A widely adopted approach to end-of-life ethical questions fails to make explicit certain crucial metaphysical ideas entailed by it and when those ideas are clarified, then it can be shown to be inadequate. These metaphysical themes cluster around the notions of personal identity, personhood and humanness, and the metaphysics of substance. In order to clarify and critique the approach just mentioned, I focus on the writings of Robert N. Wennberg as a paradigm case by, first, stating his views of personal identity, humanness, personhood, and the relations among them; second, offering a comparison of a view of humans as substances (understood in the classic interpretation of Aristotle and Aquinas) vs. a view of humans as property-things; third, applying the metaphysical distinctions surfaced in the second section towards a critique of Wennberg.

During the last decade, there has been a growing body of literature about the ethics of abortion, infanticide, euthanasia, and suicide. In spite of the claims of philosophers like John Rawis and Kai Nielsen, who assert that ethics can and ought to be done without metaphysics, the central issues emerging in this body of literature involve, crucially and essentially, a treatment of metaphysical themes-the nature of being human, personhood, and personal identity. Ultimately, these themes will turn on what I take to be the most basic metaphysical question(s) lurking in the neighborhood: Are persons in general, and human persons in particular substances or property-things and how are we to understand personal identity in light of this distinction? Unfortunately, among ethicists who treat end-of-life issues there is a widespread trend of avoiding serious metaphysical analysis in conjunction with these issues. Often, what follows are not conclusions purged of metaphysics, but rather, conclusions guided by an inadequate metaphysical perspective implicit (or supposedly implicit) in natural science.

In what follows, then, I want to illustrate the importance of the metaphysical question(s) cited above for the ethics of life and death and to show, as clearly as possible, just how one’s answer to it will affect one’s overall position about the ethical matters involved. I also wish to clarify and criticize the widely accepted metaphysical viewpoint on these matters just mentioned. To do this, I will focus on an important discussion of end-of-life ethics by Robert N. Wennberg.¹ I choose Wennberg as a paradigm case because, in my view, he exemplifies some of the unfortunate tendencies listed above. Moreover, his work is substantive and important in its own right and he is a Christian thinker who tries to relate personhood to the notion of the image of God.

In what follows, I will, first, state my understanding of his views of humanness, personhood, and personal identity. Next, the differences between a substance and a property-thing will be spelled out, followed by a critique of Wennberg’s position. Of my two goals-making explicit the metaphysical issues involved in the line of thought to be examined and criticizing that line of thought-the former is more pressing than the latter due to the widespread neglect, mentioned earlier, of detailed metaphysical analysis as part of ethical reflection on end-of-life issues. If I can make certain neglected metaphysical issues clear in this context, especially issues in the metaphysics of substance, the relationship between personhood and humanness, and the importance of the soul for grounding biological functioning and giving unity to the body and making it human, then I trust that more metaphysical critique will be forthcoming. In light of this, there will be times that I will content myself with mentioning a line of argument without developing it in detail. Let us begin in earnest, then, and see what Wennberg tells us about personhood, personal identity, and being human.

Wennberg on Personhood, Personal Identity, and Being Human

Among other things, Wennberg is concerned with ethical issues involved in terminal choices regarding permanently unconscious patients. He summarizes his own view in this way:

I argued that what is of special value about human life is personal consciousness, which makes it possible for the individual to participate in God’s creative and redemptive purposes for human beings; biological human life is valuable because it sustains and makes possible personal consciousness, but where there is only biological or somatic human life, that special value no longer attaches to the individual, and biological or somatic death may be allowed to proceed unimpeded.²

We can break this thesis down into three important sub-theses:

1. Personal identity. Though he does not explicitly say so, Wennberg’s view of personal identity would seem to be an echo of the view of John Locke.³ For one thing, Wennberg takes a substance to be a propertyless substratum and that was Locke’s view.⁴ Further, Wennberg says that "When an individual becomes permanently unconscious, the person has passed out of existence, even if biological life continues. There cannot be a person where there is neither the capacity for having mental states nor even the potentiality for developing that capacity."⁵ Elsewhere he says that "psychic life is what is essentially significant about human beings."⁶ It becomes clear that personal identity is constituted by continuity of consciousness or the developed capacity of consciousness, e.g., of personality, agency, memory, purposeful action, social interaction, sentience, thought, will, and emotional states. This leads Wennberg to define the image of God as the actual or potential capability of "engaging in acts of intellect, emotion, and will" and of participating "in God’s creative and redemptive purposes for human life ."⁷ To be in the image of God is to be a human person and that image is conferred on those with the capacity for personhood.⁸ On this view, death is the total and irreversible loss of these capacities. When these are gone, personhood itself is gone and the person has ceased to exist.

Finally, when it comes to the unity of a person at a time, Wennberg approvingly cited Paul Churchland’s claim that "it is the maturing of the nervous system that more than anything else renders the fetal organism a unity and not a collection of cells." As we will see later, Wennberg’s statements lead to a rejection of absolute personal identity through change and unity at a time and persons turn out to be property-things.

