Animalism and the Unborn Human Being
Christopher Tollefsen
University of South Carolina
Recent work in the metaphysics of identity seems indebted to a revival of the Aristotelian
distinction between substance and accident, a revival possibly to be attributed to David
Wiggins’ Sameness and Substance. As Wiggins points out, everything that exists is a
“this such,” and it is the concept under which a thing falls as a this such, rather than
concepts that indicate what it is doing, or what color it is, and so on, that tells us what the
thing is.1 For at least some things that we ordinarily characterize as particulars, the
concept under which they fall as particulars will be their substance concept.2 It is this
concept that tells us what the thing in question most truly is, and, as Eric Olson writes, it
is this concept that “determines persistence conditions that necessarily apply to all (and
perhaps only) things of that kind.”3
The language of substance may not be equally amenable to all, but everyone
involved in the abortion debate at a philosophical level has an interest in understanding
what you and I and things of our sort are most fundamentally, because this understanding
will determine when we come to be, as well as when we cease to be. And, as Patrick Lee
has pointed out, what most defenders of abortion have held, implicitly or explicitly, until
recently, is that you and I are essentially persons.4 “Person” was then understood in a
quasi-Lockean way to involve such properties as psychological continuity or
1
David Wiggins, Sameness and Substance (Oxford: Blackwell, 1980) p. 15.
Although the sortal concepts under which particular artifacts fall are analogous to substance concepts, I do
not think artifacts are substances in a proper sense, as I will argue below.
3
Eric Olson, The Human Animal (Oxford: Oxford University Press, 1997) p. 28. v “Kind” here should be
understood with some specificity: not just “animal,” but “dog” or “cat.” So if a dog were to gradually be
changed into a cat, that dog would cease to exist.
4
Patrick Lee, “A Christian Philosopher’s View of Recent Directions in the Abortion Debate,” Christian
Bioethics, forthcoming.
2
connectedness, and from this it was inferred that no person existed prior to the presence
of such psychological properties. It was an easy step from this to the conclusion that
embryos and fetuses, lacking the relevant psychological properties, were not persons, and
thus were not entitled to the respect ordinarily due persons.
Problems with the view that you and I are essentially persons have been apparent
for quite some time; for one thing, this would mean that you and I were the same kind of
substance as intelligent Martians, angels, and perhaps members of the Trinity; but why
think we have their persistence conditions? But Eric Olson has raised perhaps the most
damning objection. Olson points out that on the received view, you and I were never, for
example, fetuses, for you and I are essentially persons, and substances of the person sort
do not come to exist until the onset of psychological traits. But fetuses themselves seem
to belong to a substance class – they are particulars of the substance sort “human animal.”
And this raises problems for the view that you and I are essentially persons. What, for
example, has happened to that other substance, the human animal? Does it continue to
exist in the same space as the human person? Did it cease to exist with the coming to be
of the human person? If the former, how can it not share exactly all of the person’s
properties, and if so, why is it not also a person? If the latter, is there now no longer a
human animal in the space that I occupy? None of the options seems metaphysically
palatable.5
The solution is that you and I are essentially human animals; thus you and I were
once fetuses, and, at least plausibly, embryos as well. But if you and I are not essentially
See Olson, The Human Animal, especially chapter 4. Lynne Baker’s “Constitutionalism” attempts to
provide a middle account between the previous dualism and Olson’s animalism. I critique her arguments
against animalism, and her defense of constitutionalism in my “Persons in Time,” American Catholic
Philosophical Quarterly, forthcoming.
5
persons, but animals, what sort of concept is the concept “person”, and when and how do
we become persons? Olson’s answer might seem to be the only possible option here:
“person” is a phased sortal, like “teacher” or “ambulator.” Human animals move into a
stage of personhood, and possibly out of it, while remaining the same substance, just as a
baby’s substance does not change when she learns to walk.
This move from the metaphysics of identity has been appropriated in the ethics of
abortion. It is no longer metaphysically plausible to hold that you and I are essentially
persons which come to be late in the career of an animal; so personhood should, like
“ambulator” be viewed as an achievement, rather than a status; and human animals, like
other animals, may be killed when they are not persons.
