Christian theology has always seen human beings as having a special place in creation and in salvation history. God creates humans in His image, but humans subsequently fall into sin. Accounts of the extent to which the image of God was lost after the fall into sin differ, but most theological traditions affirm that some damage was done. As a result of this damage, humanity's relationship to God and his fellow men was broken. To redeem humans and remove them from their sinful state, God the Son becomes man, dies, and is resurrected. By this act of God, the broken relationship is again mended and by gradually becoming closer and closer to Christ humans can start to regain the imago Dei that was lost. Ultimately, humans will be united with God again at the end of the fallen creation. In the new creation, the saved will be united with God and they will again be full images of God in Christ. Such a narrative of creation‐Fall‐redemption‐fulfillment is, very roughly, the standard framework for Christian theological anthropology. Now, in the context of such a narrative, many Christian theologians have assumed that there is a specific component or capacity that humans have which grounds their being images of God. For the most part, this has been associated with having a soul and the capacities that it provides. Let us call such a view the structural view of the image of God, since it entails the existence of certain structural features that ground the imago Dei relationship.

In the last hundred years, the structural view of the image of God (henceforth, SID) has been challenged in many ways and most contemporary theologians have moved away from it (see also Vainio ). In what follows, I will examine some challenges to SID and argue that their significance has been largely overstated. Since a complete defense of the structural view is not possible in one article, I will focus on three specific challenges. The first challenge has to do with our view of how the mind works and how it relates to nature. More specifically, the claim is that in the time of neuroscience and evolutionary psychology, the idea of nonphysical souls is implausible. The second challenge is somewhat more theological in nature: that SID exemplifies disrespect for the material world and the body. The third challenge is related to the first: given a Darwinian view of species and human evolution, it seems that there is nothing uniquely human, nothing to distinguish us from animals the way in which the structural view entails. With the help of contemporary philosophical developments, the structural view—it will be argued—is able to withstand at least some of the criticisms leveled against it.

Traditional SID and Dualism

I will begin by giving an extremely crude and brief overview of the traditional SID and its links to mind/body dualism. I will be following Marc Cortez () and Wentzel van Huyssteen (). In SID, the image of God in humans can be seen as a kind of reflecting relation between God's nature and human nature. In other words, there is a certain kind of structural similarity between humans and God.

In what way, then, do humans reflect God? According to SID, humans reflect God in having certain kinds of mental capacities that are uniquely human. Traditionally, these capacities have been associated with rationality and intellect. Not only do these capacities make rational action possible, they also make it possible for humans to grasp abstract and universal truths and respond to the special revelation of God in the life of Christ. There are many ways to fill in the details (see Robinson ).

The uniquely human mental capacities are also the capacities that make human beings personal beings. It is the capacity for intellect or rationality and subsequent freedom that make humans more than animals, namely, persons with intrinsic value. The intrinsic value of the personal is grounded in God. God is a perfectly rational and free person and by virtue of the substantial and supernaturally endowed soul, human persons have capacities that are analogous of those of God. From this human uniqueness also follows: human persons, by virtue of their intellect and will, are unlike anything else in creation and are destined to relate to God in a special way. This also grounds the special dignity of human persons: not only does God love them, but they also participate in God's likeness via their souls. Finally, it is true that sin has corrupted some of the capacities of the soul (will and desire), but this does not mean that the imago Dei is completely lost. Again, the exact amount of corruption is a matter for theological debate, but it is clear that the image of God is somehow realized by our fallen human nature as well.

This description of SID is, of course, simplified to the extreme. But I do want to point out that mind/body dualism does a lot of work here. First, it identifies a similarity between God and humans. This similarity is being a person, which is in turn grounded in mental functioning. It runs personhood and the mental together to make sense of the personality of God and humans. Second, it distinguishes humans from other animals by identifying a set of capacities that nonhuman beings seem to lack. This neatly makes sense of the fact that the image of God is something uniquely human. Finally, it also makes sense of several other theological convictions (which I will not be discussing in this article) such as life after death and the central Christian doctrines that involve the notion of “person” (Trinity and Incarnation).

Three Challenges to SID

In his ambitious Reforming Theological Anthropology (), theologian F. LeRon Shults (, chapter 8) argues against what he holds to be the two driving forces behind the SID: substance dualism and faculty psychology.