2. Humanness.

Humanness itself is merely a biological notion. To be a human is simply to have "human or ganic life" or "biological human life" and be a "human biological organism."¹⁰ Wennberg explicitly claims that to be a human is merely to fall under a biological classification, viz. Homo sapiens.¹¹ Thus, biology (and, perhaps, chemistry and physics) exhaust what it is to be human.

Wennberg’s views about being human, contrary to what he claims elsewhere, represent a clear departure from the traditional Christian view which takes being human to go beyond mere biological description and to include theological and philosophical aspects as well. In any case, this is Wennberg’s position and in this regard it bears a family resemblance to a frequently asserted train of thought that goes something like this:¹² The best, perhaps only way to justify the belief that all humans have equal and unique value simply as such is in light of the metaphysical grounding of the Judeo-Christian doctrine of the image of God. Such a view depicts humans as substances a human nature and for at least two reasons, that framework must be abandoned. For one thing, the progress of science has regularly shifted entities (e.g., heat) from the category of substance to the category of quality, relation, or quantity. Thus, there most likely is no such thing as a human nature, and talk of such should be understood solely within the categories of biology, chemistry, and physics and with a view of humans as property-things.

Second, Darwin’s theory of evolution has made belief in human nature, though logically possible, nevertheless, quite implausible. As E. Mayr has said:

The concepts of unchanging essences and of complete discontinuities between every eidos (type) and all others make genuine evolutionary thinking impossible. I agree with those who claim that the essentialist philosophies of Aristotle and Plato are incompatible with evolutionary thinking.¹³

This belief has, in turn, lead thinkers like David Hull to make the following observation:

The implications of moving species from the metaphysical category that can appropriately be characterized in terms of ‘natures’ to a category for which such characterizations are inappropriate are extensive and fundamental. If species evolve in anything like the way that Darwin thought they did, then they cannot possibly have the sort of natures that traditional philosophers claimed they did. If species in general lack natures, then so does Homo sapiens as a biological species. If Homo sapiens lacks a nature, then no reference to biology can be made to support one’s claims about human nature.’ Perhaps all people are ‘persons,’ share the same ‘personhood,’ etc., but such claims must be explicated and defended with no reference to biology. Because so many moral, ethical, and political theories depend on some notion or other of human nature, Darwin’s theory brought into question all these theories. The implications are not entailments. One can always dissociate ‘Homo sapiens‘ from ‘human being,’ but the result is a much less plausible position.¹⁴ 

Finally, this observation has lead a number of thinkers to claim that the traditional sanctity of life view of human beings is guilty of speciesism and to settle on personhood and not simply on being human, as constituting our locus of value.

I am not claiming that Wennberg agrees with this entire line of thought, though his views do coincide at crucial points with much of it. My purpose here has been to locate his position about personhood in a broader intellectual context that will prove helpful when we turn to a critique of this notion of humanness.

3. Personhood itself.

For Wennberg, the paradigm case of a person is an adult human being, i.e., a creature with the developed capacities to think, will, feel, and have agency.15 Both the soul and personhood are properties (or sets of properties and the capacities for them) that supervene upon human biological life. It is possible to be a human non-person when psychic death occurs and there is irreversible loss of the capacities of consciousness cited above. In cases like this, there is a human present because human biological life continues, but the person has ceased to be. In general, being human is neither necessary nor sufficient for personhood.¹⁶

I have suggested that we understand Wennberg to mean that personhood supervenes upon a biological human life that is capable of sustaining psychic functioning. An example may help to clarify what is meant here. Wetness is an emergent or supervenient property that arises when water molecules are structured in a certain way. If we boil water, then although we still have water molecules themselves in the form of a gas, we can no longer have wetness because this property supervenes upon a specific structured arrangement of water molecules sufficient for its emergence.

There are different understandings of supervenience.17 However, a generally accepted understanding of it for properties runs as follows: Property P supervenes on property Q just in case 1) P and Q are completely distinct properties in that neither P nor Q enters into the very being or constitution of the other; 2) P is ontologically dependent on and determined by Q; 3) the relation between P and Q is non-reductive; 4) For any possible world in which some entity x exists, if x has Q that is sufficient for its having P; there cannot be two entities alike in having Q but differing with respect to P. An entity cannot change in respect to P, cease to be P, or become more or less P without changing in respect to Q. For Wennberg, the supervenience relation obtains between personhood (the properties and capacities of consciousness) and being a certain functionally structured biological human. If a biological human is structured in a certain way so as to sustain personhood, then personhood supervenes. However, if the biological human becomes structured in a different, dysfunctional way, then even though it would still be a biological human, personhood would disappear. No change can occur at the personhood level (e.g., from the presence to the absence of personhood) unless there is a change-of a certain sort at the level of humanness (e.g., from a functional human to a dysfunctional biological human). Personhood supervenes upon a properly structured, functioning brain.¹⁸

Thus, personhood is a supervenient property for Wennberg.¹⁹ Moreover, he claims that there are such things as potential persons. He also says that personhood can be possessed to a greater and greater degree as someone develops until a point is reached where it is fully possessed. 20 This means that personhood is also a degreed property with an intrinsic maximum. Some properties (e.g. oakness, being even) are non-degreed because they are either exemplified fully or not. Other properties are degreed because they can be qualified as being more or less. Some degreed properties do not have an upper limit or intrinsic maximum. The property of having weight or size would be an example. Other degreed properties do have intrinsic maxima, e.g., being cloudy. These properties can increase (or decrease) until a limit is reached beyond which no further increase is possible.

