The Reluctant Mr. Darwin (4 page)

Seventy-five pages into the “C” notebook, in spring 1838, Darwin's confidence swelled. Grappling with these questions, he admitted, was “a most laborious, & painful effort of the mind,” the difficulties of which would never be solved without long meditation or by someone prejudiced against the whole notion. But once you grant that species “may pass into one another,” then the “whole fabric totters & falls.” Look around the world, Darwin coached himself. Study the gradation of intermediate forms. Study geographical distribution. Study the fossil record, and the geographical overlap between extinct creatures and similar living species. Consider all this evidence, he argued excitedly, and “the fabric falls!”

The fabric was natural theology. For him it
had
fallen. Behind where that drapery had hung, Darwin saw the reality of evolution. It wasn't just a matter of mockingbirds, rabbits, and skinks. It was the whole natural world. “But Man—wonderful Man,” he wrote, trying out ideas on this most dangerous point, “is an exception.” Then again, he added, man is clearly a mammal. He is not a deity. He possesses some of the same instincts and feelings as animals. Three lines below the first statement about man, Darwin negated it, concluding firmly that, no, “he is no exception.” From that terrible insight, despite pressures and implications, Charles Darwin would never retreat.

4

Did it make him physically sick? Possibly. Darwin's work on the transmutation notebooks coincided with his early complaints about what became chronic bad health. The symptoms were mysterious—jumpy heart, nausea, vomiting, headaches, nervous excitement, inordinate flatulence—but real enough to make him miserable and to slow his work. Was he a hypochondriac? A neurasthenic? Had he been bitten and infected by some nasty disease-bearing bug during a
Beagle
stopover in Argentina? Many guesses have been made but nobody knows, to this day, what ailed him.

Just before the voyage, he had experienced some cardiac discomfort, possibly reflecting his high state of nervous anticipation. He seemed otherwise to be a healthy young man, and he stayed robust throughout most of those five years. He suffered seasickness, yes, and an occasional bout of bad stomach or fever, not unusual for a stranger to the tropics; but during shore time in South America he managed long stretches of adventuresome hiking and riding. Since his return he had gained sixteen pounds, a good sign that the food at the Athenaeum Club agreed with him. Then, in September 1837, he said in a letter to his old Cambridge mentor, John Henslow: “I have not been very well of late with an uncomfortable palpitation of the heart.” His doctors had advised him to quit work and get a country vacation, he added, and he was taking their advice. “I feel I must have a little rest, else I shall break down.” After a few weeks home in Shrewsbury, with his father and sisters, he reported again to Henslow that “anything which flurries me completely knocks me up afterwards and brings on a bad palpitation of the heart.” Social gatherings flurried him. Intense conversations flurried him. Conflict, or the very idea of it, was highly flurrisome. Eight months later he repeated to his old friend W. D. Fox the same muted phrase he'd written Henslow: “I have not been very well of late….” There was too much to do, too much to learn and consider. He couldn't afford being sick. But the workload of his
Beagle
-related chores, and the sense of dreadful mission involving transmutation, didn't help his stomach. To make life more complicated (though maybe he imagined it would simplify things), he started thinking about marriage.

Not about marrying somebody in particular—just about
marriage
as a state, a condition, a step in the progress of a man. Was it something he should do? The daughters of Leonard Horner don't seem to have tempted him; possibly they were too smart and lively. He didn't mention any favored candidate, but the question of marriage had risen big in his mind, partly because it was related to another that also seemed urgent: money. How would he, over the long term, pay his bills? He had to eat, he had to buy books. He thought that he wanted to travel again (more comfortably than on a crowded naval ship). His current allowance might cover all that, but not the costs of a wife and children, too. At this point, unaware of how wealthy and generous his scary father was, Darwin imagined that choosing marriage would mean resigning himself to the necessity of a salaried job. Doing what? He had never finished medical training and he was definitely unfit—given what he believed, what he didn't believe—to masquerade as a clergyman. He considered wangling a professorship at Cambridge, maybe in geology. Nerdy, systematic, prone to anxiety, he tried to work through his confusion about marriage and money as he was working through the idea of transmutation, by scribbling notes. Since he was parsimonious about paper, not just about time and energy, he did it on the blank sides of a letter from Leonard Horner. Maybe that was also his way of turning the page on the Horner daughters.