Shults’ first argument is an argument from science. Here, he simply states that since neuroscience and psychology have made considerable advances in understanding the physiological basis of mental functioning, dualism and faculty psychology are not plausible anymore. According to Shults,

the activities once ascribed to the “soul” and its “faculties” are now accounted for by consciousness as an emergence of patterns of neuronal functioning in the human brain, which in turn are connected to chemical interactions throughout the body. These give rise to “feeling,” which cannot be separated from “thinking.” Conversely, how we think affects how we feel and act. (2003, 179)

What were once called faculties of the soul are now understood as different aspects of the behavior of the whole person—a whole that can be understood in terms of its physical constitution. This suggests, as the argument seems to go, that dualism and faculty psychology are wrong or at least explanatorily superfluous.

Shults also makes a series of brief critical remarks against dualism. He claims that the Christian hope of resurrection and immortality does not require the existence of a substantial soul. We could survive the death of our body in some other way. Further, dualism separates the knower from the known, the subject from the object. Because of his relational understanding of how humans are situated in the world, Shults rejects this dichotomy. Finally, Shults, like many other theologians, implies that a dualist view of persons gives implicit support to individualism: instead of understanding individuals as parts of an interdependent community, it supports the denigration of the body and focuses on the individual.

Such arguments are not the province of Shults only; indeed, many theologians appeal to similar considerations in their rejection of dualism and SID (e.g., Brown et al. ; Murphy ). Wentzel van Huyssteen makes similar arguments in his book Alone in the World. After stating that most contemporary theologians have left the dualism of the SID behind, van Huyssteen presents a neat package of reasons why this is the case:

An anthropology that finds the imaging of God only in the mental aspects of the human person inevitably denigrates the physical and directly implies that God, and the image of God, can be related only to theoretical analysis and control.… Identifying a specific disembodied capacity like reason or rationality as the image of God by definition implies a negative, detrimental view of the human body – a move that inevitably leads to abstract, remote notions of imago Dei. In this sense substantive definitions of the image of God can rightly be seen as too individualistic and static. (2006, 134)

The argument is that if humans reflect God in their mental aspects only, then this means that the human body and the whole physical world is of lower value. Further, understanding imago Dei in terms of rationality and intellect lead to the idea that the best in humans has to with theoretically controlling and analyzing the environment.

Now that we have an idea of the first two challenges to SID, let me turn to the third, namely, the evolutionary challenge. The evolutionary challenge is not so much one challenge but many. In what follows, I will only focus to two interrelated aspects of this challenge. Recall how the traditional SID assumed a rather stark human uniqueness: by virtue of their nonnatural souls, humans have mental capacities that other animals lack and they are like their Creator in ways that other living beings are not. If we accept an evolutionary view of humans, two problems emerge. First of all, if modern humans have indeed evolved, their bodies and their culture as well as their mental capacities have developed gradually. This means that there is no distinct point where the “human” emerges from “nonhuman.” The second evolutionary challenge is even deeper than the first. The traditional SID assumes that the special mental capacities rooted in the soul are essential for what it is to be human. To put it more precisely, there is a set of properties that all members of the category “human” share and these properties have to do with having a soul and at set of mental capacities that it provides. But if we adopt a Darwinian notion of species, there are no essential properties for being a member of the species Homo sapiens. Indeed, according to the Darwinian view, species do not have essences, that is, a set of properties that all members of the species share. Instead, species are seen in terms of the continuity of historical populations. Thus, on the biological view there are no species‐essences that make an individual organism a member of species Homo sapiens. If the traditional SID assumes something like a species‐essence, the biological view of humans radically challenges it.

Dualism(s), Persons, and the Mental

Now, I think that if certain assumptions of SID are reformulated, SID will have the resources to respond to the three challenges that I just outlined. The most central issue to be reformulated is the relationship between mental and physical properties and their bearers. In this section, I mostly follow Dean Zimmerman (, 13–28; Zimmerman ).

First of all, we must draw a distinction between property dualism and substance dualism. The distinction is based on a distinction between substances, things existing in their own right, and properties of those substances. In property dualism, there are only physical substances like human bodies, TVs, and brains. Some properties that these substances have (e.g., being of a certain shape, color, or softness) are physical properties in the sense that they supervene, reduce, or are identical with simple physical properties posited by contemporary theories of physics (atoms, forces, so on).

Now, the question is what it means to have mental properties and what kind of things these mental properties latch onto themselves. Mental properties are here understood as properties like “believing that it will rain tomorrow” or “thinking about one's lost love.” According to the property dualist, the world consists of physical substances only: there exist no other kind of things than physical things. But some of these physical things have properties that are nonphysical, and mental properties are paradigmatic nonphysical properties. On this view, mental properties are nonphysical properties in the sense that they do not reduce to physical properties, nor do they supervene on physical properties.

