Many things we have learned contradicts much of what we previously thought about the mind.  For example, it is quite common and sensible to believe that we come into the world with minds that are essentially “blank slates,” and that what we know is written on those slates by experience alone.  But that view appears to be wrong.

The human mind consists of a variety of distinct and interacting mental tools, each of which comes pre-loaded with some quite specific content and some processing algorithms.  For example, it is now clearly demonstrated that human beings are naturally endowed with what we might reasonably describe as innate beliefs and innate cognitive processors.

On the belief side, developmental psychologists have identified numerous domains of understanding that are native to us, such as folk physics, folk biology, folk psychology, agency detection tendencies, and so on. What these discoveries seem to show is that our minds are pre-disposed to come to think about the world in very specific ways—ways that are determined by the kinds of minds we have.

So it looks like from birth, or rather through a regular and maturationally natural process, we have dispositions for form beliefs in the following domains.

“Folks Physics”:

• Objects move on inertial paths
• Objects cannot move through other objects
• Objects must move through space
• Objects must be supported

“Folk Psychology”:

• Agents act to satisfy desires
• Agents have beliefs

“Folk Biology”:

• Animals bear young similar to themselves
• Living things need nutrients

In addition to these innate dispositions toward certain kinds of beliefs, we also seem to have cognitive mechanisms that dispose us to crunch sensory inputs in specific ways. We might call these “innate cognitive processors.” Examples of these would include things like contagion avoidance and agency detection.

Contagion avoidance is a natural aversion human beings share to things like dead bodies, animal waste and vomit, rotting food, etc. These things “gross us out” from a very early age.  Indeed, the aversions we have towards them pre-date any data we might come to possess that would lead us to judge them dangerous.  We are also repelled by them in ways that are independent of other aversive stimuli like smell (that is, you can’t explain this aversion by noting that people are scared off because of an unpleasant odor since studies show that the aversions are independent of that).

A second processor is our Agency Detection Device. Here, psychologists have identified a cognitive processor that seems to pre-dispose us to form beliefs in the reality and presence of (sometimes invisible!) agents under certain conditions. In these cases, when we look for the cause of certain events, motions, sounds, or structures, we are disposed to think that it was caused by a someone rather than by a something. Our ADD appears to be hypersensitive.  It is very good at detecting agency, and in fact is more likely to generate false positives than false negatives.  This is often referred to as our hypersensitive agency detection device (HADD), and may be reflected in manifold attributions of ghosts, fairies, forest spirits, and even personalities of machines!

In sum, psychologists have shown that our initial presumption about the contents of our mind was wrong. Our minds are not blank slates, but processing devices that come endowed with a complex operating system.

Many are quick to point out that this should not be surprising.  When we look across times and cultures and find very similar beliefs concerning the nature of physical, biological, and psychological reality, those similarities cry out for some explanation. Since these diverse individuals have a very wide range of experience, something other than, or in addition to, common experience would seem to account for the similarities of belief. And so it is natural to conclude that there is some fundamental similarity among human minds that explains it. And recent empirical evidence has in fact confirmed this conclusion.

One type of belief that is pervasive across times and cultures is religious belief.  One is thus led to wonder whether those sorts of beliefs are among those that we are naturally disposed to believe.  One New Zealand religion scholar, Joseph Bulbulia, argues that the emerging consensus is yes: “The view of mind expressed by Descartes as composed of innate understandings given in advance of any experience has been thoroughly vindicated after sixty years of cognitive psychology. It may be that Descartes will be shown correct on another score, namely that knowledge of the Divinity is imprinted on every mind [as well]”

Bulbulia’s remark invites us to entertain three key questions:

• Is there any evidence that we are naturally disposed to religion?
• How do we explain the origin of these dispositions?
• What are the implications of such explanations for belief itself?

These will be explored in the next post.

A common argument leveled against the theory of evolution is that scientists have not been able to produce the expected transitional fossils that show the change of one species into another. If evolution were true, wouldn’t there be instances of clear intermediary species, like, for example, a species that was half whale and half hippo to show the transition between those two? In this BioLogos podcast, Kelsey Luoma addresses this misconception about what a transitional fossil actually is. Rather than a mix between two related species, transitional fossils point back to the common ancestors that modern species share. The fact is that the number of transitional species is massive and it grows with each passing year. Given the rarity with which organisms are actually fossilized, the amazing thing is actually the completeness of the fossil record, not its incompleteness. The transitional species story strongly supports, and certainly does not disprove, evolutionary theory. ¹

1. To hear the full audio clips which have been referenced go to:

• Rational Response Debate with Kirk Cameron (from Way of the Masters)
• Behind the Scenes with Dr. Neil Shubin (from Cincinnati Museum Center)
• Mark Norell Publishes New Archaeopteryx Findings (from American Museum of Natural Sciences)
• Texas A&M Professor Discusses Findings of Autralopithecus Sediba and its Relationship to Humans (from Texas A&M University)
• Intro/outro music composed by Martin Minor (Minor2Go).

An audio only version of the podcast can be downloaded here.

Transitional Fossils

Some time ago, the Discovery Institute’s Casey Luskin commented on the human origins exhibit at the Smithsonian Institution, suggesting that palaeoanthropologists use evolutionary theory to describe the progression of the human lineage even when they don’t have transitional fossils with which to work. He writes:

What's ironic, however, is that if you ask the question How Do We Know Humans Evolved? the answer you’re given is, “Fossils like the ones shown in our Human Fossils Gallery provide evidence that modern humans evolved from earlier humans.” So whether you find fossils or you don’t, that’s evidence for evolution.

Indeed, it has become an article of faith for those espousing both the young earth creation (hereafter YEC) model and many who hold to the intelligent design model that transitional fossils do not exist and therefore evolution has not taken place. Support for this position usually entails attacking the weak areas of the fossil record, where burial processes have left us little with which to work, or the creation of straw men arguments in which transitional fossils are defined in such a way that none could ever be found. Often this centers on the concept of “missing link,” a term that is habitually used in the popular press and young earth creation and intelligent design literature when referring to fossil remains but which has little to no meaning for biologists or palaeontologists. As Ahlberg and Clack (Ahlberg and Clack 2006) write:

But the concept has become freighted with unfounded notions of evolutionary ‘progress’ and with a mistaken emphasis on the single intermediate fossil as the key to understanding evolutionary transitions. Much of the importance of transitional fossils actually lies in how they resemble and differ from their nearest neighbours in the phylogenetic tree, and in the picture of change that emerges from this pattern.

Contrary to common misconceptions, the fossil record does not record one single lineage for any family of organisms but rather a series of branches, with many related species coexisting synchronously. Darwin hypothesized that the evolutionary record reflected this bushiness and drew such a diagram in his journal. At the time, though, he had little in the way of fossil evidence to back up this position. Much has changed since his day.

An analogy for understanding this “bushiness” was best described by Prothero and Buell (Prothero and Buell 2007). They suggest that the reader consider his or her own genealogy. You and your siblings are the direct descendents of your parents and, while you are similar to them, each of you has different characteristics not shared with them as well as characteristics that you do share. Your parents have siblings as well (your aunts and uncles), and your grandparents are their last common ancestors. These siblings have their own children (your cousins), who have different and similar traits relative to their parents. They are broadly recognizable as being related to you (“oh, I see you have Aunt Edna’s nose”) but three or four generations out, they will become less and less so. These are the “nearest neighbours” that Ahlberg and Clack describe. In this analogy, each of these cousins represents a transitional form from what was (your grandparents) to what will be down the road.

For example, no one would confuse a frog with a salamander but if you trace the fossil record of each back in time, eventually you encounter a fossil, Gerobatrachus hottoni which was recently discovered (Anderson et al. 2008) that is best described as a “frogamander,” having the basal characteristics of both frogs and salamanders. Had we seen such an animal at the time, it is likely we would not have found it remarkable because it would have resembled the species around it. One lineage eventually diverged into frogs, salamanders and other amphibians. Most (just like Darwin proposed in his tree diagram with the little hatch marks at the tip of many branches) went extinct.

Taxonomy and the Beginnings of Human Origins

All life is classified based on a system devised by Carolus Linneaus in 1735 in his remarkable work Systema Naturae. This system gives all recognized species an individual place based on a system of hierarchy. The study of classification is known as taxonomy. A taxonomic ranking for humans would be this:

When a fossil is excavated, the first thing that the palaeontologist does is make a taxonomic assessment of where it fits in a sequence of known fossils. Traits that are shared with other like species or genera are referred to as primitive traits. Examples of this in humans are five fingers and the presence of three arm bones. We share this with all mammals. Traits that are new or are not shared with other like species are referred to as derived traits. Examples of this in humans are the skeletal changes in the pelvis and the foot to allow for walking upright. We do not share these with any other primates.

Transitional fossils in the human fossil record are distinguished at both the genus and species level. This group includes the extinct genera Ardipithecus and Australopithecus and the current genus Homo. All species except Homo sapiens are extinct. Much of the recent study of early humans focuses on the transition from Ardipithecus (‘Ardi’) to Australopithecus (‘Lucy’ and similar fossils) and from Australopithecus to Homo, the genus that led eventually to us. While each of the australopithecine species identified in the fossil record has derived characteristics that separate them from their ancestors and from each other, only one led to the genus Homo.

In future posts, I will describe the evidence for human evolution and why this evidence is compelling. It suggests that we have had a long, varied history filled with great leaps of change, crushing defeat, and eventual expansion into all areas of the globe.

Notes

Ahlberg, P. & J. Clack (2006) A firm step from water to land. Nature, 440.

Anderson, J. S., R. R. Reisz, D. Scott, N. B. Frobisch & S. S. Sumida (2008) A stem batrachian from the Early Permian of Texas and the origin of frogs and salamanders. Nature, 453, 515-518.

Prothero, D. & C. Buell. 2007. Evolution: What the fossils say and why it matters. Columbia Univ Pr.

Introduction

One of the reasons that some of us are hesitant to accept evolutionary creation is that it seems to make God responsible for the suffering and death of innumerable creatures over millions of years—before humans ever existed or sinned against their creator. Since we believe in and worship a God who is loving, benevolent, and all-powerful, it sounds quite implausible that our God would have created a world like that; therefore, any scientific evidence for evolution must be incorrect.

Other people look at the scientific evidence for evolution and find a compelling case that it has taken place during our earth's history. On this basis they may conclude that if evolution is true, then the belief in an all-powerful, perfectly good God must be false!

The trouble with both of these views is that they tend to invoke a completely abstract, philosophical god, not the living God of the Bible—the God who became a human being, experienced unimaginable suffering, and died in a grotesque and humiliating public display. The death of Jesus completely defied the expectations (and common sense) of his followers, as well as the expectations of any “rational” understanding of the way the Creator of the universe should act in the world. On the cross, in the person of Jesus, God took upon himself far more suffering than any creature has ever experienced.

If God himself is willing to die, particularly in such a gruesome way, then perhaps we should at least consider the possibility of God allowing the death of other creatures, too. But would this really be compatible with what we know of God through Scripture? In this essay, we will explore this quandary through a “theology of the cross”, a concept articulated by pastor George Murphy in his book Cosmos in the Light of the Cross.¹

Theology of the cross

Before we jump into the theological problems associated with evolution, let’s take a look at how we understand Christian theology itself. For the reformer Martin Luther, any theology (or science) that tries to reach knowledge of God apart from the cross is bad theology.² Instead, Luther pointed to a theologia crucis, in which the true God is seen first and foremost “through suffering and the cross”. To make his point even clearer, Luther insisted that “the CROSS alone is our theology”.³ It is the lens through which we view everything.

Of course Martin Luther, having lived in the 16th century, was not aware of the vast history of life on our planet (or any other aspect of modern science, for that matter), but George Murphy draws from Luther’s teachings the foundation that all human knowledge begins with the Word made flesh and crucified.⁴ With the cross of Christ as the ultimate framework through which we view reality, we are bound to view the processes of nature quite differently. As Murphy explains it,

A theology of the cross is an explication of belief in a God who becomes a participant in the history of the universe and thereby shares in the suffering, loss, and death that are part of worldly experience.⁵

God does not sit idly by and watch unaffected as his creatures suffer, but neither does he swoop in and make everything completely effortless and easy. Instead he chose another way, the crucifixion of Jesus—certainly not the approach that we would have preferred! The apostle Peter went so far as to try to talk Jesus out of it, but he was met with a stern rebuke (Matthew 16:21-23).

Why is evolution so disconcerting to Christians?

