Whitgift made him his Vicar-General of the diocese of Canterbury in 1583, and Dean of the Arches in 1590. Cosin also had duties as a censor of publications.
In the major confrontation of the 1590s between Anglicans and Thomas Cartwright and his Puritan and presbyterian allies, Cosin with Matthew Sutcliffe for the church lawyers faced the common lawyers Richard Beale and James Morice. Morice attacked the ex officio oath, which Cosin staunchly defended. He argued from the existence, in medieval understanding, of many exceptions to the requirement of an accuser.[6][7]
His 1592 pamphlet Conspiracie, for Pretended Reformation: viz. Presbyteriall Discipline exploited the scare after the 1591 plot of William Hacket, Edmund Coppinger, and Henry Arthington.[8] Cosin noted in it that the presbyterian notion of discipline included the ideas of resistance to bad magistrates, and deposition of kings.[9] It also contains discussion, relating to Hacket, showing contemporary definitions of degrees of insanity.[10]
An apologie for sundrie proceedings by jurisdiction ecclesiastical (1593) is his major work. He expressed the views that Magna Carta implied that the English monarchy did not have absolute power, but that it had no application to ecclesiastical jurisdiction.[11]
He supported the education of William Barlow,[12] his biographer (1598).
^Donna B. Hamilton, Theological Writing and Religious Polemic, p. 595 in Michael Hattaway (editor), A Companion to English Renaissance Literature and Culture (2003).
^R. H. Helmholz, The Privilege and the ius commune: The Middle Ages to the Seventeenth Century, p. 23 in R. H. Helmholz, Charles M. Gray, John H. Langbein, Eben Moglen, Albert W. Alschuler, The Privilege Against Self-incrimination: Its Origins and Development (1997).