Substances vs. Property-things

At this point it will be helpful to step back for a moment and compare two different metaphysical positions about two very different kinds of wholes with parts: substances, understood in the classic interpretation of Aristotle and Aquinas, vs. property-things or ordered aggregates.²¹

Living organisms are paradigm cases of substances according to the tradi- tional view. A substance is a thing which has or owns properties but is not had by something more basic than it. Second, a substance is a deep unity at a point in time of parts, properties, and capacities, and it maintains absolute sameness through (accidental) change. Substances are wholes that are ontologically prior to their parts in that those parts are what they are in virtue of what the substance is, taken as a whole. A chamber of a heart is defined in terms of the heart as a whole, the heart is defined in terms of the circulation system as a whole and that system is defined in terms of the organism as a whole. Third, a substance is a this-such, i.e. an individuated member of its natural kind which, in turn, constitutes its essence. For example, two dogs are different particular animals with the same nature. The unity and nature of a substance derives from its essence that lies within it, and its parts (e.g., the nose and claws of a dog) stand in internal relations to each other in that if a part is removed from its whole, it looses its identity with itself. As Aristotle said, a severed human hand is, strictly speaking, no longer human, a fact that will become evident in a few days.

An artifact like a table or automobile is a paradigm case of a property-thing. Property-things derive their unity from an external ordering principle (either in the mind of a designer or from a law of nature) that is imposed from the outside on a set of parts to form the object. A property-thing is structured stuff, i.e., parts placed in some type of ordering relation. In such wholes, the parts are prior to the whole, the whole contains some sort of structural property that supervenes upon those parts (it is defined in terms of the parts and the ordering relation), the parts are related to each other by means of external relations, they remain identical to themselves regardless of whether or not they are in the whole property-thing (e.g., a car door is still what it is when detached from a car), and property-things do not maintain strict identity through loss of old parts or properties and gain of new ones. There are two other features of the traditional view of substance that are crucial to our topic. As was mentioned above, substances are a unity of capacities. Now, capacities come in hierarchies. There are first-order capacities, second-order capacities to have these first-order capacities, and so on, until ultimate capacities are reached. For example, if! can speak English but not Russian, then I have the first-order capacity for English as well as the second-order capacity to have this first-order capacity (which I have already developed). I also have the second-order capacity to have the capacity to speak Russian, but I lack the first-order capacity to do so.

Higher order capacities are realized by the development of lower order capacities under them. An acorn has the ultimate capacity to draw nourishment from the soil, but this can be actualized and unfolded only by developing the lower capacity to have a root system, then developing the still lower capacities of the root system, and so on. When a substance has a defect (e.g., a child is color blind), it does not loose its ultimate capacities. Rather, is lacks some lower order capacity it needs for the ultimate capacity to be developed.

A substance’s capacities culminate in a set of its ultimate capacities that are possessed by it solely in virtue of the substance belonging to its natural kind, e.g., Smith’s ultimate capacities are his because he belongs to the natural kind "being human." A substance’s inner nature is its ordered structural unity of ultimate capacities. A substance cannot change in its ultimate capacities; that is, it cannot loose its ultimate nature and continue to exist. Smith may replace his skin color from exposure to the sun and still exist, but if he looses his humanness, his inner nature of ultimate capacities that constitutes being human, then Smith ceases to exist. As we will see later, the fact that substances contain a hierarchy of capacities makes ambiguous the notion that a human being has lost such and such a capacity.

Finally, sometimes properties relate to each other as a genus does to a species. Here are some genus/species relationships: being a color/being red; being a shape/being square; and, according to the traditional view, being a person/being a human. The species is a way by which the genus exists. Being red, square, or human are ways that being colored, shaped, or being a person exist in individual things.

There can be colored things that are not red things, but there cannot be red things that are not colored things. Similarly, there can be persons that are not humans (Martians, angels), but there are no humans that are not persons. In fact, there is no such thing as a colored thing or person plain and simply. There are only kinds of colored things (e.g. red things) and kinds of persons (e.g., divine, human, angelic). Thus, in the classic doctrine of substance, there are no such things as human non-persons (e.g., defective newborns, permanent vegetative state or PVS patients). Given these points about the ultimate capacities 2and inner natures of substances and the notion that personhood is a genus,²² and without claiming to give a fully adequate definition of a person, we can, nevertheless, offer this general characterization: A person is a certain kind of living entity that has a certain fairly standard set of ultimate capacities (e.g., intellectual, volitional) that constitute its inner nature the way a genus constitutes the nature of a species. From what has been said, it seems clear that Wennberg’s understanding of individual human beings, in a way reminiscent of Locke, is one that depicts them as property things qua persons irrespective of what we would say of them qua human.

Before turning to a critique of Wennberg’s position, it may be helpful to state and briefly sketch out a general response to two closely related objections to the view that living organisms like humans are substances. First, it could be argued that this view is just a form of biological vitalism and vitalism has been uniformly and justifiably rejected by modern biologists. Second, the substance view, with its notion of a single, underlying, unifying essence is inconsistent with certain empirical facts, e.g., various cases of fission such as identical twins or organisms that can have a piece broken off to form a whole new organism.

