Heresy

Heresy, according to the Oxford English Dictionary, is a "theological or religious opinion or doctrine maintained in opposition, or held to be contrary, to the Roman Catholic or Orthodox doctrine of the Christian Church, or, by extension, to that of any church, creed, or religious system, considered as orthodox. By extension, heresy is an opinion or doctrine in philosophy, politics, science, art, etc., at variance with those generally accepted as authoritative." The study of heresy is heresiology. The founder of a heresy is called a Heresiarch.