The problem of suffering throughout all of human history is troubling enough for us to reconcile with a loving, personal God. But in addition to that, the discovery of vast numbers of fossils reveals that death has taken place on a far greater scale than we had ever imagined. Both the wide variety of extinct creatures and their sheer numbers is quite staggering, and it raises questions about our Creator:

The picture of a God who is immune from suffering and death but who forces organisms through millions of generations and extinction is disturbing to those who believe in a God of love.⁷

The mass extinction of life on earth was already well established by the early 19th century—decades before Darwin’s research—and extinction can be empirically verified independent of any theory of evolution.⁸ The fact that the earth’s crust is a veritable graveyard of long-lost creatures is deeply troubling, and as late as the 1790’s, distinguished intellectuals such as Thomas Jefferson denied the very possibility of extinction.⁹

But in addition to the reality of species extinction, the theory of evolution by natural selection proposes that new species also arise in an environment containing widespread pain and death. Both the creatures that are now living and those that are gone are tainted by an “acrid smell of death”.¹⁰ It makes us wonder, if our Creator is not the God of the dead, but of the living (Mk. 12:27), where is God’s presence in the evolutionary picture?

In all honesty, creation through evolution is not what we would expect from God, but Scripture is full of examples in which God acts in unexpected ways. After all, God’s choosing to undergo an agonizing death on a cross is not what we would expect from the all-powerful Creator of the universe, either. In both cases, new life comes about through pain, suffering, and death. As George Murphy puts it,

A priori ideas about God have to be overcome, and God's character has to be learned from God's self-revelation.¹¹

God’s fullest self-expression is in Jesus Christ himself, one who is intimately familiar with and personally endured creaturely pain and death. The theology of the cross reveals that God's self-revelation takes place in situations of suffering, loss, and apparent hopelessness, much like situations that occur through natural selection.¹²

The crucifixion is disconcerting too

Not only is creation through evolution an unexpected and unsettling process, but so is the crucifixion of Jesus! Killing someone by hanging them on a cross is an unbearably painful, prolonged, humiliating form of death. It was such a horrific type of public execution that it wasn't until after the Roman Empire stopped the practice of crucifixion—and people no longer witnessed it personally—did the cross become a visual object of devotion.¹³ Our culture is sufficiently removed from crucifixion that we are desensitized to its original significance, but to connect it to our current context, imagine the reaction you would get by wearing jewelry designed to look like an electric chair.¹⁴

Once we are more attuned to the brutality of crucifixion, it seems all the more striking that the cross is the sign of God’s work, what George Murphy calls “the trademark of God”.¹⁵ The suffering and death of Jesus is featured prominently in the Gospels, but the crucifixion-resurrection pattern is strongly resonant within the Old Testament, too. Israel suffered and toiled as slaves in Egypt for centuries before they were rescued in the Exodus, bringing life to a people who were spiritually dead. Centuries later, the nation of Israel would experience death again when the Babylonians destroyed the Davidic monarchy, burned their Temple, killed their people, and sent many into exile.¹⁶ Neither Israel (God’s chosen people) nor Jesus (God’s own son) were spared from death and suffering; rather, suffering seems to have been the way in which God re-forms and renews humanity to fully bear His own image.

Redemption extends to all of creation

Fortunately, God’s story does not end with death. God gives new life after his creatures have been subjected to terrible circumstances. Redemption was promised to Israel itself—Ezekiel’s vision of the valley of dry bones describes how God would renew His chosen people (Ezek 37:1-14). Later, the astonishing resurrection of Jesus made salvation possible not only for Jews, but for all people in Christ (Gal 3:26-29). Ultimately, the New Testament makes it clear that God’s renewal will encompass the entire Creation:

For God was pleased to have all his fullness dwell in him, and through him to reconcile to himself all things, whether things on earth or things in heaven, by making peace through his blood, shed on the cross. (Colossians 1:19-20)

With all wisdom and understanding, he made known to us the mystery of his will according to his good pleasure, which he purposed in Christ, to be put into effect when the times reach their fulfillment—to bring unity to all things in heaven and on earth under Christ. (Ephesians 1:8-10)

Christians are accustomed to thinking of the death of Christ in regard to humans, but our culture rarely acknowledges God plan for the redemption of His entire creation. This is partly attributable to the fact that discussions of creation and origins are often separated from the topic of salvation.¹⁷ In doing so we tend to marginalize Jesus as we argue about Genesis. Rather than fall into this trap, if we view nature through a theology of the cross, we will see Christ as both the alpha and the omega point in discussions of life’s history and life’s future. With this perspective, we are more apt to sense our solidarity with the rest of creation as we wait in eager anticipation of a glorious future:

The creation waits in eager expectation for the children of God to be revealed. For the creation was subjected to frustration, not by its own choice, but by the will of the one who subjected it, in hope that the creation itself will be liberated from its bondage to decay and brought into the freedom and glory of the children of God. (Romans 8:19-21)

Conclusion

As part of the Church’s conversation about the problem of natural evil, this essay is meant to be a brief introduction to a “theology of the cross”. One can explore this concept in greater detail in Murphy’s book The Cosmos in the Light of the Cross. While there is a lot more to be said, let me conclude with the following observation: though evolution may not be compatible with some interpretations of Christianity, evolutionary creation is certainly compatible with the crucified Christ and the theology of the cross. In the person of Jesus, God suffers with the world and ultimately redeems it. As George Murphy puts in, “The world's pains are God's stigmata.”¹⁸

Explore this Topic Further

• Miller, Keith. “And God saw that it was good”: Death and Pain in the Created Order. BioLogos series
• Murphy, George L. The Cosmos in the Light of the Cross. Harrisburg, PA: Trinity Press, 2003.
• Murphy, George L. “Cross, Evolution, and Theodicy: Telling It Like It Is”. In The Evolution of Evil. Edited by G. Bennett, M.J. Hewlett, T. Peters, and R.J. Russell. Göttingen: Vandenhoeck & Ruprecht, 2008.
• Southgate, Christopher. The Groaning of Creation: God, Evolution, and the Problem of Evil. Louisville, KY: Westminister John Knox Press, 2008.

Notes

1. Murphy, George L. The Cosmos in the Light of the Cross. Harrisburg, PA: Trinity Press, 2003.
2. Murphy, p34
3. “CRUX Sola Est Nostra Theologia,” in D. Martin Luthers Werke, Kritische Gesammtausgabe (Weimar: Hermann Boehlau, 1892), 5:172. The captitalization is in the original. Cited in Murphy, p26.
4. Murphy, p108
5. Murphy, p4
6. Murphy, p43
7. Murphy, p3
8. Some Christians ascribe animal death to some combination of Adam’s fall and Noah’s flood, but this does not resolve the problem that the animals are still suffering and dying through no fault of their own. See Keith Miller’s BioLogos series Death and Pain in the Created Order for the limitations inherent in a fall-based theodicy.
9. Rudwick, Martin. The meaning of fossils: Episodes in the history of paleontology. Chicago, University of Chicago Press, 1985.
10. See Jeff Schloss’ BioLogos essay Evolution, Creation, and the Sting of Death
11. Murphy, p63
12. Murphy, p122
13. Murphy, p27
14. This example is drawn from an evangelical outreach event held by a Christian student group in Innsbruck, Austria. On campus one day, they started conversations with their classmates by asking the question, “Would you wear an electric chair on your neck?”
15. Murphy, George L. The Trademark of God: A Christian Course in Creation, Evolution, and Salvation. Wilton, Conn.: Morehouse-Barlow, 1986.
16. Murphy, Cosmos in the Light of the Cross, p 31-32.
17. Murphy, p35
18. Murphy, p87

1. We are a world that longs for goodness and beauty, whether we are believers or not.

2. The data from emerging neuroscience and attachment research points us to a world of goodness and beauty.

3. This same data reflects and energizes the biblical narrative. Creation itself points us to the very story God is telling.

4. One of the most integral processes—that helps us get to truth and beauty—involves the changing (and renewal) of our minds. The renewal of our minds is a subset of the renewal of everything. God is on a mission of complete renewal, albeit on his timetable.

In this mission for renewal, one of the most important aspects is the interpersonal experience of being known. We change primarily not by what we know, but by how we are known. We live in a culture that is really good at knowing things, but not so good at being known.

5. Our first reaction is likely to be, “How will knowing this stuff change me?” But the biblical narrative is not just about us as individuals, it is about a world of mercy and justice. In order for us to have mercy and justice, we don’t do it primarily as individuals, we do it as institutions. God’s renewal is not just about changing us, it is about changing everything.

See part 2 for the second half of Dr. Thompson's presentation

In Part 2 of this series, we concluded by noting that, as Christian geologists willing to consider the possibility, we find no compelling evidence that the earth’s geological features can be explained by a global Flood. Here we consider three lines of evidence: global salt deposits, the order of deposition of sediment layers in the Grand Canyon, and the sequence of fossils in geological strata.

Salt Deposits

There are many places around the earth with layers of salt, some thousands of feet in thickness. Just off the southern coast of the United States in the Gulf of Mexico, thick salt deposits sit beneath thousands of feet of sediment (Fig. 1). These deposits lie within the layers that are said to have been deposited by the Flood.

We understand how salt beds form. At locations such as the Bonneville Salt Flats of Utah, or at the Dead Sea at the border of Israel and Jordan, salt is actively forming. Salt beds form when water is evaporated. During evaporation, the concentration of dissolved ions increases until the water cannot hold the salt in solution anymore and mineral salt begins to form. If a presently unknown or poorly understood process could produce salt without evaporation, as argued by young-earth advocates¹, it would quickly dissolve as soon as it came into contact with flood water, just as the salt from your saltshaker rapidly dissolves when added to water or moist food.

One might argue that the waters from the Flood could have evaporated to leave behind the salt deposits we see today, but there is a serious problem. The thousands of feet of sediment on top of the salt is also said to be from the Flood, meaning the flood waters cannot have evaporated to produce the salt and still be present and violent enough to transport thousands of feet of sediment to the same location. In other words, a single flood cannot be called upon to explain both the salt and the overlying sediment. For those who wish to argue that natural processes could have been vastly different during the Flood, there are at least two replies. First, under such a scenario, there is no point in Flood Geology studies any more than in normal studies, for nothing could be gained by the study of unknowable processes. A more important question, however, would be to ask why God would alter natural processes just to make Flood sediments look like they are not flood sediments. What would the purpose be? (We will revisit this thought later.)

Grand Canyon: Order of Deposition

The Grand Canyon is made up of a sequence of layers that defies any reasonable attempt to explain by a single flood. The alternating layers of limestone, sandstone and shale each form in unique environments. If these deposits were formed at different times under various sea-level stages, it is quite simple to explain the different grain sizes and rock types as a function of depth and distance from the shore line. If explained with a single catastrophic flood that abided by God’s natural laws of physics and chemistry, logic must be stretched beyond the breaking point.

As a very simple observation, consider instructions given in virtually every gardening book. A good soil will have a mix of sand, silt and clay. To determine the quality of your soil, you take a handful or two, put it in a clear container, add water and shake it up. When you stop shaking, the coarse grained material will settle out first resulting in a sequence of layers: sand on the bottom, then silt, then clay. You can readily see how much of each you have by the thickness of each layer.

This is informative of what we see in flood deposits. As moving flood waters slow down, finer and finer grained sediment settles out resulting in a “fining upward” sequence. If most of the Grand Canyon layers were laid down by the Flood, then we should see the same thing – a “fining upward” sequence. Instead, we see a series of alternating layers of fine and coarse grained material, with smaller-scale alternating layers within the larger ones (Fig. 2). Increasing the violence of a flood does nothing to negate the standard order of deposition. Repeated surging of flood waters across the surface likewise offers little explanatory power; in this case we might expect successive layers, each with their own “fining upward” sequence, but such is not what is observed. Further, the Grand Canyon includes multiple layers of limestone, which are never found in flood deposits of any magnitude. Even in floods as massive as one thought to have catastrophically deluged the once dry Mediterranean Sea basin with thousands of feet of water – limestone beds are conspicuously absent.

Fossil Sequence

If a massive flood were responsible for the fossil record, what would we expect to see? If the Flood was violent enough to rip chunks of rock up from the earth and move entire continents (standard Young Earth claims)², then it should be obvious that life forms from every imaginable niche would be tumbled and mixed together (Fig. 3a). We should find numerous examples of mammoths mixed with triceratops, and pterodactyls mixed with sparrows. Ferns and meadow flowers should be found in the same deposits, along with trilobites and whales. Further, we should find all major life forms still living today, for Genesis 7:8-9 is clear in stating that all terrestrial animals were preserved on the ark.

What we actually observe is far different (Fig. 3b). There is an orderly sequence where trilobites only occur in very old rocks, dinosaurs in later beds, and mammoths in still later layers. Organisms like flowers and ferns are present together in more recent deposits, but only ferns with no flowers are found in older deposits. Some readers will recognize this as an example from the “geologic column” and be tempted to discount it as a fabrication. For those thinking this way, consider what Henry Morris had to say in both editions of Scientific Creationism:

“Creationists do not question the general validity of the geologic column, however, at least as an indicator of the usual order of deposition of the fossils…”⁵

If we revisit the Grand Canyon for a moment, is it not striking that there is not a single dinosaur, mammoth or bird in the entire exposed sequence? Not one. To find these, you have to go to younger sediments found in deposits outside the canyon that have not been fully eroded away yet. How could such a lack of mixing be possible if the Flood was violent enough to move continents?