One upshot of this discussion is this: Insofar as defenders of abortion accept that
you and I are essentially animals, then they must argue that you and I are not as such
worthy of respect. Many philosophers have pointed out how deeply arbitrary such a
position is bound to be in determining who is worthy of respect. But it seems to me to be
subject to even further difficulties.
The earlier view was dualistic, separating the
substance that I am, from the animal substance I am associated with. This involves an
alienation from that bodily nature, an alienation that Germain Grisez, John Finnis, and
Joseph Boyle have argued is theoretically untenable.6 Still, untenable though it may be
philosophically, it seems psychologically possible – I take myself not to be that animal,
and am alienated from it as from other things that I am not.
The new account seems even more problematic from the first person practical
standpoint, however, for it seems to involve, as did the earlier account, a rejection of my
6
See John Finnis, Joseph M. Boyle, Jr., and Germain Grisez, Nuclear Deterrence, Morality, and Realism
(Oxford: Oxford University Press, 1987) pp. 308-309.
bodily nature, but now with that nature understood as mine. That is, under the earlier
conception, on which you and I were essentially persons, the animal, the embodied being,
was other than I, other than you. You and I were essentially alienated from that bodily
nature, but there was perhaps some solace in the essentiality of the alienation. On the
new conception, I am that bodily being, but if I am valuable only insofar as I have
achieved the status of personhood, then I am not only, on my own self conception,
alienated from the embodied animal, but from myself, for I am, by my own self
understanding, that embodied animal. I can not, on this view, attribute to myself as such
the value and worth that demands respect, from others or from myself. This would seem
to be a form of practical alienation from oneself that gives reason to reject the claim that
the animal that I essentially am only gradually becomes worthy of respect. 7
So
animalism leads quite naturally to the view that respect is due to a human being from the
time that it starts to exist as a human being.8
7
This difficulty is replicated in our relations to others. Consider in this light also the related, and very
disturbing, set of attitudes manifested by David Boonin towards his son, Eli. Boonin, in his recent book on
abortion, writes that on his desk are several pictures of his son at various ages. But “through all the
remarkable changes that these pictures preserve, he remains unmistakably the same little boy.” Boonin
then goes on to say: “In the top drawer of my desk I keep another picture of Eli. This picture was taken on
September 7, 1993, 24 weeks before he was born…There is no doubt in my mind that this picture, too,
shows the same little boy at a very early stage in his physical development. And there is no question that
the position I defend in this book entails that it would have been morally permissible to end his life at this
point.” But what can the willingness to have ended what he acknowledges was his own son’s existence be
but an alienation from his son, a failure to fully accept his son’s existence as in a relationship to his own.
8
What, then, should we say about the relationship between the concepts of “human being” and “person”?
Two possible strategies seems promising. The first would be to abandon the notion of “person” altogether.
A direct argument to the effect that human animals were the sorts of beings that deserved moral respect
would then be required, and would presumably, be available on grounds familiar from earlier stages of the
debate. I view this as rather a pragmatic move, which concedes that the concept of person has been so
abused in the abortion debate that it is no longer helpful in making the essential points that you and I are
deserving of moral respect in virtue of what we are, rather than what we achieve. Jenny Teichman seems to
adopt such a strategy.
A second strategy is that pursued by, e.g., David Braine, in The Human Animal. Braine denies
that the only two options are that “person” is a substance concept or a phased sortal concept, arguing
instead that it is a “range concept.” Such concepts “always indicate the subjects, not of just one predicate,
but of a family of interrelated predicates, a family united by a role in a mass of discourse, in the case of
‘person’ a role in statements with a certain place in schemes of historical explanation.”8
Animalism has at least tacitly been a crucial element in another discussion
concerning unborn human life in recent years. Discussion of abortion has recently been
somewhat surpassed by discussion of embryo creation and research. But the strategy of
those favoring creation of, and research on early human embryos is not simply to deny
personhood to these embryos but to make the stronger claim that these embryos, because
of their potentiality for twinning, are not even human beings at all.
Why should twinning be thought to militate against the humanity of the early
embryo? One crucial consideration in the argument concerns the individuality of that
early embryo. Recall the Aristotelian suggestion hearkened to by David Wiggins, that
everything that exists exists as a this such. So any particular substance will be a member
of some substance kind, but it will also be an individual in its own right. Indeed, this
consideration is of somewhat unrecognized importance in considering whether certain
sorts of entities that appear to be substances really are. For if something genuinely is a
this such  a substance  then it should be the case that it has determinate identity
conditions, even if it is not always possible to identify them, or to identify whether they
are satisfied or not. That is, there should always be a definite yes or no answer to the
question: is this the same substance as that (was).
