How did New England Puritans reconcile their faith with the emergence of scientific empiricism? As Sarah Rivett, a literary scholar at Princeton, tells it, they did so with relative ease. Rivett argues that both Puritans and practitioners of the new science grappled with the limitations of humankind’s perceptive faculties. By the middle of the 17th century, the “study of the soul and the study of the world” had emerged as “parallel empirical techniques.” Animated by the essential optimism of John Calvin’s Institutes, Puritan studies of the soul and scientific studies of the world eagerly sought answers for seemingly unknowable questions. Like Charles Webster, a towering figure in the history of science and medicine, Rivett clarifies the often-murky relationship between religion and science in the early modern world. Unlike Webster, Rivett closely considers the place of women and native peoples in that history, as well as the nature of the evidence that “soul” scientists examined.

In her study of the Puritan soul, Rivett looks at the public testimonials of faith that ministers recorded in order to verify congregants’ experiences with God’s grace. As testimonials gained in popularity, there emerged in New England a “science of self-scrutiny” that was akin to an “experimental religious empiricism.” Men and women engaged with that science differently, for ministers rarely encouraged women to speak publicly. Although a few of the men who developed the “science of the soul” valued female public testimony, Rivett finds that masculine voices dominated the genre, rendering women socially invisible in it. Other sources of religious knowledge, though, were much more feminine.

Whereas masculine testimony dominated the congregation, feminine testimony dominated the home. Rivett concludes that the Puritans privileged the deathbed testimonies of faith given by women above those of men. Unencumbered by the formalities of public testimony, this “soul data” was outside of the congregational, public worship context and thus considered purer. Living out the ars moriendi—the art of dying well—provided data closer to the early modern philosopher John Locke’s tabula rasa or blank slate, free of preconceptions. In keeping with her theme of the cohesion between religion and science at the time, Rivett shows that both clerics and natural philosophers valued this pure data. For the minister Cotton Mather, it evidenced God’s grace; for the scientist Thomas Willis, it revealed spirits lurking in the optic nerve. And women were not the only marginalized group of people that ministers and natural philosophers relied upon in their search for truth.

Turning her attention to praying towns—settlements in Massachusetts designed to convert native peoples—Rivett shows that soul scientists took the opportunity to make ethnographic and linguistic observations about the Indian inhabitants. As with women’s deathbed testimonies, priests and scientists alike used this indigenous data, although for different purposes. For missionaries like John Eliot, learning native tongues facilitated conversion and might even bring about Christ’s second coming. For those who were keen on taxonomy, linguistic study had the potential to uncover a universal, pre-Babelian tongue, a general human language before separate languages arose. Rivett notes that King Philip’s War and the ensuing decimation of Northeastern indigenous people eliminated whatever hope ministers and natural philosophers had for using Indian testimony and language as “evidence of biblical prophecy and natural history.” But this violence did not defeat the soul scientists, for a different instance of brutality provided a host of new data.

Against the historiographical grain, Professor Rivett interprets the Salem witch trials as a dispute over the validity of supernatural evidence. In her narrative, the trials epitomized the rational application of empirical methods to the preternatural world. In this moment, the purposes of theologians and scientists diverged. Scientists were none too happy with Cotton Mather’s appropriation of their techniques, for Mather bridged the once-solid divide between the visible, knowable world and the invisible, unknowable one. A contest between theologians and mechanical philosophers followed, with profound consequences: spectral evidence—evidence that was unseeable and unverifiable—now received legal recognition. Although Rivett’s interpretation of the trials is sound, her use of Mather presents an interpretive challenge. As is clear in his ruminations in The Christian Philosopher, Mather occupied a space between theologians and natural philosophers. If he had truly split the two groups of enquirers, he would have had to split himself.

The “science of the soul” ended with the theologian and minister Jonathan Edwards. Attempting to revive the testimonial form in Northampton and Stockbridge, Massachusetts, he connected the natural world to the divine. A transitional figure, Edwards as Rivett presents him was the last Puritan to search the soul for evidences of grace. He was also a leader of what some historians call the “Evangelical Enlightenment,” a Protestant strand of the larger 18th-century shift towards scientific thought. Because Edwards could not sustain that Enlightenment, argues Rivett, his retirement ended the Puritan knowledge quest that defiantly insisted on the human capacity to know. And, according to Rivett, thus ended the application of empirical, scientific tools to the study of divinity. A “new independent and self-sufficient” religion (self-sufficient in the sense that it was independent of scientific inquiry) took hold of New England.

Despite its provocative arguments and interpretive brilliance, The Science of the Soul has three weaknesses that may lessen its impact. Firstly, its dependence on theoretical jargon can be confusing. Secondly, the author (somewhat haphazardly) inserts performance theory into her analysis, yet makes no mention of the performance theorists whom she draws upon. This stilted and overly academic interpretation understands all phenomena to be performances. At one point, Rivett claims that Edwards’s “sermon series performs the infinite expandability of the cosmic circles …” How a sermon could “perform” something is beyond me.

Although I was annoyed by the book’s jargony language and tendency to emphasize theoretical frameworks more than strong archival evidence, it has a greater flaw. Rivett gives so much attention to the close reading and literary criticism of published works that readers are left wondering how the illiterate, and people who lacked access to printed materials, engaged with soul science. The reader could get the impression that the narrative begins with John Calvin, changes with Cotton Mather, and ends with Jonathan Edwards. “Vernacular” belief, the beliefs of the common people, has little role in Rivett’s high-level intellectual history.

Because of these criticisms, The Science of the Soul is likely more useful for specialists in early American religion and science than it is for generalists. That said, historians who consider those subjects would do well to engage with Rivett’s retelling of the early relationship between science and faith in New England. Rivett’s work testifies to the fact that reason and religion were very much in harmony in early New England. If that is no longer the case, that is because students have lost a sense of history. In reading this book, they should regain that perspective.