Baptism through Incision is the latest volume in the Latin American Originals series, a collection of primary source texts translated into English that has mostly focused on the early church and the spiritual conquest of Spanish America in the sixteenth century. The translation of Pedro José de Arrese's Physical, Canonical, Moral Principles [ . . . ] on the Baptism of Miscarried Fetuses and the Cesarean Operation on Women Who Die Pregnant brings the series into the eighteenth century to explore the intersection between faith and science. This medical treatise, published in Guatemala in 1786, is part of a genre of texts produced throughout the Spanish empire in which physicians and priests provided detailed instructions on the cesarean operation to make the procedure accessible to other clergymen, physicians, surgeons, barbers, midwives, and even laypeople. Not simply a surgical intervention, the cesarean operation was mainly meant to ensure the spiritual salvation of thousands of fetuses through baptism.Martha Few, Zeb Tortorici, and Adam Warren, specialists respectively in Guatemala, Mexico, and Peru, offer a thorough study of the cesarean operation's long history in Europe and Spanish America, building on recent work by scholars such as Nora Jaffary, who elucidates the gendered controversies surrounding childbirth and contraception in Mexico over the long nineteenth century. Readers learn that Arrese's work was made possible by the convergence between theological debates about the soul, medical discussions around life's beginning, and developments in European science (such as the microscope) that enabled embryos to be seen for the first time and fetuses to be observed in unprecedented ways. Heavily influenced by the work of the Spaniard Antonio José Rodríguez and the Italian Francesco Cangiamila, Arrese joined theologians and medical experts in bringing the female body under the purview of the medical gaze. By elucidating these intellectual genealogies, the authors reframe the question of why women's wombs became, in the eighteenth century, the new battleground for both the spiritual conquest of Spanish America and the growing specialization of medical knowledge.Arrese's treatise, translated by Nina Scott, was written in question/answer format and targeted a wide audience of potential practitioners. This fascinating text, among other things, explains why the postmortem cesarean operation was considered a tool for saving souls, the conditions under which baptism should be administered, and how one could ascertain if a fetus was alive—and thus required baptism. For scholars of gender and sexuality, the text offers especially intriguing insights into the construction of abortion as a crime: Arrese creates (illusory) boundaries between life and death, claiming definitively that fetuses can survive one or even two days after the mother passes away and affirming that it is possible to easily distinguish between miscarriages and abortions—things we know today to be false.Beyond Arrese's text, the volume also includes a chapter in which the authors bring to bear their regional expertise and include translated excerpts from a wide range of texts, exemplifying collaborative work at its best. Among these texts are a medical treatise by Valencian surgeon Jaime Alcalá y Martínez, scientific and political journals, Friar Francisco González Laguna's El zelo sacerdotal para con los niños no-nacidos, further medical instructions from Guatemala's government and doctors, and an intriguing document written by missionary priest Vicente Francisco de Sarría in Alta California. These brief excerpts show the variety of medical and theological opinions around the cesarean operation and confirm the wider transatlantic Enlightenment culture that the authors foregrounded in the introduction. For instance, we learn that González Laguna adapted his text to Upper Peru's local context of rebellion, while Alcalá y Martínez seems unique in advocating that the cesarean operation be performed on women still alive. As a last resort, Alcalá y Martínez maintained, the surgery might save the life of the mother or the fetus in cases of imminent death—a position closer to the contemporary use of the cesarean operation yet overwhelmingly considered unacceptable at the time.An invaluable classroom resource, the volume intersects with a wide range of subjects, including law, religion, gender, sexuality, and science, and invites further investigation into this medical genre in regions not covered here (the Viceroyalties of New Granada and Río de la Plata, for instance). Perhaps an aspect that could have been analyzed was the circulation of these medical treatises within the viceroyalties. In New Granada during the eighteenth and nineteenth centuries, for example, not only were Rodríguez's and Cangiamila's texts circulating but also Arrese's treatise, González Laguna's guide, and even some copies of El Mercurio Peruano. What might attention to these circuits reveal about the movement of medical knowledge within Spanish America? And to what extent can we discern medical knowledge's reception by practitioners on the ground? How often postmortem cesareans were performed remains to be fully assessed. As the authors recognize, the number of recorded cases is minuscule (more were performed in Spain than in Spanish America), though new cases are increasingly brought to light by researchers. Even if the cesarean operation was rare, that fact still merits investigation. Birth and death certificates, as well as untapped regional records, may help explain this intriguing, albeit understudied, history.