The short answer to these problems is this: the classic doctrine of substance is an intellectual response to a set of distinctively metaphysical issues that are relatively independent of (and arguably conceptually prior to) and not in competition with most of the more empirical, scientific issues associated with living organisms. This point can be expanded to address the two objections just cited.

Consider first the problem of vitalism. The debate about vitalism has been misunderstood frequently since the concepts of that debate have been used in many different ways. For example, during its zenith as a scientific research program, there were at least five distinct forms of vitalism.23 The more crude forms of vitalism have rightly been rejected because of their tendency to depict the individuated essence as either a spatially located vital entity, a force, or a fluid (like caloric or phlogiston) that was viewed as a mechanistic entity alongside other mechanical parts. The effect of this strategy was actually to reduce the living organism to a special sort of property-thing and it was used as a quick and easy solution that closed enquiry.

A more adequate vitalism, if we wish to use this term of the substance view, grounds the doctrine of substance in factors like the irreducible organic, holistic relation among parts to parts and parts to whole (and vice versa), the species specific immanent law of organization and development, and the internal structural form and functioning found in living things. Such a position does not eschew the methodological use of a machine metaphor as a means of answering how questions about organisms as long as this is not taken to reduce those organisms to mere heaps or property-things.

Regarding fission cases, the notions of substance and essence are grounds of and not replacements for the a posteriori, scientific search for more detailed species specific principles of individuation. There is no a priori way to read off from the abstract notion of a thing’s essence the precise nature of the immanent laws that constitute it. If we assume a Traducian view of generation or focus on cases like mitosis, identical twins, or starfish-type fissions, we simply discover as a brute fact that certain substances, once they have developed a structure adequate to provide a framework for part replacement or for generating new substances, have the capacities in question. Nothing whatsoever in the notion of substance provides a bar to these realities.

It may be claimed that my response here is ad hoc, but such an assertion would be wide of the mark for the following reason. My treatment of fission cases is not an adjustment of the substance view but a natural outgrowth of it. The substance position allows for all sorts of empirical possibilities and merely grounds the empirical investigations rather than trying to answer them in advance. However, as I will argue later, what does seem ad hoc is the claim by advocates of the property-thing view that personhood supervenes upon a properly structured, functioning human brain. This is ad hoc because
neither the nature of personhood itself, nor the fact of supervenience follows naturally from nor is verifiable by any detailed advance in knowledge of the physical aspects of the brain (or body) considered solely at that level of description. More could be said about these matters, but I want to set them aside and turn to a critique of Wennberg’s position.

A Critique of Wennberg’s View

1. Problems with personal identity.

Wennberg’s view of persons implies that they do not maintain absolute identity through change or absolute unity at a time. This is due to his apparent advocacy of some version of the memory view of personal identity (where this is taken to cover any view of personal identity constituted by continuity of consciousness or a low order capacity for it) and his view of persons as property-things. Because of space limitations and the massiveness of this topic, I can only gesture at a few points here. But I hope to make clear what is at stake in Wennberg’s view.

First, based on common sense intuitions, counter examples exist to the effect that continuity of consciousness is neither necessary nor sufficient for personal identity. Surely, it is logically possible that two persons could have all and only the same memories, character traits, etc., and that a person could still sustain personal identity even if a total loss of memory, etc. were to obtain. Further, fear of the future and punishment for past deeds would seem to presuppose absolute personal identity. A denial of absolute personal identity appears to require a radical revision of our basic intuitions about future fear and punishment, e.g., what we fear is the failure of our present projects to be fulfilled, we punish merely to deter, rehabilitate, or protect society. I know my terse remarks here do not settle this issue, but one ought to think long and hard before abandoning the insights about personal identity gained from reflection on these problems. Of course, these intuitions can be called question-begging or simply denied. But I don’t think they can be dismissed that easily. We are owed some account of why they have such prima fade plausibility and, apart from the claim that our concept of personhood is conventional and arbitrary — which I deny and I suspect Wennberg does too — I know of no such account that does justice to the power of these intuitions apart from the view that personal identity is absolute.

This leads to a second point. Our knowledge that we are first person substantial, unified, enduring selves that have bodies and mental states but are not identical to them is grounded in our own awareness of ourselves. It is hard to see what kind of knowledge could be more certain than this and what better example of unity there could be than my awareness that Jam only one self at a time, an enduring self through time, and that I am the owner of my mental states, Experiences like listening to a song present themselves,
phenomenologically speaking, as experiences had by an enduring substantial self and not as a stream of person stages constituted my consciousness or actual first order capacities that can come and go. I experience myself as the same I that simultaneously has different mental states and I experience myself to be the substantial owner of those states and not as a collection of them or as something predicated of a more basic entity. These features of first person awareness are hard to square with Wennberg’s claims that the brain is the center of mental functioning (as opposed to being causally related to my substantial self which is the true center of mental functioning) and that I have the type of unity possessed by a property-thing due to the fact that my unity "emerges" upon a mature nervous system.

