C. Stephen Evans
Should Christians Be Physicalists?
Too many Biblical scholars see their work as a narrow, technical specialty, and show great reluctance to venture into questions of theology. In Body, Soul, and Human Life, part of the Studies in Theological Interpretation series, Joel Green (who is himself one of the editors of this series) shows a commendable willingness to think about the significance of biblical texts to deal with contemporary issues. Green wants to give a fresh look at what the Bible says about human beings in this work. Furthermore, he wants to look at the biblical teachings in light of contemporary scientific findings about humans, especially the findings of cognitive neuroscience.
Green often calls cognitive neuroscience just "cognitive science," but this is misleading. Cognitive science is an interdisciplinary field that is much broader than cognitive neuroscience. In particular, cognitive science includes the work of philosophers and researchers in the field of artificial intelligence (AI), a subject that Green almost entirely ignores. This is not too surprising, since Green's aim is to affirm the importance of the human body for our understanding of humans, an aim that attention to AI, with its emphasis on formal programs and understanding of intelligence as functional, would make more difficult to fulfill. For AI theorists, especially those committed to what is called "strong AI theory," what we call "minds" are functional systems that in principle can be realized in many kinds of hardware—or "wetware," in the case of human brains.
Most of Green's positive contentions in this book strike me as completely right. He affirms, for example, that it is legitimate, even necessary, to consider contemporary scientific findings when interpreting the Bible. Biblical interpreters at least from the time of Augustine on have followed this principle, which is based on the conviction that all truth is God's truth and thus that God's revelation in nature must ultimately cohere with what God reveals in Scripture. Apparent contradictions between science and Scripture must not be ignored; rather, we should attempt to find consistency, by adjusting our understanding of either science or Scripture, or sometimes both.
However, I do not think Green is sensitive enough to the way in which scientific findings change over time, and thus does not adequately consider the situation in which faithfulness to biblical teachings might require that Christians question the claims particular scientists make. It is instructive at this point to recall that a behaviorism that ruled out human freedom and responsibility was regarded as the established scientific perspective on humans from the mid 1950s until the "cognitive revolution" in psychology that began in the 1970s. It would have been a mistake for Christians during this period to slavishly accept a behavioristic perspective simply because it carried the prestigious label of being "scientific."
Green thinks that we are now in the fortunate situation in which contemporary scientific findings about human beings cohere with biblical teachings. Contemporary cognitive neuroscience, as Green tells the story, affirms the basic unity of the human person, and makes clear the total dependence of mental activity on neural activity. Green is particularly impressed by the way contemporary neuroscience has successfully pursued a strategy of "localization," in which particular mental functions are associated with particular regions of the brain. New techniques for brain-scanning show, for example, that particular regions of the brain show increased electrical activity when humans pray or meditate.
Human mental life is also strongly shaped by our genetic inheritance, but Green rejects a genetic determinism, holding that a person's mental life is also a product of the person's "learning"—the person's development and experiences, including especially the impact of relations with other persons. This last point is one Green emphasizes strongly, since it fits well with the biblical view that personal transformation occurs through relationships with God and God's people. Salvation should not be construed in purely individualist terms: both the process and end result require us to see the individual person as part of a community.
These claims border on the platitudinous. Christian theologians have always held that an individual's salvation is tied to the person's relation to Christ and Christ's body, the church. And does anyone today really doubt that mental activity depends on the brain? After all, people have known for a long time that a person's mental life can be severely impaired, even ended, by bashing open the skull. Contemporary neuroscience gives us valuable accounts of the particular ways mental life depends on the brain, but this is filling in the details. Those details are fascinating, and contemporary neuroscience has made many discoveries about the way the mind depends on the brain for which all of us can be profoundly grateful. We have gained many significant benefits from these findings, both for medical science and for our understanding of such issues as the relation between emotion and cognition. But the philosophical implications of these discoveries are not so clear as Green thinks.
For Green, these neuroscientific findings about the dependence of our mental life on the brain are momentous, because they call for a wrenching re-examination of the traditional Christian claim that humans have a non-physical soul. Green's book is from beginning to end a polemic against this "dualism." Although Green realizes that mind-body (or, to use alternative language, soul-body) dualism was virtually the unanimous Christian view at least until the 19th century, he thinks that it is ruled out by contemporary neuroscience. (Green's book would have benefitted greatly from a serious look at what such theologians as Aquinas and Calvin actually said, but no such discussion is present.) Fortunately, Green concludes, the Bible itself, as understood by contemporary biblical scholars, supports a monistic (non-dualistic) view of the person that is congenial to the physicalism of contemporary science. For many centuries, Green thinks, the theologians and philosophers of the church got the Bible wrong, reading into the text their own dualistic philosophical convictions.