It is clear that this condition is not met by some things that for more or less
pragmatic and social reasons are given names and treated as if they were genuine
individuals. For example, a pile of trash is not really a substance. Its beginnings and its
endings are vague and a matter of convention, as are, in fact, its physical boundaries.
When large bits of the pile are replaced, there need be no definite yes or no answer to the
question “Is this the same pile of trash as the one that was here yesterday?”
There are other arguments for not treating the pile of trash as a genuine substance.
The pile of trash, for instance, does not have its own causal powers. Although it appears
to stink, and to thus to cause the wrinkling of noses in its vicinity, and to attract flies, the
causal powers of the trash seem entirely reducible to the causal powers of its parts, and
ultimately to its smallest parts. This does not appear to be true of organisms: that this is a
dog, or a cat, or a human being, enters necessarily into our explanation of why this is
chasing a rabbit, or a mouse, or a high paying job.9
Philosophers such as Trenton Merricks and Peter van Inwagen have extended
these arguments so as to argue that in fact none of the ordinary artifacts that we find
around us daily are, after all, genuine individual substances. Merricks and van Inwagen
thus conclude that such artifacts are not really entities after all: there are no baseballs, no
statues, no flags, merely simples arranged baseball-wise, statue-wise and flag-wise. In
essence, it seems to me, there arguments work by showing that everything that is not an
individual substance is ultimately a kind of heap, any one of which might be more or less
important to us in our social life, but all of which are ontologically on par with one
another.
There are of course, counterexamples, but even these serve to bring out the
differences between the causality of a substance and that of, especially artifacts. It is
true, as Lynne Baker argues, that statues, not statue shaped rocks, raise our insurance
premiums, and that flags bring a tear to our eye.10 But they do not do this in the way that
I raise my hand, or the dog brings the ball. The statue and the flag interact with members
of the social world in such a way that members of the social world themselves change or
9
Thanks to Pat Lee for this.
Lynne Rudder Baker, “Review: Trenton Merrics Objects and Persons,” Australasian Journal of
Philosophy 81 (2003) 597-598.
10
bring about change.
But while the flag qua flag has this sort of derivative social
causality, it has no agency of the sort that humans, dogs, and cats have. Such entities
themselves act, albeit in different ways.
The agency of substances, and their individuality in a substance kind, are not
unrelated. Individual substances have the sort of agency that they have in virtue of the
sorts of things they re – dogs have a doggy agency just as humans have a human agency.
And this is in turn related to the claims about the persistence conditions for substances
following from what they are: they persist as long as they able minimally to maintain the
processes necessary for their particular, i.e., species specific, forms of agency, and to
continue, even if in a greatly attenuated manner, some form of their appropriate agency.
Substances are self-movers, and their form of motion is species specific; hence any
individual substance will play a crucial and unique explanatory role as a substance in a
number of causal stories.11
This hardly exhausts what can be said about substances, but many of the
traditional attributes of substance would seem to follow from these: an individual
substance would need to have fairly definite boundaries, for example. But two further
characteristics deserve mention here. First, substances must have definite beginnings and
endings; I will briefly defend this claim later in the paper. Second, substances cannot be
composed of other substances. As discussed above, substances are agents, and their
autonomy is not entirely derivative from the action of their parts. But this in turn must
mean that the activity of the parts is not entirely intelligible apart from their role in their
11
It follows that artifacts of any kind, and non-organic but natural beings are not substances. Does this
mean that they are not objects or entities as Merricks and van Inwagen would have it? I see no reason to be
so parsimonious: “object” and entity”, like “exist”, don’t seem to me to be univocal terms. A baseball is an
entity in a lesser sense than a dog because it is not a substance.
whole – their substance. Thus Aristotle’s famous claim about the detached finger being a
finger in name only – separate a part of a substance from the whole of which it is a part,
and it is no longer the sort of thing it was as a part. But if the substance-parts cannot, as
such, have this kind of independent agency and intelligibility, then they cannot
themselves be substances.12
So why, then, does the early embryo’s capacity for twinning render it unfit to be
an individual substance? Which specific criterion does it fail to meet? And what is its
status supposed to be in the time period in which “it” is not yet a human animal? Two
proposals in particular are of importance here.