Third, as I have argued elsewhere, human action (e.g., thinking through a syllogism and drawing a conclusion, carrying out an intention) seems to require a unified, enduring self to be possible. I cannot develop the argument here. But if this is correct, then moral acts require an enduring self, which, it could be arued, would seem to require as a necessary condition, an enduring essence.²⁵

Furthermore, William Rowe and others have claimed, correctly in my view, that libertarian freedom and agency have a substance view of the self as a necessary condition.²⁶ If libertarian freedom is a necessary condition for moral responsibility, then a substantial self is necessary for morally responsible action. Wennberg’s view of the self as a property thing, then, is hard to square with moral responsibility if, in fact, libertarian freedom is a necessary condition.

In addition, it is worth mentioning in this context that advocates of the supervenience view of personhood have difficulty avoiding an epiphenomenal view of the mental. The two main desiderata of the supervenience treatment of the mental are to advocate non-reductive physicalism and the dependency of the mental on the physical. This latter goal is an expression of the idea that the physical is basic and causally closed. Taken together, these two goals are hard to sustain simultaneously so as to avoid turning the mental into epiphenomena. If the mental are reduced to the physical, then the mental can be causally efficacious, but this violates desideratum one. On the other hand, if this reduction is denied in the interests of supervenience, then there is no room for "top-down" causation due to the second desideratum and the closed causality of the physical.

I am not claiming to have demonstrated here that absolute personal identity through change and libertarian freedom are necessary conditions for morally responsible action, nor have I demonstrated that these necessary conditions require a substance view of the self and are incompatible with the self as a property-thing or the supervenience view of personhood. I am merely pointing to a widely recognized connection among these notions.

In addition, if this connection is correct, as I believe it to be, then it serves as an undercutting defeater for Wennberg’s position in this way.²⁷ Wennberg begins by focusing on what are and are not our morally responsible actions regarding certain end-of-life issues. His reflections lead him to a view of personal identity (a person is a property-thing and persons are series of events with temporal parts) that are inconsistent (so I claim) with the necessary conditions of morally responsible actions themselves (a substantial self to ground absolute personal identity through change and libertarian freedom and agency). This generates a skeptical situation in which his own views of personal identity serve as undercutting defeaters of the very thing (morally responsible action) his views were formulated to explain. Again, Wennberg can escape this problem by claiming that the necessary conditions cited are not, in fact, necessary at all. I cannot enter into that dialogue here, but I hope that I have placed Wennberg’s views in a broad, metaphysical context and clarified what his position seems to imply.

Finally, it would seem that personal identity in a disembodied state would be problematic for Wennberg’s view. For one thing, what if two disembodied persons had the very same psychological traits? Which one would be I? Second, his view of personal identity would seem to imply that persons essentially have temporal parts. But this means, among other things, that 1) someone could not have been born at a time other than that person’s actual birth, and 2) a person could not cease to be at one moment and come to be at a later time.

Both of these possibilities are ruled out by Wennberg’s views of personal identity because they entail what Wennberg’s position denies, namely, that temporal parts are not necessary constituents of persons. But 1 see no difficulty in conceiving a possible world in which I was born at a different time than that of my actual birth. And biblical teaching would seem to affirm that I myself will exist in an afterlife.

Wennberg agrees with this teaching, but I can see only two ways he might try to allow for it.²⁸ It may be that the person goes out of existence when he or she becomes a PVS patient and God recreates that person ex nihilo in the afterlife. But, as I just pointed out, this option is not available for Wennberg. On the other hand, God may simply preserve a specific set of personhood properties or series of person stages into the afterlife. Consider personhood properties first. This suffers from the fact that a specific set of properties can be exemplified by more than one object. Pure properties do not individuate and cannot be sufficient for personal identity. A person is a substance with properties, not a set of properties. The person stage option suffers from the standard difficulties with denials of absolute personal identity. In this context, it means that a Doppelganger survives in the afterlife and not I myself.

Finally, as we have just seen, Wennberg’s views imply that for PVS patients (where no person is present), a person existed before the PVS state, went out of existence during the PVS state, and is recreated ex nihilo in heaven. But apart from problems of personal identity cited above, it just seems more natural to say that during the PVS state, the person is still present though in a severely defective state and that in the afterlife, God does not recreate the person or continue a series of events, but merely restores some lost lower order capacities to the very same person who existed before the PVS state.

2. Personhood and the personhood/humanness relation.

It is well known that detailed, widely shared criteria for personhood are hard to come by. We have a general notion of some traits of persons, but our ability to recognize persons is not dependent upon noting that some entity satisfies a cluster of supervenient properties or capacities. I suggest it is much more natural to view the personhood/humanness relation in light of a metaphysical pattern widely exemplified in reality, namely, as a genus/species relation.²⁹ This would explain how there could be non-human persons just as there can be non-red colored things, without having to hold the controversial thesis that there could be humans that are not persons. Metaphysically speaking, the relation between personhood and humanness is more intimate than is allowed if the relation is taken to be a supervenience one. Personhood and humanness are different entities, but personhood enters into the very being of humanness — humanness is a way personhood can exist — and humanness is metaphysically dependent upon personhood as a species is dependent upon its genus, not the other way around.

