The approach to ethical problems in which the circumstances of cases affect the application of general rules; a casuist is one who distinguishes and marshals the relevance of different cases and rules. The Resolutiones morales (1659) of the Spanish ‘prince of casuists’ Antonio Diana (1585–1683) discusses some 20,000 cases. The term is often used pejoratively, implying the multiplication of doubtful distinctions, and their use to defend apparently self-serving and conflicting moral verdicts. Casuistry as a discipline declined in the 17th century with the rise of Protestant and pietistic approaches to religion and morality. However, ‘situation ethics’ provides the ground for the re-emergence of attention to the special circumstances of any object of a moral verdict.