of human nature, see Reichlin
(1997, pp. 19ff). Reichlin refers to the human person as an existentia rather than a
substantia, whose ‘‘essence lies properly in her unfinished character.’’
5. For a comprehensive survey of the long history of the interpretation of these verses, see
Cohen (1989).
6. I have not dealt here with Marx and Darwin, whose theories undermine the
traditional concept of human nature, the former by denying its trans-historical and
universal character, the latter by challenging the sharp distinction between the human
and the animal.
7. This immunity of human nature from degradation is reminiscent of the inviolability of
human dignity by human behavior. If by dignity we mean the inner worth of a human being
as a human being (rather than mere self-respect or honor), no humiliating act can destroy
that dignity.
8. For a scientific support of this claim, see Dawkins (1998, pp. 57–59). Dawkins mentions
the paradox of sexual reproduction, which is a less efficient mechanism for the selfish gene
to perpetuate itself than asexual reproduction (cloning).
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