The denial of this is usually called physicalism. Since physicalism has many different forms, we must be careful in the way we use the term. In what follows, I will use it to mean something like this: physicalists believe in global supervenience, namely, that all substances are physical substances and all properties are either physical properties or supervene on physical properties. For the physicalist, everything that exists can be described in terms of ideal physics. This ideal physics is, of course, only attainable somewhere in the future, not now. In addition, the physicalist believes that (1) the ideal physics does not include plainly mental terms and (2) although even ideal physics might not explain everything about the movement of macrophysical objects, if worlds A and B have the same microphysical description given by ideal physics, then they will also have the same macrophysical structure. This is what global supervenience means: “everything about our universe ‘supervenes upon’ or is determined by the way in which fundamental physical properties are exemplified throughout the universe” (Zimmerman , 16).

So far, I have said nothing about the bearers of mental properties. Property dualism, as I have been describing it, is perfectly compatible with the view that there is only one type of substance, that is, material substance. The claim is simply that some material substances, like human bodies or brains, have properties that are not material. Contrary to this, substance dualism posits a substance, a bearer of mental properties that is distinct from material substances like human bodies or brains. This is what is traditionally called the soul—essentially a thinking thing. There are many different versions of substance dualism but they all share these two features I just mentioned: (1) for every thinking person, there is such a thing as a soul that lacks most physical properties of the body and other nonthinking substances, and (2) this soul is essential to the person and to a large extent responsible for the person's mental life. Such a definition of dualism is rather broad, but is nevertheless defended by Zimmerman (, 19–20).

There are several issues that need addressing in this definition, but I will forgo the discussion at this point. I will return to the issues when describing some forms of contemporary substance dualism. For now, one point will do. Among substance dualists defined in this way, there are many views as to what the carriers of mental properties actually are. For the classical Cartesian dualist, the body is the carrier of all the physical properties and the soul is the carrier of the mental properties. This seems to be what SID also assumes. On this view, there is a tendency to think that persons are identical with souls, identical with thinking things. On the other side of the spectrum are compound dualists who attribute mental properties not to the substantial soul, but to the composite of body and soul. Followers of Thomas Aquinas argue that the human soul is the form that informs the body, gives it the functions that it has. Consequently, a compound dualist of this type would say that it is the body/soul composite that thinks, not the soul by itself.

Notice that the issue so far has been the relationship between mental substance and properties and physical substances and properties. Now, one might ask what this has to do with persons and what persons are. Such a critic would be making a valid point: souls are not necessarily identical to persons. This being said, however, the SID and substance dualism that I sketched above, does indeed identify the personal with the mental: persons are essentially thinking beings, that is, mental beings. More precisely, human persons are identical to essentially nonphysical souls and only contingently have physical bodies. This is, as we have seen, what substance dualism says. Contrary to this, compound dualists do not identify persons with a nonphysical mental substance, but rather they understand persons as composites of form (soul) and matter (body). In other words, the compound dualist would resist identifying the person with the mental only. Body and soul are both required for human persons to exist and function.

To identify mental as essential to persons seems extremely intuitive, but this does not mean that all theories of what persons are “mentalistic” or “psychological.” In Western philosophical tradition, this has been a standard way of conceptualizing persons: theories range from being souls to the temporal continuity of mental properties. Many contemporary views, however, depart from this tradition. Defenders of animalism, for instance, argue that to be a human person is to be identical with a human animal (human organism). No mental life is needed in defining what persons are. Along similar lines, others have argued that being a person simply means being identical with certain human brains. Finally, there are those who believe that there are no such things as persons at all (see Olson ).

Dualism and the Brain

Now, we are finally in the position where we can start to address the first challenge to SID. First, we should note how vague the arguments of Shults and van Huyssteen actually are. Shults retells the familiar story of Phineas Cage to show how changes in the brain can affect mental properties in a radical way: as a consequence of his having a steel rod puncture his left frontal lobe, Cage became a different person. His previously friendly and calm behavior became increasingly erratic and aggressive. There might be some doubts about the historicity of these stories, but that is beside our point here. From this Shults derives the lesson that a strict separation of soul and brain is not plausible (2003, 179–180). Let me just take this story at face value and grant that many mental functions previously attributed to the soul can be now attributed to our bodies and brains. Where does this leave dualism? In a very good position, I believe.

