Spanish physician and theologian whose unorthodox teachings led to his condemnation as a heretic by both Protestants and Roman Catholics and to his execution by Calvinists from Geneva.
(...) While living in Toulouse, France, Servetus studied law and delved into the problem of the Trinity. In February 1530 he accompanied his patron, the Franciscan Juan de Quintana, to the coronation of Emperor Charles V at Bologna. Distressed by papal ostentation and by the emperor's deference to the worldly pope, he left his patron and visited Lyon, Geneva, and Basel. At Basel and Strasbourg he met with Reformation leaders John Oecolampadius, Martin Bucer, and Kaspar Schwenckfeld. Servetus published his new ideas on the Trinity in De Trinitatis erroribus libri vii (1531), attacking the orthodox teaching and attempting to form a view of his own, asserting that the Word is eternal, a mode of God's self-expression, whereas the Spirit is God's motion or power within the hearts of men. The Son is the union of the eternal Word with the man Jesus. Although both Catholics and Protestants may have had difficulty following Servetus' involved speculations, what he proposed was clearly odious to them. He therefore published a revised formulation, Dialogorum de Trinitate libri ii (1532).
(...) Servetus forwarded the manuscript of an enlarged revision of his ideas, the Christianismi Restitutio, to Calvin in 1546 and expressed a desire to meet him. After their first few letters, Calvin would have nothing more to do with him and kept the manuscript. He declared to his eloquent French preacher colleague Guillaume Farel that if Servetus ever came to Geneva he would not allow him to leave alive. A rewritten version of Servetus' manuscript was secretly printed in 1,000 copies at Vienne in 1553. In discussing the relationship between the Spirit and regeneration in that book, Servetus almost incidentally made known his discovery of the pulmonary circulation of blood. In the book, Servetus argued that both God the Father and Christ his Son had been dishonoured by the Constantinian promulgation of the Nicene Creed, thus obscuring the redemptive role of Christ and bringing about the fall of the church; Servetus felt he could restore the church by separating it from the state and by using only those theological formulations that could be proved from Scripture and the pre-Constantinian fathers.
(...) He quixotically appeared in Geneva and was recognized, arrested, and tried for heresy from Aug. 14 to Oct. 25, 1553. Calvin played a prominent part in the trial and pressed for execution, although by beheading rather than by fire. Despite his intense biblicism and his wholly Christocentric view of the universe, Servetus was found guilty of heresy, mainly on his views of the Trinity and Baptism. He was burned alive at Champel on October 27. His execution produced a Protestant controversy on imposing the death penalty for heresy, drew severe criticism upon John Calvin, and influenced Laelius Socinus, a founder of modern unitarian views.
Michael Servetus, Encyclopedia Britannica
The earliest criticism of orthodox dogma came in the age of the Reformation, not from the reformers but from the ''left wing of the Reformation,'' from Michael Servetus (1511?-53) and the Socinians. This criticism was directed against the presence of nonbiblical concepts and terms in the dogma, and it was intent upon safeguarding the true humanity of Jesus as a moral example. There were many inconsistencies in this criticism, such as the willingness of Servetus to call Jesus ''Son of God'' and the Socinian custom of addressing prayer and worship to him. But it illustrates the tendency, which became more evident in the Enlightenment, to use the Reformation protest against Catholicism as a basis for a protest against orthodox dogma as well. While that tendency did not gain much support in the 16th century because of the orthodoxy of the reformers, later criticism of orthodox Christology was able to wield the ''Protestant principle'' against the dogma of the two natures on the grounds that this was a consistent application of what the reformers had done. Among the ranks of the Protestant laity, the hymnody and the catechetical instruction of the Protestant churches assured continuing support for the orthodox dogma.
The Reformation and Classical Protestantism, Encyclopedia Britannica
The doctrine of the Trinity is among the central, essential teachings of the Christian faith. As Robert Bowman states, heresy is "[doctrine] which is erroneous in such a way that Christians must divide themselves as a church from all who teach or accept it; those adhering to heresy are assumed to be lost, although Christians are unable to make definitive judgments on this matter." (See: A Biblical Guide to Orthodoxy and Heresy). However, the torture and killing of heretics, which occured in church history, is to be condemned as a sinful act that stands in stark contrast to the Bible's teachings on how to deal with false teachers.
