Syllabus, a term from the Greek usually applied to a compendium or abstract of a lecture or series of lectures, is specially used of the papal syllabus which accompanied the Encyclical (q.v.) Quanta Cura, addressed by Pius IX. to all Catholic bishops on 8th December 1864. This syllabus is a catalogue of eighty errors or heresies, and implicitly enjoins the opposite truths; and by Protestants has generally been regarded as a declaration of war against all freedom of thought, modern civilisation, and social progress, and a reassertion of the extravagant claims of the mediæval papacy to supreme authority on every subject. The syllabus is divided into ten sections, condemning (1) pantheism, naturalism, thorough-going rationalism; (2) milder rationalism; (3) latitudinarianism; (4) socialism, communism, secret societies, &c.; (5) errors as to the rights of the church; (6) as to the constitution of society; (7) as to ethics; (8) as to marriage; (9) as to the temporal power of the pope; (10) the errors of modern liberalism. The infallibility of the pope is indirectly asserted, as is the right of the Roman Catholic Church to exercise complete control over education, literature, and science. Catholics have debated amongst themselves whether the syllabus is an ex cathedra papal utterance, and so to be regarded as de fide and infallible, in terms of the Vatican decree.
See Mr Gladstone's Vatican Decrees in their bearing on Civil Allegiance (1875); Cardinal Manning's reply with the same date and title, and the Letter to the Duke of Norfolk; and, again, Mr Gladstone's answer in Vaticanism (1875). The text of the syllabus will be found in Schaff's Creeds of Christendom, vol. ii.