 A second epistemological issue was also raised by Luther’s claims for the priority of scripture over ecclesiastical authority, which Luther had argued (for example in The Bondage of the Will against Erasmus; see WA 18:603–14/LW 33:19–36) would make possible a certainty that such authority lacked—but which as a method had itself proved problematic in settling disputes between Luther and those who challenged his scriptural interpretations (see  Luther entry §2).  As Richard Popkin (1979) has argued, this impasse led to significant debates between subsequent Reformers and Catholics concerning which approach, if any, could avoid scepticism, or indeed if faith required accommodation with scepticism in some form (which Luther himself had vehemently denied against Erasmus: see  Luther entry §4).