Chance is an uncomfortable thing. So Curtis Johnson argues in Darwin's Dice: The Idea of Chance in the Thought of Charles Darwin, and he makes a compelling case. The central controversy, and the central innovation, in Darwin's work is not the theory of natural selection itself, according to Johnson, but Darwin's more basic, and more innovative, turn to randomness as a way to explain natural phenomena. This application of randomness was so controversial, Johnson argues, that Darwin tried to cover it up, replacing words like "accident" and "chance" with terms like "spontaneous variation" in later editions of his work. Nonetheless, the terminological shift was cosmetic: Randomness remained, and still remains, the disturbing center of Darwin's theories.
Johnson, a political theorist at Lewis & Clark College, explains that there are two basic kinds of chance in Darwin's thought. The first—most familiar and least disconcerting—is chance as probability. According to the theory of natural selection, individuals with advantageous adaptations are most likely to survive. A giraffe with a longer neck has a better shot of reaching those lofty leaves and living to munch another day; a polar bear blessed with a warmer coat has a higher probability of surviving a frigid winter than one with less hair. The long-necked giraffe may not always win—it may, for example, be pulverized by a meteor before it can pass on its long-necked genes. But over time, the odds will go its way. There is randomness here, but it is controlled and predictable: It works in accordance with a rule. Natural selection makes sense.
Darwin can be used to tell the rich that they amassed their wealth by being the fittest, perhaps, but he can also be used to point out to the rich that they really could just as easily have been someone else. The person you're stepping on—it's only the roll of a dice that that person isn't you.
The second kind of chance in Darwin's work, though, is more mysterious. For natural selection to work, you need to have a range of traits to select among. That range is provided by individual variation, the fact that two different animals (whether giraffe or bear) are different from each other. Some giraffes have longer necks than others. Some bears have thicker fur than others. Why should this be? Darwin's answer was chance.
Sometimes, Johnson writes, Darwin would argue that "chance" stood in for unknown laws—consistent rules which were not yet known, but which, when discovered, would explain exactly why individuals, both within and across species, were different. But "in his more private and less guarded moments," Johnson explains, Darwin suggested that "the cause of at least some variations is unknowable, even in principle." And, in fact, as Johnson suggests, this second interpretation—that the cause of variation is unknowable—has only become more persuasive over time. "The mechanisms of variation are better understood than ever," Johnson writes, "but the ability to predict what variations will occur and what will not is not much better off than when Darwin wrote." As biologist and feminist theorist Julia Serano argues in her recent book Excluded, we can't currently predict whether someone will be homosexual or heterosexual, cis or trans, based on their genetic code, and there's no reason to think we ever will be able to do so.
Thinkers in Darwin's day had largely made their peace with Newton, and were therefore able to see God's hand behind the operation of natural laws. But for Darwin, variation did not conform to laws. Instead, God appeared to be playing dice with creation—and as Einstein would later suggest, a dice-playing God begins to look like not a God at all. For Darwin, in particular, the fact that variations were as likely to be negative as positive created serious problems for his faith. As Johnson writes:
Some creatures are born so ill-adapted that they do not really have any chance at all to survive or at least to propagate. That did not seem to Darwin to reflect intelligence.... How could a good God plan a world destined to be filled with so much senseless death and evidence misery?
Attributing variation to chance leads inevitably to a particularly sticky version of the theodicy problem. If God is all powerful, how can he roll the dice with each infant, doling out disadvantages and, at worst, crippling, painful, terminal birth defects? Darwin had no answer, which is why he appears to have lost his faith in God, and why he hid his commitment to chance from his theistic colleagues and the public. Eventually, Johnson suggests, Darwin quietly adopted a full-blown materialist determinism, in which natural forces governed all aspects of life. Since unknown laws of chance were responsible for individual character and appetites, Darwin thought, there was no space left for free will.
Johnson does not take the story of Darwin and chance beyond the naturalist's own lifetime. It seems clear, though, that even our more secular age is uncomfortable with this aspect of Darwin's thought. Natural selection became popularized through Social Darwinism and eugenics, and still resonates in discussions around meritocracy. The argument that those who succeed are the most fit to succeed has a reassuring teleology; CEOs, venture capitalists, politicians, or, for that matter, freelance writers, can look to Darwin to assure themselves they have succeeded not by chance, but by skill and/or virtue.
Similarly, pop evolutionary psychology retails stories in the same vein, about how men are from Mars and women are from the savannah. They explain social interactions in terms of an all-purpose predictive rubric, one which rationalizes everything—from attitudes toward short skirts to the Oscars—in terms of mating probabilities. Darwin himself recognized that not all variations were necessarily beneficial—that some traits or behaviors might have no grand effect on survival, or might even be harmful but not harmful enough to be selected against. But in pop culture, the shadow of meaninglessness is dispersed, and, in some way, Darwin's theories are used to make what could otherwise be seen as random seem predictable and meaningful.
Johnson's book challenges us, at least implicitly, to rethink these comforting Darwinisms. In particular, acknowledging chance seems like it could be a way to think about the arbitrariness of success and power. Meritocracy is false for a lot of reasons, but Johnson's Darwin points to a very basic flaw—namely, that individuals are not responsible for their own merits, whatever those merits may be. Whatever skills or talents or character traits you have, whatever self you were born with, is the product of random variation. Darwin can be used to tell the rich that they amassed their wealth by being the fittest, perhaps, but he can also be used to point out to the rich that they really could just as easily have been someone else. The person you're stepping on—it's only the roll of a dice that that person isn't you.
Beyond that, chance opens materialism to something, or somewhere, else. Darwin rejected miracles adamantly, but surely if the creation of each individual is radically unpredictable, then each individual is (as Alan Moore and Dave Gibbons argue in Watchmen) a miracle in him-, her-, or zir-self. Natural selection is often used to argue that the individual is defined by the struggle for survival. But random variation seems to suggest instead that people (and not just people) are too random to be predicted or defined. We can't predict why, or how, a new baby will vary from everyone before or since. Life after Darwin is still, and in some ways more than ever, a mystery. For Darwin, chance meant determinism, but it seems like it could just as easily mean possibility.