Adnan Bseisu, Contributing Photographer

When Scott Mandelbrote, director of studies in history at Peterhouse College, Cambridge, traveled to the auction house Bonhams in London in 2021, he had to sneak into the building behind someone because the house was closed due to the COVID-19 pandemic. He wanted to look at a notebook that Bonhams had unofficially attributed to Isaac Newton’s closest friend at Cambridge, John Wickins.

The visit sparked a months-long study of the notebook in which Mandelbrote set out to determine the authenticity of the notebook and make a recommendation to the Cambridge University Library on whether or not to purchase it. 

On Nov. 16, the Beinecke Library invited Mandelbrote to deliver the 2022 Van Sinderen Lecture to an audience of Yale community members and the general public. Mandelbrote focused the talk on the process he undertook to authenticate the notebook.

“[We must] think through the problem of how one tries to avoid being a victim of forgery,” Mandelbrote told the audience at the start of the lecture. “If any of you decide that you don’t agree with me and that you think I and the institution I have advised have been guilty of such a mistake, please say so.”

Written in English and Latin in the late 1670s, the notebook contains evidence that Newton’s views on religion were already veering away from, or at least contemplating, Christian orthodoxy at the time. It also holds correspondences between Newton and Wickins about Newton’s scientific work. Wickins would often find necessary materials for and help Newton with his experiments. 

Sidney Hirschman ’22 cherished the opportunity to learn about the extensive process behind authenticating a manuscript like the lost notebook through Mandelbrote’s talk. 

“If he just showed it to me, I would be like yes, it’s real, because you’re the Isaac Newton scholar,” Hirschman said. “It’s very interesting to see how you go about doing that investigative work to determine if something is possibly authentic or not.”

Mandelbrote explained that authenticating the manuscript was important because it would change the understanding of Newton in the public realm. 

Mandelbrote argued a better understanding of Newton as a person would contribute to an improved historical understanding of the scientific practices that yielded the important discoveries of the late 17th and early 18th centuries.

“The [Bonhams] description of the notebook ended with a note that the manuscript usually ascribed to [Wickins] does bear substantial differences to the hand in [the] notebook,” Mandelbrote said. “So the question is: is any of this true? That was the question I was setting myself when I got into [related] volumes eventually.”

Mandelbrote said that answering this question was made difficult by the fact that little of Wickins’ handwriting existed beyond a signature attributed to him in a book of admissions, which experts believe he signed when he applied for a minor fellowship at Trinity College in 1660. As the Bonhams label noted, the hand of this signature differs from that of the notebook. 

During his research, Mandelbrote discovered another manuscript — a letter to the Dutch natural philosopher Christiaan Huygens — that matched the hand of the notebook. His job, then, became to find out who had written this manuscript before attributing the notebook to that same author. 

“Fortunately, and I was really pleased when I remembered this … in Newton’s letter to [his friend] Halley, he says ‘yesterday I unexpectedly struck upon a copy of the letter I told you of to [Huygens]. Tis in the hand of one Mr John Wickins who was then my chamber fellow,’” Mandelbrote told the audience. “That tells me that this is authentically Wickins’ hand.”

Yet, Mandelbrote still acknowledged the possibility, however unlikely it may be, that a sophisticated forger made the same link between Newton’s letter to Halley and the letter to Huygens. They could have then proceeded to copy the hand of the letter to Huygens when forging Wickins’ notebook.

To eliminate this possibility, Mandelbrote continued researching and stumbled across an unpublished manuscript by Joseph Beaumont, a Cambridge academic.The manuscript discussed a rite of passage he resurrected at the University that required all resident Masters of Arts to undergo a public display of theological orthodoxy through questions and discussion. 

Mandelbrote noticed that the theological contents of the notebook exactly answered the questions Beaumont asked the academics to discuss, concluding that some of the text in the notebook was a transcript of a speech Newton gave at Cambridge.

“So the notebook must be what it says it is,” Mandelbrote said. “It must be a lost notebook of Isaac Newton’s in the hand of his friend John Wickins.” 

Hirschman was most surprised by what Newton scholars, and scholars in general, still don’t know about their subjects of study. 

“You tend to think that scholars on a certain subject, or a certain person, will know everything about it,” Hirschman told the News. “But that’s actually not possible. People are just piecing things together the best they can, like everybody is. It makes you remember that scholars are also people.” 

Rustam Nuriev ’26 also attended the lecture and found the bidding process for manuscripts like the lost notebook most surprising. He noted that he was especially intrigued by how the process is open and advantages wealthy collectors over institutions like Cambridge.

“Collectors can pay millions of dollars to get a sheet of paper that was written by Newton or any other important historical figure,” Nuriev said. “And they are not even legally obliged to preserve the historical manuscript … they should be stored and preserved by universities like Cambridge or Yale.” 

Indeed, Mandelbrote confirmed to the News that collectors outbidding universities for important works can be problematic. He said the Cambridge University Library was lucky that the auction of the notebook was not popular among wealthy collectors.

Bonhams lists the final sale price at £62,750, many times under the £250,000 “conservative estimate” Mandelbrote told the library they should have been willing to pay for the manuscript before the bid.

Isaac Newton gifted a copy of his most important work, the Principia, to Yale College in 1717. It now resides at the 1742 Library at the Beinecke.