The question of the imamate has historically stimulated and elucidated a variety of responses from scholars within Muslim society. Among the genre of such works is one by Ahmad b. Ibrahim al-Naysaburi, an Ismaili scholar during the time of the Fatimid Imam-Caliph al-Hakim bi-amr Allah (386/996 - 411/1021). His work, Ithbat al-Imama seeks to affirm the imamate from the perspective of rational and philosophical arguments instead of establishing it on the basis of the Qur’an and hadith exclusively. Beginning with a premise that the imamate is the pole and foundation of religion, he uses numerous ways of establishing his thesis ranging from the ten categories of the philosophers to several biological metaphors from plants and trees to animals and minerals. Accepting that there are differences and disparities in every genus and species, he gives paradigms of perfect examples in each variety demonstrating in a parallel manner that the Imam is at the apex of humanity.
Al-Naysaburi does not mention al-Hakim by name in his treatise but refers to him as the ‘commander of the believers’ and feels compelled to comment on ‘the time in which we live’. A number of reasons could have inspired him to write on the subject of the imamate. He was certainly not the only one perplexed by the circumstances of the day. Two other writers, al-Kirmani, the more explicit of the two and Abu’l Fawaris have both written on the subject. The ‘Baghdad Manifesto’ sponsored by the ‘Abbasid caliph, al-Qadir (381/991 - 422/1031) denying the ‘Alid geneology of the Fatimids in the early part of the fifth century as well as the refutation of Abu’l Qasim al-Busti against the Ismailis would clearly seem to have been the external reasons. However, the internal challenges faced by al-Hakim from his own family and followers, some of whom wished to ascribe divinity to him, appear to have been the more obvious reasons. Like his contemporary Hamid al-Din al-Kirmani, al-Naysaburi also rejects the ascription of divinity to al-Hakim but denotes the actions of the Imam as inspired. He characterises al-Hakim’s purpose as ‘enjoining the good and forbidding the evil’ amr bi’l ma‘ruf wa nahy ‘an al-munkar, being a duty of the Imam.