While belief in the theory of "naskh" of Islamic revelation is part of Sunni Muslim orthodoxy, there are more than a few scholars who do not accept it, including most twentieth century modernist reformist scholars. In addition some non-mainstream sects of Islam — such as the Mu'tazili, Zaidiyah, and Quranists, and more recently the Ahmadiyya — have rejected "naskh" on the rationalist grounds that the word of God can not contain contradictions. Other scholars did/do not dismiss the theory of naskh but consider it poor scholarship.