Moreover, the supervenience view implies that the coming-to-be and ceasing-to-be of a person is not the same event as the birth and death of the human. That is, my coming to be took place after the formation of the human which was to become me and my ceasing to be antedated the death of the human that was me. As I-I. Tristram Engelhardt notes, this view implies that "one is, or should be, concerned with determining when in human ontogeny humans become persons."³⁰ But apart from the arbitrariness and opacity of such judgements and the bizarre implications that follow from it (I myself was not conceived at intercourse or carried in my mother’s body but, rather, I came into existence sometime before a functioning human body became two years old), this flies in the face of clear Biblical passages that identify the person himself, and not a non-identical precursor, with the entity in the womb (cf. Psalm 139:13-15, Jeremiah 1:5, Luke 1:41).

Further, if we take the relation between personhood and humanness to be one of supervenience, then personhood becomes ontologically dependent upon humanness. This means that it is metaphysically impossible for disembodied existence to obtain if humanness is understood in Wennberg’s sense as biological human life. But Scripture seems to teach a disembodied intermediate state in which human persons exist even though they have no organic, biological life. Even if someone does not think this is the correct way to understand Scripture (and this would be hard to sustain exegetically), surely such a view is at least possible. But if Wennberg is right, disembodied existence (at least for human persons) must be judged metaphysically impossible, and this is a strong position indeed. Moreover, the genus/species view explains how non-human persons like God or angels could obtain (as Wennberg himself admits), but the supervenience view makes this possibility unintelligible due to its rendering of personhood ontologically dependent on a properly functioning human brain.

Of course, it could be argued that it is only human personhood that requires a properly functioning brain for its supervenience, and not divine or angelic personhood. But, apart from the fact that this seems a bit ad hoc, it also threatens to divide the unity of the class of persons. That unity is grounded in a univocal sense of personhood true of each member of the class. But if one embraces different notions of personhood itself, it will be hard to have a unified class of persons. Why? Because this would entail the idea that there is a human personhood (which requires a functioning brain) and a non-human personhood (which has no such requirement) without utilizing the standard genus/species model to explicate this. It preserves the unity of the class of persons to treat personhood as a genus with humanness as one of its specific differentia. And such a view explains the differences between humans and other types of persons by means of the species, not the genus. If there is more than one genus of personhood, then the unity of the class of persons is lost and an equivocal notion of "personhood" is used of humans and other "persons."

There is another difficulty with taking personhood to be a property that supervenes on a properly functioning brain. In every case I can think of in science, when one thing is said to supervene upon another, we can tell that the supervenient property is there by inspecting the subvenient entity. This, in turn, implies that we are able to be aware of the two entities that stand in the supervenience relation, even if we do not have exhaustive knowledge of either. For example, we are able to inspect water itself to see if it has wetness and we are aware of the distinction between water and the wetness that supervenes upon it.³¹

But such is not the case for personhood and the human brain. In fact, I myself do not believe that thoughts, sensations, agency, etc. are "in" the brain in any interesting sense of the word. To be sure, there is a causal connection between mental and brain phenomena, but the same could be said for mental and other bodily phenomena.

But regardless of this point, no amount of inspection of the brain can establish the emergence of personhood upon it. And if we take the phenomenological data of first person introspection seriously, then we are not aware of any aspect of the brain 1) existing or 2) being the subject of predication (or supervenience) for states of personhood or 3) being the center of mental functioning and unifier of the person as Wennberg claims. Thus, personhood fails to fit the pattern true of other examples of supervenience in science and for that reason I suggest we abandon the supervenience model of personhood.

3. The nature of a capacity.

Another problem is that Wennberg fails to have a sufficient understanding of the nature of a capacity and, thus, he does not take into account the ambiguity in what it means to say a person has, does not have, or has lost such and such a capacity. I now have the capacity to speak English but not Russian. I use to have the capacity to do differential equations but, alas, I no longer possess that capacity. The kind of capacities in view here are first order capacities. I do not have the first order capacity to speak Russian or do differential equations, but I do have the second order capacity to develop these capacities. Thus, the absence of a lower order capacity says nothing about the absence or presence of a higher order capacity. In fact, as already pointed out, a higher order capacity unfolds and develops by a process of realization in which lower order capacities under it are cultivated in lawlike ways grounded in a thing’s inner nature.

Moreover, a defect merely signals the loss of a lower order capacity, not the absence of a thing’s ultimate capacities that make up its nature. A defect is the absence of a lower order capacity that blocks the development of a higher order one. When a metal bar is heated, it looses the first order capacity to reflect certain kinds of light, but not the higher capacity to have that first order capacity as becomes obvious when the metal cools. Note, even if a lower order capacity is irreversibly lost, that by itself does not mean the higher order ones are gone. Ultimate capacities are developed through the cultivation of lower order capacities that realize the ultimate ones, and defects do not signal the non-existence of ultimate capacities, but merely the failure of those capacities to be realizable in the appropriate ways.

Consider again a PVS patient. The absence of certain capacities should be understood as the absence of first order capacities, not ultimate capacities, even if such loss is irreversible in the bodily state. Why? Because this way of understanding fits the pattern of substances in general and it implies that in the afterlife God merely restores lower capacities to enduring persons, rather that recreating the person ex nihilo.