Let me be clear. I do not reject dualism on account of any kind of philosophical or other kind of argument. In fact, I find many arguments against dualism—philosophical and otherwise—to be pretty weak specimens. I’m what a friend calls an antecedent materialist. In other words, I come to the discussion assuming I am a physical object, since that is what I have always seemed to myself to be for as long as I can remember. A non-physical soul doesn’t explain anything about consciousness that cannot be explained without it, and it is furthermore a wholly unnecessary hypothesis for many religious doctrines, despite intuitions to the contrary by many religious believers. For example, belief in an afterlife, belief in the peculiarly Christian idea of the incarnation of Christ, as well as the belief that we human beings bear the image of God—none requires belief in a non-physical soul in order to be made sense of. So until I am confronted with some knock-down, drag-out argument to the contrary, or until I am presented with some phenomena that cannot be accounted for in naturalistic terms or, yet again, until I have something resembling a conversion experience that forces me to renounce my physicalism, I'm sticking with it.

To go a bit further, let’s consider several theological doctrines that seem to cut against a physicalist conception of human personhood. These constitute perhaps the three most common objections Christian physicalists receive to their physicalism. After I address these objections, I will say a little more about the content of my own physicalist conception of human persons, The Constitution View. Perhaps in a future post I can say a little bit about the science of consciousness itself and address some of the most common objections to physicalism based on that mysterious phenomenon.

Theological Objections to Physicalism about Humans

The Incarnation of Christ

The doctrine of the incarnation of Christ is a central tenet of Christianity, and it may seem that the doctrine is inconsistent with a physicalist conception of human personhood. Yet I believe a physicalist view of human persons—like my own—actually makes better sense of the incarnation than does dualism. Let me explain.

The putative problem for the physicalist is this: if God (or the second person of the Trinity in particular) is essentially a non-physical being, then how could such a being become purely physical without losing an essential property? And if the second person of the Trinity loses an essential property, then wouldn’t he not simply cease to be fully God but simply cease to exist? (An essential property is a property a thing has and can’t lack without ceasing to exist. For example, my dog has the property of being a canine. He can’t lose that property without ceasing to exist—he is essentially a canine.)

Well, according to the Chalcedonian formulation, the incarnate Christ is one Person with two natures, a fully divine nature (that of the Second Person of the Trinity) and a fully human nature (that of Jesus from Nazareth). The Constitution View I hold divides things just where one would expect—between the human nature and the divine nature of the single person. And keep in mind, by the way, that the person of Christ is not human; he is divine, being the second person of the Trinity. But this one person, in the incarnation, had two natures--human and divine. In this understanding of the dual natures, Christ is wholly non-physical in his divine nature and wholly physical in his human nature. Now consider the somewhat-awkward cleavage Substance Dualists must offer. According to Substance Dualism, Christ is wholly non-physical in his divine nature and partly physical and partly non-physical in his human nature. Not especially elegant. To my mind, far from being unable to accommodate the doctrine of the incarnation, my physicalist view of human persons is actually better able to explain the doctrine than is dualism.

Notice that if what I said above is true, the way this objection is often put contains an important mistake in assuming that the second person of the Trinity ceased to be something he was apart from the incarnation. Indeed, the second person of the Trinity did not become purely physical (or even partly physical!). The second person of the Trinity did not give up non-physicality in the incarnation. Remember: one person (Divine and non-physical) with not one but (in the incarnation) two natures—one non-physical, the other physical. How can that be? I don’t have the slightest idea; but, the mystery of the incarnation is not explained away by any account, be it dualist or physicalist.

The Imago Dei

Now, what of the imago Dei or image of God? If it’s true that we human persons are wholly physical beings—as any version of physicalism must claim—then what does it now mean to say that we have been created in God’s image? Doesn’t having been created in the image of God just mean having a non-physical soul and the features of intellect, will and emotion that characterize soul? I do not believe that our having been created in the image of God means that we are non-physical as God is non-physical. What then does it mean?

Well, there are many ways of understanding the claim that we human beings image God. One might mean that we image God when we care for Creation and contribute to the terrestrial flourishing of the Created order. This, after all, is what the Bible means when it speaks of our having been given “dominion”. We are God’s vice-regents, as it were. To have dominion is to care for others, including non-human “others” like oceans and streams, octopus and salamander; in other words to have dominion is tend to the well being of all the earth. Second, one might mean that we image God when we live in loving relation to other human beings and invest ourselves in their flourishing and well being. For we are essentially persons-in-relation. Since God is a Trinity, it is not surprising that we should image God in virtue of our essentially social nature. The tenor of the relation between the three persons of the trinity is one of a harmonious and free exchange of love and joy. So engaging in acts of mercy, hospitality, love, kindness, etc. is to act like God. In fact, we image God when we image Jesus, who welcomed the outcast, fed the hungry, clothed the naked, hated evil and delighted in doing the work of the Father. Finally, one might claim that we image God in our suffering. God is love. To love is to open oneself up to suffering. And suffering love is God-love.

Now of course none of these ways that I have mentioned that we image God rules out the possibility that we are wholly or partly non-physical beings; but it doesn’t imply it either. The fact that we have been created in the image of God is perfectly compatible with the claim that we are wholly physical beings. Indeed, there is nothing in the doctrine of the imago Dei, rightly understood, that entails a dualist view of human nature.

But even if neither the doctrine of the incarnation nor the doctrine of humanity as reflecting the imago Dei require that we be at least partially non-physical beings, what about the issue of life after death? I’ll address that third challenge to a Christian physicalism tomorrow.

Yet it doesn’t follow that we are mere animals, and our rationality is what sets us apart from the rest of the genus. Indeed, for Aristotle, and for Aquinas after him, rationality is unlike our other capacities in having an essentially immaterial and non-bodily aspect. The reason has to do with our capacity to form abstract concepts, which underlies all our other distinctively rational activities. It is because you can grasp what it is to be a man -- not just this particular man or that one, but any possible man, man as a universal -- that you can go on to form judgments like the judgment that all men are mortal, can reason from that judgment together with the judgment that Socrates is a man to the conclusion that Socrates is mortal, and so forth.

There are several arguments that establish that this capacity for abstract thought cannot in principle be reduced to or otherwise entirely explained in terms of brain activity, even if brain activity is part of the story. The arguments have their roots in Plato and Aristotle and have been defended in recent years by Aristotelian philosophers like Mortimer Adler, John Haldane, David Oderberg, and James Ross.¹ Answering the various objections to (and misunderstandings of) these arguments takes some work, but the basic idea can be set out fairly simply.²

Let us take as an example the thought that triangles have three sides. For that thought (or any other) plausibly to be material, it would have to be identifiable with something like a symbol or set of symbols encoded in the brain -- something analogous to the symbols encoded in the electronic circuitry of a computer. But there is no way a thought could be entirely reducible to that sort of thing. For no material symbol could possibly have the determinate or unambiguous content that at least many of our concepts have; and no material symbol could possibly have the universal reference that our concepts have.

Consider the most unambiguous symbol of triangularity there could be -- a picture of a triangle, such as the one to the right. Now, does this picture represent triangles in general? Or only isosceles triangles? Or only small isosceles triangles drawn in black ink? Or does it really even represent triangles in the first place? Why not take it instead to represent a dinner bell, or an arrowhead? There is nothing in the picture itself that can possibly tell you. Nor would any other picture be any better. Any picture would be susceptible of various interpretations, and so too would anything you might add to the picture in order to explain what the original picture was supposed to represent. In particular, there is nothing in the picture in question or in any other picture that entails any determinate, unambiguous content. And even in the best case there is nothing that could make it a representation of triangles in general as opposed to a representation merely of small, black, isosceles triangles specifically. For the picture, like all pictures, has certain particularizing features -- a specific size and location, black lines as opposed to blue or green ones, an isosceles as opposed to scalene or equilateral shape -- that other things do not have.

Now what is true of this “best case” sort of symbol is even more true of linguistic symbols. There is nothing in the word “triangle” that determines that it refers to all triangles or to any triangles at all. Its meaning is entirely conventional; that that particular set of shapes (or the sounds we associate with them) have the significance they do is an accident of the history of the English language. But something similar could be said of any material symbols whatever. Even if we regarded them as somehow having a built-in meaning or content, they would not have the universality or determinate content of our concepts, any more than the physical marks making up the word “triangle” or a picture of a triangle do. But then the having of a concept cannot merely be a matter of having a certain material symbol encoded in the brain, even if that is part of what it involves. Nor can it merely be a matter of having a set of material symbols, or a set of material symbols together with certain causal relations to objects and events in the world beyond the brain. For just as with any picture or set of pictures, any set of material elements will be susceptible in principle of alternative interpretations; while at least in many case, our thoughts are not indeterminate in this way.

We might understand the point by analogy with sentences. If you are going to use the English sentence “Snow is white,” you are typically going to have to express it via some material medium -- ink marks, pixels, sound waves, or what have you. All the same, the meaning of that sentence cannot be accounted for in terms of any of the physical properties of those media. There is nothing in the shapes of the letters that make up the words of the sentence, or the chemistry of the ink in which they are written, or the physics of the compression waves in the air that you generate when uttering them, that makes them refer to snow or to whiteness or indeed to anything at all. A sentence is a seamless unity of the material and the immaterial, and it is created by another seamless unity of the material and immaterial -- a human being.

At this point there will no doubt be those who object that positing ectoplasm or spook stuff is hardly a better explanation of thought than an appeal to brain activity is. And that is quite true. But then, I said nothing about ectoplasm or spook stuff in the first place. When a mathematician points out that it is just muddleheaded to speak of the square root of 25 as if it were a kind of physical object, it would be silly to accuse him of believing that the square root of 25 is made out of ectoplasm or spook stuff. If your picture of reality cannot accommodate numbers alongside physical objects, that is your problem, not his. Mathematics simply provides a powerful example of a body of truths that cannot be captured in the language of physics, chemistry, neuroscience, and the like.

Similarly, to point out that whatever a thought is, it cannot in principle be reduced to the physical properties of brain activity, is simply to provide another example of an aspect of reality that cannot be entirely captured in such language. Only if we assume that all of reality must be so captured will this sound odd, but that we should not assume this is, of course, precisely the point. And if we do assume it, we are doing so in the face of the evidence, and not on the basis of the evidence. For it is precisely what we know about thought from our everyday familiarity with it -- such as the fact that it sometimes has a determinate content, and a universal reference -- that tells us that it cannot be entirely material, just as it is what we know about numbers from our everyday familiarity with them that tells us that they cannot be physical objects.

But doesn’t neuroscience show that there is a tight correlation between our thoughts and brain activity? It does indeed. So what? If you smudge the ink you’ve used to write out a sentence or muffle the sounds you make when you speak it, it may be difficult or impossible for the reader or listener to grasp its meaning. It does not follow that the meaning is reducible to the physical or chemical properties of the sentence. Similarly, the fact that brain damage will seriously impair a person’s capacity for thought does not entail that his thoughts are entirely explicable in terms of brain activity.

Aristotle and Aquinas, though they regarded the human intellect as immaterial, would not have been surprised in the least by the findings of modern neuroscience. Indeed, they would have been surprised had neuroscience not turned up the correlations it has. This will sound surprising if you take Descartes as your paradigm of a philosopher who affirms the immateriality of the human mind. But defending Descartes is exactly the reverse of what I have been doing. For it was Descartes who substituted the real, concrete human being -- a seamless unity of the physical and the mental, the bodily and the immaterial -- with a bizarre patchwork of abstractions of his own devising. Materialists have followed him ever since. Materialism is just a riff on Cartesianism, not its opposite. Tomorrow, I’ll explain exactly what I mean.

Notes

1. See Mortimer Adler, Intellect: Mind Over Matter (New York: Collier Books, 1990); J. J. C. Smart and J. J. Haldane, Atheism and Theism, Second edition (Oxford: Blackwell, 2003), pp. 96-109; David S. Oderberg, “Hylemorphic Dualism,” Social Philosophy and Policy 22 (2005); and James Ross, “Immaterial Aspects of Thought,” Journal of Philosophy 89 (1992).
2. I provide an exposition and defense of such arguments in chapter 7 of my book Philosophy of Mind and chapter 4 of my book Aquinas. An especially detailed exposition and defense can be found in my article “Kripke, Ross, and the Immaterial Aspects of Thought,” forthcoming in the American Catholic Philosophical Quarterly.

What Is at Stake?

