There are three main groups within Shi‘ism – Imamis (Twelver-Imamis), Ismailis and Zaydis – and all have theological positions which often differ significantly from one another. The Imamis and Zaydis are heavily influenced by Mu‘tazili theology, so on many theological positions they could be considered an extension of the Mu‘tazilis. The Ismailis however, with their emphasis on esoteric interpretation, differ significantly from Imamis and Zaydis. The systematic elaboration of Imami belief was the work of a number of scholars such as Ibn Babawayh al-Qummi (d. 381/991). The earliest full statement of doctrinal belief is the Epistle ( Risala ) on Imami beliefs composedby Ibn-Babawayh. Key Imami theological positions include: