The twenty-first century opened with major announcements related to human biology. In February of 2001, the Human Genome Project reported in Nature that the sequencing of human DNA was essentially complete.[1] In this same issue of the journal, an initial analysis of that sequence revealed that the number of genes that constitutes the human genome was reduced from the original estimate of 100,000 to a new estimate of 30,000 to 40,000, or about twice the number as the fruit fly.[2] The first of these milestones represents a major vindication for the molecular biological orientation of the neo-Darwinian synthesis. On the other hand, the second report highlights the difficulty of the presumption by some biologists that the complete sequence of human DNA will be synonymous with what it means to be human. The philosophical tension that underlies these two advances in biology dramatizes the current status of this discipline and frames Ian Barbour's critique of it.
Now that a working draft of a sequence for at least a representative human DNA chromosomal complement is finished, biology is moving into a new and dramatic phase. What some believe to be the culmination of a program of research that began in the 19th century with Darwin, Mendel, and Miescher may be at hand.
The "modern synthesis" (so named by Julian Huxley in 1942[3]) resulted from the fusing of Darwinian evolutionary theory and Mendelian genetics. When, in 1943, DNA, the substance that Miescher had found in the nucleus of cells, was identified as the chemical that constitutes the gene, the stage was set for the program that has dominated much of biology for the last 60 years.
At the heart of Darwin's model is the idea of selection of characteristics and the reproductive survival of those that best fit the environmental circumstances. This force of natural selection then drives the evolutionary history of life. In 1859 there was no idea about the ÒthingÓ upon which this force would act. However, after the rediscovery of Mendel, the thing at least had a theoretical shape: the unit of inheritance called the gene. Once the chemical identity of the gene was established as DNA, the thing upon which selection acts took physical form. More importantly, the work of Luria and DelbrŸck demonstrated that genetic variations arise by chance or random events (mutations) that change the sequence of the DNA.[4] Thus, the source of variation in the population that is so essential to the evolutionary model was discovered.
It could be easily demonstrated in model systems such as the bacterium Escherichia coli and the bacterial virus phage T4 that a one-to-one correspondence exists between the sequence of DNA (the genotype) and the product of the gene as it acts in the organism (the phenotype). This seminal observation spurred the search for ways to read the entire sequence of A's, G's, C's, and T's that constitute the genome of an organism, including humans. Thus the technology and terminology of molecular biology, born, in part, within the cybernetic community of post-World War II, began to permeate all of the sub-disciplines of the life sciences.
As a methodology, molecular biology is, by its very nature, reductive. One cannot examine the structure of the macromolecules that constitute the cell without taking that cell apart and examining the DNA "...right down to the atomic level."[5] The method is powerful and seductive. Vast arrays of data have been obtained for a number of organisms, ranging from bacteria to plants, from worms to man. The mining of this database is just beginning and is already yielding astonishing conclusions about the nature of genes and their expression. The reductive method does, indeed, work to give molecular level information about the gene.
However, as Ian Barbour points out, there are three forms of reduction.[6] The first form, the methodology described above, is a research strategy. The second and third forms are philosophical statements. When, in addition, a biologist claims that the principles at one level of organization can be completely connected to and derived from the principles in effect at a lower level of organization, an epistemological argument is being set forth. The third form of reduction is, in fact, an ontological position:
"When it is stated that organisms consist of 'nothing but atoms,' a metaphysics of materialism and atomism is asserted. It is assumed that the true nature of an entity is manifest at its lowest level."[7]
It might be sufficient if the differences between these levels were recognized by those scientists engaged in the discipline of biology. However, it is all too often the case that conclusions are drawn which are either uncritical or ignorant of the philosophical assumptions that are being made. Barbour indicts the writings of evolutionary biologists and commentators such as Daniel Dennett, Richard Dawkins, and Edward Wilson:
"I suggest that these authors have failed to distinguish between scientific and philosophical (author's italics) questions. Scientists in their popular writing tend to invoke the authority of science of ideas that are not a part of science itself."[8]
Before any kind of productive encounter between two disciplines can take place, some sort of roadmap or set of guidelines is essential. Ian Barbour has provided an immense service to science and theology by describing the typologies of interaction between these two seemingly unrelated areas. He uses the following four categories: conflict, independence, dialogue, and integration.[9] By detailing, with specific examples, how each of these categories of interaction work, he offers a way out of the simplistic mode of seeing science and religion at war. Certainly the conflict model can be thought of as Òwarfare,Ó as it is generally characterized in the popular press. However, this can hardly be called an interaction, since both sides in the conflict are fundamentally fixed and not truly open to intellectual exchange.