“If
not
marry,” he wrote, topping one section; then he listed a scenario of advantages. European travel. He might go to America, do some geologizing in the United States or Mexico. Or he'd get a better house in London, near Regent's Park, and work on the species question. He could keep a horse. Take summer tours. Make himself a specialist collector in some line of zoological specimens and study their affinities. It didn't sound bad. “If marry,” he wrote—then another list, this one mainly disadvantages, as though he were talking himself out of it. “Feel duty to work for money.” No summer tours, no getaways to the countryside, no large zoological collection, no books. Ugh. Could he tolerate this, living in London, in a little house full of children and the dreary food smells of poverty, “like a prisoner?” Cambridge might be better, if he could get a professorship. “My destiny will be Camb. Prof. or poor man,” he thought. He was wrong. But his resignation to that pair of options suggests he wanted a wife pretty badly.

He needed to ventilate his brain. In late June 1838, he broke away from London and its pressures—his editorial work on the
Zoology
, his chores for the Geological Society, possibly also the secret notebooks, unless he tucked “C” into a pocket—and went off to Scotland for a bit of geological fieldwork. He visited Glen Roy, a valley in the Highlands famous for the strange unexplained terraces traversing its slopes. Vacationing or not, he was a keen observer and a restless theorizer. After eight days in Glen Roy, he had his own notion about the origin of the shelves, and once back in London, amid all the other work, he'd make time to write a Glen Roy paper. But on the way south he stopped again in Shrewsbury for a family visit.

Talking with his father, Darwin got some brusque, cheerful advice: Quit worrying about money, you'll have plenty, and get married before you're too old to enjoy the kids. Dr. Darwin himself had been forty-three when Charles was born. The good news about financial support helped to rearrange Darwin's thinking. He drew up another orderly page of marital pros and cons, and this time “Marry” headed the longer column on the left, “Not Marry” the shorter one on the right. Marriage would give him a constant companion and a friend in old age, who would be “better than a dog anyhow.” It was intolerable to think of spending one's whole life on nothing but work. “Only picture to yourself a nice soft wife on a sofa with good fire, & books & music perhaps.” The Horner girls didn't fit that picture. Turning the sheet over, he wrote: “It being proved necessary to Marry…When? Soon or Late.” The other question he might have added was: Whom?

Before heading back to London he visited his cousins, the Wedgwoods (of the famous pottery business and the family fortune it had built), at their mansion in the next shire. It was the safest household he knew outside his own family home. Considering the gruffness of his father and the supportive amiability of his uncle, Josiah Wedgwood, maybe it was the safest household, period. And, oh, there were unmarried Wedgwood girls.

5

By then he had begun notebook “D,” the third in his transmutation series. “Mine is a bold theory,” Darwin wrote, meaning the big one about species, not the little one he'd just concocted about Glen Roy, “which attempts to explain, or asserts to be explicable every instinct in animals.” Yes, it asserted that animal instincts and much more were “explicable,” but it did
not
explain those phenomena; it merely noted the fact that species are interconnected by common ancestry. Darwin still hadn't proposed a mechanism for how transmutation occurs. Noodling on, he recorded some facts about Muscovy ducks, white-headed Sussex cattle, glowworms, and again the apteryx. From the anatomist Richard Owen he gleaned that reptilian skeletal structure is very similar to avian skeletal structure, as evident in a young ostrich. But Owen wasn't inclined to make as much of the reptile-bird similarity as he did. “There must be some law,” Darwin told the notebook, “that whatever organization an animal has, it tends to multiply &
IMPROVE
on it.” But what was the law? He still didn't know.

Despite the time lost to his unexplained illness early in the summer, by autumn he was back in a groove. He finished the Glen Roy paper. He worked on another geology manuscript, related to those endlessly ongoing
Beagle
publications. He pondered transmutation and also, by testimony to another little diary, he “thought much upon religion.” The entry is cryptic, but it's safe to assume he wasn't experiencing an accession of piety. Probably he was worrying over the conflict between religious dogma as filtered through natural theology and, on the other hand, the view of origins he now held. He cast about for facts, alternative perspectives, and authority, reading the journal of an expedition to eastern Australia, Edward Gibbon's autobiography, John Ray's
The Wisdom of God,
and three volumes of a biography of Walter Scott. He read books about birds, Mt. Aetna, physiognomy, epistemology, and Paraguay. And then, in September of that year, 1838, he picked up the sixth edition of Thomas Malthus's
Essay on the Principle of Population
.