Unfortunately, this polemical thesis is directed against a caricature of the traditional view, and does not make contact at all with contemporary forms of dualism. For Green, "dualism" is the view that humans have a mysterious non-physical "part" or "entity" within them called "the soul." He sees dualism, to recall the phrase made famous by philosopher Gilbert Ryle more than fifty years ago, as the belief that there is a "ghost in the machine." Early in the book Green distinguishes what he calls "radical dualism" from other forms, such as the "emergent dualism" of William Hasker or the "holistic dualism" of John Cooper. (He completely overlooks the complex kind of dualism found in Thomas Aquinas, even though the Thomistic view, like Green's own, holds that embodiment is essential to a person's existence.) However, having admitted that there are many different kinds of dualism, Green proceeds to ignore this fact entirely in the rest of the book. "Dualism" is consistently treated as the view that a person has a non-physical entity called the soul that has no significant relationship with the body—contrary to the views of contemporary dualists. Thus, the dualism Green tries to refute is entirely a straw man. He never considers how a contemporary (or traditional) dualist might make sense of the scientific findings he brings forward, and thus it is completely unclear whether his preferred physicalist view is in fact more strongly supported by the scientific evidence he cites than the contemporary dualist views he mentions in the first chapter.
That Green fundamentally does not understand the views he is trying to combat is made clear at many points. For example, he speaks of "an ontologically distinct soul, which constitutes the 'real person' and which guarantees survival of personal identity from this life to the next." On Green's own physicalist account, apart from divine intervention, "there is no part of us, no aspect of our personhood, that survives death." It must be admitted that many patristic, medieval, and early modern Christians did hold that the human soul was created by God to be immortal. However, contemporary dualists, such as Hasker and Cooper, reject the idea that the soul is "naturally" immortal. They think we are embodied souls, completely dependent on the body during this life. Only God's miraculous power is capable of sustaining the personal conscious life of an individual beyond the grave.
The question is not whether the soul "guarantees" survival after death, but whether it keeps this open as a logical possibility. God can do what is physically or naturally impossible, but not even God can do what is logically impossible. God cannot make a square circle. If physicalism is true, and a person is identical to his or her body, then it is necessarily true that if a person's body ceases to exist the person ceases to exist. If it is possible for me to continue to exist after my body ceases to function (and ultimately disintegrates), then I cannot be identical to my body. A natural way to express this is to say that I am not identical to any particular material object, including my current body, however intimately tied to the body and dependent on the body I currently may be. This will be the case even if it is true, as Green believes, that it is not possible for a human person to exist in a disembodied state; if it is possible for me to exist with a new body then I cannot be identical to my current body. I am a person or a self or soul; an embodied soul to be sure, but I am not identical to any physical object. Dualism is then not primarily a claim about an entity inside myself; it is a claim about what kind of thing a self is.
Although Green thinks he is committed to a physicalist view in which a person is identical to his body, he appears to affirm some claims that are logically incompatible with such a view. He holds that after death there is an immediate resurrection of the person from the viewpoint of "the consciousness of the departed believer," although a period of time may elapse between death and resurrection as experienced "from an earthly viewpoint." I find this unclear. Does Green mean that, although there is a temporal gap between death and the resurrection, from the viewpoint of the individual, who does not exist during this gap, the next moment of consciousness after death will be an experience of the resurrection? I doubt that this can be what Green means, since it would imply that the departed believer is not now enjoying the presence of Christ. (Indeed, since the believer would not exist during this gap, he or she would not be enjoying anything.) So perhaps what Green means is that immediately upon death, the believer is invested with a resurrection body in some other space and time than our own. If that is what he means to affirm, it seems clear to me that Green does not think that a person is tightly connected to his or her body at all. For surely the body the resurrected person gains in this other space-time world is not the body the person had during this life, since that body is disintegrating in this world. One might think that a robust Christian view of resurrection would be one that affirms that the body I currently have, in this world, will be brought back to life and transformed. Green's view (if it is his view) of a new body in a different world of space and time than our own looks more like reincarnation than resurrection. Perhaps I have misunderstood Green here, but if so, it is because he has been reticent about telling us what he really thinks.
A particular problem here stems from understanding Christ's resurrection. The church has traditionally affirmed that Christ rose "on the third day" and this was "according to the Scriptures." A view such as Green's would seem to imply that either Jesus did not exist between his death and his resurrection or that the third day tradition is mistaken, since the resurrection occurred immediately upon Christ's death. Neither view is attractive. Perhaps Green would reply that the resurrection occurred on the third day "relative to our earthly time" but happened immediately after Jesus' death "relative to his consciousness" or "relative to some other time." However, I do not understand what this means. Christ's body would seem to be a physical object that exists, like all physical objects we know, in our space time. What would it mean to say that on Holy Saturday this body was both resurrected and lying in the tomb? It sounds like a sheer contradiction.
