Jafar al-Sadiq

Ja'far al-Sadiq (c. 702-765) was a great-great-grandson of the Prophet Muhammad, descended through both Husayn and, on his mother's side, from Abu Bakr. In Twelver Shia Islam he is the sixth Imam, and he is one of the rare early figures held in high honour across the sectarian divide.

He lived in Medina through the turbulent decades in which the Umayyad dynasty fell and the Abbasid rose, and he largely held himself apart from the revolts that convulsed the period, devoting himself instead to teaching. His circle in Medina was famous: the tradition credits him with thousands of students, and among those who are said to have studied with him or transmitted from him are Abu Hanifa and Malik ibn Anas, the eponyms of two of the four great Sunni schools of law. The saying attributed to Abu Hanifa, that he had never met anyone more learned than Ja'far, became a byword for the cross-sectarian esteem in which he was held.

His honorific, al-Sadiq, the truthful, marks that reputation. Much that is ascribed to him in later collections is difficult to verify at this distance, but the breadth of his renown as a teacher is not in doubt.

Ja'far al-Sadiq gives his name to the Ja'fari school (madhhab), the system of law followed by Twelver Shia Muslims and standing alongside the four Sunni schools; in this sense he is regarded as its founder, the Imam whose teaching became the basis of Shia fiqh. Distinctive features later associated with the school, such as the recognition of temporary marriage (mut'a) and particular rules of inheritance and ritual, are traced in the tradition to his instruction.

More fundamentally, his period is associated with the maturing of the Shia doctrine of the Imamate itself: the teaching that after the Prophet, authority to guide the community and to interpret the faith rests with a divinely designated line of Imams from the house of Ali, each appointed by explicit designation (nass) from the last, and each possessing a God-given knowledge of religion. The elaboration of this doctrine of designated, infallible guidance is bound up with the figure of Ja'far and the circle around him.

The great early Shia collections of tradition, above all the Kitab al-Kafi of al-Kulayni, preserve a large body of teaching reported from him on law, theology and the conduct of life, making him one of the most frequently cited authorities in Shia literature.

Ja'far's death in 765 produced one of the decisive divisions of Shia history. His designated successor, his son Isma'il, appears to have died before him, and the majority followed another son, Musa al-Kazim, as the seventh Imam, the line that Twelver Shia Islam continues to the twelfth. But a body of followers held that the Imamate had passed through Isma'il and his descendants, and from them descend the Ismailis, the branch that would later found the Fatimid caliphate and that survives in several communities today. The split turns directly on the succession to Ja'far.

A quite different afterlife attached his name to the esoteric sciences. Later alchemical and occult literature claimed him as a master: the vast corpus of works ascribed to the alchemist Jabir ibn Hayyan presents Jabir as Ja'far's pupil, and traditions of lettrism, divination and the properties of things were fathered upon him. Modern scholarship regards these attributions as largely legendary, the borrowing of an authoritative name by later writers, much as happened with Solomon and Hermes.

Across law, theology and legend alike, Ja'far al-Sadiq stands as one of the pivotal transmitters of early Islamic learning, honoured by Sunni jurists and revered by Shia as their Imam.