What does it mean to be human? In what ways, if any, is our essential humanity tied to body and soul, mind and brain? This is not the stuff of mere curiosity. A host of pressing issues are at stake:

• Is there anything about humans that our mechanical creations, our innovations in Artificial Intelligence, will be unable to duplicate?
• What view of the human person helps us to find what we want to know about ourselves theologically — about sin, for example, as well as moral responsibility, repentance, and growth in grace?
• Am I free to do what I want? Given what we have learned about brain functioning, how might we understand the “free” in “free will”?
• What portrait of the human person is capable of casting a canopy of sacred worth over human beings, so that we have what is necessary for discourse concerning morality and for ethical practices?
• If humans, like sheep, can be cloned, will the resulting life form be a “person”?
• How should we understand “salvation”? Does salvation entail a denial of the world and embodied life, focusing instead on my “inner person” and on the life to come?
• How ought the church to be extending itself in mission? Mission to what? The spiritual or soulish needs of persons? Society-at-large? The cosmos?
• What happens when we die? What view(s) of the human person is consistent with Christian belief in life-after-death?

For many, and not least for many Christians, what makes a human genuinely human is the identification of the human person with his or her soul. From the second century on, theologians debated the origin of the soul: Are souls created by God ex nihilo at the moment of their infusion into the body? Are body and soul formed together? Are souls preexistent? Indeed, in the late-second century it was clear to many, as the Letter to Diognetus puts it, that “the soul dwells in the body, yet is not of the body” (1.27). Traditionally, systematic theology has discussed the uniqueness of humanity in two theological loci: human creation in the divine image and the human possession of a soul. Often these two are reduced to one, with the soul understood as the particular consequence of creation in God’s image.

For persons of faith — Christians included, but many others besides — the idea of a soul separable from the body is not only intuitive but necessary. We have regularly appealed to the soul as proof that humans are not mere animals, and so as a foundation for our views of the sacredness of human life. Moreover, Christians generally have derived from belief in the existence of the soul their affirmation of the human capacity to choose between good and ill. Further, the existence of a nonphysical soul, distinct and separable from the body, is typically regarded as the means by which human identity can cross over the bridge from this life to the next. Indeed, traditional Christian thought has tended to regard the body as frail and finite, the soul as immortal.

But it is the human possession of a “soul” that science now questions. When, as neurobiology and evolutionary psychology increasingly urge, the attributes and capacities traditionally allocated to the human soul are conditioned at point after point by biological processes, on what basis can belief in a soul be maintained? If science is generating “a radically new understanding of what it means to be human,”³ then those of us in the church must prepare ourselves for searching questions about the propriety of Scripture and traditional Christian thought in our talk about humanity, salvation, the end time, and more.

Before we engage too much in worried hand-wringing, however, we should ask whether our situation is so dire. Do these innovations in our understanding of personhood in fact call into question our deepest beliefs as Christians? Interdisciplinary study — with contributions from neuroscience, but also from biblical studies, theological studies, ethics, and philosophy (see “Further Reading,” below) — are demonstrating that emerging scientific portraits of the human person are neither as novel as we might imagine, nor as threatening to the essential tenets of Christian faith.

Biblical Contributions

In the context of current discussion on the nature of the human person, the Christian Scriptures have two primary contributions. First, taken as a whole, the biblical witness is fully congruent with a view of the person that affirms the human being as bio-psycho-spiritual unity. Neurobiological evidence and/or philosophical arguments favoring some form of monism are not at all hostile to the witness of Scripture. Second, we must recognize that the Old and New Testaments do not define the human person in essentialist but above all in relational terms. Put differently, the Bible’s witness to the nature of human life is at once naive and profound. It is naive not in the sense of gullibility or primitiveness, but because it has not worked out in what we may regard as a philosophically satisfying way the nature of embodied existence in life, death, and afterlife. It is profound in its presentation of the human person fundamentally in relational terms, and its assessment of the human being as genuinely human and alive only within the family of humans brought into being by Yahweh and in relation to the God who gives life-giving breath. This non-negotiable biblical insight is being recovered by some scientists today — e.g., by J. Polkinghorne and W.S. Brown, each of whom has urged that the notion of “soul” be recast in relational terms.⁴

We can press further. First, Scripture outlines a series of qualities of the human person that contrast sharply with the “modern self” derived from dualistic portraits. In his Sources of the Self, C. Taylor finds that, for modern folk, personal identity has come to be shaped by such assumptions as self-sufficiency, self-determination, and self-referentiality (“I am who I am”); that persons have an inner self, which is the authentic self; and that self-autonomy and self-legislation are basic to authentic personhood (Harvard University Press, 1989). Without majoring on the notion of a metaphysical entity of the “soul,” Taylor’s analysis nonetheless intimates how modern, personal identity has been cultivated in the garden of anthropological dualism.

In Scripture, however, we find such emphases as the following: the construction of the self as deeply embedded in social relationships and thus the importance of dependence/interdependence for human identity; a premium on the integrity of the community and thus the contribution of individuals to that integrity; the assumption that a person is one’s behavior; an emphasis on external authority — that is, the call to holiness is a call to a human vocation drawn from a vision of Yahweh’s “difference”; and the reality of dualism vis-à-vis good/evil, resident in and manifest both outside and inside a person. The line from a substance dualism that locates personal essence in the “soul” to this vision of personal identity is not easily drawn.

The point is that the construction of personal identity that pervades modernity is at odds with biblical anthropology at almost every turn, while the witness of Scripture and the findings of neuroscience are converging at significant points.

Second, negatively, we err when we imagine that it is the “soul” that distinguishes humanity from non-human creatures. Aristotle is closer to the biblical tradition in his view that the soul is that in virtue of which an organism is alive (On the Soul 2.1 §§412a-413a10). Given this conceptualization, there is no particular reason to limit the idea of “soul” to the human person. Within the Old Testament, “soul” (Hebrew: nepheš) refers to life and vitality — not life in general, but life as instantiated in human persons and animals. Nepheš is not a thing to have but a way to be. To speak of loving God with all of one’s “soul,” then, is to elevate the intensity of involvement of one’s whole being. Accordingly, the Common English Bible gets it right when it translates “the first and greatest commandment” in this way: “You must love the Lord your God with all your heart, with all your being, and with all your mind” (Matthew 22:37). Morever, in the creation accounts of Genesis 1-2, the Hebrew term used of human beings in 2:7, nepheš, is also used with reference to all sorts of wildlife, to everything “in which there is life (nepheš)” (1:30). This demonstrates incontrovertibly that “soul” (nepheš) is not, under this accounting, a unique characteristic of the human person. Accordingly, one might better translate Genesis 2:7 with reference to the divine gift of life: “the human being became a living person” — or, to quote again from the Common English Bible: “The human came to life.”

Third, thinking still of Genesis 2, it is instructive that the same texts that are silent on the infusion of a human soul into a dust-created body nevertheless distinguish by their use of the term nepheš between a being that has life and lifelessness. This speaks against any dualism that deprecates the body in favor of the soul and against any conceptualization of disembodied human existence in this life or the next. It also contravenes the widely held view that the quality of human life is vested in some thing or quality intrinsic to the individual person and that, in order to speak meaningfully of an afterlife, this “thing” must survive death. The soul does not distinguish human life as human or of particular value, but the graciousness of God does. Scripture situates the human family within the grand narrative of God’s doing; this narrative places a premium on human relatedness to God, humanity, and the cosmos because it is determined by God’s own character; and it is precisely within this narrative that the human creature draws both its value and its reason for being.

Hence, from a vantage point within the biblical narrative, avenues determined by autonomous individualism, interior psychic and/or mental processes, or the behavior of a vast assembly of nerve cells are mistaken, however well-worn they may have become. Although each of these accounts might appear to support a workable portrait of the human person and of human health, none of these carry us far in our concern to address our deepest human questions about what it means to be fully human.

What does it mean to be human? From a perspective within the biblical narrative, the way forward is marked by an account that rejects the necessity of a separate, metaphysical entity such as a soul to account for human capacities and distinctives; that underscores the material location of the human person in relation to the created order; that refuses to reduce personal identity to our neural equipment but rather emphasizes the personal contribution and relatedness of human beings to the human family and the cosmos; and thus that has as its primary point of beginning and orientation the human in a partnering relationship with God.

Further Reading

• W.S. Brown et al., eds., Whatever Happened to the Soul? Scientific and Theological Portraits of Human Nature (Fortress, 1998)
• J.B. Green, Body, Soul, and Human Life: The Nature of Humanity in the Bible (Baker Academic, 2008)
• J.B. Green, ed., What about the Soul? Neuroscience and Christian Anthropology (Abingdon, 2004)
• M.A. Jeeves, ed., Rethinking Human Nature: A Multidisciplinary Approach (Eerdmans, 2011).

Notes

1. P. Churchland, Brain-Wise. MIT Press, 2002: 2
2. S. Blakeselee, “Humanity? Maybe It’s All in the Wiring,” New York Times, 9 December 2003, F1
3. T. Metzinger, “Consciousness Research at the End of the Twentieth Century,” in Neural Correlates of Consciousness: Empirical and Conceptual Questions. ed. T. Metzinger; MIT Press, 2000: p. 6
4. See J. Polkinghorne, “Eschatology: Some Questions and Some Insights from Science,” in The End of the World and the Ends of God. ed. J. Polkinghorne and M. Welker. Trinity Press International, 2000: 29-41 and W. S. Brown, “Cognitive Contributions to Soul,” in Whatever Happened to the Soul? ed. W.S. Brown et al.; Fortress, 1998: 99-125.

For more, be sure to read our FAQs How are the ages of the Earth and universe calculated? and What scientific evidence do we have about the first humans?, as well as our recent infographic How Do We Know the Earth is Old?.

Author's Note from Joy Walters

As I mentioned in my first post, I grew up skeptical of the whole idea of evolution. One contributor to my disbelief was the lengthy timescale for the “tree of life” that was presented with the theory. I would hear, for example, that dinosaurs lived hundreds of millions of years ago, but there was no explanation of why this was true; it was just given as a fact. No one explained the methods of dating, and so I thought biologists simply estimated the ages of species to fit their preconceived notions of how long it would take for one species to emerge from another. It also seemed like the ages were periodically revised and extended farther back in time, and I figured scientists needed to manipulate numbers to make evolution plausible. This, in my mind, made the theory both unbelievable and dismissible.

Once I learned about the techniques used to date fossils, I realized that my first impressions were wrong; the ancient ages of species are scientific determinations rather than scholarly conjectures. However, I have found in recent conversations that Christians remain skeptical of old ages and the evolutionary time scale. For this reason, I wanted the videocast to address the process of fossil dating (what the methods are and why they are accurate) while focusing on cases where hominid fossils were discovered and dated using these very methods. My hope is that Believers would be informed about the evidence for human evolution and its scientific grounding.

There are two opposite errors which need to be countered about the fossil record: 1) that it is so incomplete as to be of no value in interpreting patterns and trends in the history of life, and 2) that it is so good that we should expect a relatively complete record of the details of evolutionary transitions within all or most lineages.

What then is the quality of the fossil record? It can be confidently stated that only a very small fraction of the species that once lived on Earth have been preserved in the rock record and subsequently discovered and described by science.

There is an entire field of scientific research referred to as "taphonomy" -- literally, "the study of death." Taphonomic research includes investigating those processes active from the time of death of an organism until its final burial by sediment. These processes include decomposition, scavenging, mechanical destruction, transportation, and chemical dissolution and alteration. The ways in which the remains of organisms are subsequently mechanically and chemically altered after burial are also examined -- including the various processes of fossilization. Burial and "fossilization" of an organism's remains in no way guarantees its ultimate preservation as a fossil. Processes such as dissolution and recrystallization can remove all record of fossils from the rock. What we collect as fossils are thus the "lucky" organisms that have avoided the wide spectrum of destructive pre- and post-depositional processes arrayed against them.

Soft-bodied organisms, and organisms with non-mineralized skeletons have very little chance of preservation under most environmental conditions. Until the Cambrian nearly all organisms were soft-bodied, and even today the majority of species in marine communities are soft-bodied. The discovery of new soft-bodied fossil localities is always met with great enthusiasm. These localities typically turn up new species with unusual morphologies, and new higher taxa can be erected on the basis of a few specimens! Such localities are also erratically and widely spaced geographically and in geologic time.

Even those organisms with preservable hard parts are unlikely to be preserved under "normal" conditions. Studies of the fate of clam shells in shallow coastal waters reveal that shells are rapidly destroyed by scavenging, boring, chemical dissolution and breakage. Occasional burial during major storm events is one process that favors the incorporation of shells into the sedimentary record, and their ultimate preservation as fossils. Getting terrestrial vertebrate material into the fossil record is even more difficult. The terrestrial environment is a very destructive one: with decomposition and scavenging together with physical and chemical destruction by weathering.

The potential for fossil preservation varies dramatically from environment to environment. Preservation is enhanced under conditions that limit destructive physical and biological processes. Thus marine and fresh water environments with low oxygen levels, high salinities, or relatively high rates of sediment deposition favor preservation. Similarly, in some environments biochemical conditions can favor the early mineralization of skeletons and even soft tissues by a variety of compounds (eg. carbonate, silica, pyrite, and phosphate). The likelihood of preservation is thus highly variable. As a result, the fossil record is biased toward sampling the biota of certain types of environments, and against sampling the biota of others.

