On 18th (some say 11th) September, 1697 the book “Christianity Not Mysterious” was burned in front of the Irish Parliament Buildings. This had been ordered by the Parliament who declared some days earlier that the heretical book “be publickly burnt by the hands of the common hangman” and the author “be taken into the custody of the Serjeant at Arms and…prosecuted”. Such burning of books by the hangman had been done in England since 1634 (ref), though letters from Molyneaux to Locke suggest it had not happened in Ireland before.
The book had already caused controversy. It was denounced when it was first published in 1696, the first edition anonymously and the second under Toland’s name. The book argues that “[T]here is nothing in the Gospel contrary to Reason, nor above it; and … no Christian Doctrine can be properly called a Mystery.” In other words, nothing in the Gospel can conflict with reason, the Gospel cannot transcend reason (so apparent conflicts with reason cannot be explained away as a mystery) and that no doctrine can at once be Christian and mysterious. The creation of mysteries within Christianity he attributed to innovations of competing sects.
This theory of the relationship between religion and reason went further than other supporters of reason such as Locke had dared. It was especially contentious in Ireland, since it undermined the position of the established Anglican Church over other churches. Archbishop Narcissus Marsh (of the Library) requested the Provost of Trinity College, Dr. Peter Browne, to write an answer to Toland’s book. Browne did so in his 1797 A Letter in answer to a book entitled Christianity not mysterious, condemning Toland as ‘an inveterate enemy of revealed religion’. Browne was later made the Bishop of Cork, due to Marsh’s influence, leading Toland to boast he had ‘made Browne a bishop’.