A bibliographer could be forgiven for concluding that in 1640–2, some of his most active years, Henry Parker was primarily a religious pamphleteer. According to the standard reckoning, Parker took leave of “pure” politics after the The Case of Shipmony (which appeared in late 1640 or early 1641), not returning to the subject until mid-1642, in Some Few Observations and Observations. In the same interval, Parker wrote A Discourse Concerning Puritans (which appeared about the time of The Case of Shipmony), The Altar Dispute, The Question Concerning the Divine Right of Episcopacie Truly Stated, and The True Grounds of Ecclesiasticall Regiment. While the received view probably understates Parker's involvement in “political” pamphlets, by any calculation Parker devoted well over half his literary activity in 1640–1 to religious and ecclesiological questions. Nor did he neglect these topics later; they engaged him at intervals throughout his literary career.

But the bare bibliography is misleading. Theological disputation was not Parker's metier, and he knew it. By Parker's own reckoning, he wrote The Altar Dispute only by ignoring the “dissuasions” of his “owne particular professions, interest, and want of learning.” Parker approached his religious pamphlets gamely, and his quick but steady scholarship and his cleverness. served him well. Yet Parker was not prepared to do battle with his intellectual equals in the ecclesiastical structure on their own ground –no more than the churchmen were suited to combat with Parker when armed with the weapon of his choice, the political analysis of clerical pretension.