In his 1705 Thesaurus the English antiquarian George Hickes published lengthy criticisms of the approach to forged documents advocated by Jean Mabillon in his seminal De re diplomatica. Mabillon argued against rash rejection of swathes of documents, and emphasized the mixture of genuine and false material in many archives; Hickes alleged that Mabillon's position would allow even rank forgeries to be defended as genuine. The disagreement between Hickes and Mabillon casts light on the particular intellectual and religious orientations of the (...) two scholars, but more broadly on the fault-lines across which debate took place within the Republic of Letters. (shrink)