Casuistry is an applied ethics term referring to case-based reasoning. Casuistry is used in juridical and ethical discussions of law and ethics, and often is a critique of principle or rule-based reasoning. The term 'Casuistry' originates from the Latin casus (cases). Critics use the term pejoratively for the use of clever but unsound reasoning, especially in relation to moral questions. Casuistry is reasoning used to resolve moral problems by applying theoretical rules to particular instances.