I once had dinner with Janet Browne, author of what I think is the best biography of Darwin (it’s in two volumes; do read it!), and took the opportunity to ask her a question. “If you had Darwin here at the table,” I said, “and could ask him one question, what would it be?” Janet didn’t hesitate in her answer: “I’d like to know about the missing letter from Wallace.”
She was referring to a well known incident involving a famous letter. While Darwin was slowly preparing On the Origin of Species for publication, he received, supposedly on June 18, 1858, a letter from Alfred Russel Wallace. And that letter contained an essay (written in Frebruary of that year) outlining Wallace’s theory of evolution by natural selection, which of course was something Darwin had been ruminating about for years. Wallace’s piece, “On the tendency of varieties to depart indefinitely from the original type,” has become known as the “Ternate” essay from the Indonesian island where it was supposedly penned, and you can find it here.
Darwin was, of course, upset. He’d been mulling over his ideas, and collecting evidence to support them, for two decades, and all of a sudden some upstart naturalist had stolen his thunder. Moreover, Wallace asked Darwin to pass the essay on to the geologist Charles Lyell if he found it interesting.
What could Darwin do to preserve both his integrity and his ideas? He sent Wallace’s essay to his friends Charles Lyell and botanist Joseph Hooker, who brokered a solution: Darwin would write a short precis of his own ideas, which, along with Wallace’s essay, would be presented at a meeting of the Linnean Society of London. A letter from Darwin to Hooker on June 19, 1858, shows how distraught Darwin was about the possibility that he’d lost the priority of his great ideas. He was sending Hooker his own contribution for the joint Linnean Society publication as part of the brokered solution:
My dear Hooker
I have just read your letter, & see you want papers at once. I am quite prostrated & can do nothing but I send Wallace [i.e., Wallace’s manuscript] & my abstract of abstract of letter to Asa Gray, which gives most imperfectly only the means of change & does not touch on reasons for believing species do change. I daresay all is too late. I hardly care about it.—
But you are too generous to sacrifice so much time & kindness.—It is most generous, most kind. I send sketch of 1844 solely that you may see by your own handwriting that you did read it.—
I really cannot bear to look at it.—Do not waste much time. It is miserable in me to care at all about priority. . .
Darwin’s cobbled-together contribution, and Wallace’s essay, were read at the Linnean Society on July 1, 1858, and the essays were published. That was the gentlemanly solution to a thorny problem. Darwin, of course, is now the name associated with evolution and natural selection, for Wallace did not capitalize on his ideas, while Darwin rushed The Origin into print, securing his place in history. (See Steve Jones’s essay from the 2008 Guardian, “How Darwin won the evolution race.“)
Historians, mulling over this episode, found two problems. First, the letter from Wallace to Darwin is missing among Darwin’s correspondence. Darwin slavishly saved all his correspondence, so why was this crucial document not in his collection?
Second, some historians have questioned whether Darwin really did receive the letter on June 18. Wallace had mailed some letters from Ternate on March 9, 1858, and these arrived in London on June 3. If Wallace’s letter to Darwin was in that same packet of mail, then why did it take until June 18 to reach Darwin?
Based on this, several historians have suggested that Darwin did indeed receive the letter in early June, and held onto it, not only delaying its conveyance to Lyell, but actually stealing Wallace’s ideas in the interim. While most historians pooh-pooh this idea (after all, Darwin’s correspondence and notebooks show he had had the idea of natural selection well before this), this conspiracy theory has been persistent. Indeed, Roy Davies wrote a book on it: The Darwin Conspiracy: origins of a scientific crime, and called the supposedly delayed letter “a deliberate and iniquitous case of intelletual theft, deceit, and lies perpetuated by Charles Darwin.” And several other historians have agreed, though not in such damning ways.
And that is why Janet wanted the issue of the letter cleared up.
Well, we still don’t know why it’s missing, but a new paper in the Biological Journal of the Linnean Society by John van Wyhe and Kees Rookmaker, two historians of science at the National University of Singapore, make a strong case that Darwin did not hold onto Wallace’s letter, much less steal its ideas.
van Wyhe and Rookmaaker painstakingly traced the routes of steamers from Indonesia to London, and have created a plausible and unbroken chain of transmission that indeed puts the letter in Darwin’s hands on 18 June, 1858. A few excerpts from their paper:
The route taken by Wallace’s letter and essay sent to Darwin from Ternate can be reconstructed confidently, assuming that it was deposited at the Ternate post office before 25 March, when Wallace left the island for a collecting trip to New Guinea. The mail service from Ternate (April) to Down House (June) in 75 days can be described in ten stages.
I’ll spare you these, but the letter went via Surabaya, Jakarta, Singapore, Suez, Egypt, and Southampton. The postal service was far more efficient than I thought back then, and it’s always been efficient in the UK. The letter arrived in Southampton on 16 June and was at Down two days later. The authors conclude:
The transit of Wallace’s letter from Ternate to Down House took the normal period of 75 days. If Darwin told the truth, then the arrival of Wallace’s letter on 18 June should actually have a fully connecting service route all the way back to Ternate in the Dutch East Indies – something that Darwin could not have known. We have now shown this to be the case.
Therefore, contrary to the frequent assertions of conspiracy theorists, Darwin did not lie about the receipt of Wallace’s Ternate essay, and in fact sent it on to Lyell the very same day. Hence, we should restore the story of the joint announcement of the theory of evolution by natural selection from the recent version of dishonesty and conspiracy to one of those inspiring cases of cooperation in the history of science.
This, of course, doesn’t solve the problem of why Wallace’s letter is missing, but it shows (as I fully expected) that Darwin was not a plagiarist. He was subject to the normal concerns of priority that affect every scientist, but his behavior in this matter was—as in all his scientific dealings—scrupulous.