Spencer J. Weinreich is a Junior Fellow in the Harvard Society of Fellows (on leave 2023–24) and a Lecturer on the History of Science. A historian of early modern Europe, he works at the intersection of the history of science, carceral studies, and the history of Christianity. His first book, An Experimental Box: A History of Solitary Confinement (under contract with Harvard University Press), charts the history of solitary confinement from the late Middle Ages to the present, as the history of serial experimentation with the disturbing powers of isolation. His other projects include the material culture of early modern Christianity, the history of hunger-striking, and the kinship between prisons and utopias.

He received his Ph.D. in the History of Science from Princeton University, an M.Phil. in Theology (Ecclesiastical History) from the University of Oxford, and a B.A. in History from Yale University. His research has been published in Early Science and Medicine, Journal of the History of Ideas, Social History of Medicine, History Workshop Journal, Renaissance Quarterly, Punishment & Society, Church History, and Journal of Social History, among other fora.