Book excerpt: Rethinking Cooperation with Evil: A Virtue-Based Approach applies Thomistic virtue theory to today's most challenging questions of cooperation with evil. For centuries, moralists have struggled to determine the conditions necessary to justify moral cooperation with evil. The English Jesuit Henry Davis even observed: "[T]here is no more difficult question than this in the whole range of Moral Theology." This important book addresses this challenge by applying the virtue-based method of moral reasoning of St. Thomas Aquinas to issues of cooperation with evil. Those who pastor souls report frequently receiving questions from attentive believers about whether a particular human action inadvertently contributes to some moral evil. Examples of potentially immoral cooperation with evil include whether one may shop at a particular franchise known for its support of abortion, whether Catholics may attend civil marriages outside the Church, or whether an organization may submit to government mandates that health insurance include payment for immoral practices. Although recent moralists have tackled specific topics related to cooperation with evil, agreement on an overall common paradigm has not yet been reached. Rethinking Cooperation with Evil proposes a method for Christian believers and others to approach these questions from the foundation of the thought of St. Thomas Aquinas and the magisterial teaching of the Catholic Church. This text provides both an overall method for how to understand the issue of cooperation, as well as practical counsel for specific cases. Rethinking Cooperation with Evil advances the theological conversation on this topic from both speculative and practical vantage points. To facilitate his argument, Connors utilizes historical analyses that contrast Aquinas's method of moral reasoning with that of the casuist treatment of cooperation. Consequently, the book includes numerous case studies that will be of interest both to moral theologians and readers new to the topic.