Interdisciplinary efforts, for all their ostensible appeal, are more often praised than practiced, especially when it comes to combining the humanities and sciences. Nonetheless, connecting two intellectual perspectives that seem to be poles apart, and that have had very different fates, helps sweep away some common misconceptions—nay, fears—about modern scientific thought.
Let's look, therefore, at evolutionary biology and existential philosophy.
The former is experiencing rapid, perhaps exponential, growth, while the latter appears to have had its day and is (unjustifiably, in my opinion) in decline. Collectors of oxymorons—"freezer burn," "jumbo shrimp," "military intelligence"—might well appreciate the prospect of "evolutionary existentialism." They might also ask whether the bottom line involves mere alliterative appeal, in which case why not "molecular metaphysics" or "epigenetic epistemology."
Here's why these two seemingly strange bedfellows belong together: They are, in fact, a compatible couple. What they share suggests that science has not completely destroyed our understanding of free will, as so many critics contend. A philosophy of "human meaning" can coexist quite well with a science of "genetic influence."
First let's turn to some of the prominent incompatibilities between the two. Existentialism has, as one of its organizing principles, the notion that human beings have no "essence." As Jean-Paul Sartre famously put it, "existence precedes essence." For existentialists, there is no Platonic form of the person, no ideal self of which our corporeal reality is a pale instantiation. Rather, we define ourselves, give ourselves meaning, establish our essence only via our existence, by what we do, how we choose to live our individual lives. We have no "human nature," just our own intentions.
Thus choice is especially important for existentialists, because we are free; in Sartre's paradoxical words, we are "condemned to be free." In a universe devoid of purpose and uncaring about people, it is our job to give meaning to our lives.
That is vastly different from evolutionary premises. At the heart of an evolutionary view of human nature—or of hippopotamus, halibut, or hickory-tree nature—is the idea that living things are a concatenation of genes, jousting with other, similar genes to get ahead. Free, conscious, intentional choices seem out of place for a creature who is merely the physical manifestation of DNA programmed to succeed.
For evolutionary biologists, all living things have a purpose. It is neither divine nor Platonic. It is also not a choice, at least for nonhuman species, because their purpose is generated, quite simply, by the reward that natural selection provides for creatures that succeed in projecting their genes into future generations. Living things are survival vehicles for their potentially immortal genes. Biologically speaking, that is what they are—and all that they are.
At this point, most existentialists can be expected to disagree.
For evolutionary biologists, behavior is one way genes go about promoting themselves. Other ways are by producing a body that is durable, adapted to its ecological situation, capable of various physiological feats like growth, metabolism, repair, and so on. Probably the most obvious way in which behavior promotes genes is the powerful inclination that adults (of any sexually reproducing species) have to mate, and then, depending on the species, to care for their offspring. Seen in that light, our essence—our genotype—seems to precede our existence, contrary to what the existentialists would have us believe. We are, in a sense, slaves to the selfish genes that created us, body and mind, even though, as is increasingly recognized, sometimes those genes perform their work by "altruistically" benefiting other individuals, offspring not least.
Halibut and hickory trees don't know what they're doing, or why. Human beings do. "Man is but a reed, the most feeble thing in nature, but he is a thinking reed," wrote the French mathematical genius, religious mystic, and precursor of existentialism, Blaise Pascal. "A vapor, a drop of water, is enough to kill a human being.
"But even if the universe should crush him, man would still be more noble than that which destroys him, because he knows that he dies, and he realizes the advantage that the universe possesses over him; the universe knows nothing of this."
Thanks to evolutionary insights, people are acquiring a new knowledge: what their genes are up to, i.e., their evolutionary "purpose." An important benefit of evolutionary wisdom is that, by giving us the kind of knowledge about the universe that Pascal so admired, it leaves us free to pursue our own, chosen purposes. Sometimes those purposes involve a conscious decision to refrain from, say, reproducing—something unimaginable in any other species. At other times (all too rarely), they might involve deciding to extend an ethic of caretaking to include other human beings to whom we are not immediately related, or even to include other species, with whom we share comparatively few genes.
