Erastianism is the belief that the State has absolute primacy
over the church. The name of this doctrine
stems from the Latinized pen-name of Thomas Lieber
, Erastus, a Protestant theologian
and physician who lived from September 7, 1524
to December 31, 1583
Erastus was born in Baden, Switzerland and studied theology in Basel. During his time in Basel, he lost the use of his right arm and taught himself to write left-handed. He was also in the that city during an out-break of plague. Though he contracted plague, he wasn't severly afflicted and recovered quickly. Because of the out-break of disease, school was suspended, so he went onto Bologna, Italy and studied philosophy and medicine and he also studied at the University of Padua. In 1553 Erastus moved to Germany and became the court physician of the Prince of Henneberg. There is little information regarding Erastus' activities between the time of 1553 and 1558 when he again emerges as a physician, this time to the Elector Palatine, Otho Heinrich and holding a chair in medicine at the University of Heidelberg.
Heidelberg, at this time, was involved in a theological controversy regarding the right of the church to excommunicate the congregants. Erastus was a supporter of Ulrich Zwingli, and Zwingli doctrine, and therefore was an opponent of Martin Luther, and became embroiled in the controversy. The Calvinists held that the religious leaders had the right to excommunicate any who were perceived to be sinners or doctrinal deviates. Erastus evolved his theory, or doctrine, during this time. Briefly stated, he held that only the State could punish those people because civil authorities had final jurisdiction in all areas, even in religious issues such as excommunication. His theological basis for this was based on Scripture and how the Jewish Commonwealth was structured as shown in the Bible.
I see no reason why the Christian magistrate at the present day should not possess the same power which God commanded the magistrate to exercise in the Jewish commonwealth. Do we imagine that we are able to continue a better constitution of Church and State than that?
In 1589 his 75 theses, The Nullity of Church Censures and Confirmatio Thesium, were published in London. The book was not translated from the original Latin into English until 1689. Despite his, and others, best efforts, the presbyterian system was established in Heidelberg in 1570 and he was excommunicated on the grounds of being a Unitarian at that time. After a long and controversial battle with the church authorities he eventually proved the allegation false and the excommunication was lifted in 1575.
His book on the subject of the State's authority over the church, which was published after his death and did not have his name on it at first, was never promulgated by any Protestant sect or group of followers. However, his ideas had a significant influence on the English theories of the State's control over the church during the 17th century. At the Westminster Assembly of Divines, 1643 to 1647, the Erastian doctrine was debated and by the end of the Assembly, a resolution was announced affirming that the church had its own government distinct (separate) from the civil authorities, which was a rejection of the Erastian doctrine.