One of the most heated debates in recent times among Christian ethicians has been over what has come to be called proportionalism. Opponents have argued that proportionalists are intent on relativizing theological norms and the concept of intrinsic evil. Proponents on the other hand argue that they are merely developing a traditional notion of proportion of reason. Bernard Hoose puts this debate in context by showing its roots in the writings of European moral theologians and its flowering in the writings of their American colleagues. He uncovers a number of confusions that have bedeviled the argument while revealing how important the issues are for establishing a coherent Christian ethics in the twentieth century.