Just over a year ago, I was searching for the details of a death. It was the tail end of December, and I was in the final days and pages of writing my book Pure Wit. Each morning I would brave the journey to the British Library, in London—past Christmas lights and crowds of people whose presence seemed to proclaim that the working year was over—and sit back down in the manuscripts room. I was writing about Margaret Cavendish, the first Duchess of Newcastle and one of England’s first professional female authors, who had died 350 years earlier, at age 50.

Over a hundred thousand words and two laptops down, I should have been done with my research. Instead of calling up more boxes from the stacks, I should have been tied to my keyboard. If I typed without too many breaks for coffee or Instagram, I could be done by Christmas.

That rationale must have escaped me when I filled in one more request form. I already knew the facts of Cavendish’s death: that it occurred without warning on December 15, 1673; that she died before her husband, William Cavendish, the first Duke of Newcastle, who was some three decades older than she; and that he was too frail and too old to come to London for her lavish funeral, in Westminster Abbey. I was searching for something else—some clue to what the brilliant polymath scientist-poet-philosopher had been working on when she died. Some clue to what work was lost with her.

But in the midst of searching for this, I found something entirely different. Sitting in a box of Cavendish’s family papers was a small leather-bound volume, handwritten but so neat it aped the precision of type. It was a collection of transcribed “loose papers” by Elizabeth Brackley, her stepdaughter.

In looking for details of death, I found a record of life. Here were the countless prayers Elizabeth had written when pregnant and fearing a miscarriage; when worrying that her young children would die of illness, injury, or any of the other countless dangers in the 17th century. The prayers’ immediacy transcends the centuries they spent in the library. When one reads Elizabeth’s prayer for God to “heale” her young daughter Franck from her “great paine,” or to keep her safe when she was “in labour,” the bodily and spiritual concerns of an early-modern mother leap from the page.

This research non sequitur was, it turns out, anything but. Earlier in my writing, I had spent months reading about early-modern infertility, childbirth, and miscarriage. Although Cavendish was a marvelous polymath—a woman whose philosophical theories were in debate with Thomas Hobbes and René Descartes; a woman who wrote plays, poetry, and prose—she is remembered on her tombstone as a woman who left behind “noe issue.” While her husband had five children from his first marriage, their relationship was childless. Cavendish was infertile, and she was treated by her doctor with a foul-sounding “recipe for sterility.”

Although Margaret Cavendish was a marvelous polymath, she is remembered on her tombstone as a woman who left behind “noe issue.”

Why should it matter that such a productive, important woman—Cavendish was the first woman to visit the Royal Society, the world’s oldest scientific academy, and she was an early-modern celebrity famed for her outrageous fashions—was childless? For Cavendish herself, it wasn’t a concern: she made her books her “babes,” describing them as “infants of [her] brain.” Words became her children, a perfect replacement that let her see her legacy—lines of poetry—sprawl forth into future years.

Cavendish was, however, an outlier in this acceptance of her fate. In my research, I found heartbreaking testimonies of the pain of infertility and child loss during this period, from spiritual memoirs written about the God-given “punishment” of a lack of children, to poems written on the occasion of miscarriages. In one, written in 1657, a woman despairs over “a little embryo … void of life and feature.” Just because child-mortality rates were high back then—and the difficulties of conception and pregnancy more fatal—it did not mean that every death was not acutely felt.

In those final days of 2022, I thought I had left behind this research: the catch in the throat when reading a letter about another dead child; the tug of a poem blaming the death on a mother’s spiritual failings. But in researching Cavendish’s legacy, it came up again. While she left behind her books, other women had their children. I continued to write my chapter, leaving the book of prayers open in front of me.

Francesca Peacock’s Pure Wit: The Revolutionary Life of Margaret Cavendish is out now from Pegasus