In addition to these preservational biases, the erosion, deformation and metamorphism of originally fossiliferous sedimentary rock have eliminated significant portions of the fossil record over geologic time. Furthermore, much of the fossil-bearing sedimentary record is hidden in the subsurface, or located in poorly accessible or little studied geographic areas. For these reasons, of those once-living species actually preserved in the fossil record, only a small portion have been discovered and described by science. However, there is also the promise of continued new and important discovery.

The forces arrayed against fossil preservation also guarantee that the earliest fossils known for a given animal group will always date to some time after that group first evolved. The fossil record always provides only minimum ages for the first appearance of organisms.

Because of the biases of the fossil record, the most abundant and geographically widespread species of hardpart-bearing organisms would tend to be best represented. Also, short-lived species that belonged to rapidly evolving lines of descent are less likely to be preserved than long-lived stable species. Because evolutionary change is probably most rapid within small isolated populations, a detailed species-by-species record of such evolutionary transitions is unlikely to be preserved. Furthermore, capturing such evolutionary events in the fossil record requires the fortuitous sampling of the particular geographic locality where the changes occurred.

Using the model of a branching tree of life, the expectation is for the preservation of isolated branches on an originally very bushy evolutionary tree. A few of these branches (lines of descent) would be fairly complete, while most are reconstructed with only very fragmentary evidence. As a result, the large-scale patterns of evolutionary history can generally be better discerned than the population-by-population or species-by-species transitions. Evolutionary trends over longer periods of time and across greater anatomical transitions can be followed by reconstructing the sequences in which anatomical features were acquired within an evolving branch of the tree of life.

I am glad to have the opportunity to dialogue with Dr. John Hammett. In addition to our shared Christian faith and our shared lack of expertise in evolutionary science, we have in common one of our teaching and scholarly foci: the nature of human persons. Dr. Hammett approaches this topic as a trained theologian, whereas I approach it as a philosopher. However, on a topic such as this one, those disciplinary boundaries can get smudged a bit when the discussants approach the matter from the standpoint of a biblically-rooted Christian faith. Indeed the issue is of such importance and complexity that I would welcome continued conversation with Dr. Hammett beyond this initial exchange.

The Christian Scriptures teach that we human beings have been created in God’s image. What does that mean? I am in substantial agreement with Dr. Hammett on this question. While I think that bearing God’s image involves our having or having a potentiality for certain basic psychological capacities that we associate with the term “person”, it has to do even more profoundly with our specific capacity for relationship with God. Indeed, I would go further and say that it is not just our having this capacity that makes us divine ikons, it is also the fact that God has activated this capacity—He has given the precious gift of His self-disclosure to us. Further still, it has an eschatological dimension, based on the revealed promise of a future development and perfection of each of us, and so by implication, of human nature itself, by almighty God. We are in the process of becoming fully human: beyond a descriptive biological or even psychological notion of human nature lies a teleological one—not a telos of nature but of God's loving purposes for us. Despite our unequally born deficits—physical, cognitive, emotional, and moral/spiritual—we are destined for a fuller, supernatural realization of our common nature.

That we are in these ways God’s image bearers is a (wonderful!) teaching of our faith. The Scriptures also speak in various places of the human “soul.” The idea of the soul seems clearly connected to the idea that we are divine ikons. But here we should tread carefully. It is of course not unique to the Hebrew and Christian Scriptures to use some such singular term to refer to that which is most distinctively human and that by virtue of which we are able to survive the death and decay of our bodies. But it is one thing to use the term as a kind of placeholder for whatever it is about us that enables us to be, feel, and act in distinctively human ways in this life and to survive death into the next; it is another thing to link the term to a specific metaphysical account of the matter, such as might say whether the soul is a kind of thing or substance, what kind of thing it is, and exactly how “it” relates to the human “body.”

It is (and always has been) very common for Christians to invest the term “soul” as it used in Scripture with such a metaphysical account. As these fellow Christians understand it, when the Bible speaks of my soul, it is referring to an immaterial substance that is, in the final analysis, the thing that I am. I have my body (by interacting directly with it and only with it among physical objects), but I am my soul. Many will add that, after my death and prior to the resurrection of the dead, I will exist in a completely disembodied state—a naked soul, as it were.

However, I believe it is a mistake to interpret Scripture as teaching or implying any such metaphysical account of the underpinnings of our distinctively human personal attributes or our capacity for surviving death. Now, after reflecting on the matter, we might conclude that the only way these Scriptural teachings could be true is for such a metaphysical account to be true, as well—an account in which we are immaterial substances, entirely separate from our bodies. Indeed, many have thought hard about it and have drawn just such a conclusion, and it is not hard to see why they find it tempting to do so. But to do so is to make a disputable philosophical inference; it is not a teaching of the faith.

The general perspective of BioLogos, which I embrace, is that theorizing about the underlying nature of the soul is best done by trying to read God’s Two Books (His Word and His Works) in tandem. Both Books have a great deal to say about us, and, as common products of an infinitely wise and loving Creator, what they say must ultimately be in harmony. As with any attempt to understand something deep and wondrous in God’s Creation, we should proceed with humility and carefulness and be prepared to rethink familiar and received ideas.

Spelling it out just a bit, the common Christian understanding of what it is to have a soul involves the yoking of two radically different things, a functioning human (wholly material) body and an immaterial mental thing that is the direct bearer of psychological properties such as self-awareness, emotions, and thoughts, and is that which chooses in accordance with desires and purposes. In short, a complex biological machine and a pure subject/purposive agent which interface in the brain. I want to acknowledge that this is a very natural perspective to have, quite apart from Christian revelation (hence its popularity among humans generally). It is very natural because our psychological abilities seem, introspectively, to be plainly something more than mere resultants of impersonal physical particle interactions, however numerous and complex these are within the human brain.

We can design highly sophisticated computers that process complex bodies of information with extraordinary speed, but no computer is a subject, or has a point of view. As philosophers of mind like to say, there is nothing “it is like” to be a computer in the way that there is something “it is like” to be a conscious subject. Put another way, no mere computer is a conscious, experiencing subject, having a point of view from which it regards and interacts with its environment. Neither do computers make autonomous choices in the face of competing moral and self-interested motivations, and so on. It seems but a short step from this observation to the conclusion that human persons (and thinking/desiring/choosing things more generally) must be fundamentally different sorts of things: fundamentally distinct capacities must reside in fundamentally distinct kinds of substances (mental and spiritual substances as opposed to physical substances, however complex).

I have just described how matters appear from the ‘first-person perspective’ of conscious experience and self-awareness. Let me be clear that I take such evidence very seriously: I know my own conscious thoughts and experiences better than I know any scientific theory,—even a very well-attested one—as all of our theories are at bottom built on information we derive from our experiences. So awareness of the distinctive character of conscious experience is part of what is given to us in the Book of God’s Works, since we are a part of that Book.

But alongside that ‘first-person’ data, we have had an explosion of relevant information coming from the ‘third-person’ perspective of the natural sciences, specifically evolutionary and developmental biology and cognitive neuroscience. This information, while still incomplete and only imperfectly understood, sheds light on the deep natural history of humans and present-day animals; the processes by which individual organisms of any species develop from inception to maturity; function-specific neural structures and processes that sustain and help regulate the unfolding first-person perspective of conscious agents; and finally, observed correlations between increasing complexity of neural structures and increased psychological complexity. This last correlation between structural and cognitive complexity is evident both when examining individuals as they develop, and when making comparisons across sentient species.

I suggest that this third-personal scientific information does not comport well with the two-substance or dualist metaphysical account of human persons. The fundamental problem is that our sciences point to continuous processes of increasing complexity, but the two-substance account requires the supposition of abrupt discontinuity. The “coming to be” at a particular point in time of a new substance with a suite of novel psychological capacities would seem to be a highly discontinuous development, both in large-scale bio-geological time and within the development of individual organisms.

Since souls as purely immaterial things would lack parts, we cannot make sense of the accumulation or diminishment of capacities by proposing increased or decreased structural complexity within the bearer of such capacities. And it just seems implausible to suppose that all the necessary basic capacities for, say, calculus problem-solving are there in the soul from the beginning, awaiting only physical maturation in the body in order to become activated, but still not directly dependent on that maturation. It seems rather that psychological capacities arise and develop in tandem with the development of the brain and nervous system.

Of course, it is possible for the soul-body dualist to retrench: we might offload to the brain ‘side’ of the divide some of the psychological functioning that, prior to the advent of neuroscience, we might have mistakenly thought belonged to the soul. But that tack risks (as neuroscience progresses) reducing the soul to a simple, immaterial object that is radically incomplete, merely a “bearer of consciousness” that enables personal identity over time and through death.

Despite the fact that such future retrenchment would seem to be required, this kind of dualism remains tempting for the Christian thinker. Why? The obvious answer is that it can seem to be the only way to accommodate our specifically Christian data that human beings are not mere machines: our thoughts, emotions, goals, and intentions are deep, not superficial features of ourselves; they confer a dignity upon us that makes us suitable bearers of the divine image such that human beings, after our skin has been destroyed, will yet see God. (Job 19:26). But is it true that the coherence of Christian theology requires this account? And if coherence of Christian theology does not require this account, which account might be the best one?

Tomorrow, in Part 2, I will address this question.

Humanity is marked by the biological capacity for musicality. Every known culture has something like music. Understanding how we experience and create music in the present gives us clues to why and how music emerged as one of the defining features of human culture (and, therefore, of humanness itself) in the past. But thinking carefully about music and evolution can also help us reassess how we use music now: in the wider culture, collectively as the church, and even within our own homes. In a nutshell, then, this essay will examine how views on evolution impact how one assesses music’s effects and meaning. In many cases, problematic views about evolution and artistic creativity result in problematic views about music, but my argument is that an appropriate evolutionary view of music—one that looks at how music becomes meaningful within social relationships—is a view that actually enriches our appreciation of this most human endeavor, rather than trivializing it. In this first part I explore common discourses about the meaning of music and their relationship to ideas of creation. In part two next week, I suggest that understanding the role that music played in our biocultural evolution helps correct some of the myths that have made their way into popular discourse, especially with the growing popularity of trying to understand music via neuroscience.

Let’s begin by looking at a couple of popular ways of answering the question, “Where does musical meaning come from?” beginning with the idea that “music is in the ear of the beholder.” One thing that is clear from years of teaching classes of first-year university students is that they are musical relativists. They have ‘their’ music that they enjoy and even use to demark their identities, but are perfectly willing to allow others to like other music. After all, music is all about enjoyment, right? Historically, this cultural trope developed out of the post-Kantian argument of musical autonomy, the often-fashionable argument that music’s meaning is strictly musical and does not relate to other parts of the world. It is also reflected in Steven Pinker’s argument that music is ‘auditory cheesecake’. For Pinker, music used to be useful for things like attracting mates, but now we have evolved out of needing music: it’s not necessary, but is a nice extra. I might like cheesecake, but you might prefer ice cream. Either way, it won’t change the survival of the species, so we can enjoy what we like. This argument may have a harder time standing up when music is used as a means of torture at Guantanamo Bay, but it remains popular none-the-less. Like many ideas of creation and the arts, the idea of music as primarily pleasure (determined by individual taste) is a post-Enlightenment development.

This musical relativism takes a slightly more exacting form in another popular idea, that meaning is embedded within the ‘music itself’ not in the taste of the listener. This view of meaning is the starting point of Plato and Aristotle’s disagreement about the effect of certain modes, the disagreements in the early church about the usage of certain musical instruments, and the arguments of the detrimental moral impact of certain forms of popular music (which, by the way, is an argument not just limited to the 20th or now 21st centuries). It is also the foundation of the statement from one of my former conductors that if we played well enough, we would summon up the ‘spirit of Haydn’. In other words, ‘proper’ participation can reveal the meaning of the work—be that the composer’s meaning or another idealized meaning.

Musical autonomy in this case refers to the view that music stands apart and has no relations or meaning outside of itself. Many philosophers and musicologists rely on this view in an unreflective way, represented by Peter Kivy’s statement that music “is a quasi-syntactical structure of sound understandable solely in musical terms and having no semantic or representational content, no meaning, and making no reference to anything beyond itself”¹. For Kivy, the heart of the autonomy argument is that music is completely self-contained. Such a view is possible because of the historical development of ‘absolute music’, referring to music without a text or narrative, typified by the development of the symphonic form in the late 18th century. It is no accident that between 1750-1850, the form of the symphony developed, Kant theorized the idea of genius, and Schopenhauer claimed music to be “pure will.” In the 19th century, music came to be considered the highest of the arts, and even at the turn of the 20th century Kandinsky claimed that all art should try to achieve the autonomy and abstraction of music.

The idea of musical meaning somehow residing within the musical work is based on an assumption that the more one can isolate and analyze something, the more can be known about it. We can certainly learn much about a rock or plant by isolating it and putting it under a microscope, and those who take music to be autonomous believe that music can also be known most thoroughly by placing it ‘under the microscope’ through close analysis of a score or recording, or through close listening. It is through such pseudo-scientific analytical acts that knowledge about music is thought to be accessed. This is also the guiding ideology of ‘music appreciation.’ But while much can be gained by close examination of rocks or music, much more can be gained by studying how a rock or (especially) music is used by people—a central point to which we will return.

