Scholars who ascribe the Mihna to al-Ma'mun’s Mu'tazilite persuasion point to his close association with leading Mu’tazilites of the era. Among the Mu’tazilites al-Ma’mun appointed to high positions within his administration include Ahmed ibn Abi Du’ad, a prominent Mu’tazilite who became Chief Qadi during his rule. Due to Ibn Abi Du’ad's background as a Kalam scholar and his rigorous advocacy of the Mihna under the subsequent two caliphs, some scholars have concluded that his influence led to al-Ma’mun finally taking action and implementing the Mihna during the last year of his life. However it remains unclear whether the appointment of Ibn Abi Du’ad is a cause or reflection of al-Ma’mun's plans to institute the Mihna.