The major features of the biological origins of Homo sapiens are coming into focus, and this clarification raises the potential of a more fruitful contact between science and the humanities. The convergence between these two great branches of learning will matter hugely when enough people have thought its potential through. On the science side, genetics as well as the brain sciences, evolutionary biology, and paleontology will each be seen in a different light. Students will be taught prehistory as well as conventional history, and the whole properly presented as the living world’s greatest epic.
Pride and humility in better balance, we’ll also take a more serious look at our place in nature. Exalted we are, risen to be the mind of the biosphere without a doubt, our spirits uniquely capable of awe and ever more breathtaking leaps of imagination. But we are still part of Earth’s fauna and flora, bound to it by emotion, physiology, and, not least, deep history. It is folly to think of this planet as a way station to a better world. Equally, Earth would be unsustainable if converted into a literal, human-engineered spaceship.
Human existence may be simpler than we thought. There is no predestination, no unfathomed mystery of life. Demons and gods do not vie for our allegiance. Instead, we are self-made, independent, alone, and fragile, a biological species adapted to live in a biological world. What counts for long-term survival is intelligent self-understanding, based upon a greater independence of thought than that tolerated today even in our most advanced democratic societies.
3
Evolution and Our Inner Conflict
Are human beings intrinsically good but corruptible by the forces of evil, or the reverse, innately sinful yet redeemable by the forces of good? Are we built to pledge our lives to a group, even to the risk of death, or the opposite, built to place ourselves and our families above all else? Scientific evidence, a good part of it accumulated during the past twenty years, suggests that we are both of these things simultaneously. Each of us is inherently conflicted. Team player or whistle-blower? Charitable donation or personal certificates of deposit? Admitted traffic violation or denial? I don’t believe I can let this subject pass by leaving my own conflicted emotions unconfessed. When Carl Sagan won the Pulitzer Prize for nonfiction in 1978, I dismissed it as a minor achievement for a scientist, scarcely worth listing. When I won the same prize the following year, it wondrously became a major literary award of which scientists should take special note.
We are all genetic chimeras, at once saints and sinners, champions of the truth and hypocrites—not because humanity has failed to reach some foreordained religious or ideological ideal, but because of the way our species originated across millions of years of biological evolution.
Don’t get me wrong. I am not implying that we are driven by instinct in the manner of animals. Yet in order to understand the human condition, it is necessary to accept that we do have instincts, and it will be wise to take into account our very distant ancestors—as far back and in as fine a detail as possible. History alone cannot reach this level of understanding. It stops at the dawn of literacy, where it turns the rest of the story over to the detective work of archaeology. In still deeper time the quest becomes paleontology. For the real human story, history must comprise both the biological and cultural.
Within biology itself, the key to the mystery is the force that lifted prehuman social behavior to the human level. The leading candidate is multilevel selection, by which hereditary social behavior improves the competitive ability not just of individuals within groups but among groups as a whole.
Bear in mind that during organic evolution the unit of natural selection is not the individual organism or the group, as some popular writers have misconstrued it. It is the gene (more precisely the alleles, or multiple forms of the same gene). The target of natural selection is the trait prescribed by the gene. The trait can be individual in nature and selected in competition among individuals inside or outside the group. Or the trait can be socially interactive in nature with other members of the group (as in communication and cooperation) and selected by competition among groups. A group of uncooperative, poorly communicating individuals will lose to its better organized competitors. The genes of the losers will decline across generations. Among animals, the consequences of group selection can be most plainly seen in the exquisitely programmed caste systems of ants, termites, and other social insects, but is also manifest in human societies. The idea of between-group selection as a force operating simultaneously in addition to between-individual selection is not new. Charles Darwin correctly deduced its role, first in the insects and then in human beings, respectively in On the Origin of Species and The Descent of Man.
I am convinced after years of research on the subject that multilevel selection, with a powerful role of group-to-group competition, has been a major force in the forging of advanced social behavior—including that of humans. In fact, it seems clear that so deeply ingrained are the evolutionary products of group-selected behaviors, so completely a part of the contemporary human condition are they, that we are prone to regard them as fixtures of nature, like air and water. They are instead idiosyncratic traits of our species. Among them is the intense, even obsessive interest of people in other people, which begins in the first days of life as infants learn particular scents and sounds of the adults around them. Research psychologists have found that all normal humans are geniuses at reading the intentions of others, whereby they evaluate, proselytize, bond, cooperate, gossip, and control. Each person, working his way back and forth through his social network, almost continuously reviews past experiences while imagining the consequences of future scenarios. Social intelligence of this kind occurs in many social animals, and reaches its highest level in chimpanzees and bonobos, our closest evolutionary cousins.