A related book, Neuroscience, Psychology, and Religion, written by the distinguished neuroscientists Malcolm Jeeves and Warren Brown, avoids this kind of theological issue. The purpose of the book is to introduce non-scientists to some of the developments in contemporary neuroscience that so impress Green, and to reflect on the significance of these findings for people of faith. Jeeves and Brown do an excellent job of this. Their account of what contemporary scientists know about the brain begins with a historical survey, including a fascinating and instructive look at the history of phrenology, an earlier and now discredited scientific treatment of the way the mind depends on the brain: "Just as phrenology looked to bumps on the head, we are looking at colorful images of blood flow in specific brain areas. As noted, this can be good science but also an invitation to unwarranted claims or speculation."
The main point they make here is that we must be cautious in interpreting scientific findings about the relation of the brain to the mind. Although they are experts in understanding the ways in which many mental functions are "localized," they balance this view with an emphasis on the ways in which the brain functions as a holistic, integrated system (a point Green should have paid more attention to). In particular, they are skeptical about scientific claims to have shown that there is a particular "spirituality center" in the brain that controls our religious lives, affirming instead that it is more likely that our religious beliefs are a function of more general cognitive capacities and learning.
Like Green, Jeeves and Brown want to impress upon the reader how thoroughly dependent our mental lives are on our brain. Also, similar to Green, they see these facts as ruling out belief in "an immaterial immortal soul that is somehow and somewhere attached to our body." And, like Green, they fail to engage in a substantive way with contemporary dualism, though Hasker's emergent dualism is mentioned at one point as a view that is consistent with contemporary science.
However, Jeeves and Brown are less clear about what they wish to put in place of the Platonic dualism they reject. They emphatically reject any reductionistic form of materialism. Human thoughts and feelings are neither reducible to physical events at the chemical and physical level nor determined by events at that level. On the contrary, there are real mental properties that are "emergent," and causation is not simply "bottom-up" in character but also "top-down" because the parts of the brain are causally shaped by the "dynamic, non-linear systems" that constitute the brain as a whole. I take it that Jeeves and Brown mean to affirm that mental properties are real and irreducible, and also that, though mental events may be caused by processes in the brain, it is also true that a thought (or other mental event) may causally impact the way the brain functions (as in the placebo effect). It looks to me as if Jeeves and Brown here grant contemporary dualists most of what they want to affirm. For on the Jeeves/Brown view I may still see myself as a rational, conscious agent who can interact functionally with the parts of my body, even if this agent-self is itself embodied. If they are willing to grant that this conscious self can survive the death of the body, then this view seems very similar to Hasker's emergent dualism.
Jeeves and Brown describe their own view, somewhat confusingly, as either "nonreductive physicalism" or "dual-aspect monism." This is confusing because these two terms describe two different positions. (Given the fact that this is a dual-authored book, it is tempting to speculate that what we have here is an attempted compromise between two different views.) Nonreductive physicalism would appear to be a form of physicalism, which affirms that a person is essentially a physical object, albeit one with mental properties. Dual-aspect monism, like nonreductive physicalism, rejects a non-material soul as a separate entity from the body. However, the dual-aspect monist sees the human person as having both mental and physical aspects that are equally fundamental and therefore refuses to privilege the physical perspective on the person. Such a view would seem to require, as secular philosopher Thomas Nagel has affirmed, a fundamental revision of our understanding of what it is to be "physical." (Nagel is quoted affirmingly in the book.)
It would be instructive for writers such as Green to look more closely at the writings of secular thinkers such as Nagel. Since most contemporary materialists are atheists, they see materialism as the only game in town; a human being must be a physical creature. Yet many materialists are honest enough to admit that they have no real idea as to how such mental properties as consciousness and meaning (intentionality) can be explained by science. They know that materialism must be true of humans but cannot see how it could be true. Some have even claimed that the mind-body problem is an essential mystery, something that human reason cannot fathom.
I agree with Green, Jeeves, and Brown that contemporary Christians should fully accept an understanding of human persons as embodied, relational creatures. However, there are complex philosophical issues that the scientific findings do not by themselves resolve. In particular, we need to think harder about what it means to be embodied or incarnated. To say that human beings are embodied is not to say that they are identical to their bodies. And to say that the human soul (or self) is not an immaterial entity living somewhere inside the body is not to say that it is logically impossible for that human person to exist apart from his or her current body (even if it were true that humans cannot exist without some body or other). And that would seem to imply that we must distinguish between the person (perhaps we should give up on the word "soul") and the person's body. If the person and the person's body are separable (not separate), then they must be distinct realities. We must remember that what is possible naturally or scientifically is not identical to what is possible for a God who created the natural world with its laws.
C. Stephen Evans is University Professor of Philosophy and Humanities at Baylor University. He is the author most recently of Kierkegaard: An Introduction (Cambridge Univ. Press).
Copyright © 2010 by the author or Christianity Today/Books & Culture magazine.
Click here for reprint information on Books & Culture.
See all comments