It is more than a little ironic, then, that a further example of the belief in an intrinsic musical meaning is the argument that music is ‘universal’; that is, that at least some music can cross cultural barriers and mean the same thing to all people. Often this view assumes a primacy of the Western canon, as it is believed that Mozart has a universal meaning but Chinese qin (zither) music does not. In a globalized world where many cultures listen to and value Mozart, people who do not share a common language or view of the world may find Mozart a common point of contact. But finding Mozart a point of contact is not caused by the music having a universal meaning. Rather, it is an example of the way music can become a shared space where people enter into a relationship via art. The West-Eastern Divan Orchestra (a project of Daniel Barenboim and the late Edward Said) is an example of music being a common ground where people from different views of the world can connect, not an example of universalized meanings of music.

Indeed, there are many situations when music’s meanings are not shared, showing that meaning is most definitely not universal. Martin Lodge recounts the encounter of Dutch explorers and the Maori people of New Zealand in 1642. When the parties got close enough to see (and hear) each other, each group signalled with trumpets. The Dutch, thinking they were successful in making contact, sent a boat of unarmed sailors to shore. The boat was met by Maori warriors who killed more than half of the sailors. This misunderstanding was caused by not sharing a musical meaning: “The Maori trumpeting in this case was the music of war, an invitation to fight. On the other hand the Dutch trumpets played a variety of tunes intended to be welcoming.”² Musical meanings are often shared, but are not universal or ‘in the music’.

As we have begun to see, considering music as culturally embedded lets us recognize something quite different from the arguments that musical meaning is either subjective or encoded within the music itself. Music does allow for subjective response, but not truly autonomous response—our experience of music occurs within the bounds of cultural norms. Since music’s significance cannot be abstracted from it’s embeddedness within social relationships, an attention to culture and human intentionality (not just a reductionist sense of biology) must inform the ways that music is studied, whether in contemporary culture, in neuroscience, and with reference to human evolution. Unfortunately even many Christian views of music have relied upon some of these problematic views of musical meaning, aligning ideas like individual artistic genius and the “meaning in the music” concept with theologies of creation ex nihilo. As Bruce Ellis Benson discusses in an essay in the journal Verge (and in a shortened version here at BioLogos), this combination or paralleling of genius and ex nihilo creation complicates the church’s understanding not only of music, but also about the Creator God, downplaying the essential element of community and interpersonal relationship inherent to both.

Next week, we’ll look at a similar tendency to abstract and quantify the way music makes meaning in the burgeoning field of neuroscience (from the “Mozart Effect” to fMRI scans), and return to the way that thinking about music within the evolution of human culture might give us a deeper appreciation of music—even of worship—within the church. In the meantime, here are some questions to consider:

How do my own assumptions of the way music is meaningful affect the ways I conceive of and use music?

Are there negative consequences stemming from these assumptions?

How have problematic views of musical meaning affected the use of music as personal identity? Or in the church? Or in the media? Or in popularized science?

Notes

1. Kivy, Peter (1990) Music Alone (Cornell University Press: Ithica, NY): p. 202.

2. Lodge, Martin (2009) 'Music Historiography in New Zealand' in ed. Zdravko Blazekovic, Music's Intellectual History (RILM: New York): p. 627.

Today's video is courtesy of filmmaker Ryan Pettey, director/editor of Satellite Pictures and features physicist Ard Louis.

In today's video, Oxford physicist Ard Louis discusses the famous debate between renowned evolutionary biologists Stephen Jay Gould and Simon Conway Morris. Gould believed (and wrote in his book Wonderful Life) that if the "tape" of evolution were rerun, the chance that anything like human intelligence would emerge is essentially zero. In other words, humanity is here through random accident. Gould pointed to the work of Morris and fellow scientists in their research of the Burgess Shale as evidence for this view.

However, Morris himself disagrees, pointing to what is called evolutionary convergence. As Morris notes, there are numerous examples of identical features evolving multiple times throughout the history of life independently. Morris believes that if the tape of life were replayed, we would see something like humans emerge. A Christian might say, it looks like we were planned.

Some Christians might find Simon Conway Morris' viewpoint, with its implicit teleology, more attractive. Others, perhaps motivated by a high view of providence, may find Gould's emphasis on contingency equally congenial to their faith. What do you think?

In our previous essay, we learned that a tree summarizing species relationships can be built using DNA information, and how we can use DNA as a “molecular clock” to date ancient events. Both of these methods have made specific predictions about the origin of whales. If evolution is true: whales are related to the even-toed hoofed mammals and should share common ancestors with them; transitional fossil forms dating from about 45 to 50 million years ago should be found which can be shown to be related to both the even-toed hoofed mammals and modern whales; whales are most closely related to modern hippos, and should share a common ancestor with them.

What other types of information might we be able to use to construct a phylogenetic tree (i.e. a family tree) of species relationships? It turns out that characteristics of body structure also can be used – for example, the presence or absence of certain bones, or the specific shapes of those bones. An advantage of using bony features is that they can be recovered from fossils, whereas DNA (with only certain limited exceptions) must come from living organisms.

We can also derive functional information from an examination of bony features. The various protrusions, bumps and knobs found on bones usually have important implications. For example, smooth rounded areas at the ends of bones allow them to fit together and move easily. The shapes of such surfaces determine which bone motions are “allowed” or “disallowed”. Consider, for example, the motion of the forearm against the upper arm at the elbow. This is a “hinge” joint, whose normal motion is defined by the shapes of the upper arm bone and one of the forearm bones, where they meet each other. You might normally exercise the action of this hinge joint when you pick up a cup of coffee, bring it to your mouth, then set it back down again. Let’s try to imagine another motion. For this exercise we first need to get our arm into the proper starting position. Place your arm at your side, bent at the elbow at a ninety degree angle, with your palm up. Now, while keeping your palm up, let’s attempt to move your arm only at the elbow (no shoulder motion – that’s cheating!). Now swing your forearm out to the side and attempt to end up with your fingers pointed directly away from your side. Most of you will not be able to do this. If you can, it’s because your shoulder is rotating in spite of yourself. This motion at the elbow is normally not allowed. Hence a careful analysis of bone shapes can allow us to infer how the bones were used. This in turn can assist us in the task of phylogenetic (evolutionary) classification of organisms. That is, we will have more confidence in the grouping together of animals in our tree diagram if corresponding bones are used functionally in the same way.

Therefore we would expect that we could use various bony features to help us examine the predictions generated by our previous look at different types of DNA data. Are there any bony features that are particularly relevant to the even-toed hoofed mammals? Well, it turns out that there are. These are mainly running animals, and there are several features of their ankle bones, which taken together define the “allowed” motions which make them efficient runners. If one takes the various ankle bones of a large group of mammals, examines them carefully to note their shapes, scores that information into a table, then uses a computer program to build a phylogenetic tree, it turns out that all the even-toed hoofed mammals are placed together. So far, so good. But what about whales? Well, now we have an obvious problem. Modern whales are very specialized, - they have flippers which correspond to the forelimbs, and they have almost no hind limbs! I say “almost” because they do have small pelvic bones, which are not attached to the rest of their skeletons. But they certainly have no ankles. This is where the fossils should come in – if evolution is true, we should expect to be able to identify transitional fossils which are ancestral to whales which contain the characteristic ankle bony features of the even-toed hoofed mammals.

Now let’s look at bony features from the whale perspective. We have already mentioned the almost complete loss of hind limbs, and the presence of forelimbs modified into flippers. In addition, as air breathers, whales have a blowhole at the top of their skull. And as powerful swimmers, which use a large tail fluke in vertical motions, whales have enormous sets of muscles which attach to enlarged projections from their vertebral column. So if evolution is true, we should begin to see fossil forms which manifest changes in bony features which correspond to the gradual accumulation of these whale-like characteristics. However, we still need more, because these various bony features all would be expected to occur in largely or exclusively aquatic forms. We might expect this to correspond to the later stages of a transition from terrestrial even-toed hoofed mammals. But what about the earlier stages? It would be very helpful if we had some “defining” characteristic of whales, similar to the ankle structure of even-toed hoofed mammals.

It turns out that the structure of the bones of the skull and ear apparatus of whales are highly modified to allow efficient hearing underwater. The mechanical aspects of efficiently receiving sound through water are somewhat different than receiving sound travelling through air. If evolution is true, we should expect to be able to find key transitional fossil forms with a progressive series of modifications of the skull and ear bones, features which would not be found in any other mammals.

Now that we know what we should expect to see, if evolution is true, let’s look at what has actually been found in the fossil record. Over the last fifteen years or so, a series of fossils, many of them discovered in the Indian subcontinent, have fulfilled nearly all of our predictions.^1,2 Let’s look at the figure below (Figure 1), reproduced from a recent popular book on evolution.³ This shows a series of fossils, arranged in approximate chronological order, with a modern whale at the top. How old are these fossil forms? The entire fossil progression illustrated occurs from a little over 50 million years ago to about 40 million years ago. So a remarkable alteration in general body form occurred in a little over 10 million years. This time frame agrees well with the previous prediction from the DNA “clock” that we discussed in our previous essay. Second, the general change in body shape corresponds to what we predicted in our discussion of whale bony features above. That is, there is a gradual elongation and streamlining, there is a modification of the forelimb into flippers and progressive reduction of the hindlimb, the nostrils for breathing move toward the top of the skull to form a blowhole (not obvious from the diagram), and the vertebrae develop enlarged projections to support the attachment of swimming muscles.

Figure 1: Skeletons and Body Forms of Modern Whales and Fossil Ancestors
The reconstructed skeletons (black) from modern whales (top) and various ancestral skeletal forms (series below) are in chronological order (from Pakicetus up). Indohyus is an extinct whale “cousin”. Relative body size, to scale, is indicated by the gray shapes at the right of each animal.

There is probably little question that the last fossil species in the figure (Durodon) is well on the way to becoming a modern whale. However, it might be argued by a skeptic that the earlier species (like Rhodocetus, Ambulocetus, or Pakicetus), despite the “cetus” (whale) part of their names, are not so obviously “whale-like” that they deserve to be considered as fossil whale ancestors. However, remember the characteristic whale skull modifications for hearing? It has been shown very clearly that throughout this series of fossil species, the various bony changes necessary to support efficient hearing in water were being acquired in a stepwise fashion. Organisms earlier in the sequence had skeletal characteristics consistent with them being able to hear well in both air (using the “classic” mammalian hearing apparatus), and newly acquired changes to also allow better hearing in water. Later organisms in the sequence become increasingly specialized for hearing in water only.⁴

What of the earliest fossil shown in this diagram –Pakicetus? Careful examination shows that it has the features we would predict for an early whale ancestor. It has the ankle bone characteristics of the even-toed hoofed mammals (in fact these features are also found in several of the later fossil forms as well, ensuring their continuity). This confirms one of the predictions made by the DNA evidence we discussed earlier. Furthermore, it has some of the modifications of the skull bones necessary for more efficient underwater hearing, which were previously documented only for modern whales and their later (more obvious) ancestors.⁴ These features are also shared with the “whale cousin” Indohyus.⁵ Preservation of more of the skeleton of this latter species has allowed detailed analysis indicating characteristics likely shared with whale ancestors. Indohyus was probably a wading animal, which spent much of its time in the water. It appears to have fed mostly on land, so it is suggested that resort to the water was made to escape predators.⁵

Finally, we need to look back at the last prediction from our previous DNA evidence, namely that modern whales are most closely related to hippos. If evolution is true, we should expect to find fossil forms linking these two modern groups. This has proven to be a tougher nut to crack, mainly because the ancestral whales first appear about 50 million years ago in what is now south Asia, and the hippo family first appears about 15 million years ago, in Africa. The most recent tree diagram, produced by using a combination of skeletal features and DNA data, still supports this family connection, as shown by the following figure (Figure 2).⁶

Figure 2: Phylogenetic Tree Showing the Relationship of Modern Whales to Living and Extinct Even-Toed Hoofed Mammals
This tree is based on both bony features and DNA data. The organisms presented in blue are semi-aquatic or aquatic forms. Organisms shown in green are terrestrial even-toed hoofed mammals (Artiodactyls). In black is shown a member of the odd-toed hoofed mammals. In red is an extinct fossil ancestor group. (This figure is adapted from Fig 1a in Reference 6).

