Inoculation and the Evangelical Scientific Method of Cotton Mather

| By and (guest author) on Reading the Book of Nature

Portrait of Cotton Mather (1729), after engraving by Peter Pelham, American Antiquarian Society, Worcester, Massachusetts 

Introduction by Ted Davis

When I wrote my column on Cotton Mather, someone about whom I have not previously written anything, I didn’t realize that Rick Kennedy was about to publish a new biography, The First American Evangelical: A Short Life of Cotton Mather (2015). Once I realized this, I invited him to write a sidebar to my current series on Antebellum religion and science, based on the book. The topic he chose, Mather’s involvement with the first smallpox inoculation in America, makes a perfect complement to the theme of my own column. The next words you read are his.

Cotton Mather and the New Science

Scholars no longer write starkly and narrowly about the Enlightenment. Rather, we talk of many different types of enlightenments that shade into each other. Many of these enlightenments are rooted in Christian traditions such as French Roman Catholic Jansenism, Scottish Presbyterian Commonsense, and Saxon Lutheran Pietism. At Harvard in the beginning of the eighteenth century the kind of enlightenment most prominent is best described as a provincial British version of a moderate Protestant enlightenment.  Cotton Mather, who was twice denied the presidency of Harvard but remained influential over its intellectual life, practiced a distinct form of that enlightenment that we can call an evangelical form.  Cotton Mather promoted a biblical enlightenment that emphasized a social-scientific method, an enlightenment premised on the opportunities for progress in both human and divine communication.

All types of enlightenments share a similarity that gives them their name: their participants believed that they were turning on the lights. Optimism prevailed about knowledge progressing. Cotton Mather encouraged the development of the science program at Harvard and preached that students of nature should steer their barks with hope at the bow.

Mather believed that new methods of scientific enquiry should be embraced, especially experimentation.  The old science did not emphasize experiments to the same extent. It did observation, analysis and synthesis, and a few experiments, too, but the new natural philosophers began to see the special value of doing experiments. An experiment, we sometimes forget, is a wildly risky tool. It proposes that an individual controlled experience, if repeatable, can be extrapolated back into the past, out into the universe, and on into the future.  It shoots high and far.

Another optimistic method, most famously practiced by Isaac Newton and Edmond Halley and promoted at Harvard by Cotton Mather and Thomas Brattle, involved an expanded use of mathematics, especially geometry and statistics, to create models that are abstracted out of reality but useful for both understanding and prediction. Call the Earth a sphere.. Circumscribe it with degrees and minutes, both sideways for latitude and longwise for longitude. Create a prime meridian

at Greenwich. Do this in one’s mind and amazing feats of geodesic and celestial knowledge can be worked out and even discovered—even if the Earth is really not a sphere. Mather and Brattle were especially impressed with Halley’s way of model making:  Gather as much data as possible about such things as baptisms, marriages, deaths, tides, magnetism variations, and comet sightings, then smooth the data out, fudging some while dismissing others, and mold it into predictive models that describe social trends, geodesy, and even a comet’s return.

Mather and Brattle, along with Mather’s father, encouraged the experimental and mathematical aspects of the moderate Protestant enlightenment. The Mathers even pressed for Isaac Greenwood to become, in 1727, the first Hollis Professor of Mathematics—Harvard’s first scientific professorship. Greenwood had grown up the church youth groups led by Cotton Mather, and the Mathers had nurtured his scientific pursuits both as a young man and adult. 

Mather, himself, however, although favorable to these new scientific methods, did not do experiments nor did he create abstract models after gathering data or counting things.  He is considered one of Colonial America’s most important scientists, but he did not use the newest, coolest, tools. Frankly, he also did very little of the old stalwart method of observation, analysis, and synthesis. He was not one of those pastors that you read about in British novels or watch on PBS who avidly practiced bird-watching or systematic-gardening. He was not even the kind of guy who would stay up all night to watch the stars. He bought books, not scientific equipment. He gathered stories more than countable data. What makes him such an important scientific figure that he gained, during his life, a transatlantic reputation in natural philosophy and medicine?  What kind of method was he so good at that historians still today teach Cotton Mather as a stepping stone leading toward modern science in America?

Mather as an “Evangelical” Scientist: The Social Dimension of Scientific Knowledge

Cotton Mather’s scientific method fits the pattern most recently studied by Steven Shapin, the Franklin L. Ford Research Professor of the History of Science at Harvard. One of Shapin’s book titles, A Social History of Truth, describes best Mather’s preferred scientific method. Shapin has written a wide range of studies that focus on the way the scientific revolution in Mather’s era depended upon “social truth” made credible by testimony and the authority of the credible testifiers. The leaders of the new science who were performing experiments and making precise observations were, themselves, testifiers. The spread of their discoveries depended upon their authority of their personal reputations. The leaders of the scientific revolution, such as Robert Boyle and the fellows of the Royal Society of London, were trusted first as trustworthy testifiers then, secondarily, their experiments and calculations were trusted. The scientific revolution began as a network of social trust and still today continues as a network of trust. For Cotton Mather, as with most of us today, science is mostly known socially. Most of us today believe that gravity has an effect on light and that speed has an effect on time because we trust the people and the books that say so. In the late eighteenth and early nineteenth centuries this type of epistemology would be replaced by a romantic notion of hero-individual scientists; however, the existence and wisdom of social-scientific methods is being revived today.