Even the most zealous dualist would not deny the close connection between the soul and the brain. There is nothing in dualism that entails that physical changes cannot affect mental functioning. On the contrary, contemporary dualists often affirm a two‐way interaction between the soul and the brain and the subsequent dependency of the soul on the proper functioning of the brain (see below for details). Further, they would typically accept that most mental functions like perception, affection, cognition, and volition, are to some extent rooted in our brains and bodies. This is the reason why most contemporary dualists insist that some mental properties are assigned to the whole body/soul composite, not just the soul itself. This insistence clearly rules out a radical version of Cartesian substance dualism in which there is a clear‐cut difference between the mental and physical properties and their bearers. This will be the first modification to traditional SID.

Our question should be how many mental properties can the soul share with unambiguously physical substances and still remain a separate, nonphysical substance. I agree with Dean Zimmerman that there is no clear way to answer this question. Dualism therefore entails a spectrum, not an on/off distinction between the mind and the brain. There might be differences between compound dualists (e.g., Brian Leftow) and other substance dualists here. Since the compound dualist believes that the soul is the form of the body, he believes that the body performs most mental functions. The soul shapes the organization of the body in such a way as to perform different kinds of mental functions. It is not the soul that has mental states, but the body that is shaped by the soul. Therefore, the compound dualist would have no trouble acknowledging that brains and the nervous system are necessary for mental functioning. Although classical compound dualists like Thomas Aquinas did believe that higher level mental functions, like rational reflection, cannot be performed by any purely physical system, they nevertheless insisted that the kind of mental functions that neurosciences and cognitive sciences study (perception, memory, language skills, emotion, attention, so on) are rooted and performed by the body. However, Aquinas is rather difficult to interpret here (see, e.g., Kenny ; Stump ; Leftow ).

Some contemporary substance dualists would disagree with Aquinas to some extent. Emergent dualists, such as William Hasker, Alvin Plantinga, and Richard Swinburne, would argue that the soul is indeed a mental substance of its own right and contributes to thinking more extensively than simply shaping the body. However, the emergent soul is not as radically distinct from the body as the Cartesian soul is. The soul shares many properties with paradigmatically physical substances: it has a location, it is subject to change and it needs to be connected to a physical substance in order to function as a seat for the mental life of a person.

According to Hasker (, ), the soul is not supernaturally created but it emerges from the central nervous system after it reaches a certain level of complexity. The soul is, thus, a part of the natural order of things. The soul also has a location within the physical substance known as a human body. It emerges from the activity of the body and after its emergence it depends on the functions of the body for its existence. Hasker thinks that a substantial soul is what makes human bodies persons: the soul is the seat of the first‐person perspective and activity; it guarantees the unity of the person and his consciousness. From this we can conclude that the person's mental properties and their very existence depend on the physical substance that is his body.

Given all this, I think we should conclude that the sciences are far from making contemporary forms of dualism obsolete. First of all, most forms of contemporary dualism take the fact of interaction of bodies and souls extremely seriously. Emergent dualists hold that the soul depends on the body for its function and persistence. Further, mental functions belong to the body/soul composite, not just to the soul. What contemporary sciences of the mind are finding out does not contradict this in any way: science discovers correlations and dependency relations between mental and physical functions, not that mental functions are identical with physical ones. Indeed, Richard Swinburne (, ) insists that mental/physical laws—laws or regularities that govern the relationship between clearly mental and clearly physical properties—are impossible for science to find. Interestingly enough, many physicalists agree with this. Colin McGinn (), for instance, thinks that consciousness is for this very reason impossible for science to explain or humans to understand. Similarly, Donald Davidson thinks that although the mental is nothing more than the physical, there can be no systematic laws that describe the relationship of the mental and the physical. In addition, there are many sophisticated philosophical defenses of various forms of dualism (see, e.g., Bealer & Koons ). William Lycan () offers a reasonable defense of dualism, although he himself is a materialist. Recently, Thomas Nagel () has controversially challenged standard forms of mind/body materialism.

Dualism, Relationality, and the Body

Now, it is time to address the second challenge I outlined in the beginning, namely, the issue of alleged unethical or “static” consequences of SID and dualism. More specifically, the argument was that traditional SID leads to disvaluing the human body and the relational nature of human beings.

First of all, we should point out that the arguments examined were not clearly epistemic arguments. Their form is pragmatic rather than epistemic. In other words, they assume the truth of a certain ethical stance—a stance that entails the equal value of minds and bodies. The general form of such arguments is something like this:

1. If p, then q.

2. q is morally wrong or has morally bad consequences.

3. Therefore, p is false.

   This is clearly a fallacious argument. In the case of dualism, the argument would be something like this:

4. If SID is true, the image of God in humans is identified with human rationality and intellect.

5. Identifying the image of God with human rationality and intellect leads to the denigration of the body, individualism, and a “static” notion of the image of God.