The blue lines in the diagram show species in which the skeleton is specially thickened, and the bone structure more dense. This is an adaptation which allows wading animals (like modern hippos and the fossil Indohyus) to be good “bottom-walkers” (it prevents them from floating due to lighter body tissues), and allows fully marine organisms (like modern whales) to have “neutral buoyancy” (so they don’t always tend to pop up to the water surface, like a cork). There has also been progress in clarifying the relationships between fossil ancestors of hippos and those of modern whales. A recent study of hippo evolution, based only on skeletal characteristics, has conclusively shown that the hippo family are descended from an extinct group of fossil Artiodactyls, known to go back more than 40 million years, and whose fossils are from southern Asia. Furthermore, this study produced a phylogenetic tree predicting that this extinct hippo ancestor group also shared a common ancestor with the fossil whales.⁷ Thus the investigation of hippo origins is independently leading us back toward the origin of whales. However, in this study the statistical support for predicted common ancestor of the ancient hippo group and the ancient whale group is not as strong as scientists would like to consider this “case closed”. What is necessary is more fossils, of the appropriate age in order to complete the story of hippo evolution. We still need that to fill in the details of the predicted relationship of hippos to modern whales.

Thus the “Whales’ Tale” is not yet complete. It is a story of scientific discovery in progress. As we finish, let’s briefly summarize what we have found out. Different types of DNA evidence agree that modern whales are most closely related to the even-toed hoofed mammals, despite the obvious great changes in limb anatomy of the modern whales. This prediction has been amply confirmed by the fossil record. The DNA sequence evidence predicted a time frame during which critical early events in evolution of whale ancestors should occur. This prediction has also been amply confirmed. Finally, DNA evidence predicts that modern whales are most closely related to hippos. There is some fossil evidence supporting a predicted common ancestor, but more data is needed. A final caution to possible sceptics – this state of “unfinished business” is precisely how the scientific process works. There is no “crisis”. There is no indication that evolution is not true. There is simply the ongoing work of mapping out of various lines of evidence. A scientific conclusion is considered well supported if “all roads lead to Rome”. In the case of whale evolution it might be prudent to say that the evidence has not quite converged in Rome yet, but that we are now in the suburbs. That is precisely what makes science interesting and fun. Stay tuned!

The next blog in this series can be found here.

References:

1: Thewissen J.G.M., Williams E.M., Roe L.J. and Hussain S.T. 2001. Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls. Nature. 413: 277-281.

2: Gingerich P.D., ul Haq M., Zalmout I.S., Khan I.H., Malkani M.S. 2001. Origin of Whales from Early Artiodactyls: Hands and Feet of Eocene Protocetidae from Pakistan. Science. 293:2239-2242.

3: Coyne, J.A. 2009. Why Evolution is True. Viking Penguin, New York. Pg 50.

4: Numella S., Thewissen J.G.M., Bajpai S.,Hussain T., Kumar K. 2007. Sound Transmission in Archaic and Modern Whales: Anatomical Adaptations for Underwater Hearing. The Anatomical Record. 290:716-733.

5: Thewissen J.G.M., Cooper L.N., Clementz M.T., Bajpai S., Tiwari B.N. 2007. Whales originated from aquatic artiodactyls in the Eocene epoch of India. Nature. 450:1190-1194.

6: Geisler J.H. and Theodor J.M. 2009. Hippopotamus and whale phylogeny. Nature. 458:E1-E4.

7: Boisserie J.-R., Lihoreau F., Brunet M. 2005. The position of Hippopotamidae within Cetartiodactyla. Proceedings of the National Academy of Sciences U.S.A. 102(5):1537-1541.

In the rest of the series, we will look closely at the evolutionary explanation for the blueprint. That explanation postulates that tetrapod limbs arose during a particular era in life's history, and that they arose as modifications of the fins of fish. And the evolutionary explanation isn't just an interesting idea. It's a comprehensive explanation – it helps us to understand bones, fossils, genes, chemical signaling systems. It provides a coherent framework for understanding why limbs are the way they are, and how they got that way.

Comparing the anatomy of tetrapod vertebrates and fish

The idea that tetrapods arose from fish is not new; E.D. Cope proposed in 1892 that tetrapods descended from lobe-finned fish. (Modern lobe-finned fishes include coelacanths and lungfish, and comprise one of two divisions of the bony fishes. The other division, the ray-finned fishes, includes most familiar kinds of fish.) In the early days, biologists inferred ancestral relationships between species largely through comparative anatomy and embryology: they would carefully classify organisms according to their structure (including their structure during development) and look for relationships that generated nested hierarchies. A simple nested hierarchy goes something like this: 1) animals with backbones; 2) animals with backbones and limbs; and 3) animals with backbones, limbs, and hair. Animals in group 3 also belong to groups 1 and 2, while animals in group 2 also belong to group 1, and so the groups together define a nested hierarchy. Such studies alone could have led some scientists to infer an ancestral relationship between fish and tetrapods, and perhaps those studies did convince them. But then there were fossils of various types of fish and other vertebrates, many long extinct. That fossil record was relatively sketchy in 1892, but it nevertheless led Cope and others to conclude that certain fish had given rise to tetrapods at a particular time in natural history.

The fossil record shows a fish-to-tetrapod transition

Here are some basic findings from the fossil record that suggest a fish-to-tetrapod transition and that have been known for decades:

• Fish, including fish with bones, lived on the earth before tetrapods appeared. Specifically, fossils of bony fish first appear in rocks from about 420 million years ago.

• Tetrapods appear in the fossil record at a particular point in history and then persist and diversify in subsequent eons. Their arrival was long thought to have occurred about 365 million years ago, although some recent findings have challenged that hypothesis.

• Tetrapods that still had some fishy features were prowling the planet 365 million years ago.

• Lobe-finned fish that were starting to look more like tetrapods were eating other fish about 385 million years ago.

Even many decades ago, there were hints that something interesting happened between 400 million years ago and 365 million years ago. Let's take a close look at the ancient animals that suggest the fish-to-tetrapod transition.

Ancient animals

The most primitive known tetrapods for which we have skeletal remains lived 365 million years ago. They were undeniably tetrapods, but there was definitely something fishy about them. (Heh heh.) One of the most famous of these creatures is Acanthostega, discovered in 1987 by British paleontologist Jennifer Clack and pictured below. Acanthostega is a card-carrying tetrapod, with fingers and toes. But it has a fish tail, with fin rays. Another well-known primitive tetrapod is Ichthyostega, which lived around the same time as Acanthostega. Like Acanthostega, it is a true tetrapod, but has several odd fish-like structural features. For example, its skull is more fish-like than that of Acanthostega. In summary, both Acanthostega and Ichthyostega already used the limb blueprint, even though both also had some fish-like anatomical characteristics. Their presence 365 million years ago shows that tetrapods must be at least that old, and their mixture of anatomical features suggests that the transition happened not long before that.

And what about the lobe-finned fish that looked a bit tetrapod-ish? That animal is Panderichthys, described as “vaguely crocodile-shaped” with skeletal features that were tetrapod-like. Specifically, this ancient fish had tetrapod-like “shoulders,” and recent analysis found some finger-like bones at the ends of the fins. The creature also had a breathing hole on the top of its head. These fish lived around 385 million years ago.

The hunt for the earliest tetrapods

Taken together, these observations suggested that the fish-to-tetrapod transition occurred between 385 and 365 million years ago. Eager to see what that transition looked like, scientists began to look for 375 million-year-old rocks in which they might find animals at the beginning of tetrapod-hood. They wanted to catch evolution in the act.

Let's stop and think about this, because it's cool and because it's important to note the extent to which evolutionary biology is hypothesis-driven. Critics of evolution sometimes portray the theory as an untestable historical conjecture, depicting it as fundamentally different from experimental science in the lab. But the hunt for the earliest tetrapods was an effort to test a hypothesis that had generated a prediction. Based on the hypothesis that lobe-finned fish were ancestors of tetrapods, scientists predicted that intermediate animals, “fishapods,” would be found in the gap between Panderichthys and Acanthostega. To evaluate the prediction, all they needed to do was find some suitable 375 million-year-old rocks.

Neil Shubin describes that search in the first chapter of Your Inner Fish. He and his colleagues found suitable rocks in the islands of the Arctic: the right age, nicely exposed (by erosion), and representative of the kind of environment that their quarry would frequent – freshwater streams. They made their biggest discovery on their last trip (“a do-or-die situation”) in 2004. That discovery was Tiktaalik roseae, the “fishapod.”

The “fishapod”

Tiktaalik roseae is one of the most extraordinary fossil intermediates ever described, and its public debut in 2006 was front-page news. An artist's conception of the animal is pictured below.

There are several aspects of the anatomy of Tiktaalik that earn it the title “fishapod.” Like a good fish, it had scales and webbed fins. Like a tetrapod (more specifically, like a crocodile), it had a flat head, with eyes on the top of the head, and it had a neck. But what about those fins? Or are they limbs? Remarkably, the answer seems to be, “both.”

The fins of Tiktaalik were part fish fin, part tetrapod limb. On the outside, they looked like fins, with webbing. On the inside, though, these fins were clearly tetrapod-like. Amazingly, the fins of Tiktaalik were built using a primitive version of the limb blueprint: one bone, two bones, blobs, digits. As Shubin writes in Your Inner Fish, “We had a fish with a wrist.” (The Tiktaalik roseae web site at the University of Chicago is a great source for images and more information.)

Let's address three questions about Tiktaalik that might have occurred to you. First, why might animals like Tiktaalik have developed tetrapod-like fins? Shubin and his colleagues suggest that these limb-like fins may have been useful for doing “push-ups” in the shallow water. (Like Panderichthys, Tiktaalik had a breathing hole on top of its head and was clearly adapted for living and moving in shallow water.) Second, is Tiktaalik an ancestor of all tetrapods? No, not necessarily. What Tiktaalik shows us is that animals were developing tetrapod features in the context of fish bodies, and Tiktaalik shows us the context (shallow water) in which this likely occurred. But that doesn't mean that our lineage arose from Tiktaalik itself. Finally, is Tiktaalik now the oldest tetrapod? No, apparently not. For one thing, Tiktaalik is truly transitional, and probably therefore not worthy of full tetrapod membership. But more notably, data published in 2010 show that tetrapods are a lot older than was thought at the time of Tiktaalik's discovery. The new findings show footprints that are unmistakably those of a tetrapod, in rocks about 395 million years old. Surprisingly, then, tetrapods were already on their way long before Neil Shubin's specimen lived. Tiktaalik is truly a fish/tetrapod intermediate, which was living at the same time as animals that were fully tetrapods. A simple story of succession, in which intermediates disappear and are replaced by less intermediate types, seems to be an oversimplification.

In conclusion, the fossil record provides evidence that the fins of fish and the limbs of tetrapods are related by ancestry: limbs seem to be modified versions of fins. What other evidence supports this proposal? In the next post, we will turn to developmental biology, and explore the meaning of the term 'homology.'

Further reading:

Neil Shubin (2009) Your Inner Fish: A Journey Into the 3.5-Billion-Year History of the Human Body. New York: Vintage Books.

Carl Zimmer (2006) A Fin is a Limb is a Wing: How Evolution Fashioned its Masterworks. Online at NationalGeographic.com.

Tiktaalik roseae website at the University of Chicago.

Jennifer Clack's website at the University of Cambridge.

Images are from Wikipedia.

In 1975, Harvard biologist E. O. Wilson created a firestorm when, in his book Sociobiology: The New Synthesis, he argued that human nature might be explainable in evolutionary terms. Centuries earlier, however, a leading Christian scholar was already applying many key evolutionary principles to the understanding of man.

Thomas Aquinas (1225-1274) was the foremost Christian scholar of the High Middle Ages and is today regarded as a "doctor" of the Catholic Church. Working six centuries before Darwin, he obviously was not an evolutionist. His major project was the Christianizing of Aristotelian philosophy. As an ardent Aristotelian (enough so that some of his teachings were condemned by the Bishop of Paris in 1277), Aquinas assumed that species were fixed and unchangeable, an idea incompatible with evolution. But Aquinas was the star student of Albert the Great, an enthusiastic Medieval naturalist. Albert assiduously observed the Dominican Order's policy of walking, not riding, when traveling. Ostensibly this was to emphasize the Order's commitment to poverty, but for Albert it was an opportunity to more closely observe nature's minutiae. Under Albert and Aristotle's mentorship, Aquinas acquired a deep appreciation for nature's continuity, which he understood as reflecting purposeful design rather than common descent.

Aquinas had no doubt that humans were specially created by God. However, he was also convinced that they were created out of the same basic materials used for all creatures and were therefore connected to all of nature. In his Summa Theologica he writes:

"But it was fitting that the human body should be made of the four elements, that man might have something in common with the inferior bodies, as being something between spiritual and corporeal substances." (ST P1 Q91 A1)

Aquinas had no qualms about calling humans animals:

"Socrates and Plato ... have the same human species; others differ specifically but are generically the same, as man and ass have the same genus animal." (De Principiis Naturae 45)

Following Aristotle, Aquinas rejected the strict dualism of the Augustinian/neo-Platonic philosophy dominant at the time. No, Aquinas was not a materialist neuroscientist, but he understood the intimate interdependence of mind and body. For Aquinas, different bodies meant different levels of intelligence: "...because some men have bodies of better disposition, their souls have greater power of understanding." (ST P1 Q85 A7)

Aquinas is most famous for his Summa Theologica, much of which is considered authoritative in Catholic theology. Less known is another great summa, Summa Contra Gentiles, where he sought to persuade non-believers using purely rational arguments for Christian doctrine. It is here that we find a naturalistic discussion of marriage.

