In The Jesuit Order as a Synagogue of Jews the author explains how Christians with Jewish family backgrounds went within less than forty years from having a leading role in the foundation of the Society of Jesus to being prohibited from membership in it. The author works at the intersection to two important historical topics, each of which attracts considerable scholarly attention but that have never received sustained and careful attention together, namely, the early modern histories of the Jesuit order and of Iberian “purity of blood” concerns. An analysis of the pro- and anti-converso texts in this book (both in terms of what they are claiming and what their limits are) advance our understanding of early modern, institutional Catholicism at the intersection of early modern religious reform and the new racism developing in Spain and spreading outwards.