The three types (conversion, blasphemy and heresy) may overlap—for example some "heretics" were alleged not to be actual self-professed Muslims, but to be seeking to destroy Islam from within in the interests of the religion they truly followed. (Abdullah ibn Mayun al-Qaddah, for example, "fathered the whole complex development of the Ismaili religion and organisation up to Fatimid times," was accused by his different detractors of being (variously) "a Jew, a Bardesanian and most commonly as an Iranian dualist") In Islamic literature, the term "blasphemy" sometimes also overlaps with ("unbelief"), (depravity), (insult), and (apostasy).