Heresy

Heresy is a word for new ideas. These ideas do not match a group's rules.

A person with these ideas is called a heretic.

Many religions use this word. It is used in Judaism, Christianity, and Islam.

Some people in these groups have different beliefs.

In the past, these ideas caused big problems. Some leaders were very angry about them. This led to many fights and wars.

One man named Galileo had new ideas. He thought the Earth moved around the Sun. The leaders told him he was wrong.

Today, people still have different thoughts. It is a way to study how people think. Many people still wonder about these things.

Heresy is a word for ideas that go against a group's rules.

These ideas differ from what a religion says is true. A person who holds these ideas is called a heretic. The word comes from an old Greek word meaning "choice."

It used to mean a person chose their own path of thought.

Many religions use this term, like Judaism, Islam, and Christianity. In the past, these ideas led to big conflicts. Some leaders used laws to punish heretics. This sometimes led to death or being cast out of a group.

In the Roman Empire, leaders tried to make everyone follow one set of beliefs. This was done to keep peace in the land.

One famous story is about Galileo Galilei. He had ideas about how the stars and planets move. The leaders thought his ideas went against their holy books. He had to say his ideas were wrong. Today, people still study these different ways of thinking. It helps us learn how beliefs change over time.

Heresy is a word for ideas that go against established beliefs. It usually refers to ideas that disagree with religious laws or customs.

The word comes from the Ancient Greek word "haíresis." This originally meant "choice" or "a thing chosen." Later, it meant the school of thought a person chose. A person who holds these ideas is called a heretic. The leader of such a movement is called a heresiarch.

It is different from apostasy, which is leaving a religion. It is also different from blasphemy, which involves disrespectful actions toward sacred things.

Many different faiths use this term in their own ways. This includes Judaism, Christianity, and Islam.

In Christianity, some thinkers called correct teaching "sound" to show it was strong. They felt heresy could be a corrupting influence. In the 2nd century, a man named Irenaeus used the term to describe his opponents. He called the main group's beliefs "orthodox." This word means "straight" or "correct" belief. People who study heresy are called heresiologists.

History shows that these disagreements often led to serious consequences. In the past, some groups faced excommunication or even the death penalty.

In the Roman Empire, Emperor Constantine the Great called a council to end a debate started by Arius. Later, the Edict of Thessalonica in AD 380 made Christianity the state church. This meant the state and the church began to work together on laws. In AD 386, a man named Priscillian was executed by Roman officials. This was one of the first times a Christian heretic was put to death by the state.

Many famous people were involved in these religious debates.

Martin Luther was a German friar who was excommunicated in 1520. The scientist Galileo Galilei was also brought before the Inquisition. He believed the Sun was at the center of the universe. The leaders thought this went against Holy Scripture. He had to say his opinions were wrong and lived under house arrest. Other groups, like the Cathars, were also part of large movements that the Church tried to stop.

Today, the way people talk about these ideas has changed.

In modern times, formal charges of heresy are much less common. Some Protestant churches still discuss the nature of God or how to read the Bible. In the Catholic Church, leaders might criticize writings for errors without using the word "heresy." For example, Pope Benedict XVI once used the term "ecclesial communities" for some Protestant groups. This was to show they lacked certain elements of an apostolic church. We can still see how these old ideas shaped the world we live in today.

Heresy refers to any belief or theory that strongly disagrees with established customs or accepted religious laws.

Within a religious organization, a heretic is a person who supports these opposing ideas. The leader of a movement centered on such ideas is known as a heresiarch. The study of these disagreements is called heresiology. It is important to distinguish heresy from other concepts. Apostasy is the explicit act of renouncing one's religion or principles. Blasphemy refers to impious actions or words concerning sacred things. The word itself comes from the Ancient Greek term *haíresis*, which originally meant "choice" or "a thing chosen." Over time, it came to represent a person's chosen school of thought or philosophy.

In the context of major faiths like Judaism, Christianity, and Islam, the term carries specific weight. In early Christianity, thinkers often described correct teaching as "sound." This term suggested that true belief was strong and protected the community from corruption. Irenaeus, a 2nd-century figure, used the term "orthodox" to describe the community's official doctrines. This word comes from the Greek *orthos*, meaning "straight," and *doxa*, meaning "belief." Irenaeus used his writings to discredit opponents, such as the Gnostics. He argued for the importance of apostolic succession to maintain these correct beliefs.

The relationship between religious belief and government power changed the history of heresy. In the Roman Empire, Emperor Constantine the Great sought to end doctrinal debates, such as those started by Arius. He called ecumenical councils to resolve these issues and enforce orthodoxy for the sake of domestic peace. In AD 380, the Edict of Thessalonica made Christianity the state church of the Roman Empire. This created an overlap between the authority of the state and the Church. Consequently, the state began to share its legal enforcement powers with religious authorities. One of the first documented results of this was the execution of Priscillian in AD 386. Though Roman officials executed him for sorcery, he was a Christian heretic. Interestingly, religious leaders like Ambrose of Milan and Pope Siricius opposed his execution, viewing capital punishment as evil.

Throughout history, different groups and individuals have faced severe consequences for their views.

In the 16th century, the German friar Martin Luther was excommunicated by Pope Leo X in 1520. During the Reformation, some Protestant churches also executed those they labeled heretics. For instance, Michael Servetus was declared a heretic by both Catholic and Reformed churches for rejecting the doctrine of the Holy Trinity. Other movements, such as the Cathars in France, grew into large mass movements. The Church eventually initiated the Albigensian Crusades to eliminate the Cathar heresy.

In other instances, such as the case of the Amalricians in 1210, heretics were put to death by burning.

Scientific discovery has also intersected with religious definitions of heresy.

The scientist Galileo Galilei was famously brought before the Inquisition. He was considered "vehemently suspect of heresy" because of his views on the universe. Specifically, he held that the Sun was at the center of the universe and the Earth moved. The authorities believed these opinions contradicted Holy Scripture. To resolve the matter, Galileo was required to abjure, curse, and detest his own findings. He spent the remainder of his life under house arrest. While this was a major event, many historians view the Galileo affair as an exception in the relationship between science and faith.

In the Catholic Church, the definition of heresy remains part of its legal framework. The 1983 Code of Canon Law defines it as the obstinate denial or doubt of a truth that must be believed by divine and Catholic faith. This occurs after a person has received baptism. Such actions can lead to automatic excommunication, known as *latae sentais*. Historically, the Church dealt with various small sects, including Arianism, Pelagianism, and Donatism. In the 6th century, the *Codex Justinianus* even defined heretics as those not devoted to the Catholic Church, preventing them from holding authority in the Eastern Roman Empire.

In modern times, the way religious institutions handle disagreement has evolved.

Formal charges of heresy are much less common today. In Protestant circles, discussions often focus on biblical criticism or the nature of God. The Catholic Church's Congregation for the Doctrine of the Faith may criticize writings for errors or ambiguities without explicitly using the word "heresy." For example, in 2007, Pope Benedict XVI referred to certain Protestant groups as "ecclesial communities" rather than "Churches." He clarified that this was not an accusation of explicit heresy, but rather a statement that these groups lacked certain essential elements of an apostolic church.