 This “presumption of atheism” has been challenged in a number of ways. Alvin Plantinga (2000) has argued that reasonable belief in God does not have to be based on propositional evidence, but can be “properly basic.” On this view, reasonable belief in God can be the outcome of a basic faculty (called the sensus divinitatis by theologian John Calvin) and thus needs no support from arguments at all. In response some would argue that even if theistic belief is not grounded in propositional evidence, it still might require non-propositional evidence (such as experience), so it is not clear that Plantinga’s view by itself removes the burden of proof challenge.