The independence category of Barbour is most clearly represented in biology by the late Stephen Jay Gould's concept of non-overlapping magisterium (NOMA).[10] Gould's analysis of the situation is nicely summarized in the first paragraph of this article:
"No supposed 'conflict' between science and religion should exist because each subject has a legitimate magisterium, or domain of teaching authority - and these magisteria do not overlap (nor do they encompass all inquiry). But the two magisteria bump right up against each other, interdigitating in wondrously complex ways along their joint border."
Without the Barbour categories at hand, it is easy to be confused about this statement. Was Gould defending a religious viewpoint, as many of his critics contended? Or was he, instead, carving out clear boundaries that allowed religion to be tucked away, out of sight of scientific inquiry? By using Barbour's categories, we can see that this is a plea for independence and not for dialogue or integration, even given Gould's hand-to-hand metaphor. Thus, we have an important tool for negotiating the exchange between the life sciences and theology.
Beyond describing the landscape of the conversation, however, Ian Barbour has provided several key critiques of the biological enterprise as it is represented by the strict reductionist philosophical approach.
To begin with, his use of process philosophy and the Whiteheadian categories and levels of experience provides a way out of the conundrum into which the philosophy of science has fallen since the end of the Enlightenment in the middle of the 20th century. Instead of focusing on descriptions that are inherently reductionistic and deterministic positions, process thought allows a metaphysics that is at once consistent with the methodology of biology but avoids the philosophic traps that plague some modern commentators. Barbour states that:
"Process thought rejects determinism, allows for alternative potentialities, and accepts the presence of chance as well as lawful relationships among events. In biology, especially in molecular biology, reductionistic and mechanistic approaches remain fruitful, but I have argued that there are irreducible properties of higher-level wholes, as process philosophy asserts."[11]
How then to think about the results of modern biology and the view of the living world that they represent? Barbour argues for a critical realist position with respect to all scientific investigation. His definition of critical realism, as an intermediate position between classical realism and instrumentalism, is that science deals with "...models and theories (that) inadequately and selectively represent particular aspects of the world for specific purposes."[12] This is, after all, how most practicing scientist carry out their work.
Barbour argues for a typology in which "some sort of integration is possible between the content of theology and the content of science." And so, it is logical for him to support a theology of nature that starts "from a religious tradition based on religious experience and historical revelation," but that holds that "some traditional doctrines need to be reformulated in the light of current science."[13] This kind of two way reflection between science and theology is a characteristic of Barbour's thesis and has had a profound influence on those who have entered this field. It is this particular emphasis that, I believe, opens the future of this discourse in the most productive and beneficial manner possible.
The Human Genome Project is moving to exploit the database of information derived from the human DNA sequence. A major project will be the International Haplotype Map, or HapMap. Blood samples collected from around the globe will be used to characterize individual genetic differences, using the database sequence as a key for the comparison. The goal of this project is to allow a precise determination of genetic contributions to disease and even permit drug designed based upon a person's unique genetic makeup. There is another side to this, however. The HapMap can also be used to highlight the slight differences among various groups of the human population. Herein lies the danger. If human nature is viewed simply as the sum of the base pairs, then such differences can be used to justify a variety of ill-conceived agendas. Already, the field of evolutionary psychology seeks to characterize human behavior in genetic terms. The combination of these two approaches could result in serious social justice issues.
It is here that Ian Barbour's critique of the materialism inherent in some human biological models becomes all important. Rather than dismissing the sociobiology of Edward Wilson out of hand, Barbour shows how that work embraces a "sweeping epistemological reductionism that makes all academic disciplines into branches of biology."[14] He then points out the importance of cultural factors in human evolution and comes ultimately to a process philosophy model that views human nature as multi-level entities.