He would have known something of Malthus already, by cultural osmosis, in the same way an educated person today is at least vaguely aware of Milton Friedman or Jean-Paul Sartre. His brother's favorite dinner partner, Harriet Martineau, was an ardent popularizer of Malthus's views. The
Essay on Population
, first published anonymously in 1798 and expanded in later editions, offered a political economist's dispassionate analysis that undergirded the Whig program of hard-nosed welfare reform. Easy charity was bad and pointless, according to Malthus. It only encouraged population increase among poor people, without generating any commensurate increase in the national supply of food. That caused prices to rise for everybody. Eliminate unquestioning relief, force the poor to compete as laborers or be locked into workhouses, educate them against the disadvantages of profligate reproduction, and the problem of mass poverty would be ameliorated, if not solved. This was Malthusian social logic. It entailed stern thinking and, with a little exaggeration or distortion, could seem even sterner. Darwin was a mild, generous soul and he may have found it, as described secondhand, too callous.

What he probably didn't know until he had Malthus's book in his hands was that it mentioned animal and plant populations as well as human ones. On the first page Malthus paraphrased Benjamin Franklin, of all people, to the effect that every species has a tendency to proliferate beyond its available resources, and that nothing limits the total number of individuals except “their crowding and interfering with each other's means of subsistence.” Empty the planet of life, Franklin had posited, seed it anew with just one or two forms—fennel plants, say, or Englishmen—and within a relatively short time Earth will be overrun with nothing but Englishmen and fennel. The inherent rate of population growth is geometric—that is, any population can
multiply
itself by some factor, not just
add
to itself, with each generation. For humans, Malthus calculated, the inherent rate amounts to doubling a population every twenty-five years. For fennel, which sets hundreds of tiny fruits on each plant, the inherent rate of population growth is much higher. But the inherent rate is just a biological possibility; such extreme increases seldom happen. Under normal circumstances, on a teeming planet as opposed to an empty one, runaway population growth is prevented by what Malthus called “checks.”

The ultimate check is starvation. For humans it results from the fact that, while population is increasing geometrically, ever-intensified efforts at land clearance and agricultural improvement only increase the food supply arithmetically. That is, the sequence 2, 4, 8, 16, 32, 64, 128 runs away from the sequence 2, 3, 4, 5, 6, 7, 8. But food supply directly limits population numbers only during famine. Another kind of check is voluntary: the decision to refrain from marrying, to marry late in life, or to practice birth control (of which Malthus, a wholesome parson of pre-Victorian views, didn't approve). Still other checks operate continually: overcrowding, unwholesome work, extreme poverty, bad care of children, endemic disease, epidemic, war, and anything else that might contribute to sterility, sexual abstinence, or early death. Generally speaking, Malthus wrote, you could boil them all down into “moral restraint, vice, and misery.” Darwin read this and something went click. He was less interested in moral restraint and vice than in what “misery” might mean to a mockingbird, a tortoise, an ape, or a stalk of fennel.

He ruminated in his “D” notebook about “the warring of the species as inference from Malthus.” The geometric population increase of animals, as of humans, is prevented by such Malthusian checks, he wrote. He imagined it all freshly. Take the birds of Europe. They are well known to naturalists and their populations are (or were in his time, anyway) relatively stable. Every year, each species suffers a steady rate of death from hawk predation, from cold, from other causes, roughly maintaining its net population level against the rate of increase from fledglings. Food supply remains limited, nesting space remains limited, but breeding, laying, and hatching continue to push against those limits. Everything is interconnected and uneasily balanced. If the hawks decrease in number, the bird populations they prey upon will be affected, somehow. With new clarity Darwin saw predation, competition, excess reproduction, death—and their consequences. “One may say there is a force like a hundred thousand wedges,” he wrote, and that it's trying to “force every kind of adapted structure into the gaps in the oeconomy of Nature, or rather forming gaps by thrusting out weaker ones.” The final result of all this wedging, Darwin added, “must be to sort out proper structure & adapt it to change.”