Arguing against other faiths is impossible without accepting that faith’s authority premises

Evidence

Alan, for example, assuming that Muslims defend polygamous marriage on Old Testament grounds (the example set by the Patriarchs), iv.vii. Alexander: in Petrus. Bles., MPL 207 and Paris, yr. 1169 (personal insertion in the old chronicle). Guido: 15, citing Isa. Lxvi1.5. (Parallel to the assumption by Christian polemists that Muslims will accept the text of the canonical Old Testament, is that Jews will accept the (Catholic) deuterocanonical or (Protestant) apocryphal books of the Old Testament. This happens even in the Rabbi Samuel correspondence. — Norman Daniel, Islam and the West, 1970

Categorization

• XREF: Direct parallel with modern debates where debaters insist opponents accept texts or authorities their traditions don’t actually recognize — same structural fallacy in contemporary interreligious argument.