6. Therefore, SID is false.

Now, the fallacy is that there is no direct connection between the truth of a belief and its moral consequences. Even if SID had morally bad consequences, it could still be true. Such an argument could be salvaged, however, if some independent theological reasons were provided that would show why the denigration of the body, for instance, was against God's intentions and valuations. In such case, there would be good theological reasons to oppose dualism. Indeed, it is likely that van Huyssteen and others think exactly this without making it explicit. So, the argument ultimately depends on the plausibility of premise (5). In what follows, I will argue that dualism does not entail any of the unwanted ethical conclusions mentioned above.

For the time being, let us put the ethical challenge like this. The late Philip Quinn asks us to imagine that persons are identical with Cartesian souls, that is, purely mental beings. If this were the case,

it would seem that whatever violates this person must directly attack something mental, if we equate violations of human personhood with direct and serious attacks of human persons. A violation of the body of this person is not, in of itself, a violation of this person.… Hence, it seems that, on this view, nothing that is done to the body I happen to have is, or even could be, itself a violation of my personhood. (Quinn , 274)

Quinn is saying here that on some dualist views the body becomes simply a tool that is only of instrumental value to persons. Violating the body cannot really violate the person and we can treat our bodies and the bodies of others without giving them the value that we would give to persons. Quinn himself responds by pointing out that only radical versions of Cartesian dualism are liable to such a critique. More moderate versions of dualism, such as emergent dualism or different versions of compound dualism, can resist this conclusion. On these views,

both my mind and my body are parts or components of the person I am. Hence both violations of my mind and of my body, as well as violations of both at once, can qualify as violations of my personhood, because they are sufficiently direct attacks on this person. (Quinn , 274)

So, in the compound dualist view, the body is valuable because it is a part of what I am as a person. Furthermore, both Thomistic and emergent dualists affirm that souls are causally dependent on their bodies for their existence and function. Human bodies are what make human souls complete persons by providing the raw material for the soul to function and communicate with other people.

Finally, defenders of SID have very good reasons for ascribing high value to human bodies, because on SID the body/soul union is a part of God's plan. Alvin Plantinga agrees and writes that

on the traditional Christian view, God has designed human beings to have bodies; they function properly only if embodied; and of course Christians look forward to the resurrection of the body. My body is a crucial part of my well‐being and I can flourish only if embodied. (Plantinga , 99)

There seems to be no sign of the kind of “body as the prison of the soul” mentality that opponents of SID are afraid of. Just to take another example from the other end of the confessional spectrum, the late John Paul II has a very high view of the value and purpose of the human body in his theology of sexuality and human nature. Because human bodies are constitutive of the persons (as both Thomistic dualists and emergent dualists affirm), they are not physical objects like any other. On the contrary, it is a gross denigration of the body to see it only in the context of use and desire:

A human person, as we know, cannot be an object for use. Now, the body is an integral part of the person, and so must not be treated as though it were detached from the whole person: both the value of the body and the sexual value which finds expression in the body depend upon the value of the person. Given, then, interdependence, a sensual reaction in which the body and sex are a possible object for use, threatens to devalue the person. (John Paul II , 108)

Thus, John Paul II holds all treatment of human bodies as objects of desire or use deeply morally problematic. This hardly seems like the denigration of the human body. I think that I have said enough to show that the “inevitable” slide from SID to the denigration of the body is far from inevitable.

Finally, there is the claim that SID somehow contributes to individualism and ends up devaluing the relational nature of human beings. I am not really sure what this challenge amounts to. The most reasonable way, I think, to interpret it is to understand it in the context of relational metaphysics. Shults's whole book is a defence of what he calls “a turn to relationality,” which apparently involves a wholesale rejection of metaphysical views that talk about substances and properties. So what we have here is not simply an attack against dualism, but rather an attack against the metaphysics of individuals.

This way of understanding the situation is supported by the fact that Shults and others criticize Christian materialist views of persons on these grounds as well. Kevin Corcoran (), a well‐known theistic philosopher advancing a physicalist theory of persons, received his fair share of these criticisms some years ago. Corcoran subsequently responded and since I think that he is in the right here, let me briefly examine his response.

First, Corcoran points out that his theory of person is put together in terms of substances and properties and the like. This does not mean that it is somehow intrinsically hostile toward relational, communal, or social notions of human persons. On the contrary, relations or social contexts might very well be “essential” to the emergence of persons in the sense of providing necessary causal conditions. But “it is often the case that in stating conditions that are metaphysically or conceptually necessary for something's being a so‐and‐so, one generally does not include causally necessary conditions” (2011, 200).

