This book, originally published in 1927, has proven to be one of the most important and influential books in the field of ethics in the twentieth century. It remains a pertinent, original, and insightful work--a landmark statement of modern casuistry.

The Library of Theological Ethics series focuses on what it means to think theologically and ethically. It presents a selection of important and otherwise unavailable texts in easily accessible form. Volumes in this series will enable sustained dialogue with predecessors though reflection on classic works in the field.

Casuistry is a process of reasoning that focuses upon specific cases or moral problems, as opposed to a general study of ethical theories. In this broad sense every moral philosopher may be regarded as a casuist in some form. The term also has a narrower meaning as it refers to a group of moralists who, in the 16th and 17th century, systematically adopted this method. Casuistry is now one of the options for those who, in the framework of the post-modern anti-systematic attitude, still feel the importance of serious moral debate and reject easy-minded relativism.