A second diagnostic hereditary trait of human behavior is the overpowering instinctual urge to belong to groups in the first place, shared with most kinds of social animals. To be kept forcibly in solitude is to be kept in pain, and put on the road to madness. A person’s membership in his group—his tribe—is a large part of his identity. It also confers upon him to some degree or other a sense of superiority. When psychologists selected teams at random from a population of volunteers to compete in simple games, members of each team soon came to think of members of other teams as less able and trustworthy, even when the participants knew they had been selected at random.
All things being equal (fortunately things are seldom equal, not exactly), people prefer to be with others who look like them, speak the same dialect, and hold the same beliefs. An amplification of this evidently inborn predisposition leads with frightening ease to racism and religious bigotry. Then, also with frightening ease, good people do bad things. I know this truth from experience, having grown up in the Deep South during the 1930s and 1940s.
It might be supposed that the human condition is so distinctive and came so late in the history of life on Earth as to suggest the hand of a divine creator. Yet, as I’ve stressed, in a critical sense the human achievement was not unique at all. Biologists have identified at the time of this writing twenty evolutionary lines in the modern-world fauna that attained advanced social life based on some degree of altruistic division of labor. Most arose in the insects. Several were independent origins in marine shrimp, and three appeared among the mammals—that is, in two African mole rats, and us. All reached this level through the same narrow gateway: solitary individuals, or mated pairs, or small groups of individuals built nests and foraged from the nest for food with which they progressively raised their offspring to maturity.
Until about three million years ago the ancestors of Homo sapiens were mostly vegetarians, most likely wandering in groups from site to site where fruit, tubers, and other vegetable food could be harvested. Their brains were only slightly larger than those of modern chimpanzees. By no later than half a million years ago, however, groups of the ancestral species Homo erectus were maintaining campsites with controlled fire—the equivalent of
nests—from which they foraged and returned with food, including a substantial portion of meat. Their brain size had increased to mid-sized, between that of chimpanzees and modern Homo sapiens. The trend appears to have begun one million to two million years previously, when the earlier prehuman ancestor Homo habilis turned increasingly to meat in its diet. With groups crowded together at a single site, and an advantage added by cooperative nest-building and hunting, social intelligence grew, along with the centers of memory and reasoning in the prefrontal cortex.
Probably at this point, during the habiline period, a conflict ensued between individual-level selection, with individuals competing with other individuals in the same group, on the one side, and group-level selection, with competition among groups, on the other. The latter force promoted altruism and cooperation among all the group members. It led to innate group-wide morality and a sense of conscience and honor. The competition between the two forces can be succinctly expressed as follows: Within groups selfish individuals beat altruistic individuals, but groups of altruists beat groups of selfish individuals. Or, risking oversimplification, individual selection promoted sin, while group selection promoted virtue.
So it came to pass that humans are forever conflicted by their prehistory of multilevel selection. They are suspended in unstable and constantly changing positions between the two extreme forces that created us. We are unlikely to yield completely to either force as the ideal solution to our social and political turmoil. To give in completely to the instinctual urgings born from individual selection would be to dissolve society. At the opposite extreme, to surrender to the urgings from group selection would turn us into angelic robots—the outsized equivalents of ants.
The eternal conflict is not God’s test of humanity. It is not a machination of Satan. It is just the way things worked out. The conflict might be the only way in the entire Universe that human-level intelligence and social organization can evolve. We will find a way eventually to live with our inborn turmoil, and perhaps find pleasure in viewing it as the primary source of our creativity.
II
THE UNITY OF KNOWLEDGE
ALTHOUGH THE TWO GREAT BRANCHES OF
LEARNING, SCIENCE AND THE HUMANITIES, ARE
RADICALLY DIFFERENT IN THE WAY THEY DESCRIBE
OUR SPECIES, THEY HAVE RISEN FROM THE SAME
WELLSPRING OF CREATIVE THOUGHT.
4
The New Enlightenment
We’ve considered thus far the biological origins of human nature, and from this information the idea that a large part of human creativity is generated by the inevitable and necessary conflict between the individual and group levels of natural selection. The implied unity in the explanation leads us to the next leg of the journey I suggest. It is the concept that science and the humanities share the same foundation, in particular that the laws of physical cause and effect can somehow ultimately account for both. You will likely recognize this proposition. Western culture has already traveled this way. It was called the Enlightenment.
During the seventeenth and eighteenth centuries, the idea of the Enlightenment ruled the Western intellectual world. At that time it was a juggernaut; in the minds of many it even seemed to be the destiny of the human species. Scholars appeared on track to explain both the Universe and the meaning of humanity by the laws of science, the latter called at that time natural philosophy. The great branches of learning, Enlightenment scholars believed, can be unified by a continuous network of cause and effect. Then, when built from reality and reason alone, cleansed of superstition, all of knowledge might come together to form what in 1620 Francis Bacon, greatest of the Enlightenment’s forerunners, termed “the empire of man.”