What Corcoran, correctly in my view, is trying to say here is that when we are engaged in metaphysics, we seek conceptually necessary conditions for something to be some kind of a thing. These conceptually necessary conditions do not usually include causally necessary conditions. A defender of, say, Thomistic dualism or emergent dualism can (and most do) think that a linguistic community of complex social relationships and culture is causally necessary for the emergence of human souls. This also goes for our biological, bodily nature: the dualist can (and most do) think that a complex biological evolution is causally necessary for the emergence of souls. But this does not mean that when we are looking metaphysically necessary conditions for what it is to be a person, these causally necessary features should be included in the definition. Indeed, metaphysical necessity and physical necessity are different kinds of necessities.

Corcoran further distinguishes the metaphysical question (“What am I?”) from the social/psychological question (“Who am I?”). The metaphysical question “What am I?” is a general question about what kind of a thing I am. This is what metaphysical theories of persons seek to address. The answers they give are, for example, souls, brains, bodies, animals, or organisms with first‐person perspective. But such answers do not necessarily answer the latter question “Who am I?”—a question that has to with what distinguishes you from me. I am a person (whatever that is) and you are too, but we are not the same person. What makes you different from me is a question of sociology, psychology, and history, rather than metaphysics (Corcoran , 201).

It seems, therefore, that the representative of the “metaphysics of relationality” has not given reasons for the advocate of the metaphysics of individuals (substances, properties, so on) to give up his view. The metaphysics of individuals can incorporate strong views about relationality, social embeddedness, and embodiment of human persons without jettisoning its basic concepts. Corcoran points out that “it is, after all, concrete particulars that make up the relata of a relation. It is not, in other words, relations all the way down, so to speak, with no particulars standing in those relations” (Corcoran , 201). The defender of the “metaphysics of relationality” might be correct in claiming that philosophy has tended to emphasize particular individuals more than their relations, but this is not the fault of SID or dualism. Although SID might be interpreted in such a way as to emphasize substances over relations, this is by means a necessary entailment of SID.

Imago Dei, Essences, and Human Uniqueness

What I have said so far about contemporary dualism suggest an answer to the evolutionary challenges to SID. But before I briefly explain those answers in more detail, let me say a few words about the two evolutionary challenges that I want to address.

We should distinguish two different meanings of what it is to have an essence. On the first view, the essence of a thing is a set of properties that a thing must necessarily possess to be what it is. If one of these “essential” (as opposed to “accidental”) properties is lost, the thing in question will cease to exist. Traditionally, biological classifications were understood in this way, that is to say, species classifications were supposed to be based on essential properties of classes of organisms. In addition, there is also a slightly different notion of essence. In this view, the “essence” is one single thing that the organism possesses that in turn explains why the organism has its essential properties. In other words, not only does the organism exhibit a set of properties that make it what it is, but this fact is explained the organism's possessing one underlying property of some kind or another.

Now, here comes the evolutionary challenge. John Dupré (, 155) puts it well:

What has become increasingly clear to post‐Darwinian biologists is that there can be no necessary and sufficient condition for being an organism of a certain species, and the characteristic properties of members of a species are, first, almost always typical rather than universal in the species and, second, to be explained in various different ways rather than by appeal to any simple or homogeneous underlying property.

Dupré is saying here that Darwinism eliminates “essences” in both aforementioned senses from the biological world. Individual organisms do not exhibit a clearly delineated set of traits that would determine their species‐membership. The properties of individual organisms in populations are variable to such an extent that no single set of traits can be found in all members. To be a member of a species is to belong to a historical population with similar phylogeny. Furthermore, the biological explanation of the properties that organisms in the same population have does not make reference to one single “essential” property that would explain why the organisms are similar. Instead, biological explanations can invoke many different factors, such as natural selection, genetic drift, and so on.

From this it follows that, to the extent that we can identify something like species‐nature, it can change over time as populations evolve. This leads to a second evolutionary challenge to SID, the issue of gradualism. Since there are no permanent species‐essences, there seems to be no clear cut‐off point between being human and being nonhuman. For the traditional SID, the problem would be that there is no single point in time (or at least we cannot identify one) where supernatural souls, a specific cognitive capacity, or some other essential human property entered into the evolutionary story. Although there might be evolutionary transitions and leaps, there is still a continuous line of evolution from contemporary humans to our long extinct ancestors. We now know that this line is much more complicated than previously thought but that does not take away the very real evolution of our species (see, e.g., Fuentes ; Sterelny ; Tattersall ).