But Pascal also prefigured existential thought when he wrote that "the silence of these infinite spaces frightens me." Such fear was understandable, since the comfortable sense of human specialness that characterized the pre-Copernican world was being replaced in Pascal's day by a vast universe of astronomic distances, no longer centered on Homo sapiens. The great, empty spaces of evolutionary time and possibility—as well as human kinship with "lower" life forms that they demand—have frightened and repelled many observers of evolutionary biology as well (although so far as I can tell, it hasn't deeply troubled any scientists).
Many nonscientists, especially when first exposed to evolutionary thinking, are also chilled by the focus—characteristic of both existentialism and modern evolutionary biology—on the smallest possible unit of analysis.
The Danish philosopher and existentialist pioneer Søren Kierkegaard asked that only this should be written below his name on his gravestone: "The Individual." And in his masterful Man in the Modern Age, the existential psychiatrist and philosopher Karl Jaspers, although rejecting the label of existentialism, focused on the struggle of individuals to achieve an authentic life in the face of pressures for mass conformity.
In a parallel track, much of the intellectual impetus of evolutionary biology has come from abandoning comfortable but outmoded group-level arguments. Although the public still tends to think that evolution acts, as it's commonly put, "for the good of the species," evolutionary biologists are essentially unanimous that natural selection acts most strongly at the smallest level: individuals. Actually, the process goes farther yet, focusing when possible on individual genes. Species-wide effects are simply the arithmetic summation of these micro-impacts.
That individual, gene-centered perspective has given rise to criticism that sociobiology—the application of evolutionary insights to complex social behavior, including that of our own species—is inherently cynical, promoting a gloomy, egocentric Weltansicht. The same, of course, has been said of existentialism, whose stereotypical practitioner is the anguished, angst-ridden loner, wearing a black turtleneck and obsessing, Hamlet-like, about the meaninglessness of life.
Let's look more closely at that critique by taking an extreme position and granting, if only for the sake of argument, that human beings, like other living things, are merely survival machines for their genes, organic robots whose biologically mandated purpose is neither more nor less than the promulgation of those genes. And let's grant that existentialists are very much occupied with the meaninglessness of life and the consequent need for people to assert their own meaning, to define themselves against an absurd universe. Furthermore, let's consider the less-well-known fact that, although evolutionary biology makes no claim that it or what it produces is inherently good, it also teaches that life is absurd.
Evolutionists, after all, might well look at all living things—human beings not least—as playing a vast existential roulette game. No one can ever beat the house. There is no option to cash in one's chips and walk away a winner. The only goal is to keep playing, and indeed, some genes and phyletic lineages manage to stay in the game longer than others. But where, I ask you, is the meaning in a game whose goal is simply to keep on playing, a game that can never be won, but only lost? And for which we did not even get to write the rules?
There is, accordingly, no intrinsic, evolutionary meaning to being alive. We simply are, having been produced when one of our father's sperm connected with one of our mother's eggs, each contributing genes that combined to become a new person. Those genes, too, simply are, because their antecedents avoided being eliminated.
We have simply been, as Martin Heidegger (another precursor of existentialism, who particularly influenced Sartre) put it, "thrown into the world." None of us, after all, was consulted beforehand. Biologically, our genes did it; or rather, our parents' genes. And their parents' before them.
At this point, some critics say that if evolutionary biology reveals that life is without intrinsic meaning, then biology is mistaken. Not at all. From the perspective of natural science generally, there is no inherent reason that anything—a rock, a waterfall, a halibut, a human being—is of itself meaningful. As existentialists have long pointed out, the key to life's meaning is not aliveness itself, but what we attach to it.