 Few scholars have emphasized the social dimension of scientific knowledge more than Steven Shapin. Known for uncompromising frankness, he has turned his critical gaze even upon himself. One of his essays opens with a description of a memorial plaque for an eighteenth-century Anglican minister. “The inscription describes him as ‘a scholar, a Christian, and a gentleman.’ Some years ago, I found the plaque noteworthy enough to photograph, and I have been trying ever since to articulate why I found it so interesting. ‘A scholar, a Christian, and a gentleman’—possibly I found it remarkable because of the stranger’s natural curiosity: I have not had the good fortune to be any one of those things, let alone all three.” (Shapin, Never Pure: Historical Studies of Science as if It Was Produced by People with Bodies, Situated in Time, Space, Culture, and Society, and Struggling for Credibility and Authority, p. 142) 

Mather excelled as a listener, reader and writer—he long suffered a stutter that made him a slow, careful, talker. Like many scientists today, Mather was more a gatherer, disseminator, and promoter of information than a lab-coat practitioner. What made him evangelical was his deep commitment to believing credible people about such things as miracles and encounters with angels. Mather believed that the Bible was divine communication at its clearest. If God, as reported in the Bible, did miracles and communicated to Mary through an angel, there was no reason not to believe similar stories from credible eyewitnesses. This open-minded, social belief system, encouraged him to not only gather stories of wonders in the manner of his fellow members of the Royal Society of London who gathered curiosities for show and tell, it also encouraged him to expect new and true scientific knowledge to spread in the way the good news of salvation spreads.  

Cotton Mather’s evangelical enlightenment showed itself at its best in science’s engagement with small pox epidemics. Thomas Brattle, when wrestling the problem of small pox epidemics, turned to mathematics and statistical modeling. In 1711, working with a young Harvard tutor named Thomas Robie, Brattle searched town records for a mathematical pattern to describe the coming and going of local smallpox epidemics. They wrestled with the data, but they could not construct a working model. There seemed to be no mathematical pattern. Thomas Brattle, New England’s most systematic, sophisticated, and successful promoter of science, a man cited by Newton in the Principia, hit a wall on the small pox problem.

Cotton Mather, on the other hand, had his greatest scientific triumph dealing with small pox. In 1721 during a horrifying epidemic in Boston, Cotton recommended inoculations and even inoculated his children and associates. He inoculated the young Isaac Greenwood. Cotton Mather had read about European experiments with inoculations and his black slave, named Onesimus, told him of inoculations in Africa. The medical experts in Boston insisted that inoculation was a type of suicide, and in the furor of trying to stop Mather from inoculating people a bomb was thrown into Cotton’s study. One of Cotton’s inoculated patients was lying on a cot in the study when the bomb came through the window. The patient watched the bomb roll across the floor and breathed a sigh of relief when the fuse fell out. Tempers were hot in the midst of the epidemic, but Cotton succeeded in saving the lives of people who trusted him because he trusted the hearsay evidence of an academic journal and an African slave.

In short, both Brattle and Mather were exemplary figures of an early American scientific enlightenment, but Mather's enlightenment was of an evangelical sort rooted in his commitment to the Bible as divine encouragement of a testimony-trust social system of spreading true information. Brattle’s method of mathematical-modeling was in many ways more progressive and would flourish as the scientific establishment moved away from biblical authority. But we should not forget Cotton Mather’s evangelical method that conformed to the social-style of science that emphasized trusting experts and the character of credible witnesses. Both were methods that advanced colonial American science. 

Steven Shapin encourages the scientific establishment today to recognize and even revive its understanding of the Social History of Truth. The story of Cotton Mather’s success with his evangelical form of scientific method fits Shapin’s recommendation. It is good for us all to keep alive the role of both divine and human communication when engaged in science.




Davis, Ted. "Inoculation and the Evangelical Scientific Method of Cotton Mather" N.p., 28 May. 2015. Web. 22 February 2018.


Davis, T. (2015, May 28). Inoculation and the Evangelical Scientific Method of Cotton Mather
Retrieved February 22, 2018, from /blogs/ted-davis-reading-the-book-of-nature/inoculation-and-the-evangelical-scientific-method-of-cotton-mather

References & Credits

For fascinating commentary about Richard Dawkins, doubting Thomas, and the importance of credible testimony for establishing scientific knowledge, see Thomas Dixon’s column in Huffington Post, Science and Religion—Doubting Thomas: A Patron Saint For Scientists? Interestingly, a founder of the Royal Society, William Petty, actually suggested that the Society have an annual festival on St. Thomas’ day—for reasons that are consistent with what Dixon says. As Petty is supposed to have said, Thomas made an appropriate choice, “for he would not believe till he had seen and put his fingers into the holes, according to the motto [of the Royal Society], ‘Nullius in verba’.”

About the Authors

Rick Kennedy

Rick Kennedy received his BA, MA, and Ph.D. from the University of California, Santa Barbara and is professor of history at Point Loma Nazarene University, San Diego, California. His books include A History of Reasonableness: Testimony and Authority in the Art of Thinking (University of Rochester Press, 2004), Aristotelian and Cartesian Logic at Harvard (Colonial Society of Massachusetts and University Press of Virginia, 1995), and Faith at State: A Handbook for Christians at Secular Universities (InterVarsity, 1995).

More posts by Rick Kennedy

Ted Davis

Ted Davis is Fellow of the History of Science for the BioLogos Foundation and Professor of the History of Science at Messiah College. A former high school science teacher, Ted studied history and philosophy of science at Indiana University, where his mentor was the late Richard S. Westfall, author of the definitive biography of Isaac Newton. With the English historian Michael Hunter, Ted edited The Works of Robert Boyle, 14 vols. (London: Pickering & Chatto, 1999-2000), but his interests include the whole 2000-year interaction of Christianity and science. Author of dozens of scholarly articles and essays, Ted is one of few historians who have written extensively about both the Scientific Revolution and modern America. He and his wife Kathy enjoy theater, music, and traveling to new places.

More posts by Ted Davis