Now, these two challenges (the lack of permanent biological species‐essences and the problem of gradualism) seem to challenge all imago Dei theories that make a strong qualitative distinction between humans (as carriers of imago Dei) and nonhumans (nonimago Dei). In some traditional views this distinction is drawn in terms of humans having intellectual souls and animals either having no souls at all or having nonintellectual souls. In both cases, the dividing line is between beings capable of thought and selfhood and those incapable of it. Furthermore, according to most traditional theories the source of the capacity for selfhood and intellect is supernatural rather than natural.

What I have said so far about emergent dualism and Thomistic dualism suggests a way out. Given contemporary forms of dualism, we can drop the problematic assumptions of pure cognitive uniqueness and its supernatural origins that are built into the traditional SID. This, of course, leaves dualism “thinner” than traditional Cartesian dualism, but, as we have seen, also resolves some of the problems of more traditional dualism. Contemporary dualism has no problem in acknowledging that there is no ontological gap between nonhuman animals and humans. For the emergent dualist, for instance, mental life in general and thinking in particular is something that is at least proximately produced by nature. This is also the reason why the contemporary dualist need not believe that God creates souls in a single supernatural act.

Furthermore, since the soul is not identical with the person or person's mental life, it is not thinking or the realm of the mental per se that constitute the essence of humans, that is, human nature. So, it seems to me that SID theories need not be committed to the view that there is a Homo sapiens essence, which in itself is the carrier of imago Dei. In other words, we can identify the imago Dei with the developing of certain dispositions and capacities when the organisms in question are properly functioning. Further, there is no need to posit a supernatural soul or an essence either to explain these naturally developing capacities or to assume that all Homo sapiens share these dispositions and capacities. It is enough for SID if we can identify a set of distinctive dispositions and capacities that Homo sapiens typically develop. In other words, instead of pure human uniqueness, the modified SID points toward human continuity with the rest of creation, but also leaves room for human distinctiveness.

The account that I am suggesting here presupposes that some form of theistic evolution makes sense. In other words, the emergence of souls and thinking persons that reflect God in their mental capacities is not a result of God supernaturally “adding” souls and mental capacities to evolved bodies, but instead enabling the material nature to produce souls. This further suggests that there is at least some teleology in the process of evolution toward realizing intelligence and self‐awareness. Such assumptions, although crucial for contemporary SID, are neither discussed nor defended in this article.

Now, the question is whether there is evidence for any kind of human distinctiveness in the sciences. It seems that there is a considerable amount of evidence suggesting that, although we share some of our mental systems with nonhuman animals, human cognitive abilities greatly surpass those of even the most highly developed nonhuman animals. Some theologians, such as van Huyssteen (), have argued that symbolic reasoning and language constitute human distinctiveness. This could very well be the case, but not the whole case. I take just one example: Peter Carruthers (, 155–157) gives a list of 22 cognitive capacities that are distinctly human in their depth and the performances they enable. Here are some highlights:

1. A language capacity, involving capacities both to learn and to utilize language.

2. A sophisticated imitation ability, perhaps underpinned, in whole or in part, by some aspects of mind‐reading and by some aspects of folk physics.

3. A capacity to acquire complex skills through practice.

4. Motivational systems that underpin and guide social learning and promote successful social interaction.

5. Normative capacities, including systems specialized for learning social norms, creating motivations to follow such norms and generating emotions that have to do with such norms.

6. Capacity to reason about social exchanges and to generate appropriate motivations for engaging in them.

7. Sense of humor: a disposition to joke and play tricks and tease others.

8. An interest in stories and a disposition to invent and transmit them.

9. A capacity for exact numerical and mathematical cognition.

10. A capacity to represent counter‐factual and hypothetical states of affairs.

11. A capacity to think in terms of metaphor, analogy, and symbol. This has to do with cognitive creativity, that is, using concepts and practices in one domain in a less familiar domain of thinking and action.

12. Finally, there is the almost infinitely flexible capacity for practical reasoning and the capacity to modify and assess one's own reasoning practices.

But is it not problematic for SID that biology and psychology can explain how the aforementioned capacities arise via biological evolution? The answer is negative because giving a biological explanation of our mental capacities threatens SID only if SID entails that our mental capacities are nothing like our physical capacities and are performed solely by the immaterial soul. But as has become clear, neither the compound dualist nor the emergent dualist needs to think this way. Instead, both can affirm that most of our mental capacities are grounded in our evolved bodies, cultures and our social environment.