The first is that precisely because of the early embryo’s capacity for twinning, it
cannot be an individual. But if not an individual, then not a substance, and hence not a
human animal. This argument seeks to show that because of what the embryo can do, it
cannot be an individual; similarly, if some supposed entity was capable of shaking hands
and going two separate ways, it too would not be an individual substance.13
The second argument relies on a Lockean claim, plausible in itself, about what is
responsible for the persistence of some particular organic substance. Peter van Inwagen
summarizes the claim:
If an organism exists at a certain moment, then it exists whenever and
wherever  and only when and only where  the event that is its life at that
moment is occurring; more exactly, if the activity of the xs at t1 constitutes
12
This is not to say, of course, that we cannot say a considerable amount about the parts by abstracting
from their role in the whole: the cells of the finger have much in common with the cells of the spleen, at the
biological level. It is also worth pointing out that it is traditional to say of a cell that it is an organism, just
as the larger substance of which it is a part is an organism. This is fine, so long as it is not understood to
imply that an individual cell that is a part of a dog, say, is a substance.
13
An example which owes something to Parfit’s divided and reimplanted brain halves who eventually play
tennis together.
a life, and the activity of the ys at t2 constitutes a life, then the organism
that the xs compose at t1 is the organism that the ys compose at t2 if and
only if the life constituted by the activity of the xs at t1 is the life
constituted by the activity of the ys at t2.(145)
Now a one-celled zygote has a life; it is a single organism. And an embryo at, say, three
weeks has a life; it, too is a single organism. But van Inwagen claims that the two-celled
“organism”, and similar collections of cells, do not have a shared life:
They adhere to each other, but we have seen that that is no reason to
suppose that two objects compose anything. The zygote was a single,
unified organism, the vast assemblage of metabolic processes that were its
life having been directed by the activity of nucleic acid in its nucleus. No
such statement can be made about the two-cell embryo. No event, I
should say, is its life. The space it occupies is merely an arena in which
two lives, hardly interacting, take place….It seems to me most implausible
to suppose that the developing embryo is yet an organism if it is still at the
stage at which monozygotic twinning can occur…if an embryo is still
capable of twinning, then it is a mere virtual object. (153-4)
Here two arguments run together. The first is an empirical argument about the biological
life of the early embryo: in van Inwagen’s view, that “life” is insufficiently unified to
constitute a single life, just as the lives of two adhering paramecia would be insufficiently
unified to compose one organism.
The second argument is the earlier conceptual
argument about twinning: anything that can twin cannot itself be a single organism, for
this capacity is incompatible with being an individual.
The empirical, biological issue has a certain obvious priority over the conceptual
issue here. Surely, it is theoretically imperative first to look at whether the purported
entity in question  the early human embryo  seems to have one life, or to be a
collection of several lives.
For if it is best characterized biologically as a single
organism, then this should determine the answer to the conceptual question: can a
biologically unified substance have the potential to divide into two independent
substances?
By way of analogy: one might have thought that it was conceptually
impossible for a human organism to come to by any other means than by the fertilization
of an egg by a sperm.
But if human cloning is, as seems most likely, a physical
possibility, then the purported conceptual impossibility is not, after all, a conceptual
impossibility at all.
I believe that the biological evidence gives good grounds for thinking that the
embryo is the subject of an individual life, specifically an individual human life.14 There
is much that could be said about all that is going on in the early embryo, but I wish to
make only one general remark about the relationship between the biology and what has
been said so far. There are many good summaries of the early development of the
embryo. Barry Smith and Berit Brogaard provide an excellent such summary in their
article “Sixteen Days.”15 As they show, the process begins with fertilization, after which
there are a number of cell divisions that take place within the physical boundaries of the
zona pullicida. Some subsequent steps in the progress towards gastrulation, in which cell
See the reviews of the relevant evidence in A.A. Howsepian, “Who, or What Are We?” The Review of
Metaphysics; 45 (1992) 483-502; Mark Johnson, “Delayed Hominization: Reflections on Some Recent
Catholic Claims for Delayed Hominization,” Theological Studies 56 (1995) 743-763; and Patrick Lee, op.
cit.