Most importantly, he addresses the nature of consciousness using process thinking. He agrees with Roger Sperry[15] and ultimately with Philip Clayton[16] that "mental states are higher level emergent properties of the brain" and that "mental activity supervenes on neural activity without violating physiological laws."[17] This reflection is important for both theologians and biologists as we move into an even more detailed view of human genetic data.
A new development that suggests a powerful approach for understanding living systems is the science of networks. The ideas of complexity theory combined with a model of how linkages between entities arise and influence the higher order functioning of systems leads to a very different view of biology. Network thinking can be applied to everything from the spread of disease to an analysis of river estuaries.[18] In a recent paper, Zoltán Oltvai and Albert-László Barabási discuss the science of networks as applied to the inner biochemical workings of cells.[19] This view of biological control mechanisms that go beyond the genome level speaks directly to the process philosophy that Barbour espouses when he speaks of "multi-leveled systems and wholes" and of things that are "relational and interdependent." As these kinds of models become increasingly important, the approach to reality that they represent will likely change the way in which human biology is done.
At some time in the career of every biologist there comes a moment of wonder and awe as she or he encounters yet another seeming miracle of life. This decidedly human reaction is what Barbour might call a "religious experience," a numinous sense of the richness and complexity of creation. Indeed, even scientists that Barbour criticizes for their philosophical assumptions, such as Richard Dawkins and Edward Wilson, are deeply moved by the beauty and order that they see in nature.
But modern science has no method to describe this event, no words that are permitted to speak about this emotion. In fact, these qualitative properties are relegated to the level of epiphenomena, not truly "real," since they are not quantifiable. This stand, coupled with the flight into materialism that has characterized the scientific program since David Hume in the 18th century, leads to a veneration of Nature rather than any deity, and a rejection of any inkling of purpose or design.
In Barbour's typology, if integration could truly occur between theology and science, this situation might be altered. Process philosophy coupled with the science of networks could lead to an appreciation of the various levels of experience present in the natural world. Rather than relying on the bottom-up causality model of the reductionist paradigm, the emergence of truly new properties of systems could be recognized. This would liberate both science and theology from the assumptions that have kept them apart. Theology could be open to scientific models that are not based entirely on materialist presumptions. Science could be comfortable with the limits of its methodology and models and with the possibility of levels of experience that are outside of those limits.
In this new order, the experience of the Divine inherent in the scientific enterprise could be freed for expression. A hymn of praise to the Creator, writ in the A's, G's, C's, and T's of the genetic language, may someday rise up in harmony with the Te Deum.
[1] The International Human Genome Mapping Consortium, "A Physical Map of the Human Genome," Nature, 409, (2001), 934 - 941.
[2] The International Human Genome Mapping Consortium, "Initial Sequencing and Analysis of the Human Genome," Nature, 409, (2001), 860 - 921.
[3] Julian Huxley, "Evolution: The Modern Synthesis," Allen and Unwin, London, 1942.
[4] Salvador Luria and Hans Delbrück, "Mutations of Bacteria from Virus Sensitivity to Virus Resistance," Genetics, 28 (1943), 491-511.
[5] Francis Crick, "Of Molecules and Men," University of Washington Press, Seattle, 1966.
[6] Ian Barbour, "Religion and Science: Historical and Contemporary Issues," Harper, San Francisco, 1997, pp. 230-233.
[7] Ibid., p. 232.
[8] Ibid, p. 81.
[9] Ibid, p. 77 and ff.
[10] Stephen Jay Gould, "Non-overlapping Magisteria," The Skeptical Inquirer, 24, (1999).
[11] Ian Barbour, op. cit., p 291.
[12] Ibid, p 359
[13] Ibid, p 100.
[14] Ibid, p 257.
[15] Roger Sperry, "Science and the Moral Priority," Columbia University Press, New York, 1983, p. 92
[16] Philip Clayton, "God and Contemporary Science," W. B. Eerdmans, Grand Rapids, Michigan, 1997.
[17] Ian Barbour, op. cit., p. 262.
[18] Mark Buchanan, "Nexus: Small Worlds and the Groundbreaking Science of Networks," W. W. Norton, New York, 2002.
[19] Zoltán N. Oltvai and Albert-László Barabási, "Systems Biology: Life's Complexity Pyramid," Science, 298, (2002), pp. 763-764