one who studies and decides upon cases of conscience. Escobar has made a collection of the opinions of all the casuists before his time. M. Le Feore, preceptor to Louis XIII, said that the books of the casuists taught "the art of quibbling with God;" which does not seem far from truth, by reason of the multitude of distinctions and subtleties with which they abound. Mayer has published a bibliotheca of casuists, containing an account of all the writers on cases of conscience, ranged under three heads; the first comprehending the Lutheran; the second, the Calvinistic; and the third, the Roman casuists.