Introduction
Milton wrote and published five tracts opposing the episcopal governmental structure of the Church of England, that is, government by prelatical bishops and archbishops; this is the third. Its full title may be seen on the Title Page. Like the second, Of Prelatical Episcopacy, this tract was composed in response to a specific pamphlet defending episcopal church government, published by Bishop Joseph Hall, entitled A Defence of the Humble Remonstrance, against the Frivolous and False Exceptions of Smectymnuus (1641). Bishop Hall's Defence responds to another pamphlet, authored by the group of anti-prelatical clergy who called themselves Smectymnuus, entitled, An Answer to a Book Entituled An Humble Remonstrance (1641). Smectymnuus is a pen-name made up of the first-name and last-name initials of the antiprelatical clergy responsible for An Answer: Stephen Marshall, Edmund Calamy, Thomas Young, Matthew Newcommen, and William (with a double-u) Spurstow. Thomas Young was one of Milton's earliest teachers and it is likely that Milton had a hand in composing this pamphlet; he probably wrote its "Postscript" himself. As you may have guessed, An Answer responds to Bishop Hall's earlier publication An Humble Remonstrance to the High Court of Parliament (1641).
A full account of the pamphlet war, for and against prelatical church government, is beyond the scope of this introduction, but a brief sketch will help readers to a sense of the context. Unlike John Calvin's reformed church in Geneva, the English Church retained its governmental structure—rule by bishops and archbishops—when Henry VIII rejected Papal authority and proclaimed himself Head of the Church in England. Many who came to be called Puritans insisted that the Church needed further reform in order to conform to the earliest descriptions found in Christian scripture, where, they insisted, one could find no support for government by bishops, archbishops, popes and the like. As Milton argues here, the scriptures (the book of the Acts of the Apostles and Pauline epistles in particular) speak of only two ordained church offices—deacon and presbyter, though presbyters were also known sometimes as bishops. Milton's crucial claim is that both words designate the same church office, not one above the other.
Anti-prelatical sentiment gained steam during Elizabeth I's reign and the Presbyterian reform of the Church of Scotland. A series of anonymous tracts published under the name of Martin Marprelate prompted a defensive response from Richard Bancroft in a sermon preached at Paul's Cross on February 9, 1589 (1588 in the old calendar). In it he attacked sectarian reformers as dangerous to state and church, and declared that bishops held their positions by divine right. John Rainolds published a reply proclaiming mildly Puritan views.
Antiprelatical sentiment gathered political strength with the Root and Branch Petition of December 1640. Signed by 15,000 Londoners it called on Parliament to abolish episcopacy from the "roots" and in all its "branches." This prompted a fresh flurry of pamphlets, for and against episcopacy. In response to Bishop Hall's Episcopacie by Divine Right Asserted (1640), the antiprelatical faction reprinted Rainold's 1589 pamphlet as The Judgement of Doctor Reignolds Concerning Episcopacy, Whether it be Gods Ordinace. The Root and Branch Petition was referred to a committee of the House of Commmons. Meanwhile a pamphlet war of sorts broke out in the first half of 1641. Bishop Hall, refers to this outbreak of pamphleteering on pages 6-7 of An Humble Remonstrance: "Whiles the Orthodoxe part in this whole Realme, hath (to the praise of their patience) been quietly silent, as securely conscious of their own right, and innocence, how many furious and malignant spirits every where have burst forth into sclanderous Libels, bitter Pasquines, railing Pamphlets? (under which more Presses then one have groaned) wherein they have indeavoured, through the sides of some misliked persons, to wound that sacred Government, which (by the joynt-confession of all reformed Divines) derives it selfe from the times of the blessed Apostles, without any interruption, (without the contradiction of any one Congregation in the Christian world) unto this present age." Of course, we already know that "the Orthodoxe part" had been anything but silent; Archbishop James Ussher had already weighed in with The Judgement of Doctor Rainoldes, answered by Milton's Of Prelatical Episcopacy. And Hall himself had hardly been silent on the topic, having published his Episcopacy by Divine Right Asserted in 1640.
As in his answer to Ussher, Milton accuses Hall of sloppy, self-serving, scholarship and disingenuousness, but his attacks on Hall in this pamphlet are even more personal and detailed. Animadversions, as the title word implies, is head-on hostile criticism, censure, reproof, and blame (OED). Milton reprints, sometimes misleadingly, passages from Hall's A Defence with the speech prefix "Remonstrant" and labels his criticisms and reproofs "Answer." The effect is almost dialogic, as if this pamphlet scrimmage were to be performed orally, and this is the script.
Bishop Hall considered himself strongly anti-Papist, but Milton drives home the assertion that anyone who defends what Puritans regarded as Papist holdovers—government by prelates and a liturgy largely derived from the Roman Catholic missal—cannot be sincerely anti-Papist or even sincerely reformed. In other words, he charges Hall with being a closet Catholic, however unacknowledged or unwittingly.
The copy text for Animadversions is found on Early English Books Online.

