It’s bad enough to see basic scientific misinformation about evolution getting tossed around these days. USA Today apparently has no qualms about publishing an op-ed by a state senator from Utah (who wants to have students be taught about something called “divine design”) claiming there is no empirical evidence in the fossil evidence that humans evolved from apes. I’m not sure what we’re supposed to do with the twenty or so species of hominids that existed over the past six million years. Perhaps just file them away under “divine false starts.”

But history takes a hit as well as science. Creationists try whenever they can to claim that Darwin was directly responsible for Hitler. The reality is that Hitler and some other like-minded thinkers in the early twentieth century had a warped view of evolution that bore little resemblance to what Darwin wrote, and even less to what biologists today understand about evolution. The fact that someone claims that a scientific theory justifies a political ideology does not support or weaken the scientific theory. It’s irrelevant. Nazis also embraced Newton’s theory of gravity, which they used to rain V-2 rockets on England. Does that mean Newton was a Nazi, or that his theory is therefore wrong?

Creationists are by no means the only people who are getting history wrong these days. Yesterday in Slate, Jacob Weisberg wrote an essay in which he claimed that evolution and religion are incompatible. He claims to find support for his argument in Darwin’s own life.

That evolution erodes religious belief seems almost too obvious to require argument. It destroyed the faith of Darwin himself, who moved from Christianity to agnosticism as a result of his discoveries and was immediately recognized as a huge threat by his reverent contemporaries.

I get the feeling that Weisberg has yet to read either of the two excellent modern biographies of Darwin, one by Janet Browne and the other by Adrian Desmond and James Moore. I hope he does soon. Darwin’s life as he actually lived it does not boil down to the sort of shorthands that people like Weisberg toss around.

Darwin wrestled with his spirituality for most of his adult life. When he boarded the Beagle at age 22 and began his voyage around the world, he was a devout Anglican and a parson in the making. As he studied the slow work of geology in South America, he began to doubt the literal truth of the Old Testament. And as he matured as a scientist on the journey, he grew skeptical of miracles. Nevertheless, Darwin still attended the weekly services held on the Beagle. On shore he sought churches whenever he could find them. While in South Africa, Darwin and FitzRoy wrote a letter together in which they praised the role of Christian missions in the Pacific. When Darwin returned to England, he was no longer a parson in the making, but he certainly was no atheist.

In the notebooks Darwin began keeping on his return, he explored every implication of evolution by natural selection, no matter how heretical. If eyes and wings could evolve without help from a designer, then why couldn’t behavior? And wasn’t religion just another type of behavior? All societies had some type of religion, and their similarities were often striking. Perhaps religion had evolved in our ancestors. As a definition of religion, Darwin jotted down, “Belief allied to instinct.”

Yet these were little more than thought experiments, a few speculations that distracted Darwin every now and then from his main work: of discovering how evolution could produce the natural world. Darwin did experience an intense spiritual crisis during those years, but science was not the cause.

At age 39, Darwin watched his father Robert slowly die over the course of months. His father had confided his private doubts about religion to Darwin, and he wondered what those doubts would mean to Robert in the afterlife. At the time Darwin happened to be reading a book by Coleridge called Friend and Aids to Reflection, about the nature of Christianity. Nonbelievers, Coleridge declared, should be left to suffer the wrath of God.

Robert Darwin died in November, 1848. Throughout Charles’s life, his father had shown him unfailing love, financial support, and practical advice. And now was Darwin supposed to believe that his father was going to be cast into eternal suffering in hell? If that were so, then many other nonbelievers, including Darwin’s brother Erasmus and many of his best friends, would follow him as well. If that was the essence of Christianity, Darwin wondered why anyone would want such a cruel doctrine to be true.

Shortly after his father’s death, Darwin’s health turned for the worse. He vomited frequently and his bowels filled with gas. He turned to hydropathy, a Victorian medical fashion in which a patient is given cold showers, steam baths, and wrappings in wet sheets. He would be scrubbed until he looked “very like a lobster,” he wrote to his wife Emma. His health improved, and his sprits rose even more when Emma discovered that she was pregnant again. In November 1850 she gave birth to their eighth child, Leonard. But within a few months death would return to Down House.

In 1849 three of the Darwin girls, Henrietta, Elizabeth, and Anne suffered bouts of scarlet fever. While Henrietta and Elizabeth recovered, nine-year old Anne remained weak. She was Darwin’s favorite, always throwing her arms around his neck and kissing him. Through 1850 Anne’s health still did not rebound. She would vomit sometimes, making Darwin worry that “she inherits I fear with grief, my wretched digestion.” The heredity that Darwin saw shaping all of nature was now claiming his own daughter.

