Vol. 1 gives text of Grotius' annotations to G. Cassander's De articulis religionis inter Catholicos et Protestantes controversis consultatio, each article followed in larger print by A. Rivet's critique of Grotius. Grotius' annotations were first published in his Via ad pacem ecclesiasticam of 1641.
Vol. 2, with title: De vera Christianae pacificationis et ecclesiae reformande ratione tractatus, ante annos LXXX, ab eximio quodam theologo editus, reprints a tract of J. Calvin which appeared in 1549 in his Interim adulto-germanum, cui adiecta est, Vera Christianae pacificationis, et ecclesiae reformandae ratio.