The fourth leading jurisprudent: Jafar al-Sadiq (148/765)
The forth scholar, Abu 'Abdullah Jafar b. Muhammad al-Baqir b. 'Ali Zayn al-Abidin b. al-Husayn b. 'Ali b. Abi Talib, known as Ja'far al-Sadiq (80—148/699—765), was the sixth Imam of the Twelver Shi'is.
He claimed that this position was reserved for the offspring of al-Husayn, the son of Fatima and 'Ali b. Abi Talib, after the death of al-Hasan b. 'Ali b. Abi Talib. Al-Sadiq’s mother was Farwah bint al-Qasim b. Muhammad b. Abu Bakr al-Siddiq. A member of the Banu Hashim lineage, he transmitted from his father al-Baqir, his maternal grandfather al-Qasim, and scholars affiliated with them.Al-Sadiq was known for his views on Islam’s fundamental and subsidiary legal issues. The debates that raged between him and other scholars became common with respect to the methodological interpretation of the origin of Islamic jurisprudence. His school gathered many students from across the Muslim world, and his jurisprudence and traditions spread far afield. For that reason the Twelver Shi'i legal school was attributed to him in particular.37 In his capacity as a transmitter of hadith as well as a scholar of the disputed points of the law and an expert in legal deduction, he had a wide-ranging knowledge of the sayings and opinions of numerous scholars.
Abu Hanifa transmitted that Abu Ja'far al-Mansur said to him, ‘The people are infatuated with Ja'far b. Muhammad, so prepare for him questions that require answers’. I prepared 40 cases and asked him about them. He replied, ‘You say this... the people of Medina say this... while we say this. We might shift our opinion, or perhaps you will shift your opinion, or perhaps we will all continue in dissent’. After he had addressed all 40 issues, Abu Hanifa said, ‘He (Abu Ja'far) is the most knowledgeable scholar. He is the most knowledgeable of the jurists of differences of opinion (ikhtilaf) ’.38
Sufyan al-Thawri, Sufyan b.
'Uyayna, Malik b. Anas, Abu Hanifa, and many other leading jurists benefited from his knowledge. Moreover, al-Sadiq was a scholar of alchemy and a teacher ofJabir b. Hayyan, who compiled for him 500 alchemical treatises. He died at the age of 69. His methodological approach was to consult the Qur’an and the Prophetic Sunnah, followed by the statements of the Shi'i Imams, to respond to argument through consensus, and to reject legal analogy altogether. One of his doctrinal points was the requirement that scholars undertake Ijtihad. The most famous work attributed to him is Misbah al-Shari‘ah wa- Miftah al-Haqiqa, a 100-chapter work that consists of his sayings on ethical dimensions of the Qur ’an, Kitab Tafsir al-Qur’an, Kitab Manafi' Suwar al-Qur’an, and Kitab Khawass al-Qur’an al- Azim. In addition to works on the fundamental principles of Islam, his Kitab al-Tawhid, Kitab Ithbat al-Sani', and Adilla 'ala al-Khalq wa-l-Tadbir, he had an almanac of months and years, presenting weather forecasts and instructions on selecting days and months.39