Casuistry (from the Latin *casus*—case, instance) is the use of sophistry in arguments to prove dubious or false ideas.
In jurisprudence, casuistry is a branch of law that deals with the study of specific cases or casuses and the development of methods for resolving various legal issues. Casuists are lawyers who specialize in casuistry.
In medicine, casuistry may refer to “an isolated observation (of an injury or disease) that is of scientific and practical interest due to its rarity and unusual nature.”