Home > Glossary > Heresy

What Does Heresy Mean?

Heresy is a belief or theory that is very different from the established beliefs or customs, especially the beliefs of a church or religious group. The term is usually used to describe people who break important religious rules, but it can also be used to describe people who have very different ideas from the majority of people. A heretic is someone who spreads heresy. The term is mostly used to describe Christianity, Judaism, and Islam. In some Christian, Jewish, and Muslim cultures, among others, people who say things that are thought to be heretical have been (and in some cases still are) punished by being excommunicated or even killed. Heresy is not the same as apostasy, which is a clear statement that you no longer believe in your religion, principles, or cause; or blasphemy, which is an act or word that is blasphemous toward God or sacred things. If you want to learn about heresy, you need to learn about hermeneutics.


Heresy refers to any belief which deviates from the established belief system or custom, predominantly orthodox views of any religion. Heresy is usually understood in the context of violating religious teachings. Still, it can refer to any idea in opposition to the generally accepted beliefs. Anyone who endorses or promotes any heretical notion is called a heretic. The leader or founder of any dissident movement is called a heresiarch. The term ‘heresy’ is used primarily in Christianity, Islam and Judaism. The history of heresy and heretical cases is most explicitly documented in Christianity. In some orthodox Jewish, Christian and Muslim communities and cultures, anyone who supports unorthodox ideas may face punishment like ex-communication or, in extreme cases, the death penalty.

The study of heresy in theology is called heresiology. Tracts written in the theory of heresy are called heresiographies. These were very common in medieval Christian and Muslim cultures. The discipline of heresiology matured in the Christian state church in the Roman Empire as part of its growing orthodox culture. Scholars in the Roman Empire studied the teachings of various saints belonging to different sects of Christianity. They documented and made categorical distinctions between accepted beliefs and those considered to be heretical. A similar took place in various Muslim sects in the Islamic world.

Heresy in Christianity

In the Christian context, heresy refers to the formal doubt expressed by an individual or organization or movement about a core doctrine of Christian beliefs, as defined in the Christian churches. Heresy is different from apostasy, blasphemy or schism. Apostasy refers to the total abandonment of your faith. In other words, if someone explicitly renunciates their religion, some principle or any other belief, it is called apostasy. On the other hand, blasphemy refers to an impious statement or expression or action regarding God or any other sacred thing in a religious belief system. Schism is the formal and intentional breach or an offense against any belief or organization. Schism may or may not be against any doctrinal idea.

Heresy has a vast history in Christianity, and its meaning varies in accordance with the time period and the place it originates. For example, in the West, heresy in Christianity refers to beliefs that were seen as offensive or an abomination by the ecumenical councils of the Catholic Church. That is, anything considered anathema by the Church was heretical. But, in the East, heresy takes on more of an eclectic meaning and can be about anything opposed to the Church. The word ‘heresy’ was used for the first time in a legal context in around 380 AD by the Edict of Thessalonica of Theodosius I. This proclamation made Christianity the state church of the Roman Empire. Before this, the institution of the Church did not have any state sanctified support by any legal system to counter heresies formally. Now the Church had the power and authority to punish heretics and even give death sentences to them. The first Christian heretic executed by the Church was a wealthy nobleman of Roman Hispania called Priscillian.

He was convicted in 386 AD on charges of sorcery by Roman secular officials and condemned to death along with some of his followers.

In European history, a famous case of heresy is that of the Italian astronomer, physicist, and polymath Galileo Galilei. He was prosecuted for propounding heliocentrism – the astronomical model which stated that the Earth, along with the other planets, revolves around the Sun and that the Sun, instead of the Earth, which was the accepted belief of the Church and the Holy Scriptures, is at the center of the universe. The Roman Catholic Inquisition tried him in 1633. The Roman Catholic Inquisition was a system of tribunals developed by the Holy See of the Roman Catholic Church in the latter half of the 16th century and was responsible for prosecuting individuals accused of supporting heretical beliefs.

Heresy in Other Religions

Heresy in Judaism refers to any belief that contradicts the traditional Rabbinic Judaism doctrines and the thoughts and opinions practiced in the Jewish religious law called halakha. Orthodox Jewish sects believe that any Jewish person who deviates from the traditional Jewish principles of faith is a heretic. Judaism has various statements in its doctrines and tracts outlining laws about heretics, the punishment to be meted out to them, and how the community should deal with these dissidents. Formalized history of heresy in Islam began in the Medieval Age. Heretics or those who saw Islam as the enemy were called zindiqs and were punished with death. Zindiq or Zanadiqa initially referred to the heresy of Manichaeism. In modern usage, it refers to any individual or community which is not loyal to the core Islamic tenets. Generally, the Sunni sect of Islam considers the Shias heretics, particularly in Indonesia, Turkey and Saudi Arabia. In contemporary times, some nations and regions still punish heresy with death. A famous case is that of the author Salman Rushdie. The Iranian government issued a fatwa against him in 1989 for his heretical views in his book The Satanic Verses.

Heresy outside religion

In the context of religion, heresy is considered derogatory and defamatory. But outside religion, heresy may refer to any innovation or idea which deviates from the status quo. Such an instance of heresy may arise in any field of knowledge. It may even be seen as a positive emergence. The scientist and science fiction author Isaac Asimov delineated heresy as an abstraction and mentioned various categories of heresies like political, socioeconomic, and scientific heresy. An example of scientific heresy, as given by the palaeontologist Robert T. Bakker is the dogmatic view of the existence of dinosaurs. Heresy is not limited just to science. The term is also used in political theory and praxis. An orthodox political opinion can be seen as heretical. Sometimes, the word is used in a tongue-in-cheek fashion like a metaphor. Whatever the context, in its primary sense, heresy refers to anything different from the acceptable mainstream culture and tradition.

Spirit guide
Marut Angel
Hanibal Angel