Erastus, THOMAS (properly Liebler or Lieber), was born in 1524 at Baden in Switzerland, according to other accounts at Auggen, near Mühlheim in south-west Germany. He studied theology at Basel (where he Grecised his name), and philosophy and medicine at Bologna and Padua. After nine years in Italy, he was appointed physician to the counts of Henneberg; then (from 1558) professor of medicine at Heidelberg, and court-physician to the Elector Palatine. He removed from Heidelberg to fill the chair of Medicine at Basel in 1580, and died there, January 1, 1583. Shortly before his death he had been appointed professor of Ethics. Erastus was a skilful physician and a man of upright character, an equally vigorous writer against 'the new medicine of Philip Paracelsus' (1572) and in favour of the burning of witches (1577 et seq.). In theology he was a follower of Zwingli, and represented his view of the Lord's Supper at the conferences at Heidelberg in 1560 and Maulbronn in 1564. The fame of Erastus now rests on his strenuous opposition to Calvinist discipline and Presbyterian order. For ten years (from 1560) he resisted successfully the Calvinist party under Caspar Olevian at Heidelberg; but in 1570 Presbyterianism was introduced by the Elector Frederick III. Erastus was excommunicated on a false suspicion of heresy, founded on a correspondence with Unitarians of Transylvania, but was restored in 1575. He had carried on a private exchange of views on the subject of church discipline with his friend Beza, and after his death his widow's second husband, Castelvetro, published at London (1589), with the concurrence of Archbishop Whitgift and with a fictitious imprint, a treatise on excommunication entitled Explicatio gravissimæ questionis utrum Excommunicatio . . . mandato nitatur divino, an excogitata sit ab hominibus. This was answered by Beza in his De verâ Excommunicatione et Christiano Presbyterio (1590). A translation of Erastus's treatise was published with a preface by Dr Robert Lee (Edin. 1844). Erastus maintained that no member of the church should be excluded from her communion as a punishment for sin. Punishment is 'the special duty and office' of the civil magistrate. He was familiar with the system of Zurich, where the Christian magistrate administered ecclesiastical discipline in the name of the Christian community, and he dreaded that Presbyterianism, unchecked, might exercise a tyranny over men's consciences as absolute as that of the Spanish Inquisition.
In England, the name of Erastians was applied to the party that arose in the 17th century, denying the right of autonomy to the church—a right neither maintained nor denied by Erastus. The Erastian controversy broke out at the time of the Westminster Assembly. The leading Erastians in that assembly were Lightfoot and Coleman, who were supported by Selden and Whitelocke in the House of Commons. Since the time of the Reformation the controversy has been confined chiefly to the church in Scotland.
See on the one side, Gillespie, Aaron's Rod Blossoming (1646), Sam. Rutherford, Divine Right of Church Government (1646), and Cunningham's Historical Theology, vol. ii. chap. xxvii. (1863); and on the other, Seldeu, De Synedriis (1650-53), and Du Moulin, Of the Right of Churches (1658).