Having a soul is not a competing explanation for the evolutionary story for basic human mental capacities. Souls do a different explanatory job than evolutionary explanations. As I pointed out before, the fact that there is a close correlation between mental and physical properties presents no difficulty for dualists. What the dualist wants to claim is that since mental properties are not necessarily connected to specific set physical properties and there is no systematic supervenience, the relationship between the mental and the physical will remain inscrutable to science. Evolutionary psychologists seek to explain why our perceptual, conceptual, and emotional systems work the way they do in terms of their selective advantage in our ancestral environment. In contrast, souls are responsible for mental processes that do not map onto physical properties in any systematic way. Souls account for phenomena like the unity of consciousness, the qualitative aspects of consciousness, the capacity for reason‐based agency, free will, intentionality, human dignity and value, the personal identity through time as well as survival after death. In this sense, cognitive psychology and evolutionary psychology explain the “raw material” of our mental life, but not the first‐person perspective that our mental life presumes. To put the point in a more philosophical way, dualism is a metaphysical hypothesis that is designed to explain phenomena that seem either intractable science or beyond any conceivable scientific theory.

There might still be a lingering worry that evolutionary gradualism somehow threatens SID and especially the idea that humans have nonphysical souls as proper parts. If the soul is the seat of the mental and animals exhibit rudimentary forms of the mental, is it not the case that animals have souls (and they are also images of God) or that the mental has really nothing to do with souls?

Again, this worry is rooted in the idea that the soul is all by itself responsible for a person's mental life and identical to the person itself. But as we have seen, the contemporary dualist need not take these assumptions aboard. Instead, the contemporary dualist can posit the existence of different kinds of souls, human souls and animal souls. Indeed, even contemporary Cartesians, like Swinburne, think that animals have souls to the extent they possess mental life. Given the fact that we share many of our cognitive capacities and thus brain structures with animals, it seems reasonable for the dualist to assume that they also have a mental life somewhat similar to ours. If this is true, then they have souls as well. Animal souls, of course, come in many varieties and differ from human souls, but they are still souls, nonphysical mental substances that anchor certain mental properties (Swinburne , chapter 10).

Conclusion

In sum, the modified SID theory that I have been outlining here differs from traditional SID in the following ways. First of all, we must recognize that we cannot identify a clear‐cut divide between reflecting God and not reflecting God. It follows from this that being the image of God is a gradual matter. A being is not simply an image of God or not, but rather beings reflect the image of God more or less. On the modified SID, humans indeed reflect God now by having certain mental capacities to a higher degree than other species, but this is not necessarily so and could change in the future. The image of God is as much about being as it is about becoming. Consequently, if some other species were to develop similar capacities to us, they would, at least to some extent, be images of God as well.

Second, there is a “natural” or ontological basis for imago Dei. Imago Dei is, thus, not simply being in a certain kind of relationship with God, other humans and the created world (although this might too be the case). It might be the case that being the image of God is something more than having certain mental capacities, like having a God‐given mission to care for creation or be responsive to God's address. Nevertheless, the SID theory that has been elaborated here maintains that these other aspects of the image of God entail the existence of distinctly human capacities. Indeed, an argument could perhaps be made to the effect that all competing theories of the image of God (functional, relational, eschatological, so on) presuppose the existence of some distinctively human capacities (for the interrelation between different concepts of imago Dei, see also De Smedt and De Cruz ). Therefore, the modified SID entails that having a soul is a necessary condition for being the image of God but it is not a sufficient condition. As we have seen, to be able to develop mental capacities that reflect God, a body and a set of relations is required. I want to emphasize this for those who go for strong communal and relational views about imago Dei: the modified SID positively invites such emphasis. Nevertheless, the modified SID maintains that it is the soul that functions as the core of each person, the ground of first‐person awareness, freedom, and intentionality.

If we are to develop a contemporary SID theory further, we need to address several issues that I have not discussed in this article. First, responses to standard critiques of dualism must be explored and explicated. This, I think, is a task that is not impossible and has mostly been done already. The standard objections to dualism, such as the interaction problem, crumble when subjected to close scrutiny. Second, a detailed discussion of the benefits and problems of competing theories of the image of God is needed. Again, this is something that has been done to some extent. There is an emerging literature on the imago Dei in systematic theology and biblical studies. Third, I have said nothing here about the scriptural basis of SID. To make SID a plausible theological view, this topic would have to be revisited.

What I have argued in this article is that SID theories are far from being dead and buried and they might have more going for them that many contemporary theologians think. Whether this will lead us, all things considered, to adopt a contemporary form of SID instead of some other notion of the image of God, we will have to wait and see.