The darkest blot on Protestantism is the burning of Servetus for heresy and blasphemy, at Geneva, with the approval of Calvin and all the surviving Reformers, including Melanchthon (1553). He had been previously condemned, and burnt in effigy, by a Roman-Catholic tribunal in France. Now such a tragedy would be impossible in any church. The same human passions exist, but the ideas and circumstances have changed.
The History of the Christian Church, Phillip Schaff
It has long been the delight of both infidels and some professed Christians, when they wish to bring odium upon the opinions of Calvin, to refer to his agency in the death of Michael Servetus. This action is used on all occasions by those who have been unable to overthrow his opinions, as a conclusive argument against his whole system. ''Calvin burnt Servetus!--Calvin burnt Servetus!'' is a good proof with a certain class of reasoners, that the doctrine of the Trinity is not true-that divine sovereignty is Antiscriptural,--and Christianity a cheat. We have no wish to palliate any act of Calvin's which is manifestly wrong. All his proceedings, in relation to the unhappy affair of Servetus, we think, cannot be defended. Still it should be remembered that the true principles of religious toleration were very little understood in the time of Calvin. All the other reformers then living approved of Calvin's conduct. Even the gentle and amiable Melancthon expressed himself in relation to this affair, in the following manner. In a letter addressed to Bullinger, he says, ''I have read your statement respecting the blasphemy of Servetus, and praise your piety and judgment; and am persuaded that the Council of Geneva has done right in putting to death this obstinate man, who would never have ceased his blasphemies. I am astonished that any one can be found to disapprove of this proceeding.'' Farel expressly says, that ''Servetus deserved a capital punishment.'' Bucer did not hesitate to declare, that ''Servetus deserved something worse than death.'' The truth is, although Calvin had some hand in the arrest and imprisonment of Servetus, he was unwilling that he should be burnt at all. ''I desire,'' says he, ''that the severity of the punishment should be remitted.'' ''We wndeavored to commute the kind of death, but in vain.'' ''By wishing to mitigate the severity of the punishment,'' says Farel to Calvin, ''you discharge the office of a friend towards your greatest enemy.'' ''That Calvin was the instigator of the magistrates that Servetus might be burned,'' says Turritine, ''historians neither anywhere affirm, nor does it appear from any considerations. Nay, it is certain, that he, with the college of pastors, dissuaded from that kind of punishment.'' It has been often asserted, that Calvin possessed so much influence with the magistrates of Geneva that he might have obtained the release of Servetus, had he not been desirous of his destruction. This however, is not true. So far from it, that Calvin was himself once banished from Geneva, by these very magistrates, and often opposed their arbitrary measures in vain. So little desirous was Calvin of procuring the death of Servetus that he warned him of his danger, and suffered him to remain several weeks at Geneva, before he was arrested. But his language, which was then accounted blasphemous, was the cause of his imprisonment. When in prison, Calvin visited him, and used every argument to persuade him to retract his horrible blasphemies, without reference to his peculiar sentiments. This was the extent of Calvin's agency in this unhappy affair. It cannot, however, be denied, that in this instance, Calvin acted contrary to the benignant spirit of the Gospel. It is better to drop a tear over the inconsistency of human nature, and to bewail those infirmities which cannot be justified. He declared he acted conscientiously, and publicly justified the act.
An Account of the Life of John Calvin, Fox' Book of Martyrs
Calvin vs. Servetus by J. Steven Wilkins (Note, the site appears to promote King-James onlyism)
Of The Knowledge of God The Redeemer From Calvin's Institutes. "This chapter contains two principal heads: I. A brief exposition of the doctrine of Christ's two natures in one person, sec. 1-4. II. A refutation of the heresies of Servetus, which destroy the distinction of natures in Christ, and the eternity of the divine nature of the Son."
The Truth about Calvin and Servetus by Loraine Boettner, The Foundation of Biblical Studies