In the spring 1851 Anne came down with the flu, and Darwin decided to take her to Malvern, the town where he had gotten his own water-cure. He left her there with the family nurse and his doctor. But soon after, she developed a fever and Darwin rushed back to Malvern alone. Emma could not come because she was pregnant again and just a few weeks away from giving birth to a ninth child.

When Darwin arrived in Anne’s room in Malvern, he collapsed on a couch. The sight of his ill daughter was awful enough, but the camphor and ammonia in the air reminded him of his nightmarish medical school days in Edinburgh, when he watched children operated on without anesthesia. For a week–Easter week, no less–he watched her fail, vomiting green fluids. He wrote agonizing letters to Emma. “Sometimes Dr. G. exclaims she will get through the struggle; then, I see, he doubts.–Oh my own it is very bitter indeed.”

Anne died on April 23, 1851. “God bless her,” Charles wrote to Emma. “We must be more & more to each other my dear wife.”

When Darwin’s father had died, he had felt a numb absence. Now, when he came back to Down House, he mourned in a different way: with a bitter, rageful, Job-like grief. “We have lost the joy of our household, and the solace of our old age,” he wrote. He called Anne a “little angel,” but the words gave him no comfort. He could no longer believe that Anne’s soul was in heaven, that her soul had survived beyond her unjustifiable death.

It was then, 13 years after Darwin discovered natural selection, that he gave up Christianity. Many years later, when he put together an autobiographical essay for his grandchildren, he wrote, “I think that generally (and more and more as I grow older), but not always, that an agnostic would be the most correct description of my state of mind.”

Darwin did not trumpet his agnosticism. Only by poring over his private autobiography and his letters have scholars been able to piece together the nature of his faith after Anne’s death. Darwin wrote a letter of endorsement, for example, to an American magazine called the Index, which championed what it called “Free Religion,” a humanistic spirituality in which the magazine claimed “lies the only hope of the spiritual perfection of the individual and the spiritual unity of the race.”

Yet when the Index asked Darwin to write a paper for them, he declined. “I do not feel that I have thought deeply enough [about religion] to justify any publicity,” he wrote to them. He knew that he was no longer a traditional Christian, but he had not sorted out his spiritual views. In an 1860 letter to Asa Gray—a Harvard botanist, the leading promoter of Darwin in America, and an evangelical Christian–he wrote, “I am inclined to look at everything as resulting from designed laws, with the details, whether good or bad, left to the working out of what we may call chance. Not that this notion at all satisfies me. I feel most deeply that the whole subject is too profound for human intellect. A dog might as well speculate on the mind of Newton.”

In private Darwin complained about social Darwinism, which was being used to justify laissez-faire capitalism. In a letter to the geologist Charles Lyell, he wrote sarcastically, “I have received in a Manchester newspaper rather a good quib, showing that I have proved ‘might is right’ and therefore that Napoleon is right, and every cheating tradesman is also right.” But Darwin decided not to write his own spiritual manifesto. He was too private a man for that.

Despite his silence, Darwin was often pestered in his later years for his thoughts on religion. “Half the fools throughout Europe write to ask me the stupidest questions,” he groused. The inquiring letters not only tracked him down to Down House but reached deep into his most private anguish. To strangers, his responses were much briefer than the one he had sent to Gray. To one correspondent, he simply said that when he had written the Origin of Species, his own beliefs were as strong as a prelate’s. To another, he wrote that a person could undoubtedly be “an ardent theist and an evolutionist,” and pointed to Asa Gray as an example.

Yet to the end of his life, Darwin never published anything about religion. Other scientists might declare that evolution and Christianity were perfectly in harmony, and others such as Thomas Huxley might taunt bishops with agnosticism. But Darwin would not be drawn out. What he actually believed or didn’t, he said, was of “no consequence to any one but myself.”

Darwin and and his wife Emma rarely spoke about his faith after Anne’s death, but he came to rely on her more with every passing year, both to nurse him through his illnesses and to keep his spirits up. At age 71, a few weeks before his death, he looked over the letter she had written to him just after they married. At the time she was beginning to become worried about his faith and urged him to remember what Jesus had done for him. On the bottom he wrote, “When I am dead, know that many times, I have kissed & cryed over this.”

It is a disservice to Darwin, and to history, to turn his tortured, complex life into a talking point in a culture war.

(Much of this post is adapted from the last chapter of my book, Evolution.)

Originally published August 11, 2005. Copyright 2005 Carl Zimmer.