At one point in Douglas Adams's hilarious The Hitchhiker's Guide to the Galaxy, as a sperm whale plummets toward the planet Magrathea, it wonders: "Why am I here? What is my purpose in life?" The appealing but doomed creature has just been "thrown into" its world, which happens to be several miles above the planet's surface; the creature exists as a whale because it had inexplicably been transformed from a nuclear missile, directed at our heroes' spaceship, into a briefly airborne cetacean when the occupants of said spaceship activated their Infinite Improbability Drive.
Evolution, too, is an improbability generator, although its outcomes are considerably more finite. After being called into existence by that particular improbability generator called natural selection, we have no more purpose in life than Adams's naïve and ill-fated whale, whose blubber was soon to bespatter the Magrathean landscape.
Think back, now, to Pascal and his successors, whether atheist (Nietzsche, Sartre) or religious (Kierkegaard, Jaspers), for whom there are many ways that human beings can and do say no to their genes. Sartre, for example, encouraged rebellion against the pressures of conformity and the lack of authenticity inherent in denying one's freedom, just as Camus urged his readers to reject any complicity in lethal violence, to be "neither victims nor executioners." By the same token, Kierkegaard led the way for the "truly religious" to take deep and often personal responsibility for their spiritual lives.
As descendants of both existential and evolutionary perspectives, we have the opportunity to assert ourselves as creative rebels. We may elect intentional childlessness. We may choose to be less selfish and more genuinely altruistic than our genes might like. We may decide to groom our sons to be nurses and our daughters to be corporate executives. I would go farther, and suggest that we must do such sorts of things—deny aspects of our own biological heritage—if we want to be fully human. The alternative—to let biology carry us where it will—is to forgo the responsibility of being human, and to be as helpless and abandoned as a (briefly) airborne Magrathean whale.
Going with the flow of our biologically generated inclinations is very close to what Sartre called "bad faith," whereby people pretend—to themselves and others—that they are not free. That is not to claim that human beings are perfectly free. When the early-20th-century philosopher José Ortega y Gasset observed that "man has no nature, only a history," he neglected to add that this includes an evolutionary history, as a result of which we are constrained as well as impelled in certain ways and directions. We cannot assume the lifestyle of honeybees, or Portuguese men-of-war. But such restrictions are trivial and beside the point: Within a remarkable range, our evolutionary bequeathal is wildly permissive.
This uniquely human potential to resist our own genes might help explain why people expend so much effort trying to induce others, especially the young and impressionable, to practice what is widely seen as the cardinal virtue: obedience. To recast Freud's argument about incest restraints, if we were naturally obedient, we probably wouldn't need so much urging. And yet, on balance, it seems that far more harm has been done throughout human history by obedience—to Hitler's Final Solution, Stalin's elimination of opponents real and imagined, Mao's Cultural Revolution, Pol Pot's genocide—than by disobedience.
On the basis of evolutionary existentialism, I would therefore like to suggest the heretical and admittedly paradoxical notion that, in fact, we need to teach more disobedience. Not only disobedience to political and social authority but especially disobedience to some of our troublesome genetic inclinations.
Along with a capacity for altruism, we also appear to have been endowed with occasional tendencies to ill-treat stepchildren (who are, of course, unrelated to one's self), to give free rein to any number of violent tendencies, to discriminate against others who appear different from ourselves, to value short-term successes over long-term consequences. It is a good thing that we are not marionettes, dancing at the end of strings pulled by our DNA. It is also a good thing that we can identify any such tendencies, and decide whether to defy our inclinations or go along with them. It is largely when we act in ignorance of our biology that we are most vulnerable to it.
As Albert Camus wrote, reconfiguring Descartes's cogito, "I rebel, therefore we exist." Or, as André Malraux put it, "The greatest mystery is not that we have been flung at random among the profusion of the earth and the galaxy of the stars, but that in this prison we can fashion images of ourselves sufficiently powerful to deny our nothingness."
In that denial lies not only a great mystery but also a thrilling hope.