Michael Servetus

Servetus argued from Scripture and reason against post-biblical doctrinal development; his method is rationalist-biblical, refusing creedal authority where it lacked direct scriptural warrant.

"The Trinity is a doctrine of the schools, not of the Scriptures; I find no place where it is stated in the form the church-fathers later imposed." (*De Trinitatis Erroribus*, opening)

Anachronistic in name, but Servetus's biological work (pulmonary circulation, anatomy) was thoroughly empirical, and his theological work shares an empirical-historical method against tradition-grounded dogma.

"The blood passes through the lungs; I have seen this in dissection and the church has no doctrine about it." (paraphrasing the *Restitutio*'s anatomical sections)

Anti-Trinitarian Servetus is the negative pole against which Reformed-Calvinist trinitarianism defined itself; he is, in this sense, a key figure in the family even as he was its victim.

Servetus's name is invoked in subsequent Reformed defences of Trinitarian orthodoxy as the cautionary case.

Servetus identified with the broader Reformation impulse to read Scripture against ecclesial tradition, even where he reached anti-Trinitarian conclusions the magisterial Reformers (Luther, Melanchthon, Calvin) found unacceptable.

"The reform of the church must extend to the doctrines of the church, not only to its discipline." (paraphrasing the introductory matter of the *Restitutio*)

Anachronistic, but Servetus has become — alongside Castellio — a symbol of conscience against ecclesial-political authority; that legacy aligns with later traditions of religious-political dissent.

Castellio's 1554 *De Haereticis* defended Servetus's right to dissent and became a founding document of religious toleration.