15
Barry Smith and Berit Brogaard, “Sixteen Days,” The Journal of Medicine and Philosophy 28 (2003) 4578.
14
folds form the predecessor structures for a variety of bodily parts and organs, and
neurulation, in which the initial structures of the nervous system are generated, include
implantation, which is prior to gastrulation, and the formation of the morula.
We may note in these names the passive voice of science: the stages are viewed as
happenings, somewhat as we say that mistakes were made, when we wish to avoid taking
responsibility. But the description as a whole gives the unmistakable impression, apart
from other salient features, of a single entity acting with purpose: develop body parts, and
implant in the uterus in order that the entity in question can begin to take in nutrition and
establish firmer and more rigorous boundaries, in order that the entity in question can
continue to grow and develop. Consider the following passage from Smith and Brogaard:
The blastocyst, on completing its journey along the fallopian tube into the
uterine cavity, moves into a position where it is in contact with the uterine
wall, to which it adheres via its sticky exterior. Cells on its outer surface
then begin to grow rapidly in such a way as to disrupt the surface of the
wall. These cells actively burrow into the deeper tissue until they have
become completely embedded (Smith and Brogard, pp. 55-56).
What is the subject of this sort of activity? Is it the activity of a unified substance, or is it
the activity of a collection of substances? It should be admitted that if we look only at the
relations between the various cells of the early embryo, it can appear that they lack
sufficient connection and relation to one another, as van Inwagen suggests, to be parts of
a single entity. But leaving aside this question, on which there is also evidence to the
contrary,16 when we look at the whole we seem to see a single self-directed entity, the
nature of whose self-direction is species specific: the course of events outlined by Smith
16
See the literature cited in note 13.
and others is the characteristic course of activity of the early human embryo in much the
same way that it is characteristic of the adult dog to chase rabbits. What is the
alternative? Only that the hundreds, and eventually thousands, of cells that are present
prior to and during gastrulation and neurulation, each have their own species specific
nature that causes them to bring about, each individually, a massively complex state of
affairs that has not been coordinated by a single agent.
Such a possibility seems to violate Ockham’s razor: why think that the many do
what appears to be done by one? But suppose that that is the case. A new puzzle arises:
what is the nature of the transition from these thousands of independent substances to a
state of affairs in which there is but one unitary substance? It is this puzzle that I address
in the remainder of the paper. In what follows, I identify three possible accounts of this
position, all of which seem implausible.
The first possibility seems to be the least likely: the various cells compose
something – they are not an aggregate -- that is human, but not a human being, but that is
coming to be a human being.17 But substances, of which human animals are perhaps the
paradigm, are substances by virtue of their nature, or essence; this essence specifies the
what-it-is-to-be of the individual substance, including that substance’s species-specific
activities. Nothing is a substance without an essence. But the essence seems not only
necessary for the existence of a substance, but, when enmattered, sufficient: except in the
mind, the what-it-is of something simply does not seem to be the sort of thing that can
exist save as a this-such. But if the cells composed something human, that was not a
human being, this would seem to require the presence of the essence, in matter, without
the substance. This seems absurd.
17
This seemed to be Elizabeth Anscombe’s position.
What, then, about hearts or cell tissues, kept alive in a lab? These seem to be
human, but not human beings. But these cases do not fall outside the range of those
considered: artificially sustained hearts, or cell-lines are parts, or, better, potential parts,
of human substances. They are not, themselves, self-maintaining and self-directing. They
are not themselves, it seems, genuine entities, any more than the severed finger, but
because their potentiality to be reintegrated into a substance en masse can be artificially
maintained, it makes pragmatic sense to treat them as discrete realities. They are not
good analogues for some real thing that is human but not a human being.
Moreover, the way in which they eventually achieve a substantial existence, if
they do, is crucial: it is only by integration that they will ever exist “as” substances.18
This is an instance of what Smith and Brogaard, in their taxonomy of “The Varieties of
Substance Formation,” call absorption. It is not, in fact, a mode of substance formation,
since there are no more, and no new substances, than before.19 But it is a way in which
something appropriately related to a substance becomes “substantial.” But if the early
embryo were like this, then it too would require the presence of a substance into which it
would become integrated, nor would it be capable on its own of achieving that
integration. But this is not the case. So the early embryo – the so-called pre-embryo –
cannot be “human” in the way that a heart or a cell line is.
