Sarah Walsh's original history of intellectual elites, science, health, and white supremacy in Chile covers the associations between eugenics, the idea of race, women, and Catholicism in the early twentieth century. The Religion of Life: Eugenics, Race, and Catholicism in Chile is Walsh's first book and examines social constructions from the previously unexplored angle of science, medicine, and religion. The last, as the author illustrates, converges with eugenics within secular approaches, the majority of which address the “harmonious relationship” between science and religion and the notion of race as a biological categorization (p. 51). In a period in which the social question emerged and flourished, modernization, urbanization, and the tensions of modern life overlapped with disputes concerning political power voiced by the traditional sectors, with increasing input from secular groups. Here, the traditional charity of the Catholic Church and Christianism began to be seen as an inefficient strategy that merely made problems tolerable, while the scientific methods involved in social work were seen as outstandingly efficient in creating eugenic fitness. Catholic and secular Chilean intellectuals agreed on gender differences and the homogeneity of race. On the latter, the imaginary of mestizaje as a route of progress predominated. The book shows how, following the separation of church and state in 1925, the strength and influence of Catholics in Chile endured throughout the remainder of the twentieth century through eugenics. Walsh exposes how the local Catholic eugenic narrative supported positive eugenics and perpetuated the primary role of women in preserving racial health.The book explores how the imaginary of the “Chilean race” is both visualized and shaped through exclusion, a point exemplified by the work of Nicolás Palacios. The elimination of the local Indigenous peoples and the narrative of their amalgamation into a single homogeneous local race served as a point of commonality, perpetuating the myth of mestizaje across the field. Although mestizaje was also present in Brazil and Mexico, in Chile as a racial ideology it fit with ideas of national racial supremacy over other countries in the region based on the myth of the Araucanians.The Religion of Life is well founded on primary sources—namely, articles in local publications, newspapers, medical journals, and monographs from throughout the period. Walsh connects the local eugenics scene with a worldwide network of knowledge production from which developed the imprecise ties between environment, heredity, and eugenic fitness that allowed Catholic intellectuals to find a niche within the field of eugenics. The book's introduction clearly locates the field both globally and regionally, establishing the origins of eugenics in Latin America as the “synthesis of neo-Lamarckism and Darwinism” (p. 7). The book is then divided into six chapters. The first three deal with Catholicism and eugenics as intellectual frameworks that converge and interact, while the last three focus on the role of eugenics literature in the early twentieth-century emergence of racial thinking. Although repetitive at times, the book is well grounded in the history of eugenics, although it could have better contextualized this within local history. Walsh concludes by proposing a connection between Salvador Allende and Augusto Pinochet based on a shared cultural context and privileged background. However, this assertion is somewhat forced and arguably inaccurate, as Pinochet belonged to neither an intellectual elite nor a cultural aristocracy, as evidenced in a variety of research. Although certain military figures were connected with such elites, Pinochet held a lower rank than such figures, and the infantry branch to which he belonged was less well thought of among the various bodies of the armed forces. If he did indeed succeed in climbing the social ladder, this was due to his marriage to Lucía Hiriart, whose family had a richer cultural background. The fact that he was not well received initially by Hiriart's family reinforces Pinochet's nonelite background.Walsh's contribution would have been strengthened by more profound reflection on gender, social class, and the patriarchy through theory that extends the human sciences framework. Nevertheless, the book valuably explores the global, regional, and local history of eugenics and Catholicism. She unravels how the local imaginary of race was constructed and how it evolved, shedding light on subsequent interpretation of the taboos of sex, sexual desire, physical sexual malformations, and dysgenic deviance in relation to pigmentocracy as a physical expression of abnormality. She also exposes how eugenic fitness was linked to environment in a way that supported a hierarchized, classist, and exclusionary society that endures in Chile to this day. This contribution makes The Religion of Life highly relevant to current identity debates in Chile concerning its Indigenous peoples.