 In 1524, Luther faced criticism from a different quarter, as the leading Christian humanist Desiderius Erasmus was finally persuaded to engage with Luther’s position in print, and despite Luther’s earlier hopes for his  endorsement,[5]  chose instead to focus critically on the latter’s view of freedom which had been initially expressed in the thirteenth of Luther’s theses from the Heidelberg Disputation (1518) and further underlined in Luther’s response to the bull of Leo X  (1520).[6]  Erasmus replied to the latter in his A Diatribe or Discussion on Free Will (De libero arbitrio diatribe sive collatio)—where “diatribe” here is used not in the modern sense, but in the earlier sense of looking for a consensus on probable opinion through discussion. Luther, however, responded a year later to Erasmus’s intentionally measured and urbane effort with what amounts to a diatribe in the modern form, entitled De servo arbitrio, which may be translated “On the bondage [or slavery] of the will [or free choice]”. Luther’s invective shocked and offended Erasmus, who replied with his two volume Protector of the Diatribe (Hyperaspistes  diatribae)[7]  in 1526 and 1527, in which Erasmus’s language is almost as intemperate as Luther’s own. As Luther emphasised, at the heart of this dispute lay issues that were central to his thinking, concerning grace, human agency, and divine knowledge and power, played out against the background of Augustine’s earlier disputes with Pelagianism, of which Luther insistently accused Erasmus, much to the latter’s frustration.