The second possibility is that the early embryo is just an aggregate like the pile of
trash. But an aggregate of what? Clearly of human cells, i.e., potential human parts. But
then how does the aggregate cease to be an aggregate and become a substance? Potential
18
Not, of course, that they will be substances: they will be actual parts of a substance.
Smith and Broaard think there is one less substance than before, but for reasons given in the paper, I
don’t hold the heart or tissue to be substances. Smith and Brogaard’s actual example is of a cat-tail being
reattached.
19
parts seem to become actual parts by integration into a substance, which we have seen is
not the case. But can a collection ever become a substance with no external action, such
as an act of God, being wrought upon it? Unlike the meeting of sperm and egg, on which
more shortly, the purported substantial change involves no cessation of the various
“parts” which enter into the change. At one moment there is a collection insufficiently
organized and interrelated to constitute a single entity, and with no nature of its own, and
at another, magically, there is a substance. This too seems absurd.
Smith and Brogaard include “unification” in their taxonomy of varieties of
substance formation. But as they point out, this type of substance formation is most
typical of artifacts. But again, the essential point concerning the formation of entities
through unification is this: to the extent that the unification is not entirely accidental, and
hence does not result in a real substance, unification, like integration, seems to require the
presence of a prior substance doing the unifying. Unification would appear to be the only
candidate for the way in which the human being is formed on Smith and Broaard’s view,
but it seems in itself the least likely, given the only other analogues of substance
formation by unification.20
The third option avoids such difficulties, but at great cost. Ronald Green, in his
attack on the humanity of the early embryo, writes that “Biology does not admit of
definitive events.” In consequence, he argues, “the determination of significant points
within these processes inevitably involves choice and decision on our part.” 21 Green
supports his first claim not merely with his discussion of twinning, but even with claims
about the nature of fertilization and conception itself. When does an embryo begin to
Of course, as should be clear, I don’t even think that entities such as artifacts formed by unification are
ever substances. How could unification ever result in a nature?
21
Ronald Green, The Human Embryo Research Debates (Oxford: Oxford University Press, 2001).
20
exist? Green suggests a number of possibilities, some of which are quite implausible: the
mere fact that the sperm has entered the egg seems radically insufficient for us to say that
there is a new individual entity. More plausible would be some point after syngamy in
which 23 chromosomes from the egg and 23 chromosomes from the sperm line up at the
new cell’s center. Somewhere around this stage, it would appear to be the case that there
are no longer a variety of processes initiated by sperm and egg being carried out, but that
a new entity exists, which is developing itself according to a single pattern.
Conceptually, the changes that sperm and egg undergo to become a substance are
not baffling in the way the changes just canvassed would be. Sperm and egg are each
parts of a substance – not potential parts like a heart in a dish. So there is a substance – in
fact, two substances – ontologically and causally prior to the new, third, substance, which
comes about when the two parts perform their appropriate functions. Those functions can
be understood as controlled biologically by the substances of which they are parts in a
way that the thousands of adhering cells’ functions cannot be understood as controlled by
the mother within which they exist. In fertilization, two substances, a human man and a
human woman, act together to create a third substance. On the two models described
earlier, non-substances spontaneously become substances. This does not appear to be
ontologically coherent.
It is true that it is difficult to establish a precise moment when the new individual
substance exists, amid the welter of changes that take place during fertilization. But
epistemic difficulties  about the moment of death, for example, or the moment of
individuation  do not call into question the ontological claim that, pace Green, nature
does admit of definitive events. If there is such a thing as a single substance, then there is
of necessity a moment at which it exists, and a moment prior to that at which it didn’t  a
moment in which everything that was happening was a result of the play of independent
biological forces. If Green’s claim is taken seriously, then there are no human beings,
any more than there are, on Merrick’s or van Inwagen’s views, statues or flags. The most
plausible story, metaphysically and biologically, thus remains the standard biological
view of the origin of the human being: it takes place at the moment when fertilization is
complete. And this is the only position, I suggest, compatible with the animalism.