"We observe that in those animals, dogs for instance, in which the female by herself suffices for the rearing of the offspring, the male and female stay no time together after the performance of the sexual act. But in all animals in which the female by herself does not suffice for the rearing of the offspring, male and female dwell together after the sexual act so long as is necessary for the rearing and training of the offspring. This appears in birds, whose young are incapable of finding their own food immediately after they are hatched. ... Hence, whereas it is necessary in all animals for the male to stand by the female for such a time as the father's concurrence is requisite for bringing up the progeny, it is natural for man to be tied to the society of one fixed woman for a long period, not a short one." (SCG B3 Q122)

The ideas expressed above are familiar to evolutionists as part of parental investment theory -- male/female pair-bonding is more likely to emerge where offspring are highly dependent.

Aquinas also anticipated another core evolutionary concept: paternity certainty. Males find an evolutionary advantage in long-term pair bonding because it helps to insure that offspring possess their genes. Without this assurance, males are unlikely to provision or protect the offspring. Thus, monogamy serves the genetic interests of both males and females. Females and their offspring receive resources and protection from the male (paternal investment), while males gain assurance of a genetic legacy (paternity certainty).

"...every animal desires free enjoyment of pleasure of sexual union as of eating: which freedom is impeded by there being either several males to one female, or the other way about ... But in men there is a special reason, inasmuch as man naturally desires to be sure of his own offspring ... The reason why a wife is not allowed more than one husband at a time is because otherwise paternity would be uncertain." (SCG B3 Q124)

Note how Aquinas' discussion also alludes to another important evolutionary precept: male mate competition. Aquinas goes on to describe how monogamy benefits women by reducing the female competition inherent in polygynous households, thereby insuring the concentration of emotional and material resources on a single female mate.

"For among men that keep many wives the wives are counted as menial. For one man having several wives there arises discord at the domestic hearth..." (SCG B3 Q124)

Along with anticipating many key concepts in evolutionary psychology, Aquinas also understood that humans possessed a natural moral sense. Some believers today foolishly try to argue that without religion there is no morality. Aquinas would have scoffed at such simple-mindedness. Synderesis, as Aquinas called it, was the natural human inclination toward right behavior.

"Wherefore the first practical principles, bestowed on us by nature, do not belong to special power, but to a special natural habit which we call synderesis. Whence 'synderesis' is said to incite the good, and to murmur at evil, inasmuch as through first principles we proceed to discover, and judge of what we have discovered. It is therefore clear that 'synderesis' is not a power, but a natural habit." (ST P1 Q79 A12)

In contrast to Augustine, Aquinas did not see human nature as inherently depraved. Instead, his view was generally more positive. We are, as Aristotle had argued, naturally social animals who seek to get along in society. Divine grace did not radically alter human nature, it perfected it.

If he were alive today would Aquinas be an evolutionist? His writings suggest a mind already resonating with many evolutionary concepts. My sense is that Aquinas, like Aristotle and Albert before him, was just too curious and too smart not be at the intellectual vanguard wrestling with exciting new knowledge.

A.I. Artificial Intelligence (2001)

Written and directed by Steven Spielberg, based on the short story "Supertoys Last All Summer Long" by Brian Aldiss.

A.I.: Artificial Intelligence, was an idea that the late great director Stanley Kubrick had been collaborating on with Steven Spielberg before Kubrick died. After his death, Spielberg was inspired to try to bring this original vision to the screen in honor of Kubrick. The result is a sci-fi fairy tale journey, a visually stunning, philosophically thoughtful examination of what it means to be human. But it is also a story that becomes an analogy for mankind’s quest for meaning and significance in transcendent notions like religion that demythologizes that quest into a materialistic enterprise of symbol creation rather than true spiritual reality.

The story begins with the not too distant future as a world that has flooded many coastal cities because of the polar ice caps melting due to greenhouse gases. Thus mankind has fewer resources which leads to population control. Robots are created to take the place of many more “mouths to feed” because somehow they’ve discovered a way to energize these robots with less resources than humans consume. Laws regulate the amount of humans that are allowed to be birthed, making us all a little bit more lonely.

We are then treated to a literal academic exposition of scientist, professor Hobby (William Hurt) for the Cybertronics corporation which spells out clearly for us just what the ethical issues are that the movie is going to attempt to solve. Professor Hobby explains that the pursuit of creating artificial beings has been a perpetual hunger for mankind. They may have achieved artificial intelligence, but he concludes that it all amounts to “toys” of mere physical stimulus response. What they need to do is to create a robot that can love, with genuine emotional reaction to other human beings. It is through this accomplishment of creating a “mecha” (robot) that loves “orgas” (humans) that they might transcend mere physical existence. He suggests that “love will be the key by which they acquire a kind of subconscious, never before achieved -- An inner world of metaphor, of intuition, of self-motivated reasoning, of dreams.” The corporation’s goal is to create a child robot that could fulfill the parents’ needs to be loved. But then the question is put to the professor, “If a robot could genuinely love a person, what responsibility does that person hold toward that mecha in return? It’s a moral question.” “The oldest one of all,” says the Professor. “But in the beginning, didn’t God create Adam to love him?”

And so the questions are set that the film will explore: What makes a “real” person? Is our consciousness transcendent of our brains and neuronic impulses? Can a complex machine whose identity is reducible to physical and chemical properties transcend that identity by achieving metaphor, intuition and love? By referencing the Bible the storytellers also reveal that these are questions that reach into the very heart of our most cherished religious beliefs, questions of the value and dignity of human persons.

Twenty-two months later, the company has created their first child robot, and they have chosen one of the company’s employees to test it on, the perfect guinea pigs. Henry and Monica Swinton (Francis O’Connor) are a couple who have suffered the loss of their little boy to a permanent vegetative state in a comatose chamber where Monica reads to him daily and never is able to grieve her loss as science can keep him alive, but cannot bring him back. So the company offers a robot child, David (Haley Joel Osment), as a substitute for Monica’s child Martin. At first, Monica has a hard time accepting the offer, but he is so lifelike and “present” that she chooses to initiate the imprinting sequence that will bind the robot to her forever in “love.” She suddenly becomes “mommy” to David, and they enter into a simulacrum of a real mother and child union.

When a miracle occurs and their son Martin comes out of his coma and back into their lives, a new rivalry is born between brothers (well, sort of brothers). Martin gives his mother a children’s book to read to them: Pinocchio, the story of a puppet who wanted to be a real boy. This becomes the obvious central metaphor throughout the film in David’s own quest to become a human being. The original Pinocchio was a morality tale about ethically good behavior and choices being the defining characteristics of a child worthy of love to their parents. In this reimagining, the Pinocchio quest is no longer merely an ethical question but an ontological one: Can a complex machine transcend its materiality to become a person of equal worth to a human? What makes human beings any different from highly complex mechanical devices? If we can create artificial intelligence, is our human intelligence any less “artificial”?

The human Martin and his friends, devious and mischievous as most young human boys are, play tricks on David that put them in trouble and even danger, causing Monica to bring back David to the manufacturer. The only problem is, she can’t do it because she has grown fond of David, and she knows they will destroy him as defective product. So she leaves him in the woods and tells him to never come back but to run away. So David concludes from his Pinocchio story that he too wants to become a “real live boy” so that Monica will love him. He reasons that if he can just find the Blue Fairy like the wooden puppet did in the story, she will make him into a real boy. Because he is a robot incapable of understanding the metaphor, he seeks it as literally true, which sets him on his quest.

In the next post, we will continue to follow David’s journey and look more at what A.I. has to say about religion and what it means to be human.

A theological belief can grow in our minds unobserved for years, the results of many imperceptible influences, until the full flower bursts into conscious thought. Just so, the idea that our bodies are saved as well as our souls had taken root in my approach to the arts, worship, literature, and fashion long before I articulated it in conscious thought or language. The idea is radical, bordering on monism, and I hope it’s not heretical. I have come to believe that a person’s form—his or her physical organism—is inseparable from his or her content—mind, soul, spirit, psyche, personality, behavior…

Where did this idea originate, for me? While I could traces its sources through my reading, or discuss its permutations in Church history, I think it began with poetry.

Coleridge wrote in his Biographia Literaria about poetry: “whatever lines can be translated into other words of the same language, without diminution of their significance, either in sense, or association, or in any worthy feeling, are so far vicious in their diction.” In other words (although he is condemning exactly other words), there is no such thing as a synonym. In other words again: the vocabulary, rhymes, meter, line length, stanza shape, figures of speech, images, and other technical aspects of the poem—its form—are inseparable from its content: WHAT is says is constituted by HOW it says it.

Take this tiny example. There is a beautiful Puritan classic by Jeremiah Burroughs entitled The Rare Jewel of Christian Contentment. That’s a weighty, poetic title, heavy with the seventeenth century, implying the value and grace of a seriously pious life. Now, in 1988 a contemporary adaptation was released, entitled Learning to be Happy. Look what has happened in four hundred years. From The Rare Jewel of Christian Contentment to Learning to Be Happy is dumbing-down indeed. But what’s worse, the content of Burrough’s title has been altered by the alteration of its form. Indicating a mechanistic program for how to be happy is worlds away from the Christian concept that contentment is a priceless, precious gift. The English civil war; the American, French, and Russian revolutions; Marx, Freud, and Nietzsche; two world wars; and capitalistic health-and-wealth, name-it-and-claim-it gospels stand between Burroughs and his Christianity-for-dummies descendant.

Because the words matter. Words have both denotation and connotation, sound and sense, and they resonate with our minds and our bodies. It is impossible to say the same thing in other words, because once it is in other words, it is not the same thing.

To get back to Coleridge: that is why a paraphrase, though an indispensable pedagogical tool, must never be confused with the poem. Students must never read “No Fear Shakespeare” as a substitute for the play itself. Every musical setting of a poem turns the poem into something other than its original self. Every movie adaptation of a book disappoints. The movie must be evaluated on its own merits, not simply compared to the book. Words and images are not interchangeable: the Deconstructionists showed us that when they pointed out that the phonetics of “T-R-E-E” are not the tree.

And what about that tree? Are the color, shape, size, and texture of the tree something apart from the tree itself? Is the oak something separate from those particular leaves, that regal height, those glorious shades of bronze and rust in autumn? If I took away a rose’s petals in their Fibonacci whorl, the inimitable scent, the tiny pain of thorns, and the reddish-green of its woody stem, what would be left of the rose? Would a rose by any other form still be a rose? Of course it wouldn’t. The question is absurd.

But then again, the smartest folks have always been asking that question. It’s the Plato-vs-Aristotle debate all over again, about whether everything exists only here in its particulars, or in the sum total of all its physical examples, or out there somewhere in an eternal extraction from which all instances are copied. If there were a metaphysical form of “ROSE,” I suppose it would still be itself without its petal, smell, and shape. Or would it? Wouldn’t the metaphysical prototype dictate exactly those blossoms on precisely that stem? Isn’t that how it copies its eternal form: by expressing itself in those particulars?

It seems, then, that asking Plato to weigh in hasn’t changed a thing. In the natural world, “form”—like having a certain shape and scent, or like having fourteen lines of iambic pentameter with the rhyme scheme abba abba cde cde—is inseparable from “content”—the rose-ness of the rose, or a longing for the unattainable Laura. The rose is the aggregate of its essential and accidental characteristics, just as the line “A rose by any other name would smell as sweet” is itself in just those words.

Then leap to the idea that each rose, each oak tree, and each poet is a work of art carefully crafted by the great Creative Artist. Picture God making a tree (either the original Platonic tree or one specific instance in your backyard) with care, defining the path each branch will follow from the trunk. Compare His concentrated artistry to that of a poet bending over a piece of paper, carefully weighing each word and balancing the lines. Perhaps the natural world serves as analogy for the unity of form and content in the art world, or perhaps it is actually the original after which every artistic work is patterned.

This natural analogy, then, is theologically useful. If the true nature of the oak tree is inseparable from the actual material stuff, the atomic matter, from which it is made, why (or how) should I be any different? How can I abstract (in both senses) ME from the-stuff-of-which-I-am-made? This goes beyond “you are what you eat.” My body is inseparable from my personality, just as if my height and weight shape a sonnet or sestina, while my redemption is the volta after the eighth line.

That last is essential. Each human embodied story needs that turn: the about-face of repentance into the narrative trajectory of redemption. If the soul is saved, the body is too. The old faith vs. works debate is moot: either without the other is dead. The soul without the body is a ghost; the body without the soul is a corpse. A saved person must be saved all through that embodied union—in a word, INCARNATION. In flesh. Me in my body, living in grace, living towards heaven. Salvation, to be itself, must be of both form and content. No paraphrases accepted on earth or in heaven.