The Enlightenment quest was driven by the belief that entirely on their own, human beings can know all that needs to be known, and in knowing understand, and in understanding gain the power to choose more wisely than ever before.
By the early 1800s, however, the dream faltered and Bacon’s empire retreated. There were two reasons. First, although scientists were generating discoveries at an exponential pace, they were nowhere close to meeting the expectations of the more optimistic Enlightenment thinkers. Second, this shortfall allowed the founders of the Romantic tradition of literature, including some of the greatest poets of all time, to reject the presumptions of the Enlightenment worldview and seek meaning in other, more private venues. Science had no way, and it never would, to touch what people deeply feel and express only through the creative arts. Reliance on scientific knowledge, many believed and their contemporary successors continue to believe, beggars the human potential.
For the next two centuries and to the present day, science and the humanities went their own ways. Physicists of course no less continue to enjoy playing in string quartets, and novelists write books that marvel at the wonders uncovered by science. But the two cultures—as they came to be called by the middle of the twentieth century—were considered by most to be separated by a permanent chasm built into the mind, perhaps intrinsic to the nature of existence itself.
In any case there was simply no time during the long eclipse of the Enlightenment to think of unification. In order to accommodate the rising flood of information, scientific disciplines were dividing into specialties at a near-bacterial rate—fast then faster and then even faster. The creative arts for their part continued to flower with brilliant and idiosyncratic expressions of the human imagination. There was very little interest in trying to reignite what was perceived as an antique and hopeless philosophical quest. Yet the Enlightenment was never proved to be impossible. It was not dead. It was just stalled.
Is there any value in resuming the quest now, and any chance of achieving it? Yes, because enough is known today to make it more attainable than during its first flowering. And yes, because the solutions of so many problems of modern life hinge on solutions for the clash of competing religions, the ambiguities of moral reasoning, the inadequate foundations of environmentalism, and (the big one) the meaning of humanity itself.
Studying the relation between science and the humanities should be at the heart of liberal education everywhere, for students of science and the humanities alike. That’s not going to be easy to achieve, of course. Among the fiefdoms of academia and punditry there exists a great variation in acceptable ideology and procedure. Western intellectual life is ruled by hard-core specialists. At Harvard University, for example, where I taught for four decades, the dominant criterion in the selection of new faculty was preeminence or the promise of preeminence in a specialty. Starting with the deliberations of department-level search committees, then recommendations to the dean of the faculty of arts and sciences, and at last the final decision by the president of Harvard, who was assisted by an ad hoc committee drawn from both within and outside the university, the pivotal question asked was, “Is the candidate the best in the world in his research specialty?” On teaching, it was almost always an easygoing, “Is the candidate adequate?” The guiding philosophy overall was that the assembly of a sufficient number of such world-class specialists would somehow coalesce into an intellectual superorganism attractive to both students and financial backers.
The early stages of a creative thought, the ones that count, do not arise from jigsaw puzzles of specialization. The most successful scientist thinks like a poet—wide-ranging, sometimes fantastical—and works like a bookkeeper. It is the latter role that the world sees. When writing a report for a technical journal or speaking at a conference of fellow specialists, the scientist avoids metaphor. He is careful never to be accused of rhetoric or poetry. A very few loaded words may be used, if kept to the introductory paragraphs and the discussion following the presentation of data, and if added to clarify the meaning of a technical concept, but they are never used for the primary purpose of stirring emotion. The language of the author must at all times be restrained and obedient to logic based on demonstrable fact.
The exact opposite is the case in poetry and the other cr
eative arts. There metaphor is everything. The creative writer, composer, or visual artist conveys, often obliquely by abstraction or deliberate distortion, his own perceptions and the feelings he hopes to evoke—about something, about anything, real or imagined. He seeks to bring forth in an original way some truth or other about the human experience. He tries to pass what he creates directly along the channel of human experience, from his mind to your mind. His work is judged by the power and beauty of its metaphors. He obeys a dictum ascribed to Picasso: art is the lie that shows us the truth.
Wildly searching, sometimes shocking in effect, the creative arts and much of the humanities scholarship analyzing them are nonetheless in an important sense just the same old story, with the same themes, the same archetypes, the same emotions. We readers don’t care. We’re addicted to anthropocentricity, bound to a bottomless fascination with ourselves and others of our kind. Even the best-educated live on an ad libitum diet of novels, movies, concerts, sports events, and gossip all designed to stir one or more of the relatively small range of emotions that diagnose Homo sapiens. Our stories about animals require human-like emotions and behavior understandable with well-worn guidebooks of human nature. We use endearing animal caricatures, including even those of tigers and other ferocious predators, to teach children about other people.
The Meaning of Human Existence Page 2
