In his classic paper on the philosophy of religion entitled ‘The Presumption of Atheism’, Antony Flew, relying on a traditional legal rule, extracts a methodological rule according to which the burden of proof in the problem of God’s existence is non-restrictedly on the Theist. Here we argue that from another legal rule in Islamic jurisprudence, we can extract another methodological rule that, in contrast to Flew’s rule, is context-dependent; so, applying this new rule, we can imagine that in some situations, the burden of proof would be on atheist. Since there are some historical evidence for the relationship or even identification of that traditional rule and this Islamic rule, it could be concluded that Flew’s rules, too, should be context-dependence. Hence, his non-restricted claim about the burden of proof in the problem of God’s existence will be rejected.