This distinction between higher and lower order capacities serves another purpose as well. There are two things about first order capacities that are troublesome from a moral point of view. First, we do not have them when we sleep. During sleep, I do not exemplify or have certain first order capacities of consciousness. I must first awaken (I still have the capacity to be awake while sleeping), and then I can, say, exercise the capacity to make certain volitional choices.

Second, our various capacities to participate in God’s creative and redemptive purposes, which Wennberg claims constitute our personhood, are degreed properties that can be quantified in greater or smaller degrees and that do not appear to have (at least finite) intrinsic maxima. We do not all have the same capacity for thought, volition, etc. Now we do not want to say that a person ceases to exist and has no moral status while sleeping, nor do we want to say that equal rights for all persons is impossible because we do not all have pcrsonhood (understood as the possession of degreed properties or capacities without intrinsic maxima) to the same degree.

The best way to avoid these implications is to appeal to the continued possession of higher order capacities in the absence of lower order ones. But once this is done, two things seem to follow. For one thing, it is recognized that the absence of a first order capacity, permanent or otherwise, does not signal the loss of higher order ones. In addition, such an appeal implicitly utilizes the notion of the continued possession of human personhood as the inner nature of the individual in question. Thus, PVS patients may not have first order capacities, but they still have higher order ones in virtue of the continued presence of their inner nature and this is what makes them human persons.

Wennberg fails to take this possibility into account and this failure is curious in light of something he says elsewhere.³² He claims that personhood grows as a child develops until it is fully a person. But he goes on to say that the person continues to develop beyond this point. Now just what is it that continues to develop? If it is the properties that constitute personhood, how can we say that the child is fully a person? The problem here is that personhood turns out to be a degreed property without an intrinsic maximum and, thus, it cannot be exemplified to a complete degree. On the other hand, Wennberg may be thinking that when the properties of personhood are fully present then other properties emerge and begin to develop. But this move implicitly utilizes the notion of higher and lower order capacities such that some cannot obtain until others have been developed. If Wennberg uses that move in one case, why can we not use it in the case of PVS patients?

4. Being human is not merely biological.

Finally, I think that Wennberg’s view of being human is too Cartesian to do justice to a Christian theology of the body and an appropriate metaphysical treatment of it. Put briefly, his view of the human person is Cartesian in the sense that personhood and personal identity are too closely tied to the mental. As is well known, the Cartesian view cannot adequately allow for or explain the humanness of the body with its species specific set of properties and the substantial unity it possesses.

In my view, a more adequate position is the classic view of Aristotle and Aquinas in which the soul is the ground, not only of mental functioning, but also of biological processes. While I cannot develop the argument here, I take the classic view to be superior to the Cartesian position in two ways. First, it is more consistent with Biblical teaching that the body is irreducibly human (cf. I Co 15: 35-49). Second, it more adequately accounts for the specific type of unity that the human body has due to its depiction of the human being as a substance and not as a property thing. If the soul is, indeed, the ground of biological functioning, and if the human person is identical to his substantial soul, then if the human body is still functioning biologically as a unit, then the human person is still present irrespective of the presence or absence of first order mental capacities.

Wennberg and those of his persuasion may not agree with this view, but the virtual absence of taking into consideration the Aristotelean/Thomistic position is, in my view, inexcusable because that position is both defensible and clearly relevant to the issues at hand. For example, the Cartesian perspective will tend to support some sort of brain criterion of death while the Aristotelean/Thomist view will see the brain as just another bodily organ and favor a criterion focusing on the permanent cessation of functioning of the organism taken as a whole.

In conclusion, my critique of Wennberg has been a brief attempt to show that no sufficient reason has been given by him for his views about personhood, humanness, and personal identity. If I am right about this and about the issues related to it, more is going on here than PVS patients and the ethics of terminal choices.³³ Of fundamental significance is the importance for ethics of metaphysics in general, of being clear about the connection between ethical views and certain metaphysical positions, and of seeing the inadequacy of utilizing a metaphysical picture embedded in scientific explications of these three themes.³⁴

Notes

1. Robert N. Wennberg, Terminal Choices: Euthanasia, Suicide, and the Right to Die (Grand Rapids, MI: Eerdmans, 1989); Life in the Balance (Grand Rapids, Ml: Eerdmans, 1985).

2. Wennberg, Terminal Choices, p. 176.

3. See John Locke, "Of Identity and Diversity," chapter 27, Book II of An Essay Concerning Human Understanding. Though Locke was somewhat inconsistent, the standard way to understand him is note that he distinguished the identity of being a man (human) which consists in the continuity of a living organized body, from the identity of a person which consists in the "continuity" of consciousness and psychological traits, especially memory. It is important to note that, for Locke, continuity of a person is not continuity of a substance that has consciousness, but of consciousness itself.

4. Wennberg, Life, p. 49.

5. Wennberg, Terminal Choices, p. 159.

6. Ibid., p. 160. Cf. Life, pp. 31-46.

7. Wennberg, Terminal Choices, pp. 171 and 159, respectively.

8. Wennberg, Life, pp. 36, 39-40, 52.

9. Wennberg, Life, p. 29.

10. Wennberg, Terminal Choices, pp. 159, 168.

11. Wennberg, Life, pp. 27, 28, 34, 124-25. On page 124 Wennberg falsely implies that traditional sanctity of life advocates identify being human with falling under the biological classification Homo sapiens. But this is not so because traditionalists view humanness as a theological and metaphysical notion that goes beyond biology.

12. See Helga Kuhse, Peter Singer, Should the Baby Live? (Oxford: Oxford University Press, 1985). pp. 118-139; James Rachels, Created From Animals (Oxford: Oxford University Press, 1990).

13. E. Mayr, Populations, Species, and Evolution (Cambridge, MA: Harvard University Press, 1970), p.4.

14. David Hull, The Metaphysics of Evolution (Albany: State University of New York, 1989), pp. 74-75.

15. Wennberg, Life, pp. 33, 36, 42, 127.

16. Wennberg, Terminal Choices, pp. 159, 161, 163, 165, 169; Life, pp. 43-44, 117-19, 130.

17. See J. Kim, "Supervenience," in Handbook of Metaphysics and Ontology, ed. by Hans Burkhardt, Barry Smith (Munich: Philosophia Verlag, 1991): II, pp. 877-879.

18. Wennberg, Life, pp. 30. 39.

19. Wennberg, Life, pp. 66, 117-18, 136, 170-71.

20. Unfortunately, some things Wennberg says seem to conflict with this. See Life, p. 118.

21. For more on this see Richard Connell, Substance and Modern Science (Notre Dame: University of Notre Dame Press, 1988).

22. If personhood is a genus, we should call this property the property of personhood and not the property of being a person. This latter locution turns this property into an impure one, i.e., into a property whose description necessarily includes reference to a particular. Such descriptions, in my view, are circular. Moreover, they do not solve the problem of individuation since there seem to be two features of all properties: they can be exemplified and they are universals. The property of being a person fits the former but not the latter, and rather than concluding that this property is simply part of an interesting subclass of properties that individuate, I would rather go with the general pattern and deny that there is such a property, especially given the circular nature of impure properties. This insight would save some philosophers, e.g., Geoffrey Madell, from having to claim that the I, taken as the property of being a person and not as a substance, is something that, like redness, can be exemplified. Whatever else one wants to say about the I, it doesn’t seem to be exemplifiable. See Geoffrey Madell, The Identity of the Self (Edinburgh: The University Press, 1981), pp. 134-38. For more on impure properties, see J. P. Moreland, "How To Be A Nominalist in Realist Clothing," Grazer Phiiosophische Studien 39 (1991): 75-101.

23. Thomas S. Hall, Ideas of Life and Matter (Chicago: University of Chicago Press, 1969), pp. 285-87. Cf. Maurice Merleau-Ponty, The Structure of Behavior (Boston: Beacon Press, 1963), pp. 145-60; Etienne Gilson, From Aristotle to Darwin and Back Again (Notre Dame: University of Notre Dame Press, 1984), chapters 1, 2, and 5.

24. For more on this, see J. P. Moreland, "An Enduring Self: The Achilles’ Heel of Process Philosophy," Process Studies 17 (Fall 1988): 193-99.

25. This is argued rigorously in David Wiggins, Sameness and Substance (Cambridge, MA: Harvard University Press, 1980).

26. William Rowe, "Responsibility, Agent-Causation, and Freedom: An Eighteenth-Century View," Ethics 101 (January 1991): 237-57. There are three broad options one can take here: deny that agents are immaterial substances and still affirm libertarian freedom as Peter van Inwagen does, accept libertarian freedom and embrace a view of persons as (at least) immaterial substances, or deny that agents are immaterial substance and embrace compatibilism. I think option two is the most reasonable but, in any case, Wennberg would seem to be limited to one and three.

27. For a similar point regarding evolutionary naturalism, see Alvin Plantinga, Warrant and Proper Function (Oxford: Oxford University Press, 1993), chapters 11 and 12, especially pp. 229-37.

28. Wennberg, Life, pp. 46-51.

29. This same strategy has been employed by Panayot Butchvarov in treating the relationship between goodness and happiness or pleasure. He claims, correctly in my view, that this is a genus/species and not a supervenient relation. See Skepticism in Ethics (Bloomington, Indiana: Indiana University Press, 1989), pp. 59-66.

30. H. Tristram Engelhardt, Jr., The Foundations of Bioethics (New York: Oxford, 1986), p. 108.

31. l owe this point Dallas Willard.

32. See Wennberg, Life, p. 118.

33. For an alternative account of the ethics of termination and PVS patients, see Scott Rae, "Views of Human Nature at the Edges of Life: Personhood and Medical Ethics," in Christian Perspectives on Being Human, ed. by J. P. Moreland, David M. Ciocchi (Grand Rapids: Baker, 1993), pp. 235-56.

34. I wish to thank the following for their helpful comments on an earlier draft of this paper: R. Douglas Geivett, David M. Ciocchi, Stan Wallace, Stephen T. Davis